[PATCH 2/2] thermal: mediatek: add another get_temp ops for thermal sensors

From: Michael Kao
Date: Wed Oct 07 2020 - 03:55:00 EST


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: Michael Kao <michael.kao@xxxxxxxxxxxx>
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
drivers/thermal/mtk_thermal.c | 77 +++++++++++++++++++++++++++++++----
1 file changed, 70 insertions(+), 7 deletions(-)

diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
index 0bd7aa564bc2..c638a69ba632 100644
--- a/drivers/thermal/mtk_thermal.c
+++ b/drivers/thermal/mtk_thermal.c
@@ -245,6 +245,11 @@ 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;
@@ -668,7 +673,7 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
* not immediately shut down.
*/
if (temp > 200000)
- temp = 0;
+ temp = -EAGAIN;

if (temp > max)
max = temp;
@@ -679,7 +684,8 @@ 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;

@@ -698,10 +704,47 @@ 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;
+ const struct mtk_thermal_data *conf = mt->conf;
+ int id = tz->id - 1;
+ int temp = INT_MIN;
+ u32 raw;
+
+ if (id < 0)
+ return -EACCES;
+
+ 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;
+
+ *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)
@@ -992,6 +1035,7 @@ 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)
@@ -1080,11 +1124,30 @@ 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);
+ 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;
+ }
+ }
}

return 0;
--
2.18.0