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linux/drivers/iio/adc/mcp320x.c
Greg Kroah-Hartman f3cf3fb7ec First set of new device support, features and cleanups for IIO in the 4.5 cycle 
Usual mixed bag, but the big item perhaps in this series is the DMA buffer
 support added by Lars-Peter Clausen. It's been in the works for a long time
 and it will be interesting to see what hardware support shows up now that
 this is available.
 
 New core features + associate cleanup.
 * Add generic DMA buffer infrastructure
 * Add a DMAengine framework based buffer
  Also associated minor changes.
    - Set the device buffer watermark based on the minimum watermark for all
      attached buffers rather than just the 'primary' one.
    - iio_buffer_init - only set the watermark default if one hasn't already
      been provided.  This allows simple support for devices with a fixed
      watermark.
    - read only attribute for watermark on fixed watermark devices.
    - add explicit buffer enable/disable callbacks to allow the buffer to
      do more than trivial actions when it is being turned on and off.
 * IIO_VAL_INT support in write_raw_get_fmt function.
 
 New device support
 * Freescale MMA7455/7456L accelerometers
 * Memsic MXC6255XC accelerometer
 * ST lis2dh12 accelerometer
 * TI ADS8688 ADC
 * TI Palamas (twl6035/7) gpadc
 
 New driver features
 * mma8452
   - support either of the available interrupt pins to cope with the case
     where board layout has lead to a particular one being connected.
 
 Staging graduation
 * Dummy driver
   - this driver acts as both an example and a test device for those with
     out hardware to develop userspace code against.
 
 Cleanups and minor bits and bobs.
 * treewide
   - Sort out the ordering of iio_device_register/unregister vs runtime
     pm function calls so that it's all nice and consistent and not race
     prone.
   - Check sscanf return values.  None of the cases will actually happen as
     the strings are supplied internally, but best to be consistent on this.
 * ad7780
   - switch over to the gpio descriptor interface and remove the now unused
     platform data which gets rid of a header entirely.
 * ad7793
   - drop a pointless else statement.
 * at91_adc
   - Swap kmalloc_array in for a kmalloc doing the same job.
 * dummy
   - get rid of some commented out lines that snuck in during the move of
     the driver.
 * lm3533-als
   - Print an error message on provision of an invalid resistance.
 * mcp320x
   - Add compatible strings with vendor prefix and deprecate those with
     no vendor prefix.
 * mxs-lradc
   - Use BIT macro in various places rather than shifted ones.
 * pa12203001
   - Power off the chip if the registration fails.
 * pulsedlight-lidar-lite
   - add runtime PM support.
 * xilinx XADC
   - constify an iio_buffer_setup_ops structure.
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Merge tag 'iio-for-4.5a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First set of new device support, features and cleanups for IIO in the 4.5 cycle

Usual mixed bag, but the big item perhaps in this series is the DMA buffer
support added by Lars-Peter Clausen. It's been in the works for a long time
and it will be interesting to see what hardware support shows up now that
this is available.

New core features + associate cleanup.
* Add generic DMA buffer infrastructure
* Add a DMAengine framework based buffer
 Also associated minor changes.
   - Set the device buffer watermark based on the minimum watermark for all
     attached buffers rather than just the 'primary' one.
   - iio_buffer_init - only set the watermark default if one hasn't already
     been provided.  This allows simple support for devices with a fixed
     watermark.
   - read only attribute for watermark on fixed watermark devices.
   - add explicit buffer enable/disable callbacks to allow the buffer to
     do more than trivial actions when it is being turned on and off.
* IIO_VAL_INT support in write_raw_get_fmt function.

New device support
* Freescale MMA7455/7456L accelerometers
* Memsic MXC6255XC accelerometer
* ST lis2dh12 accelerometer
* TI ADS8688 ADC
* TI Palamas (twl6035/7) gpadc

New driver features
* mma8452
  - support either of the available interrupt pins to cope with the case
    where board layout has lead to a particular one being connected.

Staging graduation
* Dummy driver
  - this driver acts as both an example and a test device for those with
    out hardware to develop userspace code against.

Cleanups and minor bits and bobs.
* treewide
  - Sort out the ordering of iio_device_register/unregister vs runtime
    pm function calls so that it's all nice and consistent and not race
    prone.
  - Check sscanf return values.  None of the cases will actually happen as
    the strings are supplied internally, but best to be consistent on this.
* ad7780
  - switch over to the gpio descriptor interface and remove the now unused
    platform data which gets rid of a header entirely.
* ad7793
  - drop a pointless else statement.
* at91_adc
  - Swap kmalloc_array in for a kmalloc doing the same job.
* dummy
  - get rid of some commented out lines that snuck in during the move of
    the driver.
* lm3533-als
  - Print an error message on provision of an invalid resistance.
* mcp320x
  - Add compatible strings with vendor prefix and deprecate those with
    no vendor prefix.
* mxs-lradc
  - Use BIT macro in various places rather than shifted ones.
* pa12203001
  - Power off the chip if the registration fails.
* pulsedlight-lidar-lite
  - add runtime PM support.
* xilinx XADC
  - constify an iio_buffer_setup_ops structure.
2015-12-01 09:13:29 -08:00

446 lines
10 KiB
C
Raw Blame History

/*
* 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(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 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),
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,
};
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");
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