#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/string_choices.h>
#include "stm32-dac-core.h"
#define STM32_DAC_CHANNEL_1 1
#define STM32_DAC_CHANNEL_2 2
#define STM32_DAC_IS_CHAN_1(ch) ((ch) & STM32_DAC_CHANNEL_1)
#define STM32_DAC_AUTO_SUSPEND_DELAY_MS 2000
struct stm32_dac {
struct stm32_dac_common *common;
struct mutex lock;
};
static int stm32_dac_is_enabled(struct iio_dev *indio_dev, int channel)
{
struct stm32_dac *dac = iio_priv(indio_dev);
u32 en, val;
int ret;
ret = regmap_read(dac->common->regmap, STM32_DAC_CR, &val);
if (ret < 0)
return ret;
if (STM32_DAC_IS_CHAN_1(channel))
en = FIELD_GET(STM32_DAC_CR_EN1, val);
else
en = FIELD_GET(STM32_DAC_CR_EN2, val);
return !!en;
}
static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch,
bool enable)
{
struct stm32_dac *dac = iio_priv(indio_dev);
struct device *dev = indio_dev->dev.parent;
u32 msk = STM32_DAC_IS_CHAN_1(ch) ? STM32_DAC_CR_EN1 : STM32_DAC_CR_EN2;
u32 en = enable ? msk : 0;
int ret;
mutex_lock(&dac->lock);
ret = stm32_dac_is_enabled(indio_dev, ch);
if (ret < 0 || enable == !!ret) {
mutex_unlock(&dac->lock);
return ret < 0 ? ret : 0;
}
if (enable) {
ret = pm_runtime_resume_and_get(dev);
if (ret < 0) {
mutex_unlock(&dac->lock);
return ret;
}
}
ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en);
mutex_unlock(&dac->lock);
if (ret) {
dev_err(&indio_dev->dev, "%s failed\n", str_enable_disable(en));
if (enable)
pm_runtime_put_autosuspend(dev);
return ret;
}
if (en && dac->common->hfsel)
udelay(1);
if (!enable)
pm_runtime_put_autosuspend(dev);
return 0;
}
static int stm32_dac_get_value(struct stm32_dac *dac, int channel, int *val)
{
int ret;
if (STM32_DAC_IS_CHAN_1(channel))
ret = regmap_read(dac->common->regmap, STM32_DAC_DOR1, val);
else
ret = regmap_read(dac->common->regmap, STM32_DAC_DOR2, val);
return ret ? ret : IIO_VAL_INT;
}
static int stm32_dac_set_value(struct stm32_dac *dac, int channel, int val)
{
int ret;
if (STM32_DAC_IS_CHAN_1(channel))
ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R1, val);
else
ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R2, val);
return ret;
}
static int stm32_dac_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct stm32_dac *dac = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
return stm32_dac_get_value(dac, chan->channel, val);
case IIO_CHAN_INFO_SCALE:
*val = dac->common->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
static int stm32_dac_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct stm32_dac *dac = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
return stm32_dac_set_value(dac, chan->channel, val);
default:
return -EINVAL;
}
}
static int stm32_dac_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
struct stm32_dac *dac = iio_priv(indio_dev);
if (!readval)
return regmap_write(dac->common->regmap, reg, writeval);
else
return regmap_read(dac->common->regmap, reg, readval);
}
static const struct iio_info stm32_dac_iio_info = {
.read_raw = stm32_dac_read_raw,
.write_raw = stm32_dac_write_raw,
.debugfs_reg_access = stm32_dac_debugfs_reg_access,
};
static const char * const stm32_dac_powerdown_modes[] = {
"three_state",
};
static int stm32_dac_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
return 0;
}
static int stm32_dac_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int type)
{
return 0;
}
static ssize_t stm32_dac_read_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
int ret = stm32_dac_is_enabled(indio_dev, chan->channel);
if (ret < 0)
return ret;
return sysfs_emit(buf, "%d\n", ret ? 0 : 1);
}
static ssize_t stm32_dac_write_powerdown(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
bool powerdown;
int ret;
ret = kstrtobool(buf, &powerdown);
if (ret)
return ret;
ret = stm32_dac_set_enable_state(indio_dev, chan->channel, !powerdown);
if (ret)
return ret;
return len;
