[media] em28xx: simplify ID-reading from Micron sensors
Use i2c_smbus_read_word_data() instead of i2c_master_send() and i2c_master_recv() for reading the ID of Micorn sensors. i2c_smbus_read_word_data() assumes that byes are in little-endian, so, it uses: data->word = msgbuf1[0] | (msgbuf1[1] << 8); However, Micron datasheet describes the ID as if they were read in big-endian. So, we need to change the byte order in order to match the ID number as described on their datasheets. Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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@ -98,8 +98,6 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev)
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{
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int ret, i;
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char *name;
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u8 reg;
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__be16 id_be;
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u16 id;
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struct i2c_client *client = &dev->i2c_client[dev->def_i2c_bus];
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@ -107,10 +105,8 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev)
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dev->em28xx_sensor = EM28XX_NOSENSOR;
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for (i = 0; micron_sensor_addrs[i] != I2C_CLIENT_END; i++) {
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client->addr = micron_sensor_addrs[i];
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/* NOTE: i2c_smbus_read_word_data() doesn't work with BE data */
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/* Read chip ID from register 0x00 */
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reg = 0x00;
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ret = i2c_master_send(client, ®, 1);
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ret = i2c_smbus_read_word_data(client, 0x00); /* assumes LE */
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if (ret < 0) {
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if (ret != -ENXIO)
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dev_err(&dev->intf->dev,
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@ -118,24 +114,9 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev)
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client->addr << 1, ret);
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continue;
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}
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ret = i2c_master_recv(client, (u8 *)&id_be, 2);
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if (ret < 0) {
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dev_err(&dev->intf->dev,
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"couldn't read from i2c device 0x%02x: error %i\n",
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client->addr << 1, ret);
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continue;
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}
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id = be16_to_cpu(id_be);
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id = swab16(ret); /* LE -> BE */
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/* Read chip ID from register 0xff */
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reg = 0xff;
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ret = i2c_master_send(client, ®, 1);
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if (ret < 0) {
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dev_err(&dev->intf->dev,
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"couldn't read from i2c device 0x%02x: error %i\n",
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client->addr << 1, ret);
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continue;
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}
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ret = i2c_master_recv(client, (u8 *)&id_be, 2);
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ret = i2c_smbus_read_word_data(client, 0xff);
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if (ret < 0) {
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dev_err(&dev->intf->dev,
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"couldn't read from i2c device 0x%02x: error %i\n",
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@ -143,10 +124,9 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev)
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continue;
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}
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/* Validate chip ID to be sure we have a Micron device */
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if (id != be16_to_cpu(id_be))
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if (id != swab16(ret))
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continue;
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/* Check chip ID */
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id = be16_to_cpu(id_be);
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switch (id) {
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case 0x1222:
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name = "MT9V012"; /* MI370 */ /* 640x480 */
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