On 05/03/2013 11:58 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> Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx> > --- > drivers/iio/adc/Kconfig | 10 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/mcp320x.c | 257 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 268 insertions(+) > create mode 100644 drivers/iio/adc/mcp320x.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index ab0767e6..93129ec 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -133,6 +133,16 @@ config MAX1363 > max11646, max11647) Provides direct access via sysfs and buffered > data via the iio dev interface. > > +config MCP320X > + tristate "Microchip Technology MCP3204/08" > + depends on SPI > + help > + Say yes here to build support for Microchip Technology's MCP3204 or > + MCP3208 analog to digital converter. > + > + This driver can also be built as a module. If so, the module will be > + called mcp320x. > + > config TI_ADC081C > tristate "Texas Instruments ADC081C021/027" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 0a825be..8f475d3 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -14,6 +14,7 @@ obj-$(CONFIG_AT91_ADC) += at91_adc.o > obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o > obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_MAX1363) += max1363.o > +obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o > obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o > obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o > diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c > new file mode 100644 > index 0000000..ebc0159 > --- /dev/null > +++ b/drivers/iio/adc/mcp320x.c > @@ -0,0 +1,257 @@ > +/* > + * Copyright (C) 2013 Oskar Andero <oskar.andero@xxxxxxxxx> > + * > + * Driver for Microchip Technology's MCP3204 and MCP3208 ADC chips. > + * Datasheet can be found here: > + * http://ww1.microchip.com/downloads/en/devicedoc/21298c.pdf > + * > + * 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 > + * published by the Free Software Foundation. > + */ > + > +#include <linux/err.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 { > + mcp3204, > + mcp3208, > +}; > + > +struct mcp320x { > + struct spi_device *spi; > + struct spi_message msg; > + struct spi_transfer transfer[2]; > + > + u8 tx_buf; > + u8 rx_buf[2]; > + > + struct regulator *reg; > + 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; > + } > + > +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) \ > + } > + > +static const struct iio_chan_spec mcp3204_channels[] = { > + MCP320X_VOLTAGE_CHANNEL(0), > + MCP320X_VOLTAGE_CHANNEL(1), > + MCP320X_VOLTAGE_CHANNEL(2), > + MCP320X_VOLTAGE_CHANNEL(3), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(1), > +}; > + > +static const struct iio_chan_spec mcp3208_channels[] = { > + MCP320X_VOLTAGE_CHANNEL(0), > + MCP320X_VOLTAGE_CHANNEL(1), > + MCP320X_VOLTAGE_CHANNEL(2), > + MCP320X_VOLTAGE_CHANNEL(3), > + MCP320X_VOLTAGE_CHANNEL(4), > + MCP320X_VOLTAGE_CHANNEL(5), > + MCP320X_VOLTAGE_CHANNEL(6), > + MCP320X_VOLTAGE_CHANNEL(7), > + MCP320X_VOLTAGE_CHANNEL_DIFF(0), > + MCP320X_VOLTAGE_CHANNEL_DIFF(1), > + MCP320X_VOLTAGE_CHANNEL_DIFF(2), > + MCP320X_VOLTAGE_CHANNEL_DIFF(3), > +}; > + > +static const struct iio_info mcp320x_info = { > + .read_raw = mcp320x_read_raw, > + .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[] = { > + [mcp3204] = { > + .channels = mcp3204_channels, > + .num_channels = ARRAY_SIZE(mcp3204_channels) > + }, > + [mcp3208] = { > + .channels = mcp3208_channels, > + .num_channels = ARRAY_SIZE(mcp3208_channels) > + }, > +}; > + > +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)) { > + ret = PTR_ERR(adc->reg); > + goto iio_free; > + } > + > + 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 reg_disable; > + > + return 0; > + > +reg_disable: > + regulator_disable(adc->reg); > +reg_free: > + regulator_put(adc->reg); > +iio_free: > + iio_device_free(indio_dev); > + > + return ret; > +} > + > +static int mcp320x_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct mcp320x *adc = iio_priv(indio_dev); > + > + iio_device_unregister(indio_dev); > + regulator_disable(adc->reg); > + regulator_put(adc->reg); > + iio_device_free(indio_dev); > + > + return 0; > +} > + > +static const struct spi_device_id mcp320x_id[] = { > + { "mcp3204", mcp3204 }, > + { "mcp3208", mcp3208 }, > + { } > +}; > +MODULE_DEVICE_TABLE(spi, mcp320x_id); > + > +static struct spi_driver mcp320x_driver = { > + .driver = { > + .name = "mcp320x", > + .owner = THIS_MODULE, > + }, > + .probe = mcp320x_probe, > + .remove = mcp320x_remove, > + .id_table = mcp320x_id, > +}; > +module_spi_driver(mcp320x_driver); > + > +MODULE_AUTHOR("Oskar Andero <oskar.andero@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Microchip Technology MCP3204/08"); > +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
