| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <51838AA1.5080508@metafoo.de>
Date: Fri, 03 May 2013 12:00:01 +0200
From: Lars-Peter Clausen <lars@...afoo.de>
To: Oskar Andero <oskar.andero@...il.com>
CC: linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
Jonathan Cameron <jic23@....ac.uk>
Subject: Re: [PATCHv4] iio: adc: add driver for MCP3204/08 12-bit ADC
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@....ac.uk>
> Cc: Lars-Peter Clausen <lars@...afoo.de>
> Signed-off-by: Oskar Andero <oskar.andero@...il.com>
Reviewed-by: Lars-Peter Clausen <lars@...afoo.de>
> ---
> 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@...il.com>
> + *
> + * 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@...il.com>");
> +MODULE_DESCRIPTION("Microchip Technology MCP3204/08");
> +MODULE_LICENSE("GPL v2");
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists