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eeprom: at24: hide the read/write loop behind a macro

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Before splitting the read/write routines into smaller, more
specialized functions, unduplicate some code in advance.

Use a 'for' loop instead of 'do while' when waiting for the previous
write to complete and hide it behind a macro.

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 10:48:47 +02:00 committed by Wolfram Sang
parent 318aa9c66b
commit 9344a81efb
1 changed files with 20 additions and 22 deletions
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42
drivers/misc/eeprom/at24.c
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@ -113,6 +113,22 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
((1 << AT24_SIZE_FLAGS | (_flags)) \ ((1 << AT24_SIZE_FLAGS | (_flags)) \
<< AT24_SIZE_BYTELEN | ilog2(_len)) << AT24_SIZE_BYTELEN | ilog2(_len))
/*
* Both reads and writes fail if the previous write didn't complete yet. This
* macro loops a few times waiting at least long enough for one entire page
* write to work.
*
* It takes two parameters: a variable in which the future timeout in jiffies
* will be stored and a temporary variable holding the time of the last
* iteration of processing the request. Both should be unsigned integers
* holding at least 32 bits.
*/
#define loop_until_timeout(tout, op_time) \
for (tout = jiffies + msecs_to_jiffies(write_timeout), \
op_time = jiffies; \
time_before(op_time, tout); \
usleep_range(1000, 1500), op_time = jiffies)
static const struct i2c_device_id at24_ids[] = { static const struct i2c_device_id at24_ids[] = {
/* needs 8 addresses as A0-A2 are ignored */ /* needs 8 addresses as A0-A2 are ignored */
{ "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) }, { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
@ -225,14 +241,7 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
msg[1].len = count; msg[1].len = count;
} }
/* loop_until_timeout(timeout, read_time) {
* Reads fail if the previous write didn't complete yet. We may
* loop a few times until this one succeeds, waiting at least
* long enough for one entire page write to work.
*/
timeout = jiffies + msecs_to_jiffies(write_timeout);
do {
read_time = jiffies;
if (at24->use_smbus) { if (at24->use_smbus) {
status = i2c_smbus_read_i2c_block_data_or_emulated(client, offset, status = i2c_smbus_read_i2c_block_data_or_emulated(client, offset,
count, buf); count, buf);
@ -246,9 +255,7 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
if (status == count) if (status == count)
return count; return count;
}
usleep_range(1000, 1500);
} while (time_before(read_time, timeout));
return -ETIMEDOUT; return -ETIMEDOUT;
} }
@ -299,14 +306,7 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
msg.len = i + count; msg.len = i + count;
} }
/* loop_until_timeout(timeout, write_time) {
* Writes fail if the previous one didn't complete yet. We may
* loop a few times until this one succeeds, waiting at least
* long enough for one entire page write to work.
*/
timeout = jiffies + msecs_to_jiffies(write_timeout);
do {
write_time = jiffies;
if (at24->use_smbus_write) { if (at24->use_smbus_write) {
switch (at24->use_smbus_write) { switch (at24->use_smbus_write) {
case I2C_SMBUS_I2C_BLOCK_DATA: case I2C_SMBUS_I2C_BLOCK_DATA:
@ -331,9 +331,7 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
if (status == count) if (status == count)
return count; return count;
}
usleep_range(1000, 1500);
} while (time_before(write_time, timeout));
return -ETIMEDOUT; return -ETIMEDOUT;
} }