diff options
Diffstat (limited to 'drivers/mtd/maps/pismo.c')
| -rw-r--r-- | drivers/mtd/maps/pismo.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/mtd/maps/pismo.c b/drivers/mtd/maps/pismo.c new file mode 100644 index 000000000..946ba80f9 --- /dev/null +++ b/drivers/mtd/maps/pismo.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PISMO memory driver - http://www.pismoworld.org/ + * + * For ARM Realview and Versatile platforms + */ +#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 pismo_pdata *pdata = client->dev.platform_data; + struct pismo_eeprom eeprom; + struct pismo_data *pismo; + int ret, i; + + if (!i2c_check_functionality(client->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", + }, + .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"); |