Patchwork [2/3,upstream] TDM Framework

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Submitter Sandeep Singh
Date July 23, 2012, 10:49 a.m.
Message ID <1343040588-16002-1-git-send-email-b37400@freescale.com>
Download mbox | patch
Permalink /patch/172625/
State Not Applicable
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Sandeep Singh - July 23, 2012, 10:49 a.m.
From: Sandeep Singh <Sandeep@freescale.com>

TDM Framework is an attempt to provide a platform independent layer which can
offer a standard interface  for TDM access to different client modules.
Beneath, the framework layer can house different types of TDM drivers to handle
various TDM devices, the hardware intricacies of the devices being completely
taken care by TDM drivers.
This framework layer will allow any type of TDM device to hook with it.
For example Freescale controller as on MPC8315, UCC based TDM controller, etc

The main functions of this Framework are:
 - provides interface to TDM clients to access TDM functionalities.
 - provides standard interface for TDM drivers to hook with the framework.
 - handles various data handling stuff and buffer management.

In future this Framework will be extended to provide Interface for Line control devices also. For example SLIC, E1/T1 Framers etc.

Presently the framework supports only Single Port channelised mode.
Also the configurability options are limited which will be extended later on.
Only kernel mode TDM clients are supported currently. Support for User mode clients will be added later.

Signed-off-by: Sandeep Singh <Sandeep@freescale.com>
Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
---

Based on: git://git.am.freescale.net/gitolite/mirrors/galak-powerpc.git
Branch: master
Checkpatch: passed

First patch version was RFC.

Changes since RFC:
	- Since all read/write operations are in TDM are channel based, polling
	on TDM channel for data instead of TDM port before going for read/write.
	- Also corrected a faulty error leg
	- Removed unused function tdm_port_get_wait_queue.

	Incorporated Scott's comments:
	- Removed TDM_CORE_DEBUG.
	- Added sysfs knob to change use_latest_tdm_data at runtime.
	- Works more silently now (lesser prints).
	- Cosmetic errors rectified.
	- Removed unused function tdm_init.
	- Removed unused variables.
	- Removed unnecessary typecast and NULL check.
	- Removed #include "device/tdm_fsl.h".

	Incorporated Timur's comments:
	- Handled errors.
	- Used dev_err instead of pr_err
	- Removed extern from function declaration.



 drivers/Kconfig                 |    1 +
 drivers/Makefile                |    1 +
 drivers/tdm/Kconfig             |   18 +
 drivers/tdm/Makefile            |    5 +
 drivers/tdm/tdm-core.c          | 1082 +++++++++++++++++++++++++++++++++++++++
 include/linux/mod_devicetable.h |   11 +
 include/linux/tdm.h             |  338 ++++++++++++
 7 files changed, 1456 insertions(+), 0 deletions(-)
 create mode 100644 drivers/tdm/Kconfig
 create mode 100644 drivers/tdm/Makefile
 create mode 100644 drivers/tdm/tdm-core.c
 create mode 100644 include/linux/tdm.h
Tabi Timur-B04825 - July 23, 2012, 4:33 p.m.
On Mon, Jul 23, 2012 at 5:49 AM,  <b37400@freescale.com> wrote:
> From: Sandeep Singh <Sandeep@freescale.com>

Please fix your git configuration so that the From: line in your
emails contains your full name.   This patch was sent with this From:
line:

From: <b37400@freescale.com>

It should say:

From: Sandeep Singh <sandeep@freescale.com>

Three more things:

1) You don't need to add [upstream] to patches that are posted upstream.

2) This patch needs to be CC'd to linux-kernel@vger.kernel.org and
devel@driverdev.osuosl.org.

3) I'm concerned that there is no "struct device" anywhere in this
framework.  I think that's a serious omission, and you need to figure
out where you can put this.


> diff --git a/drivers/tdm/tdm-core.c b/drivers/tdm/tdm-core.c
> new file mode 100644
> index 0000000..9973b6b
> --- /dev/null
> +++ b/drivers/tdm/tdm-core.c
> @@ -0,0 +1,1082 @@
> +/* driver/tdm/tdm-core.c
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.

I've been seeing this copyright messages a lot recently, and I don't
understand why.  This message is incorrectly formatted.  The "(C)" is
redundant, and the phrase "All rights reserved." is wrong.  This patch
is licensed under the GPL, so we are NOT reserving all rights, we are
actually giving up some rights.

Please change this to:

Copyright 2012 Freescale Semiconductor, Inc.

> + *
> + * TDM core is the interface between TDM clients and TDM devices.
> + * It is also intended to serve as an interface for line controlled
> + * devices later on.
> + *
> + * Author:Hemant Agrawal <hemant@freescale.com>
> + *     Rajesh Gumasta <rajesh.gumasta@freescale.com>

If these two are the authors, why are they not on the signed-off-by lines?

> + *
> + * Modified by Sandeep Kr Singh <sandeep@freescale.com>
> + *             Poonam Aggarwal <poonam.aggarwal@freescale.com>

Do not add "modified" by lines to the code.  That's why we have a git history.


> + * 1. Added framework based initialization of device.
> + * 2. All the init/run time configuration is now done by framework.
> + * 3. Added channel level operations.
> + * 4. Added sysfs knob to configure use_latest_tdm_data at runtime.

Again, this is not information that belongs in the source file.

> + *
> + * Note that some parts of this code may have been derived from i2c subsystem.
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the  GNU General Public License along
> + * with this program; if not, write  to the Free Software Foundation, Inc.,
> + * 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/slab.h>
> +#include <linux/tdm.h>
> +#include <linux/init.h>
> +#include <linux/idr.h>
> +#include <linux/mutex.h>
> +#include <linux/completion.h>
> +#include <linux/hardirq.h>
> +#include <linux/irqflags.h>
> +#include <linux/list.h>
> +#include <linux/uaccess.h>
> +#include <linux/io.h>

Are you sure you need all of these header files?

> +
> +
> +static DEFINE_MUTEX(tdm_core_lock);
> +static DEFINE_IDR(tdm_adapter_idr);
> +/* List of TDM adapters registered with TDM framework */
> +LIST_HEAD(adapter_list);
> +
> +/* List of TDM clients registered with TDM framework */
> +LIST_HEAD(driver_list);
> +
> +/* In case the previous data is not fetched by the client driver, the
> + * de-interleaving function will  discard the old data and rewrite the
> + * new data */

Proper multi-line comment format is like this:

/*
 * In case the previous data is not fetched by the client driver, the
 * de-interleaving function will  discard the old data and rewrite the
 * new data.
 */

> +static int use_latest_tdm_data = 1;
> +
> +/* Data structures required for sysfs */
> +static struct tdm_sysfs attr = {
> +       .attr.name = "use_latest_data",
> +       .attr.mode = 0664,
> +       .cmd_type = TDM_LATEST_DATA,
> +};
> +
> +static struct attribute *tdm_attr[] = {
> +       &attr.attr,
> +       NULL
> +};
> +
> +const struct sysfs_ops tdm_ops = {
> +       .show = tdm_show_sysfs,
> +       .store = tdm_store_sysfs,
> +};
> +
> +static struct kobj_type tdm_type = {
> +       .sysfs_ops = &tdm_ops,
> +       .default_attrs = tdm_attr,
> +};

Why are some of these 'const' and some aren't?  They should all be 'const'

> +
> +/* tries to match client driver with the adapter */
> +static int tdm_device_match(struct tdm_driver *driver, struct tdm_adapter *adap)
> +{
> +       /* match on an id table if there is one */
> +       if (driver->id_table && driver->id_table->name[0]) {
> +               if (!(strcmp(driver->id_table->name, adap->name)))
> +                       return (int)driver->id_table;
> +       }


> +       return TDM_E_OK;

Get rid of TDM_E_OK.  It's the only error code that you've defined,
and it's set to 0.  That doesn't mean anything.

> +}
> +
> +static int tdm_attach_driver_adap(struct tdm_driver *driver,
> +               struct tdm_adapter *adap)
> +{
> +       int ret = TDM_E_OK;
> +       /* if driver is already attached to any other adapter, return*/
> +       if (driver->adapter && (driver->adapter != adap))
> +               return ret;
> +
> +       driver->adapter = adap;
> +
> +       if (driver->attach_adapter) {
> +               ret = driver->attach_adapter(adap);
> +               if (ret < 0) {
> +                       pr_err("attach_adapter failed for driver [%s] err:%d\n"
> +                                       , driver->name, ret);
> +                       return ret;
> +               }
> +       }
> +       adap->drv_count++;
> +
> +       if (!adap->tasklet_conf) {
> +               tdm_sysfs_init();
> +               tasklet_init(&adap->tdm_data_tasklet, tdm_data_tasklet_fn,
> +                               (unsigned long)adap);
> +               adap->tasklet_conf = 1;
> +       }
> +
> +       return ret;

If 'ret' can only be 0, then just return 0.

       return 0;


> +/* tdm_adap_send - issue a TDM write
> + * @adap: Handle to TDM device
> + * @buf: Data that will be written to the TDM device
> + * @count: How many bytes to write
> + *
> + * Returns negative errno, or else the number of bytes written.

"Returns negative error number, or else the number of bytes written."

You're typing this on a full keyboard, not a smart phone.  Please
don't use abbreviations unnecessarily.

> + */
> +int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count)
> +{
> +       int res;
> +
> +       if (adap->algo->tdm_write)
> +               res = adap->algo->tdm_write(adap, buf, count);

Why does tdm_write() return a u32?  And shouldn't 'res' also be a u32,
to make tdm_write()?


> +/* Port Level APIs of TDM Framework */
> +int tdm_port_open(struct tdm_driver *driver, struct tdm_port **h_port)
> +{
> +       struct tdm_port *port;
> +       struct tdm_adapter *adap;
> +       unsigned long           flags;
> +       int res = TDM_E_OK;
> +
> +       adap = tdm_get_adapter(driver->adapter->id);
> +       if (!adap)
> +               return -ENODEV;
> +
> +       /* This creates an anonymous tdm_port, which may later be
> +        * pointed to some slot.
> +        *
> +        */
> +       port = kzalloc(sizeof(*port), GFP_KERNEL);
> +       if (!port) {
> +               res = -ENOMEM;
> +               goto out;
> +       }

Just return here.  You don't need to "goto out".  And I think you
forgot to call tdm_put_adapter(), although it might be easier if you
call kzalloc() first, and then tdm_get_adapter().

> +
> +       port->rx_max_frames = NUM_SAMPLES_PER_FRAME;
> +       port->port_cfg.port_mode = TDM_PORT_CHANNELIZED;
> +
> +       snprintf(driver->name, TDM_NAME_SIZE, "tdm-dev");
> +       port->driver = driver;
> +       port->adapter = adap;
> +
> +       spin_lock_irqsave(&adap->portlist_lock, flags);
> +       list_add_tail(&port->list, &adap->myports);
> +       spin_unlock_irqrestore(&adap->portlist_lock, flags);

Are you sure you need to disable interrupts?  That seems excessive.


> +int tdm_channel_read(struct tdm_port *h_port, struct tdm_channel *h_channel,
> +               void *p_data, u16 *size)
> +{
> +       struct tdm_channel *channel;
> +       struct tdm_bd *rx_bd;
> +       unsigned long flags;
> +       int i, res = TDM_E_OK;
> +       unsigned short *buf, *buf1;
> +       channel = h_channel;
> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       spin_lock_irqsave(&channel->p_ch_data->rx_channel_lock, flags);
> +       rx_bd = channel->p_ch_data->rx_out_data;
> +
> +       if (rx_bd->flag) {
> +               *size = rx_bd->length;
> +               buf = (u16 *) p_data;
> +               buf1 = (u16 *)rx_bd->p_data;
> +               for (i = 0; i < NUM_SAMPLES_PER_FRAME; i++)
> +                       buf[i] = buf1[i];

Use memcpy() instead.



