[PATCH] add pismo support
Russell King - ARM Linux
linux at arm.linux.org.uk
Fri Dec 18 06:16:30 EST 2009
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 at 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, ®ion);
> + break;
> + case 3:
> + /* static RAM */
> + pismo_add_sram(pismo, i, ®ion);
> + 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 at 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
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