@@ -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)
{
@@ -534,7 +565,7 @@ 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(&client->dev);
@@ -627,6 +658,28 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip)
}
}
+static unsigned int at24_get_offset_adj(u8 flags)
+{
+ if (flags & AT24_FLAG_MAC) {
+ return 0x0090;
+ } 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,
@@ -743,6 +796,7 @@ 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);
at24->client[0].client = client;
at24->client[0].regmap = devm_regmap_init_i2c(client, config);
Add regmap-based read function and instead of using three different read functions (standard, mac, serial) use just one and factor out the read offset adjustment for mac and serial to at24_adjust_read_offset. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- v2: - rebased v3: - improve readability - re-introduce debug message - introduce at24_adjust_read_offset v4: - move offset adjustment calculation to probe function v5: - small style improvements to at24_get_offset_adj --- drivers/misc/eeprom/at24.c | 56 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-)