linux/drivers/iio/dac/mcp4922.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

210 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* mcp4922.c
*
* Driver for Microchip Digital to Analog Converters.
* Supports MCP4902, MCP4912, and MCP4922.
*
* Copyright (c) 2014 EMAC Inc.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/regulator/consumer.h>
#include <linux/bitops.h>
#define MCP4922_NUM_CHANNELS 2
enum mcp4922_supported_device_ids {
ID_MCP4902,
ID_MCP4912,
ID_MCP4922,
};
struct mcp4922_state {
struct spi_device *spi;
unsigned int value[MCP4922_NUM_CHANNELS];
unsigned int vref_mv;
struct regulator *vref_reg;
u8 mosi[2] ____cacheline_aligned;
};
#define MCP4922_CHAN(chan, bits) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.indexed = 1, \
.channel = chan, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = 12 - (bits), \
}, \
}
static int mcp4922_spi_write(struct mcp4922_state *state, u8 addr, u32 val)
{
state->mosi[1] = val & 0xff;
state->mosi[0] = (addr == 0) ? 0x00 : 0x80;
state->mosi[0] |= 0x30 | ((val >> 8) & 0x0f);
return spi_write(state->spi, state->mosi, 2);
}
static int mcp4922_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct mcp4922_state *state = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
*val = state->value[chan->channel];
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = state->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
static int mcp4922_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct mcp4922_state *state = iio_priv(indio_dev);
int ret;
if (val2 != 0)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0))
return -EINVAL;
val <<= chan->scan_type.shift;
ret = mcp4922_spi_write(state, chan->channel, val);
if (!ret)
state->value[chan->channel] = val;
return ret;
default:
return -EINVAL;
}
}
static const struct iio_chan_spec mcp4922_channels[3][MCP4922_NUM_CHANNELS] = {
[ID_MCP4902] = { MCP4922_CHAN(0, 8), MCP4922_CHAN(1, 8) },
[ID_MCP4912] = { MCP4922_CHAN(0, 10), MCP4922_CHAN(1, 10) },
[ID_MCP4922] = { MCP4922_CHAN(0, 12), MCP4922_CHAN(1, 12) },
};
static const struct iio_info mcp4922_info = {
.read_raw = &mcp4922_read_raw,
.write_raw = &mcp4922_write_raw,
};
static int mcp4922_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct mcp4922_state *state;
const struct spi_device_id *id;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
if (indio_dev == NULL)
return -ENOMEM;
state = iio_priv(indio_dev);
state->spi = spi;
state->vref_reg = devm_regulator_get(&spi->dev, "vref");
if (IS_ERR(state->vref_reg)) {
dev_err(&spi->dev, "Vref regulator not specified\n");
return PTR_ERR(state->vref_reg);
}
ret = regulator_enable(state->vref_reg);
if (ret) {
dev_err(&spi->dev, "Failed to enable vref regulator: %d\n",
ret);
return ret;
}
ret = regulator_get_voltage(state->vref_reg);
if (ret < 0) {
dev_err(&spi->dev, "Failed to read vref regulator: %d\n",
ret);
goto error_disable_reg;
}
state->vref_mv = ret / 1000;
spi_set_drvdata(spi, indio_dev);
id = spi_get_device_id(spi);
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &mcp4922_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mcp4922_channels[id->driver_data];
indio_dev->num_channels = MCP4922_NUM_CHANNELS;
indio_dev->name = id->name;
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&spi->dev, "Failed to register iio device: %d\n",
ret);
goto error_disable_reg;
}
return 0;
error_disable_reg:
regulator_disable(state->vref_reg);
return ret;
}
static int mcp4922_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct mcp4922_state *state;
iio_device_unregister(indio_dev);
state = iio_priv(indio_dev);
regulator_disable(state->vref_reg);
return 0;
}
static const struct spi_device_id mcp4922_id[] = {
{"mcp4902", ID_MCP4902},
{"mcp4912", ID_MCP4912},
{"mcp4922", ID_MCP4922},
{}
};
MODULE_DEVICE_TABLE(spi, mcp4922_id);
static struct spi_driver mcp4922_driver = {
.driver = {
.name = "mcp4922",
},
.probe = mcp4922_probe,
.remove = mcp4922_remove,
.id_table = mcp4922_id,
};
module_spi_driver(mcp4922_driver);
MODULE_AUTHOR("Michael Welling <mwelling@ieee.org>");
MODULE_DESCRIPTION("Microchip MCP4902, MCP4912, MCP4922 DAC");
MODULE_LICENSE("GPL v2");