> +int tdm_channel_write(struct tdm_port *h_port, struct tdm_channel *h_channel,
> +               void *p_data, u16 size)
> +{
> +       struct tdm_port *port;
> +       struct tdm_channel *channel;
> +       struct tdm_bd *tx_bd;
> +       unsigned long flags;
> +       int err = TDM_E_OK;
> +       port = h_port;
> +       channel = h_channel;
> +#ifdef DEBUG
> +       bool data_flag = 0;
> +#endif
> +
> +       if (p_data == NULL) { /* invalid data*/
> +               pr_err("Invalid Data");
> +               return -EFAULT;
> +       }

EFAULT is for invalid memory access.  I think you mean EINVAL here.

> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       spin_lock_irqsave(&channel->p_ch_data->tx_channel_lock, flags);
> +       tx_bd = channel->p_ch_data->tx_in_data;
> +
> +       if (!tx_bd->flag) {
> +               tx_bd->length = size;
> +               memcpy(tx_bd->p_data, p_data,
> +                               size * port->adapter->adapt_cfg.slot_width);
> +               tx_bd->flag = 1;
> +               tx_bd->offset = 0;
> +               channel->p_ch_data->tx_in_data = (tx_bd->wrap) ?
> +                       channel->p_ch_data->tx_data_fifo : tx_bd+1;
> +               port->port_stat.tx_pkt_count++;
> +#ifdef DEBUG
> +               data_flag = 1;
> +#endif
> +       } else {
> +               spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock,
> +                               flags);
> +               port->port_stat.tx_pkt_drop_count++;
> +               pr_err("E_NO_MEMORY -Failed Transmit");

Please review ALL of your error messages, and make sure that have a
proper prefix ("tdm: ") and all look the same.  Don't use __func__ in
any of them, and make sure the error messages are clear, English text.

> +               return -ENOMEM;

I'm not sure ENOMEM is appropriate here.

> +       }
> +       spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock, flags);
> +
> +#ifdef DEBUG
> +       if (data_flag) {
> +               int k;
> +               pr_info("\nTX port:%d - Write - Port TX-%d\n",
> +                               port->port_id, size);
> +               for (k = 0; k < size; k++)
> +                       pr_info("%x", p_data[k]);
> +               pr_info("\n");
> +       }
> +#endif
> +       return err;
> +}
> +EXPORT_SYMBOL(tdm_channel_write);
> +
> +/* Driver Function for select and poll. Based on Channel, it sleeps on
> + * waitqueue */
> +int tdm_ch_poll(struct tdm_channel *h_channel, unsigned int wait_time)
> +{
> +       struct tdm_channel *channel;
> +       unsigned long timeout = msecs_to_jiffies(wait_time);
> +       channel = h_channel;
> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       if (channel->p_ch_data->rx_out_data->flag) {
> +               pr_debug("Data Available");
> +               return TDM_E_OK;
> +       }
> +       if (timeout) {
> +               wait_event_interruptible_timeout(channel->ch_wait_queue,

It'd be more efficient if you did this:

       if (wait_time) {
               unsigned long timeout = msecs_to_jiffies(wait_time);

               wait_event_interruptible_timeout(channel->ch_wait_queue,


> +                               channel->p_ch_data->rx_out_data->flag,
> +                               timeout);
> +
> +               if (channel->p_ch_data->rx_out_data->flag) {
> +                       pr_debug("Data Available");
> +                       return TDM_E_OK;
> +               }
> +       }
> +       return -EAGAIN;
> +}
> +EXPORT_SYMBOL(tdm_ch_poll);
> +
> +unsigned int tdm_port_get_stats(struct tdm_port *h_port,
> +               struct tdm_port_stats *portStat)

Do not use CamelCase in variable names.



> diff --git a/include/linux/tdm.h b/include/linux/tdm.h
> new file mode 100644
> index 0000000..a2f9628
> --- /dev/null
> +++ b/include/linux/tdm.h
> @@ -0,0 +1,338 @@
> +/* include/linux/tdm.h
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.
> + *
> + * tdm.h - definitions for the tdm-device framework interface
> + *
> + * Author:Hemant Agrawal <hemant@freescale.com>
> + *     Rajesh Gumasta <rajesh.gumasta@freescale.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the  GNU General Public License along
> + * with this program; if not, write  to the Free Software Foundation, Inc.,
> + * 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +
> +#ifndef _LINUX_TDM_H
> +#define _LINUX_TDM_H
> +
> +#include <linux/types.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/device.h>      /* for struct device */
> +#include <linux/sched.h>       /* for completion */
> +#include <linux/mutex.h>
> +#include <linux/interrupt.h>
> +#include <linux/sysfs.h>
> +
> +#define TDM_LATEST_DATA                1
> +#define CHANNEL_8BIT_LIN       0       /* 8 bit linear */
> +#define CHANNEL_8BIT_ULAW      1       /* 8 bit Mu-law */
> +#define CHANNEL_8BIT_ALAW      2       /* 8 bit A-law */
> +#define CHANNEL_16BIT_LIN      3       /* 16 bit Linear */
> +
> +/*
> + * Default adapter configuration. All the TDM adapters registered with
> + * framework will be configured with following default configuration.
> + */
> +#define NUM_CHANNELS   16
> +
> +/* Default configuration for typical voice data sample. These parameters
> + * will generally not be required to be changed for voice type applications.
> + */
> +#define NUM_SAMPLES_PER_MS     8       /* 8 samples per milli sec per
> +                                        channel. Req for voice data */
> +#define NUM_MS                 10
> +#define NUM_SAMPLES_PER_FRAME  (NUM_MS * NUM_SAMPLES_PER_MS) /* Number of
> +                                               samples for 1 client buffer */
> +#define NUM_OF_TDM_BUF         3
> +
> +/* General options */
> +
> +struct tdm_adapt_algorithm;
> +struct tdm_adapter;
> +struct tdm_port;
> +struct tdm_driver;

I don't think you need "struct tdm_driver;"


> +/* tdm_adapter_mode is to define in mode of the device */
> +enum tdm_adapter_mode {
> +       TDM_ADAPTER_MODE_NONE = 0x00,
> +       TDM_ADAPTER_MODE_T1 = 0x01,
> +       TDM_ADAPTER_MODE_E1 = 0x02,
> +       TDM_ADAPTER_MODE_T1_RAW = 0x10,
> +       TDM_ADAPTER_MODE_E1_RAW = 0x20,

Where did these numbers come from?
Sandeep Singh - July 24, 2012, 1:22 p.m.
Hi Timur,

Thanks for your comments, please find response inline.

Regards,
Sandeep


-----Original Message-----
From: Tabi Timur-B04825 
Sent: Monday, July 23, 2012 10:03 PM
To: Singh Sandeep-B37400
Cc: linuxppc-dev@lists.ozlabs.org; Singh Sandeep-B37400; Aggrwal Poonam-B10812
Subject: Re: [2/3][PATCH][upstream] TDM Framework

On Mon, Jul 23, 2012 at 5:49 AM,  <b37400@freescale.com> wrote:
> From: Sandeep Singh <Sandeep@freescale.com>

Please fix your git configuration so that the From: line in your
emails contains your full name.   This patch was sent with this From:
line:

From: <b37400@freescale.com>

It should say:

From: Sandeep Singh <sandeep@freescale.com>

Three more things:

1) You don't need to add [upstream] to patches that are posted upstream.

2) This patch needs to be CC'd to linux-kernel@vger.kernel.org and devel@driverdev.osuosl.org.

3) I'm concerned that there is no "struct device" anywhere in this framework.  I think that's a serious omission, and you need to figure out where you can put this.

 [Sandeep] 1) & 2) Ok, Will take care. 3)Ok, will check.


> diff --git a/drivers/tdm/tdm-core.c b/drivers/tdm/tdm-core.c new file 
> mode 100644 index 0000000..9973b6b
> --- /dev/null
> +++ b/drivers/tdm/tdm-core.c
> @@ -0,0 +1,1082 @@
> +/* driver/tdm/tdm-core.c
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.

I've been seeing this copyright messages a lot recently, and I don't understand why.  This message is incorrectly formatted.  The "(C)" is redundant, and the phrase "All rights reserved." is wrong.  This patch is licensed under the GPL, so we are NOT reserving all rights, we are actually giving up some rights.

Please change this to:

Copyright 2012 Freescale Semiconductor, Inc.

 [Sandeep] Will correct this.


> + *
> + * TDM core is the interface between TDM clients and TDM devices.
> + * It is also intended to serve as an interface for line controlled
> + * devices later on.
> + *
> + * Author:Hemant Agrawal <hemant@freescale.com>
> + *     Rajesh Gumasta <rajesh.gumasta@freescale.com>

If these two are the authors, why are they not on the signed-off-by lines?
[Sandeep] Will add them to signoff.

> + *
> + * Modified by Sandeep Kr Singh <sandeep@freescale.com>
> + *             Poonam Aggarwal <poonam.aggarwal@freescale.com>

Do not add "modified" by lines to the code.  That's why we have a git history.
[Sandeep] Ok.


> + * 1. Added framework based initialization of device.
> + * 2. All the init/run time configuration is now done by framework.
> + * 3. Added channel level operations.
> + * 4. Added sysfs knob to configure use_latest_tdm_data at runtime.

Again, this is not information that belongs in the source file.
[Sandeep] OK

> + *
> + * Note that some parts of this code may have been derived from i2c subsystem.
> + *
> + * This program is free software; you can redistribute  it and/or 
> + modify it
> + * under  the terms of  the GNU General  Public License as published 
> + by the
> + * Free Software Foundation;  either version 2 of the  License, or 
> + (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, 
> + but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the  GNU General Public License 
> + along
> + * with this program; if not, write  to the Free Software Foundation, 
> + Inc.,
> + * 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/slab.h>
> +#include <linux/tdm.h>
> +#include <linux/init.h>
> +#include <linux/idr.h>
> +#include <linux/mutex.h>
> +#include <linux/completion.h>
> +#include <linux/hardirq.h>
> +#include <linux/irqflags.h>
> +#include <linux/list.h>
> +#include <linux/uaccess.h>
> +#include <linux/io.h>

Are you sure you need all of these header files?
[Sandeep] Will check.

> +
> +
> +static DEFINE_MUTEX(tdm_core_lock);
> +static DEFINE_IDR(tdm_adapter_idr);
> +/* List of TDM adapters registered with TDM framework */ 
> +LIST_HEAD(adapter_list);
> +
> +/* List of TDM clients registered with TDM framework */ 
> +LIST_HEAD(driver_list);
> +
> +/* In case the previous data is not fetched by the client driver, the
> + * de-interleaving function will  discard the old data and rewrite 
> +the
> + * new data */

Proper multi-line comment format is like this:
[Sandeep] Ok.

/*
 * In case the previous data is not fetched by the client driver, the
 * de-interleaving function will  discard the old data and rewrite the
 * new data.
 */

> +static int use_latest_tdm_data = 1;
> +
> +/* Data structures required for sysfs */ static struct tdm_sysfs attr 
> += {
> +       .attr.name = "use_latest_data",
> +       .attr.mode = 0664,
> +       .cmd_type = TDM_LATEST_DATA,
> +};
> +
> +static struct attribute *tdm_attr[] = {
> +       &attr.attr,
> +       NULL
> +};
> +
> +const struct sysfs_ops tdm_ops = {
> +       .show = tdm_show_sysfs,
> +       .store = tdm_store_sysfs,
> +};
> +
> +static struct kobj_type tdm_type = {
> +       .sysfs_ops = &tdm_ops,
> +       .default_attrs = tdm_attr,
> +};

Why are some of these 'const' and some aren't?  They should all be 'const'
[Sandeep] Ok.

