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@xxxxxxxxx>
---
v2:
- rebased
v3:
- improve readability
- re-introduce debug message
- introduce at24_adjust_read_offset
v4:
- move offset adjustment calculation to probe function
---
drivers/misc/eeprom/at24.c | 56 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 493e2b646..c16a9a495 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(&client->dev);
@@ -621,6 +652,27 @@ 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 0x90;
+ 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 BIT(11);
+ else if (flags & AT24_FLAG_SERIAL)
+ /*
+ * Otherwise the word address must begin with a '10' sequence,
+ * regardless of the intended address.
+ */
+ return BIT(7);
+ else
+ return 0;
+}
+
static const struct regmap_config regmap_config_8 = {
.reg_bits = 8,
.val_bits = 8,
@@ -749,6 +801,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
return -EINVAL;
}
+ at24->offset_adj = at24_get_offset_adj(chip.flags);
+
if (chip.flags & AT24_FLAG_SERIAL) {
at24->read_func = at24_eeprom_read_serial;
} else if (chip.flags & AT24_FLAG_MAC) {
--
2.15.0
