[PATCH v3, 7/8] thermal: mediatek: add another get_temp ops for thermal sensors

[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/

Bypass the failure that non cpu_thermal sensor is not find in thermal-zones
in dts, which is normal for mt8173, so prompt a warning here instead of
failing.

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@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/thermal/mtk_thermal.c | 74 +++++++++++++++++++++++++++++++----
 1 file changed, 66 insertions(+), 8 deletions(-)

diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
index d6fabd0a7da6..9be9fcb18d9e 100644
--- a/drivers/thermal/mtk_thermal.c
+++ b/drivers/thermal/mtk_thermal.c
@@ -225,6 +225,11 @@ 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;
@@ -607,7 +612,7 @@ 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;
@@ -618,7 +623,8 @@ 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;
 
@@ -631,16 +637,48 @@ static int mtk_read_temp(void *data, int *temperature)
 
 		mtk_thermal_put_bank(bank);
 	}
-
 	*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;
+	u32 raw;
+
+	if (id < 0)
+		return  -EACCES;
+
+	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.
+	 */
+
+	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)
@@ -873,6 +911,7 @@ 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)
@@ -954,11 +993,30 @@ 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 (IS_ERR(tzdev) != -EACCES) {
+				ret = PTR_ERR(tzdev);
+				goto err_disable_clk_peri_therm;
+			}
+		}
 	}
 
 	return 0;
-- 
2.18.0
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