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eeprom: at24: split at24_eeprom_write() into specialized functions

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Split at24_eeprom_write() into three smaller functions - one for the
i2c operations and two for the smbus extensions (separate routines for
block and byte transfers). Assign them in at24_probe() depending on
the bus capabilities.

Also: in order to avoid duplications move code adjusting the count
argument into a separate function and use it for i2c and smbus block
writes (no need for a roll-over for byte writes as we're always
writing one byte).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Bartosz Golaszewski 2016-06-06 10:48:49 +02:00 committed by Wolfram Sang
parent 9afd6866bf
commit cd0c861542
1 changed files with 93 additions and 45 deletions
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108
drivers/misc/eeprom/at24.c
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@ -281,21 +281,15 @@ static ssize_t at24_eeprom_read_i2c(struct at24_data *at24, char *buf,
* chip is normally write protected. But there are plenty of product
* variants here, including OTP fuses and partial chip protect.
*
* We only use page mode writes; the alternative is sloooow. This routine
* writes at most one page.
* We only use page mode writes; the alternative is sloooow. These routines
* write at most one page.
*/
static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
static size_t at24_adjust_write_count(struct at24_data *at24,
unsigned int offset, size_t count)
{
struct i2c_client *client;
struct i2c_msg msg;
ssize_t status = 0;
unsigned long timeout, write_time;
unsigned next_page;
/* Get corresponding I2C address and adjust offset */
client = at24_translate_offset(at24, &offset);
/* write_max is at most a page */
if (count > at24->write_max)
count = at24->write_max;
@ -305,10 +299,73 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
if (offset + count > next_page)
count = next_page - offset;
/* If we'll use I2C calls for I/O, set up the message */
if (!at24->use_smbus) {
return count;
}
static ssize_t at24_eeprom_write_smbus_block(struct at24_data *at24,
const char *buf,
unsigned int offset, size_t count)
{
unsigned long timeout, write_time;
struct i2c_client *client;
ssize_t status = 0;
client = at24_translate_offset(at24, &offset);
count = at24_adjust_write_count(at24, offset, count);
loop_until_timeout(timeout, write_time) {
status = i2c_smbus_write_i2c_block_data(client,
offset, count, buf);
if (status == 0)
status = count;
dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
count, offset, status, jiffies);
if (status == count)
return count;
}
return -ETIMEDOUT;
}
static ssize_t at24_eeprom_write_smbus_byte(struct at24_data *at24,
const char *buf,
unsigned int offset, size_t count)
{
unsigned long timeout, write_time;
struct i2c_client *client;
ssize_t status = 0;
client = at24_translate_offset(at24, &offset);
loop_until_timeout(timeout, write_time) {
status = i2c_smbus_write_byte_data(client, offset, buf[0]);
if (status == 0)
status = count;
dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
count, offset, status, jiffies);
if (status == count)
return count;
}
return -ETIMEDOUT;
}
static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf,
unsigned int offset, size_t count)
{
unsigned long timeout, write_time;
struct i2c_client *client;
struct i2c_msg msg;
ssize_t status = 0;
int i = 0;
client = at24_translate_offset(at24, &offset);
count = at24_adjust_write_count(at24, offset, count);
msg.addr = client->addr;
msg.flags = 0;
@ -320,28 +377,12 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
msg.buf[i++] = offset;
memcpy(&msg.buf[i], buf, count);
msg.len = i + count;
}
loop_until_timeout(timeout, write_time) {
if (at24->use_smbus_write) {
switch (at24->use_smbus_write) {
case I2C_SMBUS_I2C_BLOCK_DATA:
status = i2c_smbus_write_i2c_block_data(client,
offset, count, buf);
break;
case I2C_SMBUS_BYTE_DATA:
status = i2c_smbus_write_byte_data(client,
offset, buf[0]);
break;
}
if (status == 0)
status = count;
} else {
status = i2c_transfer(client->adapter, &msg, 1);
if (status == 1)
status = count;
}
dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
count, offset, status, jiffies);
@ -538,7 +579,14 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
at24->read_func = at24->use_smbus ? at24_eeprom_read_smbus
: at24_eeprom_read_i2c;
at24->write_func = at24_eeprom_write;
if (at24->use_smbus) {
if (at24->use_smbus_write == I2C_SMBUS_I2C_BLOCK_DATA)
at24->write_func = at24_eeprom_write_smbus_block;
else
at24->write_func = at24_eeprom_write_smbus_byte;
} else {
at24->write_func = at24_eeprom_write_i2c;
}
writable = !(chip.flags & AT24_FLAG_READONLY);
if (writable) {