> +
> +/* tries to match client driver with the adapter */ static int 
> +tdm_device_match(struct tdm_driver *driver, struct tdm_adapter *adap) 
> +{
> +       /* match on an id table if there is one */
> +       if (driver->id_table && driver->id_table->name[0]) {
> +               if (!(strcmp(driver->id_table->name, adap->name)))
> +                       return (int)driver->id_table;
> +       }


> +       return TDM_E_OK;

Get rid of TDM_E_OK.  It's the only error code that you've defined, and it's set to 0.  That doesn't mean anything.
[Sandeep] Ok

> +}
> +
> +static int tdm_attach_driver_adap(struct tdm_driver *driver,
> +               struct tdm_adapter *adap) {
> +       int ret = TDM_E_OK;
> +       /* if driver is already attached to any other adapter, return*/
> +       if (driver->adapter && (driver->adapter != adap))
> +               return ret;
> +
> +       driver->adapter = adap;
> +
> +       if (driver->attach_adapter) {
> +               ret = driver->attach_adapter(adap);
> +               if (ret < 0) {
> +                       pr_err("attach_adapter failed for driver [%s] err:%d\n"
> +                                       , driver->name, ret);
> +                       return ret;
> +               }
> +       }
> +       adap->drv_count++;
> +
> +       if (!adap->tasklet_conf) {
> +               tdm_sysfs_init();
> +               tasklet_init(&adap->tdm_data_tasklet, tdm_data_tasklet_fn,
> +                               (unsigned long)adap);
> +               adap->tasklet_conf = 1;
> +       }
> +
> +       return ret;

If 'ret' can only be 0, then just return 0.

       return 0;
[Sandeep] Ok, will change.


> +/* tdm_adap_send - issue a TDM write
> + * @adap: Handle to TDM device
> + * @buf: Data that will be written to the TDM device
> + * @count: How many bytes to write
> + *
> + * Returns negative errno, or else the number of bytes written.

"Returns negative error number, or else the number of bytes written."

You're typing this on a full keyboard, not a smart phone.  Please don't use abbreviations unnecessarily.
[Sandeep] Ok, will rectify.

> + */
> +int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count) {
> +       int res;
> +
> +       if (adap->algo->tdm_write)
> +               res = adap->algo->tdm_write(adap, buf, count);

Why does tdm_write() return a u32?  And shouldn't 'res' also be a u32, to make tdm_write()?
[Sandeep] tdm_write() returns number of bytes written. You are right, 'res' should be declared as u32


> +/* Port Level APIs of TDM Framework */ int tdm_port_open(struct 
> +tdm_driver *driver, struct tdm_port **h_port) {
> +       struct tdm_port *port;
> +       struct tdm_adapter *adap;
> +       unsigned long           flags;
> +       int res = TDM_E_OK;
> +
> +       adap = tdm_get_adapter(driver->adapter->id);
> +       if (!adap)
> +               return -ENODEV;
> +
> +       /* This creates an anonymous tdm_port, which may later be
> +        * pointed to some slot.
> +        *
> +        */
> +       port = kzalloc(sizeof(*port), GFP_KERNEL);
> +       if (!port) {
> +               res = -ENOMEM;
> +               goto out;
> +       }

Just return here.  You don't need to "goto out".  And I think you forgot to call tdm_put_adapter(), although it might be easier if you call kzalloc() first, and then tdm_get_adapter().
[Sandeep] Ok.

> +
> +       port->rx_max_frames = NUM_SAMPLES_PER_FRAME;
> +       port->port_cfg.port_mode = TDM_PORT_CHANNELIZED;
> +
> +       snprintf(driver->name, TDM_NAME_SIZE, "tdm-dev");
> +       port->driver = driver;
> +       port->adapter = adap;
> +
> +       spin_lock_irqsave(&adap->portlist_lock, flags);
> +       list_add_tail(&port->list, &adap->myports);
> +       spin_unlock_irqrestore(&adap->portlist_lock, flags);

Are you sure you need to disable interrupts?  That seems excessive.
[Sandeep] Will check once.


> +int tdm_channel_read(struct tdm_port *h_port, struct tdm_channel *h_channel,
> +               void *p_data, u16 *size) {
> +       struct tdm_channel *channel;
> +       struct tdm_bd *rx_bd;
> +       unsigned long flags;
> +       int i, res = TDM_E_OK;
> +       unsigned short *buf, *buf1;
> +       channel = h_channel;
> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       spin_lock_irqsave(&channel->p_ch_data->rx_channel_lock, flags);
> +       rx_bd = channel->p_ch_data->rx_out_data;
> +
> +       if (rx_bd->flag) {
> +               *size = rx_bd->length;
> +               buf = (u16 *) p_data;
> +               buf1 = (u16 *)rx_bd->p_data;
> +               for (i = 0; i < NUM_SAMPLES_PER_FRAME; i++)
> +                       buf[i] = buf1[i];

Use memcpy() instead.
[Sandeep] Ok



> +int tdm_channel_write(struct tdm_port *h_port, struct tdm_channel *h_channel,
> +               void *p_data, u16 size) {
> +       struct tdm_port *port;
> +       struct tdm_channel *channel;
> +       struct tdm_bd *tx_bd;
> +       unsigned long flags;
> +       int err = TDM_E_OK;
> +       port = h_port;
> +       channel = h_channel;
> +#ifdef DEBUG
> +       bool data_flag = 0;
> +#endif
> +
> +       if (p_data == NULL) { /* invalid data*/
> +               pr_err("Invalid Data");
> +               return -EFAULT;
> +       }

EFAULT is for invalid memory access.  I think you mean EINVAL here.
[Sandeep] Right. Will correct.

> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       spin_lock_irqsave(&channel->p_ch_data->tx_channel_lock, flags);
> +       tx_bd = channel->p_ch_data->tx_in_data;
> +
> +       if (!tx_bd->flag) {
> +               tx_bd->length = size;
> +               memcpy(tx_bd->p_data, p_data,
> +                               size * port->adapter->adapt_cfg.slot_width);
> +               tx_bd->flag = 1;
> +               tx_bd->offset = 0;
> +               channel->p_ch_data->tx_in_data = (tx_bd->wrap) ?
> +                       channel->p_ch_data->tx_data_fifo : tx_bd+1;
> +               port->port_stat.tx_pkt_count++; #ifdef DEBUG
> +               data_flag = 1;
> +#endif
> +       } else {
> +               spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock,
> +                               flags);
> +               port->port_stat.tx_pkt_drop_count++;
> +               pr_err("E_NO_MEMORY -Failed Transmit");

Please review ALL of your error messages, and make sure that have a proper prefix ("tdm: ") and all look the same.  Don't use __func__ in any of them, and make sure the error messages are clear, English text.
[Sandeep] Ok.

> +               return -ENOMEM;

I'm not sure ENOMEM is appropriate here.
[Sandeep] Will check.

> +       }
> +       spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock, 
> + flags);
> +
> +#ifdef DEBUG
> +       if (data_flag) {
> +               int k;
> +               pr_info("\nTX port:%d - Write - Port TX-%d\n",
> +                               port->port_id, size);
> +               for (k = 0; k < size; k++)
> +                       pr_info("%x", p_data[k]);
> +               pr_info("\n");
> +       }
> +#endif
> +       return err;
> +}
> +EXPORT_SYMBOL(tdm_channel_write);
> +
> +/* Driver Function for select and poll. Based on Channel, it sleeps 
> +on
> + * waitqueue */
> +int tdm_ch_poll(struct tdm_channel *h_channel, unsigned int 
> +wait_time) {
> +       struct tdm_channel *channel;
> +       unsigned long timeout = msecs_to_jiffies(wait_time);
> +       channel = h_channel;
> +
> +       if (!channel->p_ch_data || !channel->in_use)
> +               return -EIO;
> +
> +       if (channel->p_ch_data->rx_out_data->flag) {
> +               pr_debug("Data Available");
> +               return TDM_E_OK;
> +       }
> +       if (timeout) {
> +               
> + wait_event_interruptible_timeout(channel->ch_wait_queue,

It'd be more efficient if you did this:

       if (wait_time) {
               unsigned long timeout = msecs_to_jiffies(wait_time);

               wait_event_interruptible_timeout(channel->ch_wait_queue,

[Sandeep] Ok.

> +                               channel->p_ch_data->rx_out_data->flag,
> +                               timeout);
> +
> +               if (channel->p_ch_data->rx_out_data->flag) {
> +                       pr_debug("Data Available");
> +                       return TDM_E_OK;
> +               }
> +       }
> +       return -EAGAIN;
> +}
> +EXPORT_SYMBOL(tdm_ch_poll);
> +
> +unsigned int tdm_port_get_stats(struct tdm_port *h_port,
> +               struct tdm_port_stats *portStat)

Do not use CamelCase in variable names.
[Sandeep] Ok, will modify.



> diff --git a/include/linux/tdm.h b/include/linux/tdm.h new file mode 
> 100644 index 0000000..a2f9628
> --- /dev/null
> +++ b/include/linux/tdm.h
> @@ -0,0 +1,338 @@
> +/* include/linux/tdm.h
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.
> + *
> + * tdm.h - definitions for the tdm-device framework interface
> + *
> + * Author:Hemant Agrawal <hemant@freescale.com>
> + *     Rajesh Gumasta <rajesh.gumasta@freescale.com>
> + *
> + * This program is free software; you can redistribute  it and/or 
> +modify it
> + * under  the terms of  the GNU General  Public License as published 
> +by the
> + * Free Software Foundation;  either version 2 of the  License, or 
> +(at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, 
> +but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the  GNU General Public License 
> +along
> + * with this program; if not, write  to the Free Software Foundation, 
> +Inc.,
> + * 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +
> +#ifndef _LINUX_TDM_H
> +#define _LINUX_TDM_H
> +
> +#include <linux/types.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/device.h>      /* for struct device */
> +#include <linux/sched.h>       /* for completion */
> +#include <linux/mutex.h>
> +#include <linux/interrupt.h>
> +#include <linux/sysfs.h>
> +
> +#define TDM_LATEST_DATA                1
> +#define CHANNEL_8BIT_LIN       0       /* 8 bit linear */
> +#define CHANNEL_8BIT_ULAW      1       /* 8 bit Mu-law */
> +#define CHANNEL_8BIT_ALAW      2       /* 8 bit A-law */
> +#define CHANNEL_16BIT_LIN      3       /* 16 bit Linear */
> +
> +/*
> + * Default adapter configuration. All the TDM adapters registered 
> +with
> + * framework will be configured with following default configuration.
> + */
> +#define NUM_CHANNELS   16
> +
> +/* Default configuration for typical voice data sample. These 
> +parameters
> + * will generally not be required to be changed for voice type applications.
> + */
> +#define NUM_SAMPLES_PER_MS     8       /* 8 samples per milli sec per
> +                                        channel. Req for voice data */
> +#define NUM_MS                 10
> +#define NUM_SAMPLES_PER_FRAME  (NUM_MS * NUM_SAMPLES_PER_MS) /* Number of
> +                                               samples for 1 client buffer */
> +#define NUM_OF_TDM_BUF         3
> +
> +/* General options */
> +
> +struct tdm_adapt_algorithm;
> +struct tdm_adapter;
> +struct tdm_port;
> +struct tdm_driver;

I don't think you need "struct tdm_driver;"
[Sandeep] Right. Will remove.


> +/* tdm_adapter_mode is to define in mode of the device */ enum 
> +tdm_adapter_mode {
> +       TDM_ADAPTER_MODE_NONE = 0x00,
> +       TDM_ADAPTER_MODE_T1 = 0x01,
> +       TDM_ADAPTER_MODE_E1 = 0x02,
> +       TDM_ADAPTER_MODE_T1_RAW = 0x10,
> +       TDM_ADAPTER_MODE_E1_RAW = 0x20,

Where did these numbers come from?
[Sandeep] This is not related to any bit definition, just enum values.

--
Timur Tabi
Linux kernel developer at Freescale
Timur Tabi - July 24, 2012, 2:43 p.m.
Singh Sandeep-B37400 wrote:

>> +int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count) {
>> +       int res;
>> +
>> +       if (adap->algo->tdm_write)
>> +               res = adap->algo->tdm_write(adap, buf, count);
> 
> Why does tdm_write() return a u32?  And shouldn't 'res' also be a u32, to make tdm_write()?
> [Sandeep] tdm_write() returns number of bytes written. You are right, 'res' should be declared as u32

Then it should return an unsigned int.  You should used a sized integer
type only when the size really matters (e.g. hardware registers or packed
fields in a structure).

