Signed-off-by: Soeren Andersen <san at rosetechnology.dk> --- drivers/iio/adc/mcp320x.c | 352 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------------------------- 1 file changed, 267 insertions(+), 85 deletions(-) diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index 28a086e..2871777 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -1,9 +1,22 @@ /* * Copyright (C) 2013 Oskar Andero <oskar.andero@xxxxxxxxx> + * Copyright (C) 2014 Allan Bendorff Jensen <abj@xxxxxxxxxxxxxxxxx> * - * Driver for Microchip Technology's MCP3204 and MCP3208 ADC chips. + * Driver for following ADC chips from Microchip Technology's: + * 10 Bit converter + * MCP3001 + * MCP3002 + * MCP3004 + * MCP3008 + * ------------ + * 12 bit converter + * MCP3201 + * MCP3202 + * MCP3204 + * MCP3208 + * ------------ * Datasheet can be found here: - * http://ww1.microchip.com/downloads/en/devicedoc/21298c.pdf + * http://www.microchip.com/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -16,10 +29,17 @@ #include <linux/iio/iio.h> #include <linux/regulator/consumer.h> -#define MCP_SINGLE_ENDED (1 << 3) -#define MCP_START_BIT (1 << 4) +static int mcp320x_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask); enum { + mcp3001, + mcp3002, + mcp3004, + mcp3008, + mcp3201, + mcp3202, mcp3204, mcp3208, }; @@ -36,86 +56,37 @@ struct mcp320x { struct mutex lock; }; -static int mcp320x_adc_conversion(struct mcp320x *adc, u8 msg) -{ - int ret; - - adc->tx_buf = msg; - ret = spi_sync(adc->spi, &adc->msg); - if (ret < 0) - return ret; - - return ((adc->rx_buf[0] & 0x3f) << 6) | - (adc->rx_buf[1] >> 2); -} - -static int mcp320x_read_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *channel, int *val, - int *val2, long mask) -{ - struct mcp320x *adc = iio_priv(indio_dev); - int ret = -EINVAL; - - mutex_lock(&adc->lock); - - switch (mask) { - case IIO_CHAN_INFO_RAW: - if (channel->differential) - ret = mcp320x_adc_conversion(adc, - MCP_START_BIT | channel->address); - else - ret = mcp320x_adc_conversion(adc, - MCP_START_BIT | MCP_SINGLE_ENDED | - channel->address); - if (ret < 0) - goto out; - - *val = ret; - ret = IIO_VAL_INT; - break; - - 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 = 12; - ret = IIO_VAL_FRACTIONAL_LOG2; - break; - - default: - break; +#define MCP320X_VOLTAGE_CHANNEL(num) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (num), \ + .address = (num), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } -out: - mutex_unlock(&adc->lock); - - return ret; -} - -#define MCP320X_VOLTAGE_CHANNEL(num) \ - { \ - .type = IIO_VOLTAGE, \ - .indexed = 1, \ - .channel = (num), \ - .address = (num), \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ +#define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (num * 2), \ + .channel2 = (num * 2 + 1), \ + .address = (num * 2), \ + .differential = 1, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } -#define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \ - { \ - .type = IIO_VOLTAGE, \ - .indexed = 1, \ - .channel = (num * 2), \ - .channel2 = (num * 2 + 1), \ - .address = (num * 2), \ - .differential = 1, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ - } +static const struct iio_chan_spec mcp3201_channels[] = { + MCP320X_VOLTAGE_CHANNEL_DIFF(0), +}; + +static const struct iio_chan_spec mcp3202_channels[] = { + MCP320X_VOLTAGE_CHANNEL(0), + MCP320X_VOLTAGE_CHANNEL(1), + MCP320X_VOLTAGE_CHANNEL_DIFF(0), +}; static const struct iio_chan_spec mcp3204_channels[] = { MCP320X_VOLTAGE_CHANNEL(0), @@ -146,12 +117,37 @@ static const struct iio_info mcp320x_info = { .driver_module = THIS_MODULE, }; -struct mcp3208_chip_info { +struct mcp320x_chip_info { const struct iio_chan_spec *channels; unsigned int num_channels; + unsigned int resolution; }; -static const struct mcp3208_chip_info mcp3208_chip_infos[] = { +static const struct mcp320x_chip_info mcp320x_chip_infos[] = { + [mcp3001] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels) + }, + [mcp3002] = { + .channels = mcp3202_channels, + .num_channels = ARRAY_SIZE(mcp3202_channels) + }, + [mcp3004] = { + .channels = mcp3204_channels, + .num_channels = ARRAY_SIZE(mcp3204_channels) + }, + [mcp3008] = { + .channels = mcp3208_channels, + .num_channels = ARRAY_SIZE(mcp3208_channels) + }, + [mcp3201] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels) + }, + [mcp3202] = { + .channels = mcp3202_channels, + .num_channels = ARRAY_SIZE(mcp3202_channels) + }, [mcp3204] = { .channels = mcp3204_channels, .num_channels = ARRAY_SIZE(mcp3204_channels) @@ -162,11 +158,159 @@ static const struct mcp3208_chip_info mcp3208_chip_infos[] = { }, }; +static int channel_to_tx_data(const struct mcp320x_chip_info *chip_info, + const unsigned int channel, bool differential) +{ + unsigned int tx_data = 0; + + if (chip_info->num_channels - 1 == 2) { + tx_data = 0x12 | (differential ? 