[PATCH v3] thermal: imx: implement runtime PM support
Oleksij Rempel
o.rempel at pengutronix.de
Wed Nov 17 02:37:19 PST 2021
Petr, Michal,
can you please test this patch.
On Wed, Nov 17, 2021 at 11:34:26AM +0100, Oleksij Rempel wrote:
> Starting with commit d92ed2c9d3ff ("thermal: imx: Use driver's local
> data to decide whether to run a measurement") this driver stared using
> irq_enabled flag to make decision to power on/off the thermal core. This
> triggered a regression, where after reaching critical temperature, alarm
> IRQ handler set irq_enabled to false, disabled thermal core and was not
> able read temperature and disable cooling sequence.
>
> In case the cooling device is "CPU/GPU freq", the system will run with
> reduce performance until next reboot.
>
> To solve this issue, we need to move all parts implementing hand made
> runtime power management and let it handle actual runtime PM framework.
>
> Fixes: d92ed2c9d3ff ("thermal: imx: Use driver's local data to decide whether to run a measurement")
> Signed-off-by: Oleksij Rempel <o.rempel at pengutronix.de>
> ---
> drivers/thermal/imx_thermal.c | 145 +++++++++++++++++++++-------------
> 1 file changed, 91 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index 2c7473d86a59..16663373b682 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -15,6 +15,7 @@
> #include <linux/regmap.h>
> #include <linux/thermal.h>
> #include <linux/nvmem-consumer.h>
> +#include <linux/pm_runtime.h>
>
> #define REG_SET 0x4
> #define REG_CLR 0x8
> @@ -194,6 +195,7 @@ static struct thermal_soc_data thermal_imx7d_data = {
> };
>
> struct imx_thermal_data {
> + struct device *dev;
> struct cpufreq_policy *policy;
> struct thermal_zone_device *tz;
> struct thermal_cooling_device *cdev;
> @@ -252,44 +254,15 @@ static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
> const struct thermal_soc_data *soc_data = data->socdata;
> struct regmap *map = data->tempmon;
> unsigned int n_meas;
> - bool wait, run_measurement;
> u32 val;
> + int ret;
>
> - run_measurement = !data->irq_enabled;
> - if (!run_measurement) {
> - /* Check if a measurement is currently in progress */
> - regmap_read(map, soc_data->temp_data, &val);
> - wait = !(val & soc_data->temp_valid_mask);
> - } else {
> - /*
> - * Every time we measure the temperature, we will power on the
> - * temperature sensor, enable measurements, take a reading,
> - * disable measurements, power off the temperature sensor.
> - */
> - regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
> - soc_data->power_down_mask);
> - regmap_write(map, soc_data->sensor_ctrl + REG_SET,
> - soc_data->measure_temp_mask);
> -
> - wait = true;
> - }
> -
> - /*
> - * According to the temp sensor designers, it may require up to ~17us
> - * to complete a measurement.
> - */
> - if (wait)
> - usleep_range(20, 50);
> + ret = pm_runtime_resume_and_get(data->dev);
> + if (ret < 0)
> + return ret;
>
> regmap_read(map, soc_data->temp_data, &val);
>
> - if (run_measurement) {
> - regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
> - soc_data->measure_temp_mask);
> - regmap_write(map, soc_data->sensor_ctrl + REG_SET,
> - soc_data->power_down_mask);
> - }
> -
> if ((val & soc_data->temp_valid_mask) == 0) {
> dev_dbg(&tz->device, "temp measurement never finished\n");
> return -EAGAIN;
> @@ -328,6 +301,8 @@ static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
> enable_irq(data->irq);
> }
>
> + pm_runtime_put(data->dev);
> +
> return 0;
> }
>
> @@ -335,24 +310,16 @@ static int imx_change_mode(struct thermal_zone_device *tz,
> enum thermal_device_mode mode)
> {
> struct imx_thermal_data *data = tz->devdata;
> - struct regmap *map = data->tempmon;
> - const struct thermal_soc_data *soc_data = data->socdata;
>
> if (mode == THERMAL_DEVICE_ENABLED) {
> - regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
> - soc_data->power_down_mask);
> - regmap_write(map, soc_data->sensor_ctrl + REG_SET,
> - soc_data->measure_temp_mask);
> + pm_runtime_get(data->dev);
>
> if (!data->irq_enabled) {
> data->irq_enabled = true;
> enable_irq(data->irq);
> }
> } else {
> - regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
> - soc_data->measure_temp_mask);
> - regmap_write(map, soc_data->sensor_ctrl + REG_SET,
> - soc_data->power_down_mask);
> + pm_runtime_put(data->dev);
>
> if (data->irq_enabled) {
> disable_irq(data->irq);
> @@ -393,6 +360,11 @@ static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
> int temp)
> {
> struct imx_thermal_data *data = tz->devdata;
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(data->dev);
> + if (ret < 0)
> + return ret;
>