>> +/* tdm_adapter_mode is to define in mode of the device */ enum 
>> +tdm_adapter_mode {
>> +       TDM_ADAPTER_MODE_NONE = 0x00,
>> +       TDM_ADAPTER_MODE_T1 = 0x01,
>> +       TDM_ADAPTER_MODE_E1 = 0x02,
>> +       TDM_ADAPTER_MODE_T1_RAW = 0x10,
>> +       TDM_ADAPTER_MODE_E1_RAW = 0x20,
> 
> Where did these numbers come from?
> [Sandeep] This is not related to any bit definition, just enum values.

Yes, but why these particular numbers?  Also, do they really need to be an
enum?  Since you're defining hard values for each enum, you're not really
using them as an enum.  Make these into macros.
Michael Ellerman - July 24, 2012, 11:43 p.m.
On Tue, 2012-07-24 at 09:43 -0500, Timur Tabi wrote:
> Singh Sandeep-B37400 wrote:
> 
> >> +int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count) {
> >> +       int res;
> >> +
> >> +       if (adap->algo->tdm_write)
> >> +               res = adap->algo->tdm_write(adap, buf, count);
> > 
> > Why does tdm_write() return a u32?  And shouldn't 'res' also be a u32, to make tdm_write()?
> > [Sandeep] tdm_write() returns number of bytes written. You are right, 'res' should be declared as u32
> 
> Then it should return an unsigned int.  You should used a sized integer
> type only when the size really matters (e.g. hardware registers or packed
> fields in a structure).
> 
> >> +/* tdm_adapter_mode is to define in mode of the device */ enum 
> >> +tdm_adapter_mode {
> >> +       TDM_ADAPTER_MODE_NONE = 0x00,
> >> +       TDM_ADAPTER_MODE_T1 = 0x01,
> >> +       TDM_ADAPTER_MODE_E1 = 0x02,
> >> +       TDM_ADAPTER_MODE_T1_RAW = 0x10,
> >> +       TDM_ADAPTER_MODE_E1_RAW = 0x20,
> > 
> > Where did these numbers come from?
> > [Sandeep] This is not related to any bit definition, just enum values.
> 
> Yes, but why these particular numbers?  Also, do they really need to be an
> enum?  Since you're defining hard values for each enum, you're not really
> using them as an enum.  Make these into macros.

I agree these values are odd. But there's no rule that you can only use
an enum if the values are monotonically increasing.

It can still serve as helpful documentation, and reduce the number of
places you pass a bare int around.

cheers
Tabi Timur-B04825 - July 25, 2012, 2:40 a.m.
Michael Ellerman wrote:
> I agree these values are odd. But there's no rule that you can only use
> an enum if the values are monotonically increasing.
>
> It can still serve as helpful documentation, and reduce the number of
> places you pass a bare int around.

IMHO, an enum should only be used if

1) You are doing real type checking of the enum
2) You don't care what the actual values of each enum is

For this patch, neither is true.
Michael Ellerman - July 25, 2012, 5:18 a.m.
On Wed, 2012-07-25 at 02:40 +0000, Tabi Timur-B04825 wrote:
> Michael Ellerman wrote:
> > I agree these values are odd. But there's no rule that you can only use
> > an enum if the values are monotonically increasing.
> >
> > It can still serve as helpful documentation, and reduce the number of
> > places you pass a bare int around.
> 
> IMHO, an enum should only be used if
> 
> 1) You are doing real type checking of the enum

Yes, if you're going to define an enum you should use it, which this
patch doesn't, but that's just a bug in this patch.

> 2) You don't care what the actual values of each enum is

I disagree.

They make even more sense when you don't care what the values are, but
that doesn't mean you should only use them in those cases.

And the bible, K & R, includes an example of an enum which explicitly
specifies all its values. It goes on to say "enumeration variables offer
the chance of [type] checking and so are often better than #defines".

cheers
Sandeep Singh - July 26, 2012, 10:49 a.m.
Hi,

Please find my comment inline.

Regards,
Sandeep


-----Original Message-----
From: Tabi Timur-B04825 
Sent: Tuesday, July 24, 2012 8:13 PM
To: Singh Sandeep-B37400
Cc: linuxppc-dev@lists.ozlabs.org; Aggrwal Poonam-B10812
Subject: Re: [2/3][PATCH][upstream] TDM Framework

Singh Sandeep-B37400 wrote:

>> +int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count) {
>> +       int res;
>> +
>> +       if (adap->algo->tdm_write)
>> +               res = adap->algo->tdm_write(adap, buf, count);
> 
> Why does tdm_write() return a u32?  And shouldn't 'res' also be a u32, to make tdm_write()?
> [Sandeep] tdm_write() returns number of bytes written. You are right, 
> 'res' should be declared as u32

Then it should return an unsigned int.  You should used a sized integer type only when the size really matters (e.g. hardware registers or packed fields in a structure).
[Sandeep] Agreed, will rectify.
Timur Tabi - July 26, 2012, 9:28 p.m.
Michael Ellerman wrote:
> And the bible, K & R, includes an example of an enum which explicitly
> specifies all its values. It goes on to say "enumeration variables offer
> the chance of [type] checking and so are often better than #defines".

I don't want to beat a dead horse here, but if the driver doesn't do enum
type checking, then it's hard to justify using an enum.  Now you said,
"Yes, if you're going to define an enum you should use it, which this
patch doesn't, but that's just a bug in this patch."  It could be argued
that there's no real place to incorporate enum type checking in this code.

IMHO, this is pointless:

enum mytype {
	VALUE1 = 0x10,
	VALUE2 = 0x20
};
	

int func(void)
{
	if (some-condition)
		return VALUE1;
	else
		return VALUE2;
}

> And the bible, K & R, includes an example of an enum which explicitly
> specifies all its values.

First, K&R is pretty old, and there are a lot of style issues in it that
are no longer in favor.  I don't think anyone would advocate this:

int func(x, y)
int x;
int y;
{
	...
}

Secondly, one of the benefits of an enum (which again, is not actually
being used in this patch), is to be able to specify multiple constants
that are given unique values, but you don't actually care what the values
are, like this:

enum radeon_family {
	CHIP_FAMILY_UNKNOW,
	CHIP_FAMILY_LEGACY,
	CHIP_FAMILY_RADEON,
	CHIP_FAMILY_RV100,
	CHIP_FAMILY_RS100,    /* U1 (IGP320M) or A3 (IGP320)*/
	CHIP_FAMILY_RV200,
	...
};

The code will still work if I swap CHIP_FAMILY_RV100 with
CHIP_FAMILY_RS100.  As long as each value is unique, everything works.
Scott Wood - July 26, 2012, 10:09 p.m.
On 07/26/2012 04:28 PM, Timur Tabi wrote:
> Michael Ellerman wrote:
>> And the bible, K & R, includes an example of an enum which explicitly
>> specifies all its values. It goes on to say "enumeration variables offer
>> the chance of [type] checking and so are often better than #defines".
> 
> I don't want to beat a dead horse here, but if the driver doesn't do enum
> type checking, then it's hard to justify using an enum.

Enum symbols show up in a debugger, which is nice.  Why use the
preprocessor for something that can be just as well expressed in the
language itself?  The only real argument for #define in this case is
style, which in Linux does tend toward favoring #define.

-Scott

Patch

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 5afe5d1..abd6c83 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -136,4 +136,5 @@  source "drivers/virt/Kconfig"
 
 source "drivers/devfreq/Kconfig"
 
