diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 71 |
1 files changed, 64 insertions, 7 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 2591c21b2b5d..4aa96d8e78ef 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -8,6 +8,7 @@ #include <linux/acpi.h> #include <linux/bitops.h> +#include <linux/capability.h> #include <linux/delay.h> #include <linux/i2c.h> #include <linux/init.h> @@ -89,6 +90,7 @@ struct at24_data { struct nvmem_device *nvmem; struct regulator *vcc_reg; + void (*read_post)(unsigned int off, char *buf, size_t count); /* * Some chips tie up multiple I2C addresses; dummy devices reserve @@ -121,6 +123,7 @@ MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)"); struct at24_chip_data { u32 byte_len; u8 flags; + void (*read_post)(unsigned int off, char *buf, size_t count); }; #define AT24_CHIP_DATA(_name, _len, _flags) \ @@ -128,6 +131,32 @@ struct at24_chip_data { .byte_len = _len, .flags = _flags, \ } +#define AT24_CHIP_DATA_CB(_name, _len, _flags, _read_post) \ + static const struct at24_chip_data _name = { \ + .byte_len = _len, .flags = _flags, \ + .read_post = _read_post, \ + } + +static void at24_read_post_vaio(unsigned int off, char *buf, size_t count) +{ + int i; + + if (capable(CAP_SYS_ADMIN)) + return; + + /* + * Hide VAIO private settings to regular users: + * - BIOS passwords: bytes 0x00 to 0x0f + * - UUID: bytes 0x10 to 0x1f + * - Serial number: 0xc0 to 0xdf + */ + for (i = 0; i < count; i++) { + if ((off + i <= 0x1f) || + (off + i >= 0xc0 && off + i <= 0xdf)) + buf[i] = 0; + } +} + /* needs 8 addresses as A0-A2 are ignored */ AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR); /* old variants can't be handled with this generic entry! */ @@ -144,6 +173,10 @@ AT24_CHIP_DATA(at24_data_24mac602, 64 / 8, /* spd is a 24c02 in memory DIMMs */ AT24_CHIP_DATA(at24_data_spd, 2048 / 8, AT24_FLAG_READONLY | AT24_FLAG_IRUGO); +/* 24c02_vaio is a 24c02 on some Sony laptops */ +AT24_CHIP_DATA_CB(at24_data_24c02_vaio, 2048 / 8, + AT24_FLAG_READONLY | AT24_FLAG_IRUGO, + at24_read_post_vaio); AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0); AT24_CHIP_DATA(at24_data_24cs04, 16, AT24_FLAG_SERIAL | AT24_FLAG_READONLY); @@ -177,6 +210,7 @@ static const struct i2c_device_id at24_ids[] = { { "24mac402", (kernel_ulong_t)&at24_data_24mac402 }, { "24mac602", (kernel_ulong_t)&at24_data_24mac602 }, { "spd", (kernel_ulong_t)&at24_data_spd }, + { "24c02-vaio", (kernel_ulong_t)&at24_data_24c02_vaio }, { "24c04", (kernel_ulong_t)&at24_data_24c04 }, { "24cs04", (kernel_ulong_t)&at24_data_24cs04 }, { "24c08", (kernel_ulong_t)&at24_data_24c08 }, @@ -388,7 +422,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) struct at24_data *at24; struct device *dev; char *buf = val; - int ret; + int i, ret; at24 = priv; dev = at24_base_client_dev(at24); @@ -411,22 +445,22 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) */ mutex_lock(&at24->lock); - while (count) { - ret = at24_regmap_read(at24, buf, off, count); + for (i = 0; count; i += ret, count -= ret) { + ret = at24_regmap_read(at24, buf + i, off + i, count); if (ret < 0) { mutex_unlock(&at24->lock); pm_runtime_put(dev); return ret; } - buf += ret; - off += ret; - count -= ret; } mutex_unlock(&at24->lock); pm_runtime_put(dev); + if (unlikely(at24->read_post)) + at24->read_post(off, buf, i); + return 0; } @@ -654,6 +688,7 @@ static int at24_probe(struct i2c_client *client) at24->byte_len = byte_len; at24->page_size = page_size; at24->flags = flags; + at24->read_post = cdata->read_post; at24->num_addresses = num_addresses; at24->offset_adj = at24_get_offset_adj(flags, byte_len); at24->client[0].client = client; @@ -678,8 +713,30 @@ static int at24_probe(struct i2c_client *client) return err; } - nvmem_config.name = dev_name(dev); + /* + * If the 'label' property is not present for the AT24 EEPROM, + * then nvmem_config.id is initialised to NVMEM_DEVID_AUTO, + * and this will append the 'devid' to the name of the NVMEM + * device. This is purely legacy and the AT24 driver has always + * defaulted to this. However, if the 'label' property is + * present then this means that the name is specified by the + * firmware and this name should be used verbatim and so it is + * not necessary to append the 'devid'. + */ + if (device_property_present(dev, "label")) { + nvmem_config.id = NVMEM_DEVID_NONE; + err = device_property_read_string(dev, "label", + &nvmem_config.name); + if (err) + return err; + } else { + nvmem_config.id = NVMEM_DEVID_AUTO; + nvmem_config.name = dev_name(dev); + } + + nvmem_config.type = NVMEM_TYPE_EEPROM; nvmem_config.dev = dev; + nvmem_config.id = NVMEM_DEVID_AUTO; nvmem_config.read_only = !writable; nvmem_config.root_only = !(flags & AT24_FLAG_IRUGO); nvmem_config.owner = THIS_MODULE; |