On 05/03/2013 12:43 AM, Oskar Andero wrote:
> This adds support for Microchip's 12 bit AD converters MCP3204 and
> MCP3208. These chips communicates over SPI and supports single-ended
> and pseudo-differential configurations.
>
> Cc: Jonathan Cameron <jic23@xxxxxxxxx>
> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Signed-off-by: Oskar Andero <oskar.andero@xxxxxxxxx>
Looks good, except some issues with probe error path handling
> ---
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/mcp320x.c | 255 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 266 insertions(+)
> create mode 100644 drivers/iio/adc/mcp320x.c
>
[...]
> +static int mcp320x_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel, int *val,
> + int *val2, long mask)
> +{
[...]
> + case IIO_CHAN_INFO_SCALE:
> + /* Digital output code = (4096 * Vin) / Vref */
> + ret = regulator_get_voltage(adc->reg);
> + if (ret < 0)
> + goto out;
> +
> + *val = ret / 1000;
> + *val2 = 4096;
> + ret = IIO_VAL_FRACTIONAL;
You can use IIO_VAL_FRACTIONAL_LOG2 here, it is slightly more efficient and
take the log2 of the divisor for val2, e.g. 12 in this case.
> + break;
> +
> + default:
> + break;
> + }
> +
> +out:
> + mutex_unlock(&adc->lock);
> +
> + return ret;
> +}
> +
[...]
> +static int mcp320x_probe(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev;
> + struct mcp320x *adc;
> + const struct mcp3208_chip_info *chip_info;
> + int ret;
> +
> + indio_dev = iio_device_alloc(sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + adc->spi = spi;
> +
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &mcp320x_info;
> +
> + chip_info = &mcp3208_chip_infos[spi_get_device_id(spi)->driver_data];
> + indio_dev->channels = chip_info->channels;
> + indio_dev->num_channels = chip_info->num_channels;
> +
> + adc->transfer[0].tx_buf = &adc->tx_buf;
> + adc->transfer[0].len = sizeof(adc->tx_buf);
> + adc->transfer[1].rx_buf = adc->rx_buf;
> + adc->transfer[1].len = sizeof(adc->rx_buf);
> +
> + spi_message_init_with_transfers(&adc->msg, adc->transfer,
> + ARRAY_SIZE(adc->transfer));
> +
> + adc->reg = regulator_get(&spi->dev, "vref");
> + if (IS_ERR(adc->reg))
You need to free the iio device in this case
> + return PTR_ERR(adc->reg);
> +
> + ret = regulator_enable(adc->reg);
> + if (ret < 0)
> + goto reg_free;
> +
> + mutex_init(&adc->lock);
> +
> + ret = iio_device_register(indio_dev);
> + if (ret < 0)
> + goto iio_free;
> +
> + return 0;
> +
> +iio_free:
> + iio_device_free(indio_dev);
> +reg_free:
> + regulator_put(adc->reg);
> +
I think the order go reversed here, e.g. if you jump to reg_free you don't free
the IIO device. And you should also disable the regulator again in case
iio_device_register fails.
> + return ret;
> +}
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
