diff options
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 5f7d81054c11..57a317b2e9a8 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -75,6 +75,7 @@ struct at24_data { unsigned write_max; unsigned num_addresses; + unsigned int offset_adj; struct nvmem_config nvmem_config; struct nvmem_device *nvmem; @@ -312,6 +313,36 @@ static ssize_t at24_eeprom_read_smbus(struct at24_data *at24, char *buf, return -ETIMEDOUT; } +static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, + unsigned int offset, size_t count) +{ + unsigned long timeout, read_time; + struct at24_client *at24_client; + struct i2c_client *client; + struct regmap *regmap; + int ret; + + at24_client = at24_translate_offset(at24, &offset); + regmap = at24_client->regmap; + client = at24_client->client; + + if (count > io_limit) + count = io_limit; + + /* adjust offset for mac and serial read ops */ + offset += at24->offset_adj; + + loop_until_timeout(timeout, read_time) { + ret = regmap_bulk_read(regmap, offset, buf, count); + dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n", + count, offset, ret, jiffies); + if (!ret) + return count; + } + + return -ETIMEDOUT; +} + static ssize_t at24_eeprom_read_i2c(struct at24_data *at24, char *buf, unsigned int offset, size_t count) { @@ -531,7 +562,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count) while (count) { int status; - status = at24->read_func(at24, buf, off, count); + status = at24_regmap_read(at24, buf, off, count); if (status < 0) { mutex_unlock(&at24->lock); pm_runtime_put(dev); @@ -620,6 +651,29 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip) } } +static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len) +{ + if (flags & AT24_FLAG_MAC) { + /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */ + return 0xa0 - byte_len; + } else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) { + /* + * For 16 bit address pointers, the word address must contain + * a '10' sequence in bits 11 and 10 regardless of the + * intended position of the address pointer. + */ + return 0x0800; + } else if (flags & AT24_FLAG_SERIAL) { + /* + * Otherwise the word address must begin with a '10' sequence, + * regardless of the intended address. + */ + return 0x0080; + } else { + return 0; + } +} + static const struct regmap_config regmap_config_8 = { .reg_bits = 8, .val_bits = 8, @@ -746,6 +800,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) at24->use_smbus = use_smbus; at24->chip = chip; at24->num_addresses = num_addresses; + at24->offset_adj = at24_get_offset_adj(chip.flags, chip.byte_len); at24->client[0].client = client; at24->client[0].regmap = devm_regmap_init_i2c(client, config); |