Patchwork [19/29] i2400m/USB: header for the USB bus driver

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Submitter Inaky Perez-Gonzalez
Date Dec. 10, 2008, 11:13 p.m.
Message ID <d0584dc280aa91e907c7b56f6de254878d73a73d.1228948072.git.inaky@linux.intel.com>
Download mbox | patch
Permalink /patch/13358/
State RFC
Delegated to: David Miller
Headers show

Comments

Inaky Perez-Gonzalez - Dec. 10, 2008, 11:13 p.m.
This contains the common function declaration and constants for the
USB driver for the 2400m Wireless WiMAX Connection, as well as it's
debug level settings.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
---
 drivers/net/wimax/i2400m/i2400m-usb.h       |  264 +++++++++++++++++++++++++++
 drivers/net/wimax/i2400m/usb-debug-levels.h |   42 +++++
 2 files changed, 306 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/wimax/i2400m/i2400m-usb.h
 create mode 100644 drivers/net/wimax/i2400m/usb-debug-levels.h

Patch

diff --git a/drivers/net/wimax/i2400m/i2400m-usb.h b/drivers/net/wimax/i2400m/i2400m-usb.h
new file mode 100644
index 0000000..6f76558
--- /dev/null
+++ b/drivers/net/wimax/i2400m/i2400m-usb.h
@@ -0,0 +1,264 @@ 
+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * USB-specific i2400m driver definitions
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Yanir Lubetkin <yanirx.lubetkin@intel.com>
+ *  - Initial implementation
+ *
+ *
+ * This driver implements the bus-specific part of the i2400m for
+ * USB. Check i2400m.h for a generic driver description.
+ *
+ * ARCHITECTURE
+ *
+ * This driver listens to notifications sent from the notification
+ * endpoint (in usb-notif.c); when data is ready to read, the code in
+ * there schedules a read from the device (usb-rx.c) and then passes
+ * the data to the generic RX code (rx.c).
+ *
+ * When the generic driver needs to send data (network or control), it
+ * queues up in the TX FIFO (tx.c) and that will notify the driver
+ * through the i2400m->bus_tx_kick() callback
+ * (usb-tx.c:i2400mu_bus_tx_kick) which will send the items in the
+ * FIFO queue.
+ *
+ * This driver, as well, implements the USB-specific ops for the generic
+ * driver to be able to setup/teardown communication with the device
+ * [i2400m_bus_dev_start() and i2400m_bus_dev_stop()], reseting the
+ * device [i2400m_bus_reset()] and performing firmware upload
+ * [i2400m_bus_bm_cmd() and i2400_bus_bm_wait_for_ack()].
+ */
+
+#ifndef __I2400M_USB_H__
+#define __I2400M_USB_H__
+
+#include "i2400m.h"
+#include <linux/kthread.h>
+
+
+/*
+ * Error Density Count: cheapo error density (over time) counter
+ *
+ * Originally by Reinette Chatre <reinette.chatre@intel.com>
+ *
+ * Embed an 'struct edc' somewhere. Each time there is a soft or
+ * retryable error, call edc_inc() and check if the error top
+ * watermark has been reached.
+ */
+enum {
+	EDC_MAX_ERRORS = 10,
+	EDC_ERROR_TIMEFRAME = HZ,
+};
+
+/* error density counter */
+struct edc {
+	unsigned long timestart;
+	u16 errorcount;
+};
+
+static inline void edc_init(struct edc *edc)
+{
+	edc->timestart = jiffies;
+}
+
+/**
+ * edc_inc - report a soft error and check if we are over the watermark
+ *
+ * @edc: pointer to error density counter.
+ * @max_err: maximum number of errors we can accept over the timeframe
+ * @timeframe: lenght of the timeframe (in jiffies).
+ *
+ * Returns: !0 1 if maximum acceptable errors per timeframe has been
+ *     exceeded. 0 otherwise.
+ *
+ * This is way to determine if the number of acceptable errors per time
+ * period has been exceeded. It is not accurate as there are cases in which
+ * this scheme will not work, for example if there are periodic occurences
+ * of errors that straddle updates to the start time. This scheme is
+ * sufficient for our usage.
+ *
+ * To use, embed a 'struct edc' somewhere, initialize it with
+ * edc_init() and when an error hits:
+ *
+ * if (do_something_fails_with_a_soft_error) {
+ *        if (edc_inc(&my->edc, MAX_ERRORS, MAX_TIMEFRAME))
+ * 	           Ops, hard error, do something about it
+ *        else
+ *                 Retry or ignore, depending on whatever
+ * }
+ */
+static inline int edc_inc(struct edc *edc, u16 max_err, u16 timeframe)
+{
+	unsigned long now;
+
+	now = jiffies;
+	if (now - edc->timestart > timeframe) {
+		edc->errorcount = 1;
+		edc->timestart = now;
+	} else if (++edc->errorcount > max_err) {
+		edc->errorcount = 0;
+		edc->timestart = now;
+		return 1;
+	}
+	return 0;
+}
+
+/* Host-Device interface for USB */
+enum {
+	I2400MU_MAX_NOTIFICATION_LEN = 256,
+	I2400MU_BLK_SIZE = 16,
+	I2400MU_PL_SIZE_MAX = 0x3EFF,
+
+	/* Endpoints */
+	I2400MU_EP_BULK_OUT = 0,
+	I2400MU_EP_NOTIFICATION,
+	I2400MU_EP_RESET_COLD,
+	I2400MU_EP_BULK_IN,
+};
+
+
+/**
+ * struct i2400mu - descriptor for a USB connected i2400m
+ *
+ * @i2400m: bus-generic i2400m implementation; has to be first (see
