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linux/drivers/iio/dac/mcp4725.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* mcp4725.c - Support for Microchip MCP4725/6
*
* Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
*
* Based on max517 by Roland Stigge <stigge@antcom.de>
*
* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
* (7-bit I2C slave address 0x60, the three LSBs can be configured in
* hardware)
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/dac/mcp4725.h>
#define MCP4725_DRV_NAME "mcp4725"
#define MCP472X_REF_VDD 0x00
#define MCP472X_REF_VREF_UNBUFFERED 0x02
#define MCP472X_REF_VREF_BUFFERED 0x03
struct mcp4725_chip_info {
const struct iio_chan_spec *chan_spec;
u8 dac_reg_offset;
bool use_ext_ref_voltage;
};
struct mcp4725_data {
struct i2c_client *client;
unsigned ref_mode;
bool vref_buffered;
u16 dac_value;
bool powerdown;
unsigned powerdown_mode;
struct regulator *vdd_reg;
struct regulator *vref_reg;
};
static int mcp4725_suspend(struct device *dev)
{
struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
u8 outbuf[2];
int ret;
outbuf[0] = (data->powerdown_mode + 1) << 4;
outbuf[1] = 0;
data->powerdown = true;
ret = i2c_master_send(data->client, outbuf, 2);
if (ret < 0)
return ret;
else if (ret != 2)
return -EIO;
return 0;
}
static int mcp4725_resume(struct device *dev)
{
struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
u8 outbuf[2];
int ret;
/* restore previous DAC value */
outbuf[0] = (data->dac_value >> 8) & 0xf;
outbuf[1] = data->dac_value & 0xff;
data->powerdown = false;
ret = i2c_master_send(data->client, outbuf, 2);
if (ret < 0)
return ret;
else if (ret != 2)
return -EIO;
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend,
mcp4725_resume);
static ssize_t mcp4725_store_eeprom(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct mcp4725_data *data = iio_priv(indio_dev);
int tries = 20;
u8 inoutbuf[3];
bool state;
int ret;
ret = kstrtobool(buf, &state);
if (ret < 0)
return ret;
if (!state)
return 0;
inoutbuf[0] = 0x60; /* write EEPROM */
inoutbuf[0] |= data->ref_mode << 3;
inoutbuf[0] |= data->powerdown ? ((data->powerdown_mode + 1) << 1) : 0;
inoutbuf[1] = data->dac_value >> 4;
inoutbuf[2] = (data->dac_value & 0xf) << 4;
ret = i2c_master_send(data->client, inoutbuf, 3);
if (ret < 0)
return ret;
else if (ret != 3)
return -EIO;
/* wait for write complete, takes up to 50ms */
while (tries--) {
msleep(20);
ret = i2c_master_recv(data->client, inoutbuf, 3);
if (ret < 0)
return ret;
else if (ret != 3)
return -EIO;
if (inoutbuf[0] & 0x80)
break;
}
if (tries < 0) {
dev_err(&data->client->dev,
"mcp4725_store_eeprom() failed, incomplete\n");
return -EIO;
}
return len;
}
static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0);
static struct attribute *mcp4725_attributes[] = {
&iio_dev_attr_store_eeprom.dev_attr.attr,
NULL,
};
static const struct attribute_group mcp4725_attribute_group = {
.attrs = mcp4725_attributes,
};
static const char * const mcp4725_powerdown_modes[] = {
"1kohm_to_gnd",
"100kohm_to_gnd",
"500kohm_to_gnd"
};
static const char * const mcp4726_powerdown_modes[] = {
"1kohm_to_gnd",
"125kohm_to_gnd",
"640kohm_to_gnd"
};
static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct mcp4725_data *data = iio_priv(indio_dev);
return data->powerdown_mode;
}
static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned mode)
{
struct mcp4725_data *data = iio_priv(indio_dev);
data->powerdown_mode = mode;
return 0;
}
static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct mcp4725_data *data = iio_priv(indio_dev);
return sysfs_emit(buf, "%d\n", data->powerdown);
}
static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct mcp4725_data *data = iio_priv(indio_dev);
bool state;
int ret;
ret = kstrtobool(buf, &state);
if (ret)
return ret;
if (state)
ret = mcp4725_suspend(&data->client->dev);
else
ret = mcp4725_resume(&data->client->dev);
if (ret < 0)
return ret;
return len;
}
enum chip_id {
MCP4725,
MCP4726,
};
static const struct iio_enum mcp472x_powerdown_mode_enum[] = {
[MCP4725] = {
.items = mcp4725_powerdown_modes,
