From cd0c861542fc81bd3087ff1e8af0f87e2a8794c3 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 6 Jun 2016 10:48:49 +0200 Subject: [PATCH] eeprom: at24: split at24_eeprom_write() into specialized functions 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 Signed-off-by: Wolfram Sang --- drivers/misc/eeprom/at24.c | 134 +++++++++++++++++++++++++------------ 1 file changed, 91 insertions(+), 43 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index e7db1377e210..6acf35af271c 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -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, - unsigned int offset, size_t count) + +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; @@ -305,43 +299,90 @@ 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) { - int i = 0; + 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); - msg.addr = client->addr; - msg.flags = 0; + loop_until_timeout(timeout, write_time) { + status = i2c_smbus_write_i2c_block_data(client, + offset, count, buf); + if (status == 0) + status = count; - /* msg.buf is u8 and casts will mask the values */ - msg.buf = at24->writebuf; - if (at24->chip.flags & AT24_FLAG_ADDR16) - msg.buf[i++] = offset >> 8; + dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n", + count, offset, status, jiffies); - msg.buf[i++] = offset; - memcpy(&msg.buf[i], buf, count); - msg.len = i + count; + 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) { - 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; - } + 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; + + /* msg.buf is u8 and casts will mask the values */ + msg.buf = at24->writebuf; + if (at24->chip.flags & AT24_FLAG_ADDR16) + msg.buf[i++] = offset >> 8; + + msg.buf[i++] = offset; + memcpy(&msg.buf[i], buf, count); + msg.len = i + count; + + loop_until_timeout(timeout, write_time) { + 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) { -- 2.20.1