453 lines
11 KiB
C
453 lines
11 KiB
C
/*
|
|
* 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
|
|
* ------------
|
|
*
|
|
* Datasheet can be found here:
|
|
* 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
|
|
* http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf mcp3301
|
|
*
|
|
* 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/delay.h>
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/module.h>
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/regulator/consumer.h>
|
|
|
|
enum {
|
|
mcp3001,
|
|
mcp3002,
|
|
mcp3004,
|
|
mcp3008,
|
|
mcp3201,
|
|
mcp3202,
|
|
mcp3204,
|
|
mcp3208,
|
|
mcp3301,
|
|
};
|
|
|
|
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;
|
|
struct spi_transfer transfer[2];
|
|
|
|
struct regulator *reg;
|
|
struct mutex lock;
|
|
const struct mcp320x_chip_info *chip_info;
|
|
|
|
u8 tx_buf ____cacheline_aligned;
|
|
u8 rx_buf[2];
|
|
};
|
|
|
|
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:
|
|
case mcp3301:
|
|
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->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 && device_index != mcp3301) {
|
|
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;
|
|
}
|
|
|
|
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);
|
|
case mcp3301:
|
|
return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
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:
|
|
ret = regulator_get_voltage(adc->reg);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* convert regulator output voltage to mV */
|
|
*val = ret / 1000;
|
|
*val2 = adc->chip_info->resolution;
|
|
ret = IIO_VAL_FRACTIONAL_LOG2;
|
|
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(chan1, chan2) \
|
|
{ \
|
|
.type = IIO_VOLTAGE, \
|
|
.indexed = 1, \
|
|
.channel = (chan1), \
|
|
.channel2 = (chan2), \
|
|
.address = (chan1), \
|
|
.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, 1),
|
|
};
|
|
|
|
static const struct iio_chan_spec mcp3202_channels[] = {
|
|
MCP320X_VOLTAGE_CHANNEL(0),
|
|
MCP320X_VOLTAGE_CHANNEL(1),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
|
|
};
|
|
|
|
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, 1),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
|
|
};
|
|
|
|
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, 1),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7),
|
|
MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6),
|
|
};
|
|
|
|
static const struct iio_info mcp320x_info = {
|
|
.read_raw = mcp320x_read_raw,
|
|
.driver_module = THIS_MODULE,
|
|
};
|
|
|
|
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),
|
|
.resolution = 12
|
|
},
|
|
[mcp3208] = {
|
|
.channels = mcp3208_channels,
|
|
.num_channels = ARRAY_SIZE(mcp3208_channels),
|
|
.resolution = 12
|
|
},
|
|
[mcp3301] = {
|
|
.channels = mcp3201_channels,
|
|
.num_channels = ARRAY_SIZE(mcp3201_channels),
|
|
.resolution = 13
|
|
},
|
|
};
|
|
|
|
static int mcp320x_probe(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct mcp320x *adc;
|
|
const struct mcp320x_chip_info *chip_info;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(&spi->dev, 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 = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
|
|
indio_dev->channels = chip_info->channels;
|
|
indio_dev->num_channels = chip_info->num_channels;
|
|
|
|
adc->chip_info = chip_info;
|
|
|
|
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 = devm_regulator_get(&spi->dev, "vref");
|
|
if (IS_ERR(adc->reg))
|
|
return PTR_ERR(adc->reg);
|
|
|
|
ret = regulator_enable(adc->reg);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mutex_init(&adc->lock);
|
|
|
|
ret = iio_device_register(indio_dev);
|
|
if (ret < 0)
|
|
goto reg_disable;
|
|
|
|
return 0;
|
|
|
|
reg_disable:
|
|
regulator_disable(adc->reg);
|
|
|
|
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);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#if defined(CONFIG_OF)
|
|
static const struct of_device_id mcp320x_dt_ids[] = {
|
|
/* NOTE: The use of compatibles with no vendor prefix is deprecated. */
|
|
{
|
|
.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],
|
|
}, {
|
|
.compatible = "mcp3301",
|
|
.data = &mcp320x_chip_infos[mcp3301],
|
|
}, {
|
|
.compatible = "microchip,mcp3001",
|
|
.data = &mcp320x_chip_infos[mcp3001],
|
|
}, {
|
|
.compatible = "microchip,mcp3002",
|
|
.data = &mcp320x_chip_infos[mcp3002],
|
|
}, {
|
|
.compatible = "microchip,mcp3004",
|
|
.data = &mcp320x_chip_infos[mcp3004],
|
|
}, {
|
|
.compatible = "microchip,mcp3008",
|
|
.data = &mcp320x_chip_infos[mcp3008],
|
|
}, {
|
|
.compatible = "microchip,mcp3201",
|
|
.data = &mcp320x_chip_infos[mcp3201],
|
|
}, {
|
|
.compatible = "microchip,mcp3202",
|
|
.data = &mcp320x_chip_infos[mcp3202],
|
|
}, {
|
|
.compatible = "microchip,mcp3204",
|
|
.data = &mcp320x_chip_infos[mcp3204],
|
|
}, {
|
|
.compatible = "microchip,mcp3208",
|
|
.data = &mcp320x_chip_infos[mcp3208],
|
|
}, {
|
|
.compatible = "microchip,mcp3301",
|
|
.data = &mcp320x_chip_infos[mcp3301],
|
|
}, {
|
|
}
|
|
};
|
|
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 },
|
|
{ "mcp3301", mcp3301 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, mcp320x_id);
|
|
|
|
static struct spi_driver mcp320x_driver = {
|
|
.driver = {
|
|
.name = "mcp320x",
|
|
.of_match_table = of_match_ptr(mcp320x_dt_ids),
|
|
},
|
|
.probe = mcp320x_probe,
|
|
.remove = mcp320x_remove,
|
|
.id_table = mcp320x_id,
|
|
};
|
|
module_spi_driver(mcp320x_driver);
|
|
|
|
MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
|
|
MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
|
|
MODULE_LICENSE("GPL v2");
|