}
static const struct iio_enum stm32_dac_powerdown_mode_en = {
.items = stm32_dac_powerdown_modes,
.num_items = ARRAY_SIZE(stm32_dac_powerdown_modes),
.get = stm32_dac_get_powerdown_mode,
.set = stm32_dac_set_powerdown_mode,
};
static const struct iio_chan_spec_ext_info stm32_dac_ext_info[] = {
{
.name = "powerdown",
.read = stm32_dac_read_powerdown,
.write = stm32_dac_write_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &stm32_dac_powerdown_mode_en),
IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &stm32_dac_powerdown_mode_en),
{ }
};
#define STM32_DAC_CHANNEL(chan, name) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = chan, \
.info_mask_separate = \
BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
\
.scan_type = { \
.sign = 'u', \
.realbits = 12, \
.storagebits = 16, \
}, \
.datasheet_name = name, \
.ext_info = stm32_dac_ext_info \
}
static const struct iio_chan_spec stm32_dac_channels[] = {
STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_1, "out1"),
STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_2, "out2"),
};
static int stm32_dac_chan_of_init(struct iio_dev *indio_dev)
{
struct device_node *np = indio_dev->dev.of_node;
unsigned int i;
u32 channel;
int ret;
ret = of_property_read_u32(np, "reg", &channel);
if (ret) {
dev_err(&indio_dev->dev, "Failed to read reg property\n");
return ret;
}
for (i = 0; i < ARRAY_SIZE(stm32_dac_channels); i++) {
if (stm32_dac_channels[i].channel == channel)
break;
}
if (i >= ARRAY_SIZE(stm32_dac_channels)) {
dev_err(&indio_dev->dev, "Invalid reg property\n");
return -EINVAL;
}
indio_dev->channels = &stm32_dac_channels[i];
indio_dev->num_channels = 1;
return 0;
};
static int stm32_dac_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct device *dev = &pdev->dev;
struct iio_dev *indio_dev;
struct stm32_dac *dac;
int ret;
if (!np)
return -ENODEV;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*dac));
if (!indio_dev)
return -ENOMEM;
platform_set_drvdata(pdev, indio_dev);
dac = iio_priv(indio_dev);
dac->common = dev_get_drvdata(pdev->dev.parent);
indio_dev->name = dev_name(&pdev->dev);
indio_dev->dev.of_node = pdev->dev.of_node;
indio_dev->info = &stm32_dac_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
mutex_init(&dac->lock);
ret = stm32_dac_chan_of_init(indio_dev);
if (ret < 0)
return ret;
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
pm_runtime_set_autosuspend_delay(dev, STM32_DAC_AUTO_SUSPEND_DELAY_MS);
pm_runtime_use_autosuspend(dev);
pm_runtime_enable(dev);
ret = iio_device_register(indio_dev);
if (ret)
goto err_pm_put;
pm_runtime_put_autosuspend(dev);
return 0;
err_pm_put:
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
pm_runtime_put_noidle(dev);
return ret;
}
static void stm32_dac_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
pm_runtime_get_sync(&pdev->dev);
iio_device_unregister(indio_dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
}
static int stm32_dac_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
int channel = indio_dev->channels[0].channel;
int ret;
ret = stm32_dac_is_enabled(indio_dev, channel);
if (ret)
return ret < 0 ? ret : -EBUSY;
return pm_runtime_force_suspend(dev);
}
static DEFINE_SIMPLE_DEV_PM_OPS(stm32_dac_pm_ops, stm32_dac_suspend,
pm_runtime_force_resume);
static const struct of_device_id stm32_dac_of_match[] = {
{ .compatible = "st,stm32-dac", },
{ }
};
MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
static struct platform_driver stm32_dac_driver = {
.probe = stm32_dac_probe,
.remove = stm32_dac_remove,
.driver = {
.name = "stm32-dac",
.of_match_table = stm32_dac_of_match,
.pm = pm_sleep_ptr(&stm32_dac_pm_ops),
},
};
module_platform_driver(stm32_dac_driver);
MODULE_ALIAS("platform:stm32-dac");
MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 DAC driver");
MODULE_LICENSE("GPL v2");
