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path: root/drivers/iio/dac/stm32-dac.c
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Diffstat (limited to 'drivers/iio/dac/stm32-dac.c')
-rw-r--r--drivers/iio/dac/stm32-dac.c94
1 files changed, 92 insertions, 2 deletions
diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c
index cce26a3a6627..f22c1d9129b2 100644
--- a/drivers/iio/dac/stm32-dac.c
+++ b/drivers/iio/dac/stm32-dac.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include "stm32-dac-core.h"
@@ -20,6 +21,8 @@
#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 - private data of DAC driver
* @common: reference to DAC common data
@@ -49,15 +52,34 @@ 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;
+ /* already enabled / disabled ? */
+ mutex_lock(&indio_dev->mlock);
+ ret = stm32_dac_is_enabled(indio_dev, ch);
+ if (ret < 0 || enable == !!ret) {
+ mutex_unlock(&indio_dev->mlock);
+ return ret < 0 ? ret : 0;
+ }
+
+ if (enable) {
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(dev);
+ mutex_unlock(&indio_dev->mlock);
+ return ret;
+ }
+ }
+
ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en);
+ mutex_unlock(&indio_dev->mlock);
if (ret < 0) {
dev_err(&indio_dev->dev, "%s failed\n", en ?
"Enable" : "Disable");
- return ret;
+ goto err_put_pm;
}
/*
@@ -68,7 +90,20 @@ static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch,
if (en && dac->common->hfsel)
udelay(1);
+ if (!enable) {
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+ }
+
return 0;
+
+err_put_pm:
+ if (enable) {
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+ }
+
+ return ret;
}
static int stm32_dac_get_value(struct stm32_dac *dac, int channel, int *val)
@@ -272,6 +307,7 @@ static int stm32_dac_chan_of_init(struct iio_dev *indio_dev)
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;
@@ -296,9 +332,61 @@ static int stm32_dac_probe(struct platform_device *pdev)
if (ret < 0)
return ret;
- return devm_iio_device_register(&pdev->dev, indio_dev);
+ /* Get stm32-dac-core PM online */
+ 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_mark_last_busy(dev);
+ 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 int 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);
+
+ return 0;
+}
+
+static int __maybe_unused stm32_dac_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ int channel = indio_dev->channels[0].channel;
+ int ret;
+
+ /* Ensure DAC is disabled before suspend */
+ ret = stm32_dac_is_enabled(indio_dev, channel);
+ if (ret)
+ return ret < 0 ? ret : -EBUSY;
+
+ return pm_runtime_force_suspend(dev);
+}
+
+static const struct dev_pm_ops stm32_dac_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(stm32_dac_suspend, pm_runtime_force_resume)
+};
+
static const struct of_device_id stm32_dac_of_match[] = {
{ .compatible = "st,stm32-dac", },
{},
@@ -307,9 +395,11 @@ 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 = &stm32_dac_pm_ops,
},
};
module_platform_driver(stm32_dac_driver);