+source "drivers/tdm/Kconfig"
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 1b31421..7cb88e3 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -104,6 +104,7 @@  obj-$(CONFIG_INFINIBAND)	+= infiniband/
 obj-$(CONFIG_SGI_SN)		+= sn/
 obj-y				+= firmware/
 obj-$(CONFIG_CRYPTO)		+= crypto/
+obj-$(CONFIG_TDM)		+= tdm/
 obj-$(CONFIG_SUPERH)		+= sh/
 obj-$(CONFIG_ARCH_SHMOBILE)	+= sh/
 ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
diff --git a/drivers/tdm/Kconfig b/drivers/tdm/Kconfig
new file mode 100644
index 0000000..0b0fda8
--- /dev/null
+++ b/drivers/tdm/Kconfig
@@ -0,0 +1,18 @@ 
+#
+# TDM subsystem configuration
+#
+
+menuconfig TDM
+	tristate "TDM support"
+	---help---
+	  More information is contained in the directory <file:Documentation/tdm/>,
+	  especially in the file called "summary" there.
+	  If you want TDM support, you should say Y here and also to the
+	  specific driver for your bus adapter(s) below.
+
+	  This TDM support can also be built as a module.  If so, the module
+	  will be called tdm-core.
+
+if TDM
+
+endif # TDM
diff --git a/drivers/tdm/Makefile b/drivers/tdm/Makefile
new file mode 100644
index 0000000..84e2cb9
--- /dev/null
+++ b/drivers/tdm/Makefile
@@ -0,0 +1,5 @@ 
+#
+# Makefile for the TDM core.
+#
+
+obj-$(CONFIG_TDM)		+= tdm-core.o
diff --git a/drivers/tdm/tdm-core.c b/drivers/tdm/tdm-core.c
new file mode 100644
index 0000000..9973b6b
--- /dev/null
+++ b/drivers/tdm/tdm-core.c
@@ -0,0 +1,1082 @@ 
+/* driver/tdm/tdm-core.c
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.
+ *
+ * TDM core is the interface between TDM clients and TDM devices.
+ * It is also intended to serve as an interface for line controlled
+ * devices later on.
+ *
+ * Author:Hemant Agrawal <hemant@freescale.com>
+ *	Rajesh Gumasta <rajesh.gumasta@freescale.com>
+ *
+ * Modified by Sandeep Kr Singh <sandeep@freescale.com>
+ *		Poonam Aggarwal <poonam.aggarwal@freescale.com>
+ * 1. Added framework based initialization of device.
+ * 2. All the init/run time configuration is now done by framework.
+ * 3. Added channel level operations.
+ * 4. Added sysfs knob to configure use_latest_tdm_data at runtime.
+ *
+ * Note that some parts of this code may have been derived from i2c subsystem.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the  GNU General Public License along
+ * with this program; if not, write  to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tdm.h>
+#include <linux/init.h>
+#include <linux/idr.h>
+#include <linux/mutex.h>
+#include <linux/completion.h>
+#include <linux/hardirq.h>
+#include <linux/irqflags.h>
+#include <linux/list.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+
+static DEFINE_MUTEX(tdm_core_lock);
+static DEFINE_IDR(tdm_adapter_idr);
+/* List of TDM adapters registered with TDM framework */
+LIST_HEAD(adapter_list);
+
+/* List of TDM clients registered with TDM framework */
+LIST_HEAD(driver_list);
+
+/* In case the previous data is not fetched by the client driver, the
+ * de-interleaving function will  discard the old data and rewrite the
+ * new data */
+static int use_latest_tdm_data = 1;
+
+/* Data structures required for sysfs */
+static struct tdm_sysfs attr = {
+	.attr.name = "use_latest_data",
+	.attr.mode = 0664,
+	.cmd_type = TDM_LATEST_DATA,
+};
+
+static struct attribute *tdm_attr[] = {
+	&attr.attr,
+	NULL
+};
+
+const struct sysfs_ops tdm_ops = {
+	.show = tdm_show_sysfs,
+	.store = tdm_store_sysfs,
+};
+
+static struct kobj_type tdm_type = {
+	.sysfs_ops = &tdm_ops,
+	.default_attrs = tdm_attr,
+};
+
+/* tries to match client driver with the adapter */
+static int tdm_device_match(struct tdm_driver *driver, struct tdm_adapter *adap)
+{
+	/* match on an id table if there is one */
+	if (driver->id_table && driver->id_table->name[0]) {
+		if (!(strcmp(driver->id_table->name, adap->name)))
+			return (int)driver->id_table;
+	}
+	return TDM_E_OK;
+}
+
+static int tdm_attach_driver_adap(struct tdm_driver *driver,
+		struct tdm_adapter *adap)
+{
+	int ret = TDM_E_OK;
+	/* if driver is already attached to any other adapter, return*/
+	if (driver->adapter && (driver->adapter != adap))
+		return ret;
+
+	driver->adapter = adap;
+
+	if (driver->attach_adapter) {
+		ret = driver->attach_adapter(adap);
+		if (ret < 0) {
+			pr_err("attach_adapter failed for driver [%s] err:%d\n"
+					, driver->name, ret);
+			return ret;
+		}
+	}
+	adap->drv_count++;
+
+	if (!adap->tasklet_conf) {
+		tdm_sysfs_init();
+		tasklet_init(&adap->tdm_data_tasklet, tdm_data_tasklet_fn,
+				(unsigned long)adap);
+		adap->tasklet_conf = 1;
+	}
+
+	return ret;
+}
+
+/* Detach client driver and adapter */
+static int tdm_detach_driver_adap(struct tdm_driver *driver,
+		struct tdm_adapter *adap)
+{
+	int res = TDM_E_OK;
+
+	if (!driver->adapter || (driver->adapter != adap))
+		return TDM_E_OK;
+
+	adap->drv_count--;
+
+	/* If no more driver is registed with the adapter*/
+	if (!adap->drv_count && adap->tasklet_conf) {
+		tasklet_disable(&adap->tdm_data_tasklet);
+		tasklet_kill(&adap->tdm_data_tasklet);
+		adap->tasklet_conf = 0;
+	}
+
+	if (driver->detach_adapter) {
+		if (driver->detach_adapter(adap))
+			pr_err("detach_adapter failed for driver [%s]\n",
+					driver->name);
+	}
+
+	driver->adapter = NULL;
+	return res;
+}
+
+/* TDM adapter Registration/De-registration with TDM framework */
+
+static int tdm_register_adapter(struct tdm_adapter *adap)
+{
+	int res = TDM_E_OK;
+	struct tdm_driver *driver, *next;
+
+	mutex_init(&adap->adap_lock);
+	INIT_LIST_HEAD(&adap->myports);
+	spin_lock_init(&adap->portlist_lock);
+
+	adap->drv_count = 0;
+	adap->tasklet_conf = 0;
+
+	list_add_tail(&adap->list, &adapter_list);
+
+	/* initialization of driver by framework in default configuration */
+	init_config_adapter(adap);
+
+	/* Notify drivers */
+	pr_info("adapter [%s] registered\n", adap->name);
+	mutex_lock(&tdm_core_lock);
+	list_for_each_entry_safe(driver, next, &driver_list, list) {
+		if (tdm_device_match(driver, adap)) {
+			res = tdm_attach_driver_adap(driver, adap);
+			if (res == TDM_E_OK) {
+				pr_info("Driver(ID=%d) is "
+						"attached with Adapter %s(ID"
+						" = %d)\n", driver->id,
+						adap->name, adap->id);
+			} else {
+				pr_err("Driver(ID=%d) is unable "
+						"to attach with Adapter %s(ID = %d)\n",
+						driver->id, adap->name,
+						adap->id);
+			}
+		}
+	}
+	mutex_unlock(&tdm_core_lock);
+
+	return res;
+}
+
+/*
+ * tdm_add_adapter - declare tdm adapter, use dynamic device number
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * This routine is used to declare a TDM adapter
+ * When this returns zero, a new device number will be allocated and stored
+ * in adap->id, and the specified adapter became available for the clients.
+ * Otherwise, a negative errno value is returned.
+ */
+int tdm_add_adapter(struct tdm_adapter *adapter)
+{
+	int id, res = TDM_E_OK;
+
+retry:
+	if (idr_pre_get(&tdm_adapter_idr, GFP_KERNEL) == 0)
+		return -ENOMEM;
+
+	mutex_lock(&tdm_core_lock);
+	res = idr_get_new(&tdm_adapter_idr, adapter, &id);
+	mutex_unlock(&tdm_core_lock);
+
+	if (res < 0) {
+		if (res == -EAGAIN)
+			goto retry;
+		return res;
+	}
+
+	adapter->id = id;
+	return tdm_register_adapter(adapter);
+}
+EXPORT_SYMBOL(tdm_add_adapter);
+
+
+/**
+ * tdm_del_adapter - unregister TDM adapter
+ * @adap: the adapter being unregistered
+ *
+ * This unregisters an TDM adapter which was previously registered
+ * by @tdm_add_adapter.
+ */
+int tdm_del_adapter(struct tdm_adapter *adap)
+{
+	int res = TDM_E_OK;
+	struct tdm_adapter *found;
+	struct tdm_driver *driver, *next;
+
+	/* First make sure that this adapter was ever added */
+	mutex_lock(&tdm_core_lock);
+	found = idr_find(&tdm_adapter_idr, adap->id);
+	mutex_unlock(&tdm_core_lock);
+	if (found != adap) {
+		pr_err("tdm-core: attempting to delete unregistered "
+				"adapter [%s]\n", adap->name);
+		return -EINVAL;
+	}
+
+	/*disable and kill the data processing tasklet */
+	if (adap->tasklet_conf) {
+		tasklet_disable(&adap->tdm_data_tasklet);
+		tasklet_kill(&adap->tdm_data_tasklet);
+		adap->tasklet_conf = 0;
+	}
+
+	/* Detach any active ports. This can't fail, thus we do not
+	   checking the returned value. */
+	mutex_lock(&tdm_core_lock);
+	list_for_each_entry_safe(driver, next, &driver_list, list) {
+		if (tdm_device_match(driver, adap)) {
+			tdm_detach_driver_adap(driver, adap);
+			pr_info(
+					"Driver(ID=%d) is detached from Adapter %s(ID = %d)\n",
+					driver->id, adap->name, adap->id);
+		}
+	}
+	idr_remove(&tdm_adapter_idr, adap->id);
+	mutex_unlock(&tdm_core_lock);
+
+	pr_debug("adapter [%s] unregistered\n", adap->name);
+
+	list_del(&adap->list);
+	/* Clear the device structure in case this adapter is ever going to be
+	   added again */
+	adap->parent = NULL;
+
+	return res;
+}
+EXPORT_SYMBOL(tdm_del_adapter);
+
+/* TDM Client Drivers Registration/De-registration Functions */
+int tdm_register_driver(struct tdm_driver *driver)
+{
+	int res = TDM_E_OK;
+	struct tdm_adapter *adap, *next;
+
+	list_add_tail(&driver->list, &driver_list);
+
+	mutex_lock(&tdm_core_lock);
+	/* Walk the adapters that are already present */
+	list_for_each_entry_safe(adap, next, &adapter_list, list) {
+		if (tdm_device_match(driver, adap)) {
+			res = tdm_attach_driver_adap(driver, adap);
+			if (res == TDM_E_OK) {
+				pr_info("TDM Driver(ID=%d)is attached with "
+						"Adapter%s(ID = %d) drv_count=%d",
+						driver->id, adap->name,
+						adap->id, adap->drv_count);
+			} else {
+				pr_err("TDM Driver(ID=%d) unable to attach "
+						"to Adapter%s(ID = %d) drv_count=%d",
+						driver->id, adap->name,
+						adap->id, adap->drv_count);
+			}
+			break;
+		}
+	}
+	mutex_unlock(&tdm_core_lock);
+
