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path: root/drivers/iio/adc/mcp320x.c
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Diffstat (limited to 'drivers/iio/adc/mcp320x.c')
-rw-r--r--drivers/iio/adc/mcp320x.c222
1 files changed, 187 insertions, 35 deletions
diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
index 28a086e48776..efbfd12a4bfd 100644
--- a/drivers/iio/adc/mcp320x.c
+++ b/drivers/iio/adc/mcp320x.c
@@ -1,9 +1,30 @@
/*
* Copyright (C) 2013 Oskar Andero <oskar.andero@gmail.com>
+ * Copyright (C) 2014 Rose Technology
+ * Allan Bendorff Jensen <abj@rosetechnology.dk>
+ * Soren Andersen <san@rosetechnology.dk>
+ *
+ * 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@gmail.com>");
-MODULE_DESCRIPTION("Microchip Technology MCP3204/08");
+MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
MODULE_LICENSE("GPL v2");
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