Signed-off-by: Soeren Andersen <san at rosetechnology.dk> --- Changes since v1: *Rename the file Changes since v2: * Functions moved around. * Return values is simpler Changes since v3: * Functions moved around, not to have any prototypes. * Return values is simpler * Added datasheet reference again drivers/iio/adc/mcp320x.c | 222 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 187 insertions(+), 35 deletions(-) diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index 28a086e..efbfd12 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -1,9 +1,30 @@ /* * Copyright (C) 2013 Oskar Andero <oskar.andero@xxxxxxxxx> + * Copyright (C) 2014 Rose Technology + * Allan Bendorff Jensen <abj@xxxxxxxxxxxxxxxxx> + * Soren Andersen <san@xxxxxxxxxxxxxxxxx> + * + * Driver for following ADC chips from Microchip Technology's: + * 10 Bit converter + * MCP3001 + * MCP3002 + * MCP3004 + * MCP3008 + * ------------ + * 12 bit converter + * MCP3201 + * MCP3202 + * MCP3204 + * MCP3208 + * ------------ * - * Driver for Microchip Technology's MCP3204 and MCP3208 ADC chips. * Datasheet can be found here: - * http://ww1.microchip.com/downloads/en/devicedoc/21298c.pdf + * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf mcp3002 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf mcp3004/08 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf mcp3201 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf mcp3202 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf mcp3204/08 * * 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 @@ -11,19 +32,29 @@ */ #include <linux/err.h> +#include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/module.h> #include <linux/iio/iio.h> #include <linux/regulator/consumer.h> -#define MCP_SINGLE_ENDED (1 << 3) -#define MCP_START_BIT (1 << 4) - enum { + mcp3001, + mcp3002, + mcp3004, + mcp3008, + mcp3201, + mcp3202, mcp3204, mcp3208, }; +struct mcp320x_chip_info { + const struct iio_chan_spec *channels; + unsigned int num_channels; + unsigned int resolution; +}; + struct mcp320x { struct spi_device *spi; struct spi_message msg; @@ -34,19 +65,69 @@ struct mcp320x { struct regulator *reg; struct mutex lock; + const struct mcp320x_chip_info *chip_info; }; -static int mcp320x_adc_conversion(struct mcp320x *adc, u8 msg) +static int mcp320x_channel_to_tx_data(int device_index, + const unsigned int channel, bool differential) +{ + int start_bit = 1; + + switch (device_index) { + case mcp3001: + case mcp3201: + return 0; + case mcp3002: + case mcp3202: + return ((start_bit << 4) | (!differential << 3) | + (channel << 2)); + case mcp3004: + case mcp3204: + case mcp3008: + case mcp3208: + return ((start_bit << 6) | (!differential << 5) | + (channel << 2)); + default: + return -EINVAL; + } +} + +static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, + bool differential, int device_index) { int ret; - adc->tx_buf = msg; - ret = spi_sync(adc->spi, &adc->msg); - if (ret < 0) - return ret; + adc->rx_buf[0] = 0; + adc->rx_buf[1] = 0; + adc->tx_buf = mcp320x_channel_to_tx_data(device_index, + 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, &adc->rx_buf, sizeof(adc->rx_buf)); + if (ret < 0) + return ret; + } - return ((adc->rx_buf[0] & 0x3f) << 6) | - (adc->rx_buf[1] >> 2); + switch (device_index) { + case mcp3001: + return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3); + case mcp3002: + case mcp3004: + case mcp3008: + return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6); + case mcp3201: + return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1); + case mcp3202: + case mcp3204: + case mcp3208: + return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4); + default: + return -EINVAL; + } } static int mcp320x_read_raw(struct iio_dev *indio_dev, @@ -55,18 +136,17 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev, { 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; + 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); + ret = mcp320x_adc_conversion(adc, channel->address, + channel->differential, device_index); + if (ret < 0) goto out; @@ -75,18 +155,15 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev, break; case IIO_CHAN_INFO_SCALE: - /* Digital output code = (4096 * Vin) / Vref */ ret = regulator_get_voltage(adc->reg); if (ret < 0) goto out; + /* convert regulator output voltage to mV */ *val = ret / 1000; - *val2 = 12; + *val2 = adc->chip_info->resolution; ret = IIO_VAL_FRACTIONAL_LOG2; break; - - default: - break; } out: @@ -117,6 +194,16 @@ out: .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), MCP320X_VOLTAGE_CHANNEL(1), @@ -146,19 +233,46 @@ static const struct iio_info mcp320x_info = { .driver_module = THIS_MODULE, }; -struct mcp3208_chip_info { - const struct iio_chan_spec *channels; - unsigned int num_channels; -}; - -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), + .resolution = 10 + }, + [mcp3002] = { + .channels = mcp3202_channels, + .num_channels = ARRAY_SIZE(mcp3202_channels), + .resolution = 10 + }, + [mcp3004] = { + .channels = mcp3204_channels, + .num_channels = ARRAY_SIZE(mcp3204_channels), + .resolution = 10 + }, + [mcp3008] = { + .channels = mcp3208_channels, + .num_channels = ARRAY_SIZE(mcp3208_channels), + .resolution = 10 + }, + [mcp3201] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels), + .resolution = 12 + }, + [mcp3202] = { + .channels = mcp3202_channels, + .num_channels = ARRAY_SIZE(mcp3202_channels), + .resolution = 12 + }, [mcp3204] = { .channels = mcp3204_channels, - .num_channels = ARRAY_SIZE(mcp3204_channels) + .num_channels = ARRAY_SIZE(mcp3204_channels), + .resolution = 12 }, [mcp3208] = { .channels = mcp3208_channels, - .num_channels = ARRAY_SIZE(mcp3208_channels) + .num_channels = ARRAY_SIZE(mcp3208_channels), + .resolution = 12 }, }; @@ -166,7 +280,7 @@ 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 +295,7 @@ 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 +340,45 @@ 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[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], + }, { + } +}; +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 +397,5 @@ 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