.num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
.get = mcp4725_get_powerdown_mode,
.set = mcp4725_set_powerdown_mode,
},
[MCP4726] = {
.items = mcp4726_powerdown_modes,
.num_items = ARRAY_SIZE(mcp4726_powerdown_modes),
.get = mcp4725_get_powerdown_mode,
.set = mcp4725_set_powerdown_mode,
},
};
static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
{
.name = "powerdown",
.read = mcp4725_read_powerdown,
.write = mcp4725_write_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE,
&mcp472x_powerdown_mode_enum[MCP4725]),
IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
&mcp472x_powerdown_mode_enum[MCP4725]),
{ },
};
static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {
{
.name = "powerdown",
.read = mcp4725_read_powerdown,
.write = mcp4725_write_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE,
&mcp472x_powerdown_mode_enum[MCP4726]),
IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
&mcp472x_powerdown_mode_enum[MCP4726]),
{ },
};
static const struct iio_chan_spec mcp472x_channel[] = {
[MCP4725] = {
.type = IIO_VOLTAGE,
.indexed = 1,
.output = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.ext_info = mcp4725_ext_info,
},
[MCP4726] = {
.type = IIO_VOLTAGE,
.indexed = 1,
.output = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.ext_info = mcp4726_ext_info,
},
};
static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
{
struct mcp4725_data *data = iio_priv(indio_dev);
u8 outbuf[2];
int ret;
if (val >= (1 << 12) || val < 0)
return -EINVAL;
outbuf[0] = (val >> 8) & 0xf;
outbuf[1] = val & 0xff;
ret = i2c_master_send(data->client, outbuf, 2);
if (ret < 0)
return ret;
else if (ret != 2)
return -EIO;
else
return 0;
}
static int mcp4726_set_cfg(struct iio_dev *indio_dev)
{
struct mcp4725_data *data = iio_priv(indio_dev);
u8 outbuf[3];
int ret;
outbuf[0] = 0x40;
outbuf[0] |= data->ref_mode << 3;
if (data->powerdown)
outbuf[0] |= data->powerdown << 1;
outbuf[1] = data->dac_value >> 4;
outbuf[2] = (data->dac_value & 0xf) << 4;
ret = i2c_master_send(data->client, outbuf, 3);
if (ret < 0)
return ret;
else if (ret != 3)
return -EIO;
else
return 0;
}
static int mcp4725_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mcp4725_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
*val = data->dac_value;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (data->ref_mode == MCP472X_REF_VDD)
ret = regulator_get_voltage(data->vdd_reg);
else
ret = regulator_get_voltage(data->vref_reg);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static int mcp4725_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct mcp4725_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = mcp4725_set_value(indio_dev, val);
data->dac_value = val;
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static const struct iio_info mcp4725_info = {
.read_raw = mcp4725_read_raw,
.write_raw = mcp4725_write_raw,
.attrs = &mcp4725_attribute_group,
};
static int mcp4725_probe_dt(struct device *dev,
struct mcp4725_platform_data *pdata)
{
/* check if is the vref-supply defined */
pdata->use_vref = device_property_read_bool(dev, "vref-supply");
pdata->vref_buffered =
device_property_read_bool(dev, "microchip,vref-buffered");
return 0;
}
static int mcp4725_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
const struct mcp4725_chip_info *info;
struct mcp4725_data *data;
struct iio_dev *indio_dev;
struct mcp4725_platform_data *pdata, pdata_dt;
u8 inbuf[4];
u8 pd;
u8 ref;
int err;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
info = i2c_get_match_data(client);
pdata = dev_get_platdata(&client->dev);
if (!pdata) {
err = mcp4725_probe_dt(&client->dev, &pdata_dt);
if (err) {
dev_err(&client->dev,
"invalid platform or devicetree data");
return err;
}
pdata = &pdata_dt;
}
if (info->use_ext_ref_voltage && pdata->use_vref) {
dev_err(&client->dev,
"external reference is unavailable on MCP4725");
return -EINVAL;
}
if (!pdata->use_vref && pdata->vref_buffered) {
dev_err(&client->dev,
"buffering is unavailable on the internal reference");
return -EINVAL;
}
if (!pdata->use_vref)
data->ref_mode = MCP472X_REF_VDD;
else
data->ref_mode = pdata->vref_buffered ?
