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regulator: stm32-vrefbuf: add power management support

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Add support for suspend/resume and runtime PM to stm32-vrefbuf driver.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Fabrice Gasnier 2019-02-28 11:45:18 +01:00 committed by Mark Brown
parent 0e819b51fb
commit be5295f8a1
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 114 additions and 7 deletions
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121
drivers/regulator/stm32-vrefbuf.c
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@ -15,6 +15,7 @@
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include <linux/pm_runtime.h>
/* STM32 VREFBUF registers */
#define STM32_VREFBUF_CSR 0x00
@ -25,9 +26,12 @@
#define STM32_HIZ BIT(1)
#define STM32_ENVR BIT(0)
#define STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS 10
struct stm32_vrefbuf {
void __iomem *base;
struct clk *clk;
struct device *dev;
};
static const unsigned int stm32_vrefbuf_voltages[] = {
@ -38,9 +42,16 @@ static const unsigned int stm32_vrefbuf_voltages[] = {
static int stm32_vrefbuf_enable(struct regulator_dev *rdev)
{
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
u32 val;
int ret;
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
return ret;
}
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
val = (val & ~STM32_HIZ) | STM32_ENVR;
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
@ -59,45 +70,95 @@ static int stm32_vrefbuf_enable(struct regulator_dev *rdev)
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
}
pm_runtime_mark_last_busy(priv->dev);
pm_runtime_put_autosuspend(priv->dev);
return ret;
}
static int stm32_vrefbuf_disable(struct regulator_dev *rdev)
{
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
u32 val;
int ret;
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
return ret;
}
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
val = (val & ~STM32_ENVR) | STM32_HIZ;
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
pm_runtime_mark_last_busy(priv->dev);
pm_runtime_put_autosuspend(priv->dev);
return 0;
}
static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev)
{
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
int ret;
return readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
return ret;
}
ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
pm_runtime_mark_last_busy(priv->dev);
pm_runtime_put_autosuspend(priv->dev);
return ret;
}
static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev,
unsigned sel)
{
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
u32 val;
int ret;
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
return ret;
}
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel);
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
pm_runtime_mark_last_busy(priv->dev);
pm_runtime_put_autosuspend(priv->dev);
return 0;
}
static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev)
{
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
u32 val;
int ret;
return FIELD_GET(STM32_VRS, val);
ret = pm_runtime_get_sync(priv->dev);
if (ret < 0) {
pm_runtime_put_noidle(priv->dev);
return ret;
}
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
ret = FIELD_GET(STM32_VRS, val);
pm_runtime_mark_last_busy(priv->dev);
pm_runtime_put_autosuspend(priv->dev);
return ret;
}
static const struct regulator_ops stm32_vrefbuf_volt_ops = {
@ -130,6 +191,7 @@ static int stm32_vrefbuf_probe(struct platform_device *pdev)
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(&pdev->dev, res);
@ -140,10 +202,17 @@ static int stm32_vrefbuf_probe(struct platform_device *pdev)
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev,
STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_enable(&pdev->dev);
ret = clk_prepare_enable(priv->clk);
if (ret) {
dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret);
return ret;
goto err_pm_stop;
}
config.dev = &pdev->dev;
@ -161,10 +230,17 @@ static int stm32_vrefbuf_probe(struct platform_device *pdev)
}
platform_set_drvdata(pdev, rdev);
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
return 0;
err_clk_dis:
clk_disable_unprepare(priv->clk);
err_pm_stop:
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return ret;
}
@ -174,10 +250,40 @@ static int stm32_vrefbuf_remove(struct platform_device *pdev)
struct regulator_dev *rdev = platform_get_drvdata(pdev);
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
pm_runtime_get_sync(&pdev->dev);
regulator_unregister(rdev);
clk_disable_unprepare(priv->clk);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return 0;
};
static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev)
{
struct regulator_dev *rdev = dev_get_drvdata(dev);
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
clk_disable_unprepare(priv->clk);
return 0;
}
static int __maybe_unused stm32_vrefbuf_runtime_resume(struct device *dev)
{
struct regulator_dev *rdev = dev_get_drvdata(dev);
struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
return clk_prepare_enable(priv->clk);
}
static const struct dev_pm_ops stm32_vrefbuf_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend,
stm32_vrefbuf_runtime_resume,
NULL)
};
static const struct of_device_id stm32_vrefbuf_of_match[] = {
@ -192,6 +298,7 @@ static struct platform_driver stm32_vrefbuf_driver = {
.driver = {
.name = "stm32-vrefbuf",
.of_match_table = of_match_ptr(stm32_vrefbuf_of_match),
.pm = &stm32_vrefbuf_pm_ops,
},
};
module_platform_driver(stm32_vrefbuf_driver);