0 << 3 : 1 << 3) | + ((channel & 0x01) << 2); + } else if (chip_info->num_channels - 2 == 4) { + tx_data = 0x20 | (differential ? 0 << 4 : 1 << 4) | + ((channel & 0x03) << 1); + } else if (chip_info->num_channels - 4 == 8) { + tx_data = 0x20 | (differential ? 0 << 4 : 1 << 4) | + ((channel & 0x07) << 1); + } + + return tx_data; +} + +static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, + bool differential, int device_index) +{ + int ret; + u16 adc_value; + __be16 buf; + + const struct mcp320x_chip_info *chip_info = NULL; + + if (device_index == -1) + return -1; + + chip_info = &mcp320x_chip_infos[device_index]; + if (chip_info == NULL) + return -1; + + adc->rx_buf[0] = 0; + adc->rx_buf[1] = 0; + adc->tx_buf = channel_to_tx_data(chip_info, channel, differential); + + if (device_index != mcp3001 && device_index != mcp3201) { + ret = spi_sync(adc->spi, &adc->msg); + if (ret < 0) + return ret; + } else { + ret = spi_read(adc->spi, (u8 *)&buf, 2); + if (ret < 0) + return ret; + } + + switch (device_index) { + case mcp3001: + adc_value = (be16_to_cpu(buf) >> 3); + break; + case mcp3002: + spi_sync(adc->spi, &adc->msg); + adc_value = adc->rx_buf[0]; + adc_value = ((adc_value << 2) | + ((adc->rx_buf[1] & 0xC0) >> 6)) & 0x03ff; + break; + case mcp3004: + case mcp3008: + adc_value = adc->rx_buf[0] & 0x7f; + adc_value = ((adc_value << 3) | + ((adc->rx_buf[1] & 0xe0) >> 5)) & 0x03ff; + break; + case mcp3201: + adc_value = (be16_to_cpu(buf) >> 1); + break; + case mcp3202: + adc_value = adc->rx_buf[0]; + adc_value = ((adc_value << 4) | + ((adc->rx_buf[1] & 0xf0) >> 4)) & 0x0fff; + break; + case mcp3204: + case mcp3208: + adc_value = adc->rx_buf[0] & 0x7f; + adc_value = ((adc_value << 5) | + ((adc->rx_buf[1] & 0xf8) >> 3)) & 0x0fff; + break; + default: + adc_value = 0; + break; + } + + return adc_value; +} + +static int mcp320x_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask) +{ + struct mcp320x *adc = iio_priv(indio_dev); + int ret = -EINVAL; + int device_index = 0; + + mutex_lock(&adc->lock); + + device_index = spi_get_device_id(adc->spi)->driver_data; + + if (device_index == -1) + goto out; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = mcp320x_adc_conversion(adc, channel->address, + channel->differential, device_index); + + if (ret < 0) + goto out; + + *val = ret; + ret = IIO_VAL_INT; + break; + + case IIO_CHAN_INFO_SCALE: + /* + * Digital output code = (resolution * Vin) / Vref + * Get regulator output voltage in uV. + */ + ret = regulator_get_voltage(adc->reg); + if (ret < 0) + goto out; + + /* convert regulator output voltage to mV */ + *val = ret / 1000; + *val2 = -1; + if (device_index == mcp3001 || device_index == mcp3002 || + device_index == mcp3004 || device_index == mcp3008) + *val2 = 10; + else if (device_index == mcp3201 || device_index == mcp3202 || + device_index == mcp3204 || device_index == mcp3208) + *val2 = 12; + else + goto out; + + ret = IIO_VAL_FRACTIONAL_LOG2; + 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; + const struct mcp320x_chip_info *chip_info; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); @@ -181,7 +325,7 @@ static int mcp320x_probe(struct spi_device *spi) indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &mcp320x_info; - chip_info = &mcp3208_chip_infos[spi_get_device_id(spi)->driver_data]; + chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data]; indio_dev->channels = chip_info->channels; indio_dev->num_channels = chip_info->num_channels; @@ -226,7 +370,45 @@ static int mcp320x_remove(struct spi_device *spi) return 0; } +#if defined(CONFIG_OF) +static const struct of_device_id mcp320x_dt_ids[] = { + { + .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[mcp3004], + }, { + .compatible = "mcp3201", + .data = &mcp320x_chip_infos[mcp3201], + }, { + .compatible = "mcp3202", + .data = &mcp320x_chip_infos[mcp3202], + }, { + .compatible = "mcp3204", + .data = &mcp320x_chip_infos[mcp3204], + }, { + .compatible = "mcp3008", + .data = &mcp320x_chip_infos[mcp3208], + }, { + } +}; +MODULE_DEVICE_TABLE(of, mcp320x_dt_ids); +#endif + static const struct spi_device_id mcp320x_id[] = { + { "mcp3001", mcp3001 }, + { "mcp3002", mcp3002 }, + { "mcp3004", mcp3004 }, + { "mcp3008", mcp3008 }, + { "mcp3201", mcp3201 }, + { "mcp3202", mcp3202 }, { "mcp3204", mcp3204 }, { "mcp3208", mcp3208 }, { } @@ -245,5 +427,5 @@ static struct spi_driver mcp320x_driver = { module_spi_driver(mcp320x_driver); MODULE_AUTHOR("Oskar Andero <oskar.andero@xxxxxxxxx>"); -MODULE_DESCRIPTION("Microchip Technology MCP3204/08"); +MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08"); MODULE_LICENSE("GPL v2"); -- 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