MCP472X_REF_VREF_BUFFERED :
MCP472X_REF_VREF_UNBUFFERED;
data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
if (IS_ERR(data->vdd_reg))
return PTR_ERR(data->vdd_reg);
err = regulator_enable(data->vdd_reg);
if (err)
return err;
if (pdata->use_vref) {
data->vref_reg = devm_regulator_get(&client->dev, "vref");
if (IS_ERR(data->vref_reg)) {
err = PTR_ERR(data->vref_reg);
goto err_disable_vdd_reg;
}
err = regulator_enable(data->vref_reg);
if (err)
goto err_disable_vdd_reg;
}
indio_dev->name = id->name;
indio_dev->info = &mcp4725_info;
indio_dev->channels = info->chan_spec;
indio_dev->num_channels = 1;
indio_dev->modes = INDIO_DIRECT_MODE;
/* read current DAC value and settings */
err = i2c_master_recv(client, inbuf, info->dac_reg_offset);
if (err < 0) {
dev_err(&client->dev, "failed to read DAC value");
goto err_disable_vref_reg;
}
pd = (inbuf[0] >> 1) & 0x3;
data->powerdown = pd > 0;
data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
if (!info->use_ext_ref_voltage)
ref = (inbuf[3] >> 3) & 0x3;
if (!info->use_ext_ref_voltage && ref != data->ref_mode) {
dev_info(&client->dev,
"voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
data->ref_mode, ref, data->ref_mode);
err = mcp4726_set_cfg(indio_dev);
if (err < 0)
goto err_disable_vref_reg;
}
err = iio_device_register(indio_dev);
if (err)
goto err_disable_vref_reg;
return 0;
err_disable_vref_reg:
if (data->vref_reg)
regulator_disable(data->vref_reg);
err_disable_vdd_reg:
regulator_disable(data->vdd_reg);
return err;
}
i2c: Make remove callback return void The value returned by an i2c driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com> Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Crt Mori <cmo@melexis.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013 Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/* Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5 Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860 Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power Acked-by: Krzysztof Hałasa <khalasa@piap.pl> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-15 01:02:30 -07:00
static void mcp4725_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct mcp4725_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (data->vref_reg)
regulator_disable(data->vref_reg);
regulator_disable(data->vdd_reg);
}
static const struct mcp4725_chip_info mcp4725 = {
.chan_spec = &mcp472x_channel[MCP4725],
.dac_reg_offset = 3,
.use_ext_ref_voltage = true,
};
static const struct mcp4725_chip_info mcp4726 = {
.chan_spec = &mcp472x_channel[MCP4726],
.dac_reg_offset = 4,
};
static const struct i2c_device_id mcp4725_id[] = {
{ "mcp4725", (kernel_ulong_t)&mcp4725 },
{ "mcp4726", (kernel_ulong_t)&mcp4726 },
{ }
};
MODULE_DEVICE_TABLE(i2c, mcp4725_id);
static const struct of_device_id mcp4725_of_match[] = {
{
.compatible = "microchip,mcp4725",
.data = &mcp4725
},
{
.compatible = "microchip,mcp4726",
.data = &mcp4726
},
{ }
};
MODULE_DEVICE_TABLE(of, mcp4725_of_match);
static struct i2c_driver mcp4725_driver = {
.driver = {
.name = MCP4725_DRV_NAME,
.of_match_table = mcp4725_of_match,
.pm = pm_sleep_ptr(&mcp4725_pm_ops),
},
.probe = mcp4725_probe,
.remove = mcp4725_remove,
.id_table = mcp4725_id,
};
module_i2c_driver(mcp4725_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");
MODULE_LICENSE("GPL");