> /* do not allow changing critical threshold */
> if (trip == IMX_TRIP_CRITICAL)
> @@ -406,6 +378,8 @@ static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
>
> imx_set_alarm_temp(data, temp);
>
> + pm_runtime_put(data->dev);
> +
> return 0;
> }
>
> @@ -681,6 +655,8 @@ static int imx_thermal_probe(struct platform_device *pdev)
> if (!data)
> return -ENOMEM;
>
> + data->dev = &pdev->dev;
> +
> map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
> if (IS_ERR(map)) {
> ret = PTR_ERR(map);
> @@ -800,6 +776,16 @@ static int imx_thermal_probe(struct platform_device *pdev)
> data->socdata->power_down_mask);
> regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
> data->socdata->measure_temp_mask);
> + /* After power up, we need a delay before first access can be done. */
> + usleep_range(20, 50);
> +
> + /* the core was configured and enabled just before */
> + pm_runtime_set_active(&pdev->dev);
> + pm_runtime_enable(data->dev);
> +
> + ret = pm_runtime_resume_and_get(data->dev);
> + if (ret < 0)
> + goto disable_runtime_pm;
>
> data->irq_enabled = true;
> ret = thermal_zone_device_enable(data->tz);
> @@ -814,10 +800,15 @@ static int imx_thermal_probe(struct platform_device *pdev)
> goto thermal_zone_unregister;
> }
>
> + pm_runtime_put(data->dev);
> +
> return 0;
>
> thermal_zone_unregister:
> thermal_zone_device_unregister(data->tz);
> +disable_runtime_pm:
> + pm_runtime_put_noidle(data->dev);
> + pm_runtime_disable(data->dev);
> clk_disable:
> clk_disable_unprepare(data->thermal_clk);
> legacy_cleanup:
> @@ -829,13 +820,9 @@ static int imx_thermal_probe(struct platform_device *pdev)
> static int imx_thermal_remove(struct platform_device *pdev)
> {
> struct imx_thermal_data *data = platform_get_drvdata(pdev);
> - struct regmap *map = data->tempmon;
>
> - /* Disable measurements */
> - regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
> - data->socdata->power_down_mask);
> - if (!IS_ERR(data->thermal_clk))
> - clk_disable_unprepare(data->thermal_clk);
> + pm_runtime_put_noidle(data->dev);
> + pm_runtime_disable(data->dev);
>
> thermal_zone_device_unregister(data->tz);
> imx_thermal_unregister_legacy_cooling(data);
> @@ -858,29 +845,79 @@ static int __maybe_unused imx_thermal_suspend(struct device *dev)
> ret = thermal_zone_device_disable(data->tz);
> if (ret)
> return ret;
> +
> + return pm_runtime_force_suspend(data->dev);
> +}
> +
> +static int __maybe_unused imx_thermal_resume(struct device *dev)
> +{
> + struct imx_thermal_data *data = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_force_resume(data->dev);
> + if (ret)
> + return ret;
> + /* Enabled thermal sensor after resume */
> + return thermal_zone_device_enable(data->tz);
> +}
> +
> +static int __maybe_unused imx_thermal_runtime_suspend(struct device *dev)
> +{
> + struct imx_thermal_data *data = dev_get_drvdata(dev);
> + const struct thermal_soc_data *socdata = data->socdata;
> + struct regmap *map = data->tempmon;
> + int ret;
> +
> + ret = regmap_write(map, socdata->sensor_ctrl + REG_CLR,
> + socdata->measure_temp_mask);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(map, socdata->sensor_ctrl + REG_SET,
> + socdata->power_down_mask);
> + if (ret)
> + return ret;
> +
> clk_disable_unprepare(data->thermal_clk);
>
> return 0;
> }
>
> -static int __maybe_unused imx_thermal_resume(struct device *dev)
> +static int __maybe_unused imx_thermal_runtime_resume(struct device *dev)
> {
> struct imx_thermal_data *data = dev_get_drvdata(dev);
> + const struct thermal_soc_data *socdata = data->socdata;
> + struct regmap *map = data->tempmon;
> int ret;
>
> ret = clk_prepare_enable(data->thermal_clk);
> if (ret)
> return ret;
> - /* Enabled thermal sensor after resume */
> - ret = thermal_zone_device_enable(data->tz);
> +
> + ret = regmap_write(map, socdata->sensor_ctrl + REG_CLR,
> + socdata->power_down_mask);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(map, socdata->sensor_ctrl + REG_SET,
> + socdata->measure_temp_mask);
> if (ret)
> return ret;
>
> + /*
> + * According to the temp sensor designers, it may require up to ~17us
> + * to complete a measurement.
> + */
> + usleep_range(20, 50);
> +
> return 0;
> }
>
> -static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
> - imx_thermal_suspend, imx_thermal_resume);
> +static const struct dev_pm_ops imx_thermal_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(imx_thermal_suspend, imx_thermal_resume)
> + SET_RUNTIME_PM_OPS(imx_thermal_runtime_suspend,
> + imx_thermal_runtime_resume, NULL)
> +};
>
> static struct platform_driver imx_thermal = {
> .driver = {
> --
> 2.30.2
>
>
>
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