On Tue, Jun 2, 2020 at 7:49 PM Tomasz Duszynski
<tomasz.duszynski@xxxxxxxxxxx> wrote:
>
> Add I2C interface driver for the SCD30 sensor.
...
> +static u16 scd30_i2c_cmd_lookup_tbl[] = {
> + [CMD_START_MEAS] = 0x0010,
> + [CMD_STOP_MEAS] = 0x0104,
> + [CMD_MEAS_INTERVAL] = 0x4600,
> + [CMD_MEAS_READY] = 0x0202,
> + [CMD_READ_MEAS] = 0x0300,
> + [CMD_ASC] = 0x5306,
> + [CMD_FRC] = 0x5204,
> + [CMD_TEMP_OFFSET] = 0x5403,
> + [CMD_FW_VERSION] = 0xd100,
> + [CMD_RESET] = 0xd304,
Keep sorted by value?
> +};
...
> + ret = i2c_master_send(client, txbuf, txsize);
> + if (ret != txsize)
> + return ret < 0 ? ret : -EIO;
Wouldn't be better
if (ret < 0)
return ret;
if (ret != txsize)
return -EIO;
?
> + if (!rxbuf)
> + return 0;
> +
> + ret = i2c_master_recv(client, rxbuf, rxsize);
> + if (ret != rxsize)
> + return ret < 0 ? ret : -EIO;
Ditto.
...
> +static int scd30_i2c_command(struct scd30_state *state, enum scd30_cmd cmd,
> + u16 arg, void *response, int size)
> +{
> + char crc, buf[SCD30_I2C_MAX_BUF_SIZE], *rsp = response;
> + int i, ret;
i -> offset ?
> + put_unaligned_be16(scd30_i2c_cmd_lookup_tbl[cmd], buf);
> + i = 2;
> +
> + if (rsp) {
> + /* each two bytes are followed by a crc8 */
> + size += size / 2;
> + } else {
> + put_unaligned_be16(arg, buf + i);
> + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE);
> + i += 2;
> + buf[i] = crc;
> + i += 1;
buf[offset++] = crc; ?
> + /* commands below don't take an argument */
> + if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET))
> + i -= 3;
> + }
> +
> + ret = scd30_i2c_xfer(state, buf, i, buf, size);
> + if (ret)
> + return ret;
> +
> + /* validate received data and strip off crc bytes */
> + for (i = 0; i < size; i += 3) {
> + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE);
> + if (crc != buf[i + 2]) {
> + dev_err(state->dev, "data integrity check failed\n");
> + return -EIO;
> + }
> +
> + *rsp++ = buf[i];
+ 0 (for the sake of consistency?
> + *rsp++ = buf[i + 1];
> + }
> +
> + return 0;
> +}
...
> +static struct i2c_driver scd30_i2c_driver = {
> + .driver = {
> + .name = KBUILD_MODNAME,
Better to hard code.
> + .of_match_table = scd30_i2c_of_match,
> + .pm = &scd30_pm_ops,
> + },
> + .probe_new = scd30_i2c_probe,
> +};
--
With Best Regards,
Andy Shevchenko
