Re: [PATCH v2 4/4] thermal: mediatek: add another get_temp ops for thermal sensors

From: Christophe JAILLET
Date: Wed Jul 20 2022 - 14:54:57 EST

Le 20/07/2022 à 20:18, Amjad Ouled-Ameur a écrit :
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/

In mtk_thermal_bank_temperature, return -EAGAIN instead of -EACCESS
on the first read of sensor that often are bogus values.
This can avoid following warning on boot:

thermal thermal_zone6: failed to read out thermal zone (-13)

Signed-off-by: default avatarMichael Kao <michael.kao-NuS5LvNUpcJWk0Htik3J/w@xxxxxxxxxxxxxxxx>
Signed-off-by: default avatarHsin-Yi Wang <hsinyi-F7+t8E8rja9g9hUCZPvPmw@xxxxxxxxxxxxxxxx>
Signed-off-by: Amjad Ouled-Ameur <aouledameur-rdvid1DuHRBWk0Htik3J/w@xxxxxxxxxxxxxxxx>
Tested-by: Amjad Ouled-Ameur <aouledameur-rdvid1DuHRBWk0Htik3J/w@xxxxxxxxxxxxxxxx>
---
drivers/thermal/mtk_thermal.c | 100 ++++++++++++++++++++++++++--------
1 file changed, 76 insertions(+), 24 deletions(-)

diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
index 1dc276f8c4f1..79b14ce1a08d 100644
--- a/drivers/thermal/mtk_thermal.c
+++ b/drivers/thermal/mtk_thermal.c
@@ -259,6 +259,11 @@ enum mtk_thermal_version {
struct mtk_thermal;
+struct mtk_thermal_zone {
+ struct mtk_thermal *mt;
+ int id;
+};
+
struct thermal_bank_cfg {
unsigned int num_sensors;
const int *sensors;
@@ -709,6 +714,32 @@ static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
mutex_unlock(&mt->lock);
}
+static u32 _get_sensor_temp(struct mtk_thermal *mt, int id)
+{
+ u32 raw;
+ int temp;
+
+ const struct mtk_thermal_data *conf = mt->conf;
+
+ raw = readl(mt->thermal_base + conf->msr[id]);
+
+ if (mt->conf->version == MTK_THERMAL_V1)
+ temp = raw_to_mcelsius_v1(mt, id, raw);
+ else
+ temp = raw_to_mcelsius_v2(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.
+ */
+
+ if (temp > 200000)
+ return -EAGAIN;

This function returns a u32. Is it ok to return -EAGAIN?

There is also 2 spaces here...

+ else
+ return temp;

... and a tab here.

+}
+
/**
* mtk_thermal_bank_temperature - get the temperature of a bank
* @bank: The bank
@@ -721,26 +752,9 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
struct mtk_thermal *mt = bank->mt;
const struct mtk_thermal_data *conf = mt->conf;
int i, temp = INT_MIN, max = INT_MIN;
- u32 raw;
for (i = 0; i < conf->bank_data[bank->id].num_sensors; i++) {
- raw = readl(mt->thermal_base + conf->msr[i]);
-
- if (mt->conf->version == MTK_THERMAL_V1) {
- temp = raw_to_mcelsius_v1(
- mt, conf->bank_data[bank->id].sensors[i], raw);
- } else {
- temp = raw_to_mcelsius_v2(
- mt, conf->bank_data[bank->id].sensors[i], 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.
- */
- if (temp > 200000)
- temp = 0;
+ temp = _get_sensor_temp(mt, i);

Is it ok if _get_sensor_temp() returns -EAGAIN?

if (temp > max)
max = temp;
@@ -751,7 +765,8 @@ 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;
@@ -770,10 +785,28 @@ static int mtk_read_temp(void *data, int *temperature)
return 0;
}
+static int mtk_read_sensor_temp(void *data, int *temperature)
+{
+ struct mtk_thermal_zone *tz = data;
+ struct mtk_thermal *mt = tz->mt;
+ int id = tz->id - 1;
+
+ if (id < 0)
+ return -EACCES;

2 spaces.

+
+ *temperature = _get_sensor_temp(mt, id);

If _get_sensor_temp() returns -EAGAIN, should this be propagated to the caller?

+
+ 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)
@@ -1072,6 +1105,7 @@ static int mtk_thermal_probe(struct platform_device *pdev)
u64 auxadc_phys_base, apmixed_phys_base;
struct thermal_zone_device *tzdev;
void __iomem *apmixed_base, *auxadc_base;
+ struct mtk_thermal_zone *tz;
mt = devm_kzalloc(&pdev->dev, sizeof(*mt), GFP_KERNEL);
if (!mt)
@@ -1161,11 +1195,29 @@ 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);

Should this memory allocation be a devm_kmalloc(), or is this memory freed at some point by the framework?

(I don't know the thermal_zone API and the patch has no kfree())

CJ

+ 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 (PTR_ERR(tzdev) == -ENODEV) {
+ dev_warn(&pdev->dev,
+ "sensor %d not registered in thermal zone in dt\n", i);
+ continue;
+ }
+ if (PTR_ERR(tzdev) == -EACCES) {
+ ret = PTR_ERR(tzdev);
+ goto err_disable_clk_peri_therm;
+ }
+ }
}
ret = devm_thermal_add_hwmon_sysfs(tzdev);