Patchwork add pismo support

The following patch adds support for PISMO modules found on ARM Ltd
development platforms.  These are MTD modules, and can have a
selection of SRAM, flash or DOC devices as described by an on-board
I2C EEPROM.

We support SRAM and NOR flash devices only by registering appropriate
conventional MTD platform devices as children of the 'pismo' device.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
--
 drivers/mtd/maps/Kconfig  |   17 ++
 drivers/mtd/maps/Makefile |    1 
 drivers/mtd/maps/pismo.c  |  320 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/pismo.h |   17 ++
 4 files changed, 355 insertions(+)

Ping.

On Sun, Nov 29, 2009 at 03:23:51PM +0000, Russell King - ARM Linux wrote:
> The following patch adds support for PISMO modules found on ARM Ltd
> development platforms.  These are MTD modules, and can have a
> selection of SRAM, flash or DOC devices as described by an on-board
> I2C EEPROM.
> 
> We support SRAM and NOR flash devices only by registering appropriate
> conventional MTD platform devices as children of the 'pismo' device.
> 
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> --
>  drivers/mtd/maps/Kconfig  |   17 ++
>  drivers/mtd/maps/Makefile |    1 
>  drivers/mtd/maps/pismo.c  |  320 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/pismo.h |   17 ++
>  4 files changed, 355 insertions(+)
> 
> diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
> index 0b98654..631b060 100644
> --- a/drivers/mtd/maps/Kconfig
> +++ b/drivers/mtd/maps/Kconfig
> @@ -557,4 +557,21 @@ config MTD_VMU
>  	  To build this as a module select M here, the module will be called
>  	  vmu-flash.
>  
> +config MTD_PISMO
> +	tristate "MTD discovery driver for PISMO modules"
> +	depends on I2C
> +	depends on ARCH_VERSATILE
> +	help
> +	  This driver allows for discovery of PISMO modules - see
> +	  <http://www.pismoworld.org/>.  These are small modules containing
> +	  up to five memory devices (eg, SRAM, flash, DOC) described by an
> +	  I2C EEPROM.
> +
> +	  This driver does not create any MTD maps itself; instead it
> +	  creates MTD physmap and MTD SRAM platform devices.  If you
> +	  enable this option, you should consider enabling MTD_PHYSMAP
> +	  and/or MTD_PLATRAM according to the devices on your module.
> +
> +	  When built as a module, it will be called pismo.ko
> +
>  endmenu
> diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
> index 8bae7f9..cffaaf1 100644
> --- a/drivers/mtd/maps/Makefile
> +++ b/drivers/mtd/maps/Makefile
> @@ -61,3 +61,4 @@ obj-$(CONFIG_MTD_INTEL_VR_NOR)	+= intel_vr_nor.o
>  obj-$(CONFIG_MTD_RBTX4939)	+= rbtx4939-flash.o
>  obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o
>  obj-$(CONFIG_MTD_GPIO_ADDR)	+= gpio-addr-flash.o
> +obj-$(CONFIG_MTD_PISMO)		+= pismo.o
> --- /dev/null	2009-08-03 10:19:25.737008066 +0100
> +++ b/drivers/mtd/maps/pismo.c	2009-08-03 14:23:32.000000000 +0100
> @@ -0,0 +1,320 @@
> +/*
> + * PISMO memory driver - http://www.pismoworld.org/
> + *
> + * For ARM Realview and Versatile platforms
> + *
> + * 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.