+	return res;
+}
+EXPORT_SYMBOL(tdm_register_driver);
+
+/*
+ * tdm_unregister_driver - unregister TDM client driver from TDM framework
+ * @driver: the driver being unregistered
+ */
+void tdm_unregister_driver(struct tdm_driver *driver)
+{
+	/* A driver can register to only one adapter,
+	 * so no need to browse the list */
+	mutex_lock(&tdm_core_lock);
+	tdm_detach_driver_adap(driver, driver->adapter);
+	mutex_unlock(&tdm_core_lock);
+
+	list_del(&driver->list);
+
+	pr_debug("tdm-core: driver [%s] unregistered\n", driver->name);
+}
+EXPORT_SYMBOL(tdm_unregister_driver);
+
+/* Interface to the tdm device/adapter */
+
+/* tdm_adap_send - issue a TDM write
+ * @adap: Handle to TDM device
+ * @buf: Data that will be written to the TDM device
+ * @count: How many bytes to write
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+int tdm_adap_send(struct tdm_adapter *adap, void **buf, int count)
+{
+	int res;
+
+	if (adap->algo->tdm_write)
+		res = adap->algo->tdm_write(adap, buf, count);
+	else {
+		pr_err("TDM level write not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* If everything went ok (i.e. frame transmitted), return #bytes
+	   transmitted, else error code. */
+	return (res == 1) ? count : res;
+}
+EXPORT_SYMBOL(tdm_adap_send);
+
+/**
+ * tdm_adap_recv - issue a TDM read
+ * @adap: Handle to TDM device
+ * @buf: Where to store data read from TDM device
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+int tdm_adap_recv(struct tdm_adapter *adap, void **buf)
+{
+	int res;
+
+	if (adap->algo->tdm_read)
+		res = adap->algo->tdm_read(adap, (u16 **)buf);
+	else {
+		pr_err("TDM level read not supported\n");
+		return -EOPNOTSUPP;
+	}
+	/* If everything went ok (i.e. frame received), return #bytes
+	   transmitted, else error code. */
+	return res;
+}
+
+/**
+ * tdm_adap_get_write_buf - get next write TDM device buffer
+ * @adap: Handle to TDM device
+ * @buf: pointer to TDM device buffer
+ *
+ * Returns negative errno, or else size of the write buffer.
+ */
+int tdm_adap_get_write_buf(struct tdm_adapter *adap, void **buf)
+{
+	int res;
+
+	if (adap->algo->tdm_get_write_buf) {
+		res = adap->algo->tdm_get_write_buf(adap, (u16 **)buf);
+	} else {
+		pr_err("TDM level write buf get not supported\n");
+		return -EOPNOTSUPP;
+	}
+	/* If everything went ok (i.e. 1 msg received), return #bytes
+	   transmitted, else error code. */
+	return res;
+}
+EXPORT_SYMBOL(tdm_adap_get_write_buf);
+
+int tdm_adap_enable(struct tdm_driver *drv)
+{
+	int res;
+	struct tdm_adapter *adap;
+	adap = drv->adapter;
+
+	if (adap->algo->tdm_enable) {
+		res = adap->algo->tdm_enable(adap);
+	} else {
+		pr_err("TDM level enable not supported\n");
+		return -EOPNOTSUPP;
+	}
+	return res;
+}
+EXPORT_SYMBOL(tdm_adap_enable);
+
+int tdm_adap_disable(struct tdm_driver *drv)
+{
+	int res;
+	struct tdm_adapter *adap;
+	adap = drv->adapter;
+
+	if (adap->algo->tdm_disable) {
+		res = adap->algo->tdm_disable(adap);
+	} else {
+		pr_err("TDM level enable not supported\n");
+		return -EOPNOTSUPP;
+	}
+	return res;
+}
+EXPORT_SYMBOL(tdm_adap_disable);
+
+struct tdm_adapter *tdm_get_adapter(int id)
+{
+	struct tdm_adapter *adapter;
+
+	mutex_lock(&tdm_core_lock);
+	adapter = idr_find(&tdm_adapter_idr, id);
+	if (adapter && !try_module_get(adapter->owner))
+		adapter = NULL;
+
+	mutex_unlock(&tdm_core_lock);
+
+	return adapter;
+}
+EXPORT_SYMBOL(tdm_get_adapter);
+
+void tdm_put_adapter(struct tdm_adapter *adap)
+{
+	module_put(adap->owner);
+}
+EXPORT_SYMBOL(tdm_put_adapter);
+
+
+/* Port Level APIs of TDM Framework */
+int tdm_port_open(struct tdm_driver *driver, struct tdm_port **h_port)
+{
+	struct tdm_port *port;
+	struct tdm_adapter *adap;
+	unsigned long		flags;
+	int res = TDM_E_OK;
+
+	adap = tdm_get_adapter(driver->adapter->id);
+	if (!adap)
+		return -ENODEV;
+
+	/* This creates an anonymous tdm_port, which may later be
+	 * pointed to some slot.
+	 *
+	 */
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port) {
+		res = -ENOMEM;
+		goto out;
+	}
+
+	port->rx_max_frames = NUM_SAMPLES_PER_FRAME;
+	port->port_cfg.port_mode = TDM_PORT_CHANNELIZED;
+
+	snprintf(driver->name, TDM_NAME_SIZE, "tdm-dev");
+	port->driver = driver;
+	port->adapter = adap;
+
+	spin_lock_irqsave(&adap->portlist_lock, flags);
+	list_add_tail(&port->list, &adap->myports);
+	spin_unlock_irqrestore(&adap->portlist_lock, flags);
+
+	INIT_LIST_HEAD(&port->mychannels);
+
+	*h_port = port;
+
+out:
+	return res;
+}
+EXPORT_SYMBOL(tdm_port_open);
+
+int tdm_port_close(struct tdm_port *h_port)
+{
+	struct tdm_adapter *adap;
+	struct tdm_driver *driver;
+	struct tdm_port *port;
+	struct tdm_channel *temp, *channel;
+	unsigned long flags;
+	int res = TDM_E_OK;
+	port = h_port;
+
+	driver =  port->driver;
+
+	list_for_each_entry_safe(channel, temp, &port->mychannels, list) {
+		if (channel)
+			if (channel->in_use) {
+				pr_err("%s:Cannot close port. Channel in use\n",
+						__func__);
+				res = -ENXIO;
+				goto out;
+			}
+	}
+	adap = driver->adapter;
+
+	spin_lock_irqsave(&adap->portlist_lock, flags);
+	list_del(&port->list);
+	spin_unlock_irqrestore(&adap->portlist_lock, flags);
+
+	if (port->p_port_data != NULL) {
+		int i;
+		struct tdm_bd *ch_bd;
+
+		/* If the tdm is in channelised mode,
+		   de-allocate the channelised buffer */
+		ch_bd = &(port->p_port_data->rx_data_fifo[0]);
+		for (i = 0; ch_bd && i < TDM_CH_RX_BD_RING_SIZE; i++) {
+			ch_bd->flag = 0;
+			ch_bd++;
+		}
+		ch_bd = &(port->p_port_data->tx_data_fifo[0]);
+		for (i = 0; ch_bd && i < TDM_CH_TX_BD_RING_SIZE; i++) {
+			ch_bd->flag = 0;
+			ch_bd++;
+		}
+		kfree(port->p_port_data);
+	}
+	kfree(port);
+	return res;
+out:
+	if (port)
+		kfree(port->p_port_data);
+	kfree(port);
+	return res;
+}
+EXPORT_SYMBOL(tdm_port_close);
+
+int tdm_channel_read(struct tdm_port *h_port, struct tdm_channel *h_channel,
+		void *p_data, u16 *size)
+{
+	struct tdm_channel *channel;
+	struct tdm_bd *rx_bd;
+	unsigned long flags;
+	int i, res = TDM_E_OK;
+	unsigned short *buf, *buf1;
+	channel = h_channel;
+
+	if (!channel->p_ch_data || !channel->in_use)
+		return -EIO;
+
+	spin_lock_irqsave(&channel->p_ch_data->rx_channel_lock, flags);
+	rx_bd = channel->p_ch_data->rx_out_data;
+
+	if (rx_bd->flag) {
+		*size = rx_bd->length;
+		buf = (u16 *) p_data;
+		buf1 = (u16 *)rx_bd->p_data;
+		for (i = 0; i < NUM_SAMPLES_PER_FRAME; i++)
+			buf[i] = buf1[i];
+		rx_bd->flag = 0;
+		rx_bd->offset = 0;
+		channel->p_ch_data->rx_out_data = (rx_bd->wrap) ?
+			channel->p_ch_data->rx_data_fifo : rx_bd + 1;
+
+	} else {
+		spin_unlock_irqrestore(&channel->p_ch_data->rx_channel_lock,
+				flags);
+		pr_debug("No Data Available");
+		return -EAGAIN;
+	}
+	spin_unlock_irqrestore(&channel->p_ch_data->rx_channel_lock, flags);
+
+	return res;
+}
+EXPORT_SYMBOL(tdm_channel_read);
+
+
+int tdm_channel_write(struct tdm_port *h_port, struct tdm_channel *h_channel,
+		void *p_data, u16 size)
+{
+	struct tdm_port *port;
+	struct tdm_channel *channel;
+	struct tdm_bd *tx_bd;
+	unsigned long flags;
+	int err = TDM_E_OK;
+	port = h_port;
+	channel = h_channel;
+#ifdef DEBUG
+	bool data_flag = 0;
+#endif
+
+	if (p_data == NULL) { /* invalid data*/
+		pr_err("Invalid Data");
+		return -EFAULT;
+	}
+
+	if (!channel->p_ch_data || !channel->in_use)
+		return -EIO;
+
+	spin_lock_irqsave(&channel->p_ch_data->tx_channel_lock, flags);
+	tx_bd = channel->p_ch_data->tx_in_data;
+
+	if (!tx_bd->flag) {
+		tx_bd->length = size;
+		memcpy(tx_bd->p_data, p_data,
+				size * port->adapter->adapt_cfg.slot_width);
+		tx_bd->flag = 1;
+		tx_bd->offset = 0;
+		channel->p_ch_data->tx_in_data = (tx_bd->wrap) ?
+			channel->p_ch_data->tx_data_fifo : tx_bd+1;
+		port->port_stat.tx_pkt_count++;
+#ifdef DEBUG
+		data_flag = 1;
+#endif
+	} else {
+		spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock,
+				flags);
+		port->port_stat.tx_pkt_drop_count++;
+		pr_err("E_NO_MEMORY -Failed Transmit");
+		return -ENOMEM;
+	}
+	spin_unlock_irqrestore(&channel->p_ch_data->tx_channel_lock, flags);
+
+#ifdef	DEBUG
+	if (data_flag) {
+		int k;
+		pr_info("\nTX port:%d - Write - Port TX-%d\n",
+				port->port_id, size);
+		for (k = 0; k < size; k++)
+			pr_info("%x", p_data[k]);
+		pr_info("\n");
+	}
+#endif
+	return err;
+}
+EXPORT_SYMBOL(tdm_channel_write);
+
+/* Driver Function for select and poll. Based on Channel, it sleeps on
+ * waitqueue */
+int tdm_ch_poll(struct tdm_channel *h_channel, unsigned int wait_time)
+{
+	struct tdm_channel *channel;
+	unsigned long timeout = msecs_to_jiffies(wait_time);
+	channel = h_channel;
+
+	if (!channel->p_ch_data || !channel->in_use)
+		return -EIO;
+
+	if (channel->p_ch_data->rx_out_data->flag) {
+		pr_debug("Data Available");
+		return TDM_E_OK;
+	}
+	if (timeout) {
+		wait_event_interruptible_timeout(channel->ch_wait_queue,
+				channel->p_ch_data->rx_out_data->flag,
+				timeout);
+
+		if (channel->p_ch_data->rx_out_data->flag) {
+			pr_debug("Data Available");
+			return TDM_E_OK;
+		}
+	}
+	return -EAGAIN;
+}
+EXPORT_SYMBOL(tdm_ch_poll);
+
+unsigned int tdm_port_get_stats(struct tdm_port *h_port,
+		struct tdm_port_stats *portStat)
+{
+	struct tdm_port *port;
+	int port_num;
+	port = h_port;
+
+	if (port == NULL || portStat == NULL) { /* invalid handle*/
+		pr_err("Invalid Handle");
+		return -ENXIO;
+	}
+	port_num =  port->port_id;
+
+	memcpy(portStat, &port->port_stat, sizeof(struct tdm_port_stats));
+
+	pr_info("TDM Port %d Get Stats", port_num);
+
+	return TDM_E_OK;
+}
+EXPORT_SYMBOL(tdm_port_get_stats);
+
+/* Data handling functions */
+
+static int tdm_data_rx_deinterleave(struct tdm_adapter *adap)
+{
+	struct tdm_port *port, *next;
+	struct tdm_channel *channel, *temp;
+	struct tdm_bd	*ch_bd;
+
+	int i, buf_size, ch_data_len;