+ *     it's documentation in i2400m.h).
+ *
+ * @usb_dev: pointer to our USB device
+ *
+ * @usb_iface: pointer to our USB interface
+ *
+ * @urb_edc: error density counter; used to keep a density-on-time tab
+ *     on how many soft (retryable or ignorable) errors we get. If we
+ *     go over the threshold, we consider the bus transport is failing
+ *     too much and reset.
+ *
+ * @notif_urb: URB for receiving notifications from the device.
+ *
+ * @tx_kthread: thread we use for data TX. We use a thread because in
+ *     order to do deep power saving and put the device to sleep, we
+ *     need to call usb_autopm_*() [blocking functions].
+ *
+ * @tx_wq: waitqueue for the TX kthread to sleep when there is no data
+ *     to be sent; when more data is available, it is woken up by
+ *     i2400mu_bus_tx_kick().
+ *
+ * @rx_kthread: thread we use for data RX. We use a thread because in
+ *     order to do deep power saving and put the device to sleep, we
+ *     need to call usb_autopm_*() [blocking functions].
+ *
+ * @rx_wq: waitqueue for the RX kthread to sleep when there is no data
+ *     to receive. When data is available, it is woken up by
+ *     usb-notif.c:i2400mu_notification_grok().
+ *
+ * @rx_pending_count: number of rx-data-ready notifications that were
+ *     still not handled by the RX kthread.
+ *
+ * @rx_size: current RX buffer size that is being used.
+ *
+ * @rx_size_acc: accumulator of the sizes of the previous read
+ *     transactions.
+ *
+ * @rx_size_cnt: number of read transactions accumulated in
+ *     @rx_size_acc.
+ *
+ * @do_autopm: disable(0)/enable(>0) calling the
+ *     usb_autopm_get/put_interface() barriers when executing
+ *     commands. See doc in i2400mu_suspend() for more information.
+ *
+ * @rx_size_auto_shrink: if true, the rx_size is shrinked
+ *     automatically based on the average size of the received
+ *     transactions. This allows the receive code to allocate smaller
+ *     chunks of memory and thus reduce pressure on the memory
+ *     allocator by not wasting so much space. By default it is
+ *     enabled.
+ *
+ * @debugfs_dentry: hookup for debugfs files.
+ *     These have to be in a separate directory, a child of
+ *     (wimax_dev->debugfs_dentry) so they can be removed when the
+ *     module unloads, as we don't keep each dentry.
+ */
+struct i2400mu {
+	struct i2400m i2400m;		/* FIRST! See doc */
+
+	struct usb_device *usb_dev;
+	struct usb_interface *usb_iface;
+	struct edc urb_edc;		/* Error density counter */
+
+	struct urb *notif_urb;
+	struct task_struct *tx_kthread;
+	wait_queue_head_t tx_wq;
+
+	struct task_struct *rx_kthread;
+	wait_queue_head_t rx_wq;
+	atomic_t rx_pending_count;
+	size_t rx_size, rx_size_acc, rx_size_cnt;
+	atomic_t do_autopm;
+	u8 rx_size_auto_shrink;
+
+	struct dentry *debugfs_dentry;
+};
+
+
+static inline
+void i2400mu_init(struct i2400mu *i2400mu)
+{
+	i2400m_init(&i2400mu->i2400m);
+	edc_init(&i2400mu->urb_edc);
+	init_waitqueue_head(&i2400mu->tx_wq);
+	atomic_set(&i2400mu->rx_pending_count, 0);
+	init_waitqueue_head(&i2400mu->rx_wq);
+	i2400mu->rx_size = PAGE_SIZE - sizeof(struct skb_shared_info);
+	atomic_set(&i2400mu->do_autopm, 1);
+	i2400mu->rx_size_auto_shrink = 1;
+}
+
+extern int i2400mu_notification_setup(struct i2400mu *);
+extern void i2400mu_notification_release(struct i2400mu *);
+
+extern int i2400mu_rx_setup(struct i2400mu *);
+extern void i2400mu_rx_release(struct i2400mu *);
+extern void i2400mu_rx_kick(struct i2400mu *);
+
+extern int i2400mu_tx_setup(struct i2400mu *);
+extern void i2400mu_tx_release(struct i2400mu *);
+extern void i2400mu_bus_tx_kick(struct i2400m *);
+
+extern ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *,
+				       const struct i2400m_bootrom_header *,
+				       size_t, int);
+extern ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *,
+					   struct i2400m_bootrom_header *,
+					   size_t);
+#endif /* #ifndef __I2400M_USB_H__ */
diff --git a/drivers/net/wimax/i2400m/usb-debug-levels.h b/drivers/net/wimax/i2400m/usb-debug-levels.h
new file mode 100644
index 0000000..e4358bd
--- /dev/null
+++ b/drivers/net/wimax/i2400m/usb-debug-levels.h
@@ -0,0 +1,42 @@ 
+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Debug levels control file for the i2400m-usb module
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+#ifndef __debug_levels__h__
+#define __debug_levels__h__
+
+/* Maximum compile and run time debug level for all submodules */
+#define D_MODULENAME i2400m_usb
+#define D_MASTER CONFIG_WIMAX_I2400M_DEBUG_LEVEL
+
+#include <linux/wimax/debug.h>
+
+/* List of all the enabled modules */
+enum d_module {
+	D_SUBMODULE_DECLARE(usb),
+	D_SUBMODULE_DECLARE(fw),
+	D_SUBMODULE_DECLARE(notif),
+	D_SUBMODULE_DECLARE(rx),
+	D_SUBMODULE_DECLARE(tx),
+};
+
+
+#endif /* #ifndef __debug_levels__h__ */