> + */
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +#include <linux/mutex.h>
> +#include <linux/mtd/physmap.h>
> +#include <linux/mtd/plat-ram.h>
> +#include <linux/mtd/pismo.h>
> +
> +#define PISMO_NUM_CS	5
> +
> +struct pismo_cs_block {
> +	u8	type;
> +	u8	width;
> +	__le16	access;
> +	__le32	size;
> +	u32	reserved[2];
> +	char	device[32];
> +} __packed;
> +
> +struct pismo_eeprom {
> +	struct pismo_cs_block cs[PISMO_NUM_CS];
> +	char	board[15];
> +	u8	sum;
> +} __packed;
> +
> +struct pismo_mem {
> +	phys_addr_t base;
> +	u32	size;
> +	u16	access;
> +	u8	width;
> +	u8	type;
> +};
> +
> +struct pismo_data {
> +	struct i2c_client	*client;
> +	void			(*vpp)(void *, int);
> +	void			*vpp_data;
> +	struct platform_device	*dev[PISMO_NUM_CS];
> +};
> +
> +/* FIXME: set_vpp could do with a better calling convention */
> +static struct pismo_data *vpp_pismo;
> +static DEFINE_MUTEX(pismo_mutex);
> +
> +static int pismo_setvpp_probe_fix(struct pismo_data *pismo)
> +{
> +	mutex_lock(&pismo_mutex);
> +	if (vpp_pismo) {
> +		mutex_unlock(&pismo_mutex);
> +		kfree(pismo);
> +		return -EBUSY;
> +	}
> +	vpp_pismo = pismo;
> +	mutex_unlock(&pismo_mutex);
> +	return 0;
> +}
> +
> +static void pismo_setvpp_remove_fix(struct pismo_data *pismo)
> +{
> +	mutex_lock(&pismo_mutex);
> +	if (vpp_pismo == pismo)
> +		vpp_pismo = NULL;
> +	mutex_unlock(&pismo_mutex);
> +}
> +
> +static void pismo_set_vpp(struct map_info *map, int on)
> +{
> +	struct pismo_data *pismo = vpp_pismo;
> +
> +	pismo->vpp(pismo->vpp_data, on);
> +}
> +/* end of hack */
> +
> +
> +static unsigned int __devinit pismo_width_to_bytes(unsigned int width)
> +{
> +	width &= 15;
> +	if (width > 2)
> +		return 0;
> +	return 1 << width;
> +}
> +
> +static int __devinit pismo_eeprom_read(struct i2c_client *client, void *buf,
> +	u8 addr, size_t size)
> +{
> +	int ret;
> +	struct i2c_msg msg[] = {
> +		{
> +			.addr = client->addr,
> +			.len = sizeof(addr),
> +			.buf = &addr,
> +		}, {
> +			.addr = client->addr,
> +			.flags = I2C_M_RD,
> +			.len = size,
> +			.buf = buf,
> +		},
> +	};
> +
> +	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
> +
> +	return ret == ARRAY_SIZE(msg) ? size : -EIO;
> +}
> +
> +static int __devinit pismo_add_device(struct pismo_data *pismo, int i,
> +	struct pismo_mem *region, const char *name, void *pdata, size_t psize)
> +{
> +	struct platform_device *dev;
> +	struct resource res = { };
> +	phys_addr_t base = region.base;
> +	int ret;
> +
> +	if (base == ~0)
> +		return -ENXIO;
> +
> +	res.start = base;
> +	res.end = base + region->size - 1;
> +	res.flags = IORESOURCE_MEM;
> +
> +	dev = platform_device_alloc(name, i);
> +	if (!dev)
> +		return -ENOMEM;
> +	dev->dev.parent = &pismo->client->dev;
> +
> +	do {
> +		ret = platform_device_add_resources(dev, &res, 1);
> +		if (ret)
> +			break;
> +
> +		ret = platform_device_add_data(dev, pdata, psize);
> +		if (ret)
> +			break;
> +
> +		ret = platform_device_add(dev);
> +		if (ret)
> +			break;
> +
> +		pismo->dev[i] = dev;
> +		return 0;
> +	} while (0);
> +
> +	platform_device_put(dev);
> +	return ret;
> +}
> +
> +static int __devinit pismo_add_nor(struct pismo_data *pismo, int i,
> +	struct pismo_mem *region)
> +{
> +	struct physmap_flash_data data = {
> +		.width = region->width,
> +	};
> +
> +	if (pismo->vpp)
> +		data.set_vpp = pismo_set_vpp;
> +
> +	return pismo_add_device(pismo, i, region, "physmap-flash",
> +		&data, sizeof(data));
> +}
> +
> +static int __devinit pismo_add_sram(struct pismo_data *pismo, int i,
> +	struct pismo_mem *region)
> +{
> +	struct platdata_mtd_ram data = {
> +		.bankwidth = region->width,
> +	};
> +
> +	return pismo_add_device(pismo, i, region, "mtd-ram",
> +		&data, sizeof(data));
> +}
> +
> +static void __devinit pismo_add_one(struct pismo_data *pismo, int i,
> +	const struct pismo_cs_block *cs, phys_addr_t base)
> +{
> +	struct device *dev = &pismo->client->dev;
> +	struct pismo_mem region;
> +
> +	region.base = base;
> +	region.type = cs->type;
> +	region.width = pismo_width_to_bytes(cs->width);
> +	region.access = le16_to_cpu(cs->access);
> +	region.size = le32_to_cpu(cs->size);
> +
> +	if (region.width == 0) {
> +		dev_err(dev, "cs%u: bad width: %02x, ignoring\n", i, cs->width);
> +		return;
> +	}
> +
> +	/*
> +	 * FIXME: may need to the platforms memory controller here, but at
> +	 * the moment we assume that it has already been correctly setup.
