/*
* 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/slab.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];
};
static void pismo_set_vpp(struct platform_device *pdev, int on)
{
struct i2c_client *client = to_i2c_client(pdev->dev.parent);
struct pismo_data *pismo = i2c_get_clientdata(client);
pismo->vpp(pismo->vpp_data, on);
}
static unsigned int pismo_width_to_bytes(unsigned int width)
{
width &= 15;
if (width > 2)
return 0;
return 1 << width;
}
static int 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 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 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 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 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 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]);
kfree(pismo);
return 0;
}
static int 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;
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);
goto exit_free;
}
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;
exit_free:
kfree(pismo);
return ret;
}
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 = 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");
