diff options
Diffstat (limited to 'drivers/misc/eeprom/at24.c')
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 0621937e7b3a..2efb572757cc 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -113,6 +113,22 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); ((1 << AT24_SIZE_FLAGS | (_flags)) \ << 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[] = { /* needs 8 addresses as A0-A2 are ignored */ { "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; } - /* - * 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; + loop_until_timeout(timeout, read_time) { if (at24->use_smbus) { status = i2c_smbus_read_i2c_block_data_or_emulated(client, offset, count, buf); @@ -246,9 +255,7 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, if (status == count) return count; - - usleep_range(1000, 1500); - } while (time_before(read_time, timeout)); + } return -ETIMEDOUT; } @@ -299,14 +306,7 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf, msg.len = i + count; } - /* - * 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; + loop_until_timeout(timeout, write_time) { if (at24->use_smbus_write) { switch (at24->use_smbus_write) { 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) return count; - - usleep_range(1000, 1500); - } while (time_before(write_time, timeout)); + } return -ETIMEDOUT; } |