diff options
Diffstat (limited to 'drivers/iio/adc/mcp320x.c')
| -rw-r--r-- | drivers/iio/adc/mcp320x.c | 121 |
1 files changed, 44 insertions, 77 deletions
diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index 634717ae12f3..a41956eb3379 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -57,6 +57,17 @@ struct mcp320x_chip_info { unsigned int resolution; }; +/** + * struct mcp320x - Microchip SPI ADC instance + * @spi: SPI slave (parent of the IIO device) + * @msg: SPI message to select a channel and receive a value from the ADC + * @transfer: SPI transfers used by @msg + * @reg: regulator generating Vref + * @lock: protects read sequences + * @chip_info: ADC properties + * @tx_buf: buffer for @transfer[0] (not used on single-channel converters) + * @rx_buf: buffer for @transfer[1] + */ struct mcp320x { struct spi_device *spi; struct spi_message msg; @@ -76,10 +87,6 @@ static int mcp320x_channel_to_tx_data(int device_index, int start_bit = 1; switch (device_index) { - case mcp3001: - case mcp3201: - case mcp3301: - return 0; case mcp3002: case mcp3202: return ((start_bit << 4) | (!differential << 3) | @@ -100,20 +107,14 @@ static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, { int ret; - adc->rx_buf[0] = 0; - adc->rx_buf[1] = 0; - adc->tx_buf = mcp320x_channel_to_tx_data(device_index, - channel, differential); + memset(&adc->rx_buf, 0, sizeof(adc->rx_buf)); + if (adc->chip_info->num_channels > 1) + adc->tx_buf = mcp320x_channel_to_tx_data(device_index, channel, + differential); - if (device_index != mcp3001 && device_index != mcp3201 && device_index != mcp3301) { - ret = spi_sync(adc->spi, &adc->msg); - if (ret < 0) - return ret; - } else { - ret = spi_read(adc->spi, &adc->rx_buf, sizeof(adc->rx_buf)); - if (ret < 0) - return ret; - } + ret = spi_sync(adc->spi, &adc->msg); + if (ret < 0) + return ret; switch (device_index) { case mcp3001: @@ -242,7 +243,6 @@ static const struct iio_chan_spec mcp3208_channels[] = { static const struct iio_info mcp320x_info = { .read_raw = mcp320x_read_raw, - .driver_module = THIS_MODULE, }; static const struct mcp320x_chip_info mcp320x_chip_infos[] = { @@ -323,9 +323,13 @@ static int mcp320x_probe(struct spi_device *spi) 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)); + if (chip_info->num_channels == 1) + /* single-channel converters are rx only (no MOSI pin) */ + spi_message_init_with_transfers(&adc->msg, + &adc->transfer[1], 1); + else + spi_message_init_with_transfers(&adc->msg, adc->transfer, + ARRAY_SIZE(adc->transfer)); adc->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(adc->reg)) @@ -363,62 +367,25 @@ static int mcp320x_remove(struct spi_device *spi) #if defined(CONFIG_OF) static const struct of_device_id mcp320x_dt_ids[] = { /* NOTE: The use of compatibles with no vendor prefix is deprecated. */ - { - .compatible = "mcp3001", - .data = &mcp320x_chip_infos[mcp3001], - }, { - .compatible = "mcp3002", - .data = &mcp320x_chip_infos[mcp3002], - }, { - .compatible = "mcp3004", - .data = &mcp320x_chip_infos[mcp3004], - }, { - .compatible = "mcp3008", - .data = &mcp320x_chip_infos[mcp3008], - }, { - .compatible = "mcp3201", - .data = &mcp320x_chip_infos[mcp3201], - }, { - .compatible = "mcp3202", - .data = &mcp320x_chip_infos[mcp3202], - }, { - .compatible = "mcp3204", - .data = &mcp320x_chip_infos[mcp3204], - }, { - .compatible = "mcp3208", - .data = &mcp320x_chip_infos[mcp3208], - }, { - .compatible = "mcp3301", - .data = &mcp320x_chip_infos[mcp3301], - }, { - .compatible = "microchip,mcp3001", - .data = &mcp320x_chip_infos[mcp3001], - }, { - .compatible = "microchip,mcp3002", - .data = &mcp320x_chip_infos[mcp3002], - }, { - .compatible = "microchip,mcp3004", - .data = &mcp320x_chip_infos[mcp3004], - }, { - .compatible = "microchip,mcp3008", - .data = &mcp320x_chip_infos[mcp3008], - }, { - .compatible = "microchip,mcp3201", - .data = &mcp320x_chip_infos[mcp3201], - }, { - .compatible = "microchip,mcp3202", - .data = &mcp320x_chip_infos[mcp3202], - }, { - .compatible = "microchip,mcp3204", - .data = &mcp320x_chip_infos[mcp3204], - }, { - .compatible = "microchip,mcp3208", - .data = &mcp320x_chip_infos[mcp3208], - }, { - .compatible = "microchip,mcp3301", - .data = &mcp320x_chip_infos[mcp3301], - }, { - } + { .compatible = "mcp3001" }, + { .compatible = "mcp3002" }, + { .compatible = "mcp3004" }, + { .compatible = "mcp3008" }, + { .compatible = "mcp3201" }, + { .compatible = "mcp3202" }, + { .compatible = "mcp3204" }, + { .compatible = "mcp3208" }, + { .compatible = "mcp3301" }, + { .compatible = "microchip,mcp3001" }, + { .compatible = "microchip,mcp3002" }, + { .compatible = "microchip,mcp3004" }, + { .compatible = "microchip,mcp3008" }, + { .compatible = "microchip,mcp3201" }, + { .compatible = "microchip,mcp3202" }, + { .compatible = "microchip,mcp3204" }, + { .compatible = "microchip,mcp3208" }, + { .compatible = "microchip,mcp3301" }, + { } }; MODULE_DEVICE_TABLE(of, mcp320x_dt_ids); #endif |