+	u16 *input_tdm_buffer;
+	u16 *pcm_buffer;
+	int slot_width;
+	int frame_ch_data_size;
+	bool ch_data;
+	int bytes_in_fifo_per_frame;
+	int bytes_slot_offset;
+
+	ch_data_len = NUM_SAMPLES_PER_FRAME;
+	frame_ch_data_size = NUM_SAMPLES_PER_FRAME;
+	ch_data = 0;
+
+	slot_width = adap->adapt_cfg.slot_width;
+	buf_size = tdm_adap_recv(adap, (void **)&input_tdm_buffer);
+	if (buf_size <= 0 || !input_tdm_buffer)
+		return -EINVAL;
+
+	bytes_in_fifo_per_frame = buf_size/frame_ch_data_size;
+	bytes_slot_offset = bytes_in_fifo_per_frame/slot_width;
+
+	/* de-interleaving for all ports*/
+	list_for_each_entry_safe(port, next, &adap->myports, list) {
+
+		list_for_each_entry_safe(channel, temp, &port->mychannels,
+				list) {
+			/* if the channel is not open */
+			if (!channel->in_use || !channel->p_ch_data)
+				continue;
+			ch_bd = channel->p_ch_data->rx_in_data;
+			spin_lock(&channel->p_ch_data->rx_channel_lock);
+			/*if old data is to be discarded */
+			if (use_latest_tdm_data && ch_bd->flag) {
+				ch_bd->flag = 0;
+				ch_bd->offset = 0;
+				if (ch_bd == channel->p_ch_data->rx_out_data)
+					channel->p_ch_data->rx_out_data =
+						ch_bd->wrap ?
+						channel->p_ch_data->rx_data_fifo
+						: ch_bd+1;
+				port->port_stat.rx_pkt_drop_count++;
+			}
+			/* if the bd is empty */
+			if (!ch_bd->flag) {
+				if (ch_bd->offset == 0)
+					ch_bd->length = port->rx_max_frames;
+
+				pcm_buffer = ch_bd->p_data + ch_bd->offset;
+				/* De-interleaving the data */
+				for (i = 0; i < ch_data_len; i++) {
+					pcm_buffer[i]
+						= input_tdm_buffer[i*
+						bytes_slot_offset +
+						channel->ch_id];
+				}
+				ch_bd->offset += ch_data_len * slot_width;
+
+				if (ch_bd->offset >=
+						(ch_bd->length -
+						frame_ch_data_size)*
+						(adap->adapt_cfg.slot_width)) {
+					ch_bd->flag = 1;
+					ch_bd->offset = 0;
+					channel->p_ch_data->rx_in_data =
+						ch_bd->wrap ?
+						channel->p_ch_data->rx_data_fifo
+						: ch_bd+1;
+					ch_data = 1;
+					wake_up_interruptible
+						(&channel->ch_wait_queue);
+				}
+			} else {
+				port->port_stat.rx_pkt_drop_count++;
+			}
+			spin_unlock(&channel->p_ch_data->rx_channel_lock);
+		}
+
+		if (ch_data) {
+			/*	Wake up the Port Data Poll event */
+#ifdef	DEBUG
+			pr_info("Port RX-%d-%d\n", channel->ch_id, ch_data_len);
+			for (i = 0; i < ch_data_len; i++)
+				pr_info("%x", pcm_buffer[i]);
+			pr_info("\n");
+#endif
+			port->port_stat.rx_pkt_count++;
+			ch_data = 0;
+		}
+	}
+	return TDM_E_OK;
+}
+
+static int tdm_data_tx_interleave(struct tdm_adapter *adap)
+{
+	struct tdm_port *port, *next;
+	struct tdm_channel *channel, *temp;
+	struct tdm_bd	*ch_bd;
+	int i, buf_size, ch_data_len = NUM_SAMPLES_PER_FRAME;
+	bool last_data = 0;
+	u16 *output_tdm_buffer;
+	u16 *pcm_buffer;
+	int frame_ch_data_size = NUM_SAMPLES_PER_FRAME;
+	int bytes_in_fifo_per_frame;
+	int bytes_slot_offset;
+
+#ifdef DEBUG
+	u8	data_flag = 0;
+#endif
+
+	buf_size = tdm_adap_get_write_buf(adap, (void **)&output_tdm_buffer);
+	if (buf_size <= 0 || !output_tdm_buffer)
+		return -EINVAL;
+
+	bytes_in_fifo_per_frame = buf_size/frame_ch_data_size;
+	bytes_slot_offset = bytes_in_fifo_per_frame/adap->adapt_cfg.slot_width;
+
+
+	memset(output_tdm_buffer, 0, sizeof(buf_size));
+
+	list_for_each_entry_safe(port, next, &adap->myports, list) {
+
+		list_for_each_entry_safe(channel, temp, &port->mychannels,
+				list) {
+			pr_debug("TX-Tdm %d (slots-)", channel->ch_id);
+
+
+			/* if the channel is open */
+			if (!channel->in_use || !channel->p_ch_data)
+				continue;
+
+			spin_lock(&channel->p_ch_data->tx_channel_lock);
+			if (!channel->in_use || !channel->p_ch_data)
+				continue;
+			ch_bd = channel->p_ch_data->tx_out_data;
+			if (ch_bd->flag) {
+				pcm_buffer = (u16 *)((uint8_t *)ch_bd->p_data +
+						ch_bd->offset);
+				/*if the buffer has less frames than required */
+				if (frame_ch_data_size >=
+						(ch_bd->length - ch_bd->offset/
+						 adap->adapt_cfg.slot_width)) {
+					ch_data_len =
+						ch_bd->length - ch_bd->offset/
+						adap->adapt_cfg.slot_width;
+					last_data = 1;
+				} else {
+					ch_data_len = frame_ch_data_size;
+				}
+				/* Interleaving the data */
+				for (i = 0; i < ch_data_len; i++) {
+					/* TODO- need to be genric for any size
+					   assignment*/
+					output_tdm_buffer[channel->ch_id +
+						bytes_slot_offset * i] =
+						pcm_buffer[i];
+				}
+				/* If all the data of this buffer is
+				   transmitted */
+				if (last_data) {
+					ch_bd->flag = 0;
+					ch_bd->offset = 0;
+					channel->p_ch_data->tx_out_data =
+						ch_bd->wrap ?
+						channel->p_ch_data->tx_data_fifo
+						: ch_bd+1;
+					port->port_stat.tx_pkt_conf_count++;
+				} else {
+					ch_bd->offset += ch_data_len *
+						(adap->adapt_cfg.slot_width);
+				}
+#ifdef	DEBUG
+				data_flag = 1;
+#endif
+			}
+			spin_unlock(&channel->p_ch_data->tx_channel_lock);
+		}
+	}
+
+#ifdef	DEBUG
+	if (data_flag) {
+		pr_info("TX-TDM Interleaved Data-\n");
+		for (i = 0; i < 64; i++)
+			pr_info("%x", output_tdm_buffer[i]);
+		pr_info("\n");
+	}
+#endif
+	return TDM_E_OK;
+}
+
+/* Channel Level APIs of TDM Framework */
+int tdm_channel_open(u16 chanid, u16 ch_width, struct tdm_port *port,
+		struct tdm_channel **h_channel)
+{
+	struct tdm_channel *channel, *temp;
+	unsigned long		flags;
+	struct tdm_ch_data	*p_ch_data;
+	int res = TDM_E_OK;
+
+	if (ch_width != 1) {
+		pr_err("%s: Mode not supported\n", __func__);
+		return -EINVAL;
+	}
+
+	list_for_each_entry_safe(channel, temp, &port->mychannels, list) {
+		if (channel->ch_id == chanid) {
+			pr_err("%s: Channel %d already open\n",
+					__func__, chanid);
+			return -EINVAL;
+		}
+	}
+
+	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
+	if (!channel) {
+		res = -ENOMEM;
+		goto out;
+	}
+
+	init_waitqueue_head(&channel->ch_wait_queue);
+	p_ch_data = kzalloc(sizeof(struct tdm_ch_data), GFP_KERNEL);
+	if (!p_ch_data) {
+		res = -ENOMEM;
+		goto outdata;
+	}
+
+	p_ch_data->rx_data_fifo[TDM_CH_RX_BD_RING_SIZE-1].wrap = 1;
+	p_ch_data->tx_data_fifo[TDM_CH_TX_BD_RING_SIZE-1].wrap = 1;
+
+	p_ch_data->rx_in_data = p_ch_data->rx_data_fifo;
+	p_ch_data->rx_out_data = p_ch_data->rx_data_fifo;
+	p_ch_data->tx_in_data = p_ch_data->tx_data_fifo;
+	p_ch_data->tx_out_data = p_ch_data->tx_data_fifo;
+	spin_lock_init(&p_ch_data->rx_channel_lock);
+	spin_lock_init(&p_ch_data->tx_channel_lock);
+
+	channel->p_ch_data = p_ch_data;
+
+	channel->ch_id = chanid;
+	channel->ch_cfg.first_slot = chanid;
+	channel->ch_cfg.num_slots = 1;	/* This is 1 for channelized mode and
+					   configurable for other modes */
+	channel->port = port;
+	channel->in_use = 1;
+
+	spin_lock_irqsave(&port->ch_list_lock, flags);
+	list_add_tail(&channel->list, &port->mychannels);
+	spin_unlock_irqrestore(&port->ch_list_lock, flags);
+
+	*h_channel = channel;
+
+	return res;
+
+outdata:
+	kfree(channel);
+out:
+	return res;
+}
+EXPORT_SYMBOL(tdm_channel_open);
+
+int tdm_sysfs_init(void)
+{
+	struct kobject *tdm_kobj;
+	int err = 1;
+	tdm_kobj = kzalloc(sizeof(*tdm_kobj), GFP_KERNEL);
+	if (tdm_kobj) {
+		kobject_init(tdm_kobj, &tdm_type);
+		if (kobject_add(tdm_kobj, NULL, "%s", "tdm")) {
+			pr_err("Sysfs creation failed\n");
+			kobject_put(tdm_kobj);
+			err = -EINVAL;
+			goto out;
+		}
+	} else {
+		pr_err("Unable to allocate tdm_kobj\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+out:
+	return err;
+}
+
+int tdm_channel_close(u16 chanid, u16 ch_width, struct tdm_port *port,
+		struct tdm_channel *h_channel)
+{
+	struct tdm_channel *channel;
+	unsigned long		flags;
+	int res = TDM_E_OK;
+	channel = h_channel;
+
+	spin_lock_irqsave(&port->ch_list_lock, flags);
+	list_del(&channel->list);
+	spin_unlock_irqrestore(&port->ch_list_lock, flags);
+
+	if (channel)
+		kfree(channel->p_ch_data);
+	kfree(channel);
+	return res;
+}
+EXPORT_SYMBOL(tdm_channel_close);
+
+ssize_t tdm_show_sysfs(struct kobject *kobj,
+		struct attribute *attr, char *buf)
+{
+	int retval = 0;
+	struct tdm_sysfs *a = container_of(attr,
+			struct tdm_sysfs, attr);
+	switch (a->cmd_type) {
+	case TDM_LATEST_DATA:
+		pr_info("use_latest_tdm_data: %d\n", use_latest_tdm_data);
+		break;
+	default:
+		pr_info("Invalid cmd_type value\n");
+		return -EINVAL;
+	}
+	return retval;
+}
+
+ssize_t tdm_store_sysfs(struct kobject *kobj,
+		struct attribute *attr, const char *buf, size_t len)
+{
+	struct tdm_sysfs *a = container_of(attr,
+			struct tdm_sysfs, attr);
+
+	sscanf(buf, "%d", &a->data);
+	use_latest_tdm_data = a->data;
+	return strlen(buf);
+}
+
+void init_config_adapter(struct tdm_adapter *adap)
+{
+	struct fsl_tdm_adapt_cfg default_adapt_cfg = {
+		.loopback = TDM_PROCESS_NORMAL,
+		.num_ch = NUM_CHANNELS,
+		.ch_size_type = CHANNEL_16BIT_LIN,
+		.frame_len = NUM_SAMPLES_PER_FRAME,
+		.num_frames = NUM_SAMPLES_PER_FRAME,
+		.adap_mode = TDM_ADAPTER_MODE_NONE
+	};
+
+	default_adapt_cfg.slot_width = default_adapt_cfg.ch_size_type/3 + 1;
+
+	memcpy(&adap->adapt_cfg, &default_adapt_cfg,
+			sizeof(struct fsl_tdm_adapt_cfg));
+
+	return;
+}
+EXPORT_SYMBOL(init_config_adapter);
+
+void tdm_data_tasklet_fn(unsigned long data)
+{
+	struct tdm_adapter *adapter;
+	adapter = (struct tdm_adapter *)data;
+	if (adapter != NULL) {
+		tdm_data_tx_interleave(adapter);
+		tdm_data_rx_deinterleave(adapter);
+	}
+}
+
+
+MODULE_AUTHOR("Hemant Agrawal <hemant@freescale.com> and "
+	"Rajesh Gumasta <rajesh.gumasta@freescale.com>");
+MODULE_DESCRIPTION("TDM Driver Framework Core");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 83ac071..573ac40 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -425,6 +425,17 @@  struct i2c_device_id {
 			__attribute__((aligned(sizeof(kernel_ulong_t))));
 };
 
