Re: [PATCH 7/8] thermal: mediatek: add another get_temp ops for thermal sensors

Nicolas Boichat
2019-05-11T02:31:08Z

On Thu, May 2, 2019 at 7:45 PM michael.kao <michael.kao@mediatek.com> wrote:
>
> From: Michael Kao <michael.kao@mediatek.com>
>
> Provide thermal zone to read thermal sensor
> in the SoC. We can read all the thermal sensors
> value in the SoC by the node /sys/class/thermal/
>
> Signed-off-by: Michael Kao <michael.kao@mediatek.com>
> ---
> drivers/thermal/mtk_thermal.c | 68 ++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 60 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> index cb41e46..d5c78b0 100644
> --- a/drivers/thermal/mtk_thermal.c
> +++ b/drivers/thermal/mtk_thermal.c
> @@ -230,6 +230,11 @@ enum {
>
> struct mtk_thermal;
>
> +struct mtk_thermal_zone {
> + struct mtk_thermal *mt;
> + int id;
> +};
> +
> struct thermal_bank_cfg {
> unsigned int num_sensors;
> const int *sensors;
> @@ -612,7 +617,7 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
> * not immediately shut down.
> */
> if (temp > 200000)
> - temp = 0;
> + temp = -EACCES;

EACCES/permission denied doesn't really seem to be the right error
code here. Maybe EAGAIN?

>
> if (temp > max)
> max = temp;
> @@ -623,7 +628,8 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
>
> static int mtk_read_temp(void *data, int *temperature)
> {
> - struct mtk_thermal *mt = data;
> + struct mtk_thermal_zone *tz = data;
> + struct mtk_thermal *mt = tz->mt;
> int i;
> int tempmax = INT_MIN;
>
> @@ -636,16 +642,48 @@ static int mtk_read_temp(void *data, int *temperature)
>
> mtk_thermal_put_bank(bank);
> }
> -

I'd drop that change.

> *temperature = tempmax;
>
> return 0;
> }
>
> +static int mtk_read_sensor_temp(void *data, int *temperature)
> +{
> + struct mtk_thermal_zone *tz = data;
> + struct mtk_thermal *mt = tz->mt;
> + const struct mtk_thermal_data *conf = mt->conf;
> + int id = tz->id - 1;
> + int temp = INT_MIN;

No need to initialize temp.

> + u32 raw;
> +
> + if (id < 0)
> + return -EACCES;

EINVAL?

> +
> + raw = readl(mt->thermal_base + conf->msr[id]);
> +
> + temp = raw_to_mcelsius(mt, id, raw);
> +
> + /*
> + * The first read of a sensor often contains very high bogus
> + * temperature value. Filter these out so that the system does
> + * not immediately shut down.
> + */
> +

nit: Drop this blank line

> + if (temp > 200000)
> + return -EACCES;

Again, EAGAIN, maybe?

> +
> + *temperature = temp;
> + return 0;
> +}
> +
> static const struct thermal_zone_of_device_ops mtk_thermal_ops = {
> .get_temp = mtk_read_temp,
> };
>
> +static const struct thermal_zone_of_device_ops mtk_thermal_sensor_ops = {
> + .get_temp = mtk_read_sensor_temp,
> +};
> +
> static void mtk_thermal_init_bank(struct mtk_thermal *mt, int num,
> u32 apmixed_phys_base, u32 auxadc_phys_base,
> int ctrl_id)
> @@ -878,6 +916,7 @@ static int mtk_thermal_probe(struct platform_device *pdev)
> struct resource *res;
> u64 auxadc_phys_base, apmixed_phys_base;
> struct thermal_zone_device *tzdev;
> + struct mtk_thermal_zone *tz;
>
> mt = devm_kzalloc(&pdev->dev, sizeof(*mt), GFP_KERNEL);
> if (!mt)
> @@ -959,11 +998,24 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, mt);
>
> - tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, mt,
> - &mtk_thermal_ops);
> - if (IS_ERR(tzdev)) {
> - ret = PTR_ERR(tzdev);
> - goto err_disable_clk_peri_therm;
> + for (i = 0; i < mt->conf->num_sensors + 1; i++) {
> + tz = kmalloc(sizeof(*tz), GFP_KERNEL);

Are we leaking this pointer? Should this be devm_kmalloc?

> + if (!tz)
> + return -ENOMEM;
> +
> + tz->mt = mt;
> + tz->id = i;
> +
> + tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, i,
> + tz, (i == 0) ?
> + &mtk_thermal_ops : &mtk_thermal_sensor_ops);
> +
> + if (IS_ERR(tzdev)) {
> + if (IS_ERR(tzdev) != -EACCES) {

Why would EACCES ever happen? AFAICT
devm_thermal_zone_of_sensor_register does not actually try to read the
temperature value? Or does the error come from somewhere else?

> + ret = PTR_ERR(tzdev);
> + goto err_disable_clk_peri_therm;
> + }
> + }
> }
>
> return 0;
> --
> 1.9.1
>
>
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