diff options
author | Fabrice Gasnier <fabrice.gasnier@st.com> | 2019-02-25 13:42:47 +0300 |
---|---|---|
committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2019-04-04 22:19:45 +0300 |
commit | 6dc3e36fbc4c68d57f588c3241e78c25b24d48aa (patch) | |
tree | 92354d4928f04f2218c4db2c0c768e6fc84c4a77 /drivers | |
parent | 74896202dfb71e7142adc4042f0cc812cb4be4c5 (diff) | |
download | linux-6dc3e36fbc4c68d57f588c3241e78c25b24d48aa.tar.xz |
iio: counter: stm32-lptimer: Add power management support
Add suspend/resume PM sleep ops. When going to low power, disable
active counter. Only active counter should be resumed: don't touch
disabled counter, as it may be used by other LPTimer MFD child driver.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/iio/counter/stm32-lptimer-cnt.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c index 42fb8ba67090..2a49cce0edb4 100644 --- a/drivers/iio/counter/stm32-lptimer-cnt.c +++ b/drivers/iio/counter/stm32-lptimer-cnt.c @@ -14,6 +14,7 @@ #include <linux/iio/iio.h> #include <linux/mfd/stm32-lptimer.h> #include <linux/module.h> +#include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> struct stm32_lptim_cnt { @@ -23,6 +24,7 @@ struct stm32_lptim_cnt { u32 preset; u32 polarity; u32 quadrature_mode; + bool enabled; }; static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv) @@ -50,6 +52,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, if (!enable) { clk_disable(priv->clk); + priv->enabled = false; return 0; } @@ -79,6 +82,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, regmap_write(priv->regmap, STM32_LPTIM_CR, 0); return ret; } + priv->enabled = true; /* Start LP timer in continuous mode */ return regmap_update_bits(priv->regmap, STM32_LPTIM_CR, @@ -361,6 +365,56 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev) return devm_iio_device_register(&pdev->dev, indio_dev); } +#ifdef CONFIG_PM_SLEEP +static int stm32_lptim_cnt_suspend(struct device *dev) +{ + struct stm32_lptim_cnt *priv = dev_get_drvdata(dev); + int ret; + + /* Only take care of enabled counter: don't disturb other MFD child */ + if (priv->enabled) { + ret = stm32_lptim_setup(priv, 0); + if (ret) + return ret; + + ret = stm32_lptim_set_enable_state(priv, 0); + if (ret) + return ret; + + /* Force enable state for later resume */ + priv->enabled = true; + } + + return pinctrl_pm_select_sleep_state(dev); +} + +static int stm32_lptim_cnt_resume(struct device *dev) +{ + struct stm32_lptim_cnt *priv = dev_get_drvdata(dev); + int ret; + + ret = pinctrl_pm_select_default_state(dev); + if (ret) + return ret; + + if (priv->enabled) { + priv->enabled = false; + ret = stm32_lptim_setup(priv, 1); + if (ret) + return ret; + + ret = stm32_lptim_set_enable_state(priv, 1); + if (ret) + return ret; + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend, + stm32_lptim_cnt_resume); + static const struct of_device_id stm32_lptim_cnt_of_match[] = { { .compatible = "st,stm32-lptimer-counter", }, {}, @@ -372,6 +426,7 @@ static struct platform_driver stm32_lptim_cnt_driver = { .driver = { .name = "stm32-lptimer-counter", .of_match_table = stm32_lptim_cnt_of_match, + .pm = &stm32_lptim_cnt_pm_ops, }, }; module_platform_driver(stm32_lptim_cnt_driver); |