From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB
---
kernel/drivers/iio/dac/stm32-dac.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 97 insertions(+), 3 deletions(-)
diff --git a/kernel/drivers/iio/dac/stm32-dac.c b/kernel/drivers/iio/dac/stm32-dac.c
index cce26a3..12dec68 100644
--- a/kernel/drivers/iio/dac/stm32-dac.c
+++ b/kernel/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"
@@ -20,12 +21,17 @@
#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
+ * @lock: lock to protect against potential races when reading
+ * and update CR, to keep it in sync with pm_runtime
*/
struct stm32_dac {
struct stm32_dac_common *common;
+ struct mutex lock;
};
static int stm32_dac_is_enabled(struct iio_dev *indio_dev, int channel)
@@ -49,15 +55,34 @@
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(&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_get_sync(dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(dev);
+ mutex_unlock(&dac->lock);
+ return ret;
+ }
+ }
+
ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en);
+ mutex_unlock(&dac->lock);
if (ret < 0) {
dev_err(&indio_dev->dev, "%s failed\n", en ?
"Enable" : "Disable");
- return ret;
+ goto err_put_pm;
}
/*
@@ -68,7 +93,20 @@
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 +310,7 @@
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;
@@ -287,17 +326,70 @@
dac = iio_priv(indio_dev);
dac->common = dev_get_drvdata(pdev->dev.parent);
indio_dev->name = dev_name(&pdev->dev);
- indio_dev->dev.parent = &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;
- 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 +399,11 @@
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);
--
Gitblit v1.6.2