> +	 * The memory controller can also tell us the base address as well.
> +	 */
> +
> +	dev_info(dev, "cs%u: %.32s: type %02x access %u00ps size %uK\n",
> +		i, cs->device, region.type, region.access, region.size / 1024);
> +
> +	switch (region.type) {
> +	case 0:
> +		break;
> +	case 1:
> +		/* static DOC */
> +		break;
> +	case 2:
> +		/* static NOR */
> +		pismo_add_nor(pismo, i, &region);
> +		break;
> +	case 3:
> +		/* static RAM */
> +		pismo_add_sram(pismo, i, &region);
> +		break;
> +	}
> +}
> +
> +static int __devexit pismo_remove(struct i2c_client *client)
> +{
> +	struct pismo_data *pismo = i2c_get_clientdata(client);
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(pismo->dev); i++)
> +		platform_device_unregister(pismo->dev[i]);
> +
> +	/* FIXME: set_vpp needs saner arguments */
> +	pismo_setvpp_remove_fix(pismo);
> +
> +	kfree(pismo);
> +
> +	return 0;
> +}
> +
> +static int __devinit pismo_probe(struct i2c_client *client,
> +				 const struct i2c_device_id *id)
> +{
> +	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> +	struct pismo_pdata *pdata = client->dev.platform_data;
> +	struct pismo_eeprom eeprom;
> +	struct pismo_data *pismo;
> +	int ret, i;
> +
> +	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
> +		dev_err(&client->dev, "functionality mismatch\n");
> +		return -EIO;
> +	}
> +
> +	pismo = kzalloc(sizeof(*pismo), GFP_KERNEL);
> +	if (!pismo)
> +		return -ENOMEM;
> +
> +	/* FIXME: set_vpp needs saner arguments */
> +	ret = pismo_setvpp_probe_fix(pismo);
> +	if (ret)
> +		return ret;
> +
> +	pismo->client = client;
> +	if (pdata) {
> +		pismo->vpp = pdata->set_vpp;
> +		pismo->vpp_data = pdata->vpp_data;
> +	}
> +	i2c_set_clientdata(client, pismo);
> +
> +	ret = pismo_eeprom_read(client, &eeprom, 0, sizeof(eeprom));
> +	if (ret < 0) {
> +		dev_err(&client->dev, "error reading EEPROM: %d\n", ret);
> +		return ret;
> +	}
> +
> +	dev_info(&client->dev, "%.15s board found\n", eeprom.board);
> +
> +	for (i = 0; i < ARRAY_SIZE(eeprom.cs); i++)
> +		if (eeprom.cs[i].type != 0xff)
> +			pismo_add_one(pismo, i, &eeprom.cs[i],
> +				      pdata->cs_addrs[i]);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id pismo_id[] = {
> +	{ "pismo" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, pismo_id);
> +
> +static struct i2c_driver pismo_driver = {
> +	.driver	= {
> +		.name	= "pismo",
> +		.owner	= THIS_MODULE,
> +	},
> +	.probe		= pismo_probe,
> +	.remove		= __devexit_p(pismo_remove),
> +	.id_table	= pismo_id,
> +};
> +
> +static int __init pismo_init(void)
> +{
> +	BUILD_BUG_ON(sizeof(struct pismo_cs_block) != 48);
> +	BUILD_BUG_ON(sizeof(struct pismo_eeprom) != 256);
> +
> +	return i2c_add_driver(&pismo_driver);
> +}
> +module_init(pismo_init);
> +
> +static void __exit pismo_exit(void)
> +{
> +	i2c_del_driver(&pismo_driver);
> +}
> +module_exit(pismo_exit);
> +
> +MODULE_AUTHOR("Russell King <linux@arm.linux.org.uk>");
> +MODULE_DESCRIPTION("PISMO memory driver");
> +MODULE_LICENSE("GPL");
> --- /dev/null	2009-08-03 10:19:25.737008066 +0100
> +++ b/include/linux/mtd/pismo.h	2009-07-18 10:32:59.000000000 +0100
> @@ -0,0 +1,17 @@
> +/*
> + * PISMO memory driver - http://www.pismoworld.org/
> + *
> + * 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.
> + */
> +#ifndef __LINUX_MTD_PISMO_H
> +#define __LINUX_MTD_PISMO_H
> +
> +struct pismo_pdata {
> +	void			(*set_vpp)(void *, int);
> +	void			*vpp_data;
> +	phys_addr_t		cs_addrs[5];
> +};
> +
> +#endif