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authorHeiner Kallweit <hkallweit1@gmail.com>2017-11-28 21:51:50 +0100
committerBartosz Golaszewski <brgl@bgdev.pl>2018-01-01 19:40:46 +0100
commit4bb5c13cc23c647c1fb6168d08de1fbda8f2357e (patch)
treedca5dee3979ee8fc6da8a5eb6dd71b749389c78f /drivers/misc
parentd4297d6795779b0713203787eada5b8d9f0ce065 (diff)
eeprom: at24: add regmap-based read function
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> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/eeprom/at24.c57
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);

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