+/* tdm */
+
+#define TDM_NAME_SIZE   20
+#define TDM_MODULE_PREFIX "tdm:"
+
+struct tdm_device_id {
+	char name[TDM_NAME_SIZE];
+	kernel_ulong_t driver_data      /* Data private to the driver */
+			__attribute__((aligned(sizeof(kernel_ulong_t))));
+};
+
 /* spi */
 
 #define SPI_NAME_SIZE	32
diff --git a/include/linux/tdm.h b/include/linux/tdm.h
new file mode 100644
index 0000000..a2f9628
--- /dev/null
+++ b/include/linux/tdm.h
@@ -0,0 +1,338 @@ 
+/* include/linux/tdm.h
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc, All rights reserved.
+ *
+ * tdm.h - definitions for the tdm-device framework interface
+ *
+ * Author:Hemant Agrawal <hemant@freescale.com>
+ *	Rajesh Gumasta <rajesh.gumasta@freescale.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the  GNU General Public License along
+ * with this program; if not, write  to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#ifndef _LINUX_TDM_H
+#define _LINUX_TDM_H
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/device.h>	/* for struct device */
+#include <linux/sched.h>	/* for completion */
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/sysfs.h>
+
+#define TDM_LATEST_DATA		1
+#define CHANNEL_8BIT_LIN	0	/* 8 bit linear */
+#define CHANNEL_8BIT_ULAW	1	/* 8 bit Mu-law */
+#define CHANNEL_8BIT_ALAW	2	/* 8 bit A-law */
+#define CHANNEL_16BIT_LIN	3	/* 16 bit Linear */
+
+/*
+ * Default adapter configuration. All the TDM adapters registered with
+ * framework will be configured with following default configuration.
+ */
+#define NUM_CHANNELS	16
+
+/* Default configuration for typical voice data sample. These parameters
+ * will generally not be required to be changed for voice type applications.
+ */
+#define NUM_SAMPLES_PER_MS	8	/* 8 samples per milli sec per
+					 channel. Req for voice data */
+#define NUM_MS			10
+#define NUM_SAMPLES_PER_FRAME	(NUM_MS * NUM_SAMPLES_PER_MS) /* Number of
+						samples for 1 client buffer */
+#define NUM_OF_TDM_BUF		3
+
+/* General options */
+
+struct tdm_adapt_algorithm;
+struct tdm_adapter;
+struct tdm_port;
+struct tdm_driver;
+
+
+/**
+ * struct tdm_driver - represent an TDM device driver
+ * @class: What kind of tdm device we instantiate (for detect)
+ * @id:Driver id
+ * @name: Name of the driver
+ * @attach_adapter: Callback for device addition (for legacy drivers)
+ * @detach_adapter: Callback for device removal (for legacy drivers)
+ * @probe: Callback for device binding
+ * @remove: Callback for device unbinding
+ * @shutdown: Callback for device shutdown
+ * @suspend: Callback for device suspend
+ * @resume: Callback for device resume
+ * @command: Callback for sending commands to device
+ * @id_table: List of TDM devices supported by this driver
+ * @list: List of drivers created (for tdm-core use only)
+ */
+struct tdm_driver {
+	unsigned int class;
+	unsigned int id;
+	char name[TDM_NAME_SIZE];
+
+	int (*attach_adapter)(struct tdm_adapter *);
+	int (*detach_adapter)(struct tdm_adapter *);
+
+	/* Standard driver model interfaces */
+	int (*probe)(const struct tdm_device_id *);
+	int (*remove)(void);
+
+	/* driver model interfaces that don't relate to enumeration */
+	void (*shutdown)(void);
+	int (*suspend)(pm_message_t mesg);
+	int (*resume)(void);
+
+	const struct tdm_device_id *id_table;
+
+	/* The associated adapter for this driver */
+	struct tdm_adapter *adapter;
+	struct list_head list;
+};
+
+/* tdm per port statistics structure, used for providing and storing tdm port
+ * statistics.
+ */
+struct tdm_port_stats {
+	unsigned int rx_pkt_count;	/* Rx frame count per channel */
+	unsigned int rx_pkt_drop_count;	/* Rx drop count per channel to
+					 clean space for new buffer */
+	unsigned int tx_pkt_count;	/* Tx frame count per channel */
+	unsigned int tx_pkt_conf_count;	/* Tx frame confirmation count per
+					 channel */
+	unsigned int tx_pkt_drop_count;	/* Tx drop count per channel due to
+					 queue full */
+};
+
+
+/* tdm Buffer Descriptor, used for Creating Interleaved and De-interleaved
+ * FIFOs
+ */
+struct tdm_bd {
+	unsigned char flag;		/* BD is full or empty */
+	unsigned char wrap;		/* BD is last in the queue */
+	unsigned short length;	/* Length of Data in BD */
+	/*TODO: use dyanmic memory */
+	unsigned short p_data[NUM_SAMPLES_PER_FRAME];	/* Data Pointer */
+	unsigned long offset;	/* Offset of the Data Pointer to be used */
+};
+
+#define TDM_CH_RX_BD_RING_SIZE	3
+#define TDM_CH_TX_BD_RING_SIZE	3
+
+/* tdm RX-TX Channelised Data */
+struct tdm_port_data {
+	struct tdm_bd rx_data_fifo[TDM_CH_RX_BD_RING_SIZE]; /* Rx Channel Data
+								BD Ring */
+	struct tdm_bd *rx_in_data;	/* Current Channel Rx BD to be filled by
+						de-interleave function */
+	struct tdm_bd *rx_out_data;	/* Current Channel Rx BD to be
+							read by App */
+	struct tdm_bd tx_data_fifo[TDM_CH_TX_BD_RING_SIZE]; /* Tx Channel Data
+								BD Ring */
+	struct tdm_bd *tx_in_data;	/* Current Channel Tx BD to be
+						 filled by App */
+	struct tdm_bd *tx_out_data;	/* Current Channel Tx BD to be read by
+						interleave function */
+	spinlock_t rx_channel_lock;	/* Spin Lock for Rx Channel */
+	spinlock_t tx_channel_lock;	/* Spin Lock for Tx Channel */
+};
+
+/* structure tdm_port_cfg - contains configuration params for a port */
+struct tdm_port_cfg {
+	unsigned short port_mode;
+};
+
+/* struct tdm_port - represent an TDM ports for a device */
+struct tdm_port {
+	unsigned short port_id;
+	unsigned short in_use;		/* Port is enabled? */
+	uint16_t rx_max_frames;		/* Received Port frames
+					 before allowing Read Operation in
+					 Port Mode */
+
+	struct tdm_port_stats port_stat;/* A structure parameters defining
+					 TDM port statistics. */
+	struct tdm_port_data *p_port_data;	/* a structure parameters
+						defining tdm channelised data */
+
+	struct tdm_driver *driver;	/* driver for this port */
+	struct tdm_adapter *adapter;	/* adapter for this port */
+	struct list_head list;		/* list of ports */
+	struct list_head mychannels;	/* list of channels, created on this
+					 port*/
+	spinlock_t ch_list_lock;	/* Spin Lock for channel_list */
+	struct tdm_port_cfg port_cfg;/* A structure parameters defining
+					 TDM port configuration. */
+};
+
+/* tdm RX-TX Channelised Data */
+struct tdm_ch_data {
+	struct tdm_bd rx_data_fifo[TDM_CH_RX_BD_RING_SIZE]; /* Rx Port Data BD
+								Ring */
+	struct tdm_bd *rx_in_data;	/* Current Port Rx BD to be filled by
+						de-interleave function */
+	struct tdm_bd *rx_out_data; /* Current Port Rx BD to be read by App */
+	struct tdm_bd tx_data_fifo[TDM_CH_TX_BD_RING_SIZE]; /* Tx Port Data BD
+								Ring */
+	struct tdm_bd *tx_in_data;	/* Current Port Tx BD to be filled by
+						App */
+	struct tdm_bd *tx_out_data;	/* Current Port Tx BD to be read by
+						interleave function */
+	spinlock_t rx_channel_lock;	/* Spin Lock for Rx Port */
+	spinlock_t tx_channel_lock;	/* Spin Lock for Tx Port */
+};
+
+/* Channel config params */
+struct tdm_ch_cfg {
+	unsigned short num_slots;
+	unsigned short first_slot;
+};
+
+/* struct tdm_channel- represent a TDM channel for a port */
+struct tdm_channel {
+	u16 ch_id;			/* logical channel number */
+	struct list_head list;		/* list of channels in a port*/
+	struct tdm_port *port;		/* port for this channel */
+	u8 in_use;			/* channel is enabled? */
+	struct tdm_ch_cfg ch_cfg;	/* channel configuration */
+	struct tdm_ch_data *p_ch_data;	/* data storage space for channel */
+	wait_queue_head_t ch_wait_queue;/* waitQueue for RX Channel Data */
+};
+
+/* tdm_adapt_algorithm is for accessing the routines of device */
+struct tdm_adapt_algorithm {
+	u32 (*tdm_read)(struct tdm_adapter *, u16 **);
+	u32 (*tdm_get_write_buf)(struct tdm_adapter *, u16 **);
+	u32 (*tdm_write)(struct tdm_adapter *, void *, unsigned int len);
+	int (*tdm_enable)(struct tdm_adapter *);
+	int (*tdm_disable)(struct tdm_adapter *);
+};
+
+/* tdm_adapter_mode is to define in mode of the device */
+enum tdm_adapter_mode {
+	TDM_ADAPTER_MODE_NONE = 0x00,
+	TDM_ADAPTER_MODE_T1 = 0x01,
+	TDM_ADAPTER_MODE_E1 = 0x02,
+	TDM_ADAPTER_MODE_T1_RAW = 0x10,
+	TDM_ADAPTER_MODE_E1_RAW = 0x20,
+};
+
+/* tdm_port_mode defines the mode in which the port is configured to operate
+ * It can be channelized/full/fractional.
+ */
+enum tdm_port_mode {
+	TDM_PORT_CHANNELIZED = 0,	/* Channelized mode */
+	TDM_PORT_FULL = 1,		/* Full mode */
+	TDM_PORT_FRACTIONAL = 2		/* Fractional mode */
+};
+
+/* tdm_process_mode used for testing the tdm device in normal mode or internal
+ * loopback or external loopback
+ */
+enum tdm_process_mode {
+	TDM_PROCESS_NORMAL = 0,		/* Normal mode */
+	TDM_PROCESS_INT_LPB = 1,	/* Internal loop mode */
+	TDM_PROCESS_EXT_LPB = 2		/* External Loopback mode */
+};
+
+/* TDM configuration parameters */
+struct fsl_tdm_adapt_cfg {
+	u8 num_ch;		/* Number of channels in this adpater */
+	u8 ch_size_type;		/* reciever/transmit channel
+						size for all channels */
+	u8 slot_width;		/* 1 or 2 Is defined by channel type */
+	u8 frame_len;		/* Length of frame in samples */
+	u32 num_frames;
+	u8 loopback;			/* loopback or normal */
+	u8 adap_mode;			/* 0=None, 1= T1, 2= T1-FULL, 3=E1,
+						4 = E1-FULL */
+	int max_timeslots;		/* Max Number of timeslots that are
+					supported on this adapter */
+};
+
+/*
+ * tdm_adapter is the structure used to identify a physical tdm device along
+ * with the access algorithms necessary to access it.
+ */
+struct tdm_adapter {
+	struct module *owner;	/* owner of the adapter module */
+	unsigned int id;	/* Adapter Id */
+	unsigned int drv_count;	/* Number of drivers associated with the
+				 adapter */
+
+	const struct tdm_adapt_algorithm *algo;	/* the algorithm to access the
+						 adapter*/
+
+	char name[TDM_NAME_SIZE];	/* Name of Adapter */
+	struct mutex adap_lock;
+	struct device *parent;
+
+	struct tasklet_struct tdm_data_tasklet;	/* tasklet handle to perform
+						 data processing*/
+	int tasklet_conf;	/* flag for tasklet configuration */
+	int tdm_rx_flag;
+
+	struct list_head myports;	/* list of ports, created on this
+					 adapter */
+	struct list_head list;
+	spinlock_t portlist_lock;
+	void *data;
+	struct fsl_tdm_adapt_cfg adapt_cfg;
+};
+
+struct tdm_sysfs {
+	struct attribute attr;
+	int data;
+	u32 cmd_type;
+};
+
+/* functions exported by tdm.o */
+
+int tdm_add_adapter(struct tdm_adapter *adpater);
+int tdm_del_adapter(struct tdm_adapter *adapter);
+int tdm_register_driver(struct tdm_driver *driver);
+void tdm_unregister_driver(struct tdm_driver *driver);
+void init_config_adapter(struct tdm_adapter *adapter);
+
+int tdm_port_open(struct tdm_driver *driver, struct tdm_port **h_port);
+int tdm_port_close(struct tdm_port *h_port);
+int tdm_channel_read(struct tdm_port *h_port, struct tdm_channel *h_channel,
+		void *p_data, u16 *size);
+int tdm_channel_write(struct tdm_port *h_port, struct tdm_channel *h_channel,
+		void *p_data, u16 size);
+int tdm_ch_poll(struct tdm_channel *h_channel, unsigned int wait_time);
+
+int tdm_channel_open(u16 chanid, u16 ch_width, struct tdm_port *port,
+		struct tdm_channel **h_channel);
+int tdm_channel_close(u16 chanid, u16 ch_width, struct tdm_port *port,
+		struct tdm_channel *h_channel);
+/* this tasklet is created for each adapter instance */
+void tdm_data_tasklet_fn(unsigned long);
+int tdm_sysfs_init(void);
+ssize_t tdm_show_sysfs(struct kobject *kobj,
+		struct attribute *attr, char *buf);
+ssize_t tdm_store_sysfs(struct kobject *kobj,
+		struct attribute *attr, const char *buf, size_t len);
+
+struct tdm_adapter *tdm_get_adapter(int id);
+void tdm_put_adapter(struct tdm_adapter *adap);
+
+#endif /* __KERNEL__ */
+
+#define TDM_E_OK 0