[PATCH v3 0/4] thermal: k3: Add support for bandgap sensors

[PATCH v3 0/4] thermal: k3: Add support for bandgap sensors

[Keerthy]

Add VTM thermal support. In the Voltage Thermal
Management Module(VTM), K3 AM654 supplies a voltage
reference and a temperature sensor feature that are gathered in the band
gap voltage and temperature sensor (VBGAPTS) module. The band
gap provides current and voltage reference for its internal
circuits and other analog IP blocks. The analog-to-digital
converter (ADC) produces an output value that is proportional
to the silicon temperature.

Add support for bandgap sensors. Currently reading temperatures
and trend computing is supported.

Changes in v3:

  * Fixed errors seen with:
    dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml

Changes in v2:

  * Fixed yaml errors
  * renamed am654-industrial-thermal.dtsi to k3-am654-industrial-thermal.dtsi
    to follow the convention for k3 family.

Keerthy (4):
  dt-bindings: thermal: k3: Add VTM bindings documentation
  thermal: k3: Add support for bandgap sensors
  arm64: dts: ti: am654: Add thermal zones
  arm64: dts: ti: am6: Add VTM node

 .../bindings/thermal/ti,am654-thermal.yaml    |  57 +++
 arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi    |  11 +
 .../dts/ti/k3-am654-industrial-thermal.dtsi   |  45 +++
 drivers/thermal/Kconfig                       |  12 +
 drivers/thermal/Makefile                      |   1 +
 drivers/thermal/k3_bandgap.c                  | 342 ++++++++++++++++++
 6 files changed, 468 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
 create mode 100644 arch/arm64/boot/dts/ti/k3-am654-industrial-thermal.dtsi
 create mode 100644 drivers/thermal/k3_bandgap.c

-- 
2.17.1

[PATCH v3 1/4] dt-bindings: thermal: k3: Add VTM bindings documentation

[Keerthy]

Add VTM bindings documentation. In the Voltage Thermal
Management Module(VTM), K3 AM654 supplies a voltage
reference and a temperature sensor feature that are gathered in the band
gap voltage and temperature sensor (VBGAPTS) module. The band
gap provides current and voltage reference for its internal
circuits and other analog IP blocks. The analog-to-digital
converter (ADC) produces an output value that is proportional
to the silicon temperature.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---

Changes in v3:

  * Fixed errors seen with:
    dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml

 .../bindings/thermal/ti,am654-thermal.yaml    | 57 +++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml

diff --git a/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
new file mode 100644
index 000000000000..b6dc95c3acab
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/ti,am654-thermal.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments AM654 VTM (DTS) binding
+
+maintainers:
+  - Keerthy <j-keerthy@ti.com>
+
+properties:
+  compatible:
+    const: ti,am654-vtm
+
+  reg:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+    description: phandle to the associated power domain
+
+  "#thermal-sensor-cells":
+    const: 1
+
+required:
+  - "#thermal-sensor-cells"
+  - compatible
+  - reg
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/soc/ti,sci_pm_domain.h>
+    vtm: wkup_vtm0@42050000 {
+        compatible = "ti,am654-vtm";
+        reg = <0x0 0x42050000 0x0 0x25c>;
+        power-domains = <&k3_pds 80 TI_SCI_PD_EXCLUSIVE>;
+        #thermal-sensor-cells = <1>;
+    };
+
+    mpu0_thermal: mpu0_thermal {
+        polling-delay-passive = <250>; /* milliseconds */
+        polling-delay = <500>; /* milliseconds */
+        thermal-sensors = <&vtm0 0>;
+
+        trips {
+                mpu0_crit: mpu0_crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = "critical";
+                };
+        };
+    };
+...
-- 
2.17.1

[PATCH v3 2/4] thermal: k3: Add support for bandgap sensors

[Keerthy]

The bandgap provides current and voltage reference for its internal
circuits and other analog IP blocks. The analog-to-digital
converter (ADC) produces an output value that is proportional
to the silicon temperature.

Currently reading temperatures and trend computing is supported
as there are no active/passive cooling agent supported.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 drivers/thermal/Kconfig      |  12 ++
 drivers/thermal/Makefile     |   1 +
 drivers/thermal/k3_bandgap.c | 342 +++++++++++++++++++++++++++++++++++
 3 files changed, 355 insertions(+)
 create mode 100644 drivers/thermal/k3_bandgap.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 5a05db5438d6..fa598eddc7ac 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -251,6 +251,18 @@ config IMX_THERMAL
 	  cpufreq is used as the cooling device to throttle CPUs when the
 	  passive trip is crossed.
 
+config K3_THERMAL
+	bool "Texas Instruments K3 thermal support"
+	depends on THERMAL
+	depends on ARCH_K3 || COMPILE_TEST
+	help
+	  If you say yes here you get thermal support for the Texas Instruments
+	  K3 SoC family. The current chip supported is:
+	   - AM654
+
+	  This includes temperature reading functionality and also trend
+	  computation.
+
 config MAX77620_THERMAL
 	tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
 	depends on MFD_MAX77620
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 9fb88e26fb10..5ad6535139ae 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -28,6 +28,7 @@ thermal_sys-$(CONFIG_CLOCK_THERMAL)	+= clock_cooling.o
 # devfreq cooling
 thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
 
+obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o
 # platform thermal drivers
 obj-y				+= broadcom/
 obj-$(CONFIG_THERMAL_MMIO)		+= thermal_mmio.o
diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c
new file mode 100644
index 000000000000..35d904eb9857
--- /dev/null
+++ b/drivers/thermal/k3_bandgap.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI Bandgap temperature sensor driver for K3 SoC Family
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pm_runtime.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/workqueue.h>
+#include <linux/thermal.h>
+#include <linux/of.h>
+
+#define K3_VTM_DEVINFO_PWR0_OFFSET		0x4
+#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK	0xf
+#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK	0xf0
+#define K3_VTM_TMPSENS0_CTRL_OFFSET	0x80
+#define K3_VTM_REGS_PER_TS			0x10
+#define K3_VTM_TS_STAT_DTEMP_MASK	0x3ff
+#define K3_VTM_MAX_NUM_TS		8
+#define K3_VTM_TMPSENS_CTRL_CBIASSEL	BIT(0)
+#define K3_VTM_TMPSENS_CTRL_SOC		BIT(5)
+#define K3_VTM_TMPSENS_CTRL_CLRZ		BIT(6)
+#define K3_VTM_TMPSENS_CTRL_CLKON_REQ	BIT(7)
+
+#define K3_VTM_ADC_BEGIN_VAL		540
+#define K3_VTM_ADC_END_VAL		944
+
+static const int k3_adc_to_temp[K3_VTM_ADC_END_VAL - K3_VTM_ADC_BEGIN_VAL
+				+ 1] = {
+	-40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200,
+	-37800, -37400, -37000, -36600, -36200, -35800, -35300, -34700, -34200,
+	-33800, -33400, -33000, -32600, -32200, -31800, -31400, -31000, -30600,
+	-30200, -29800, -29400, -29000, -28600, -28200, -27700, -27100, -26600,
+	-26200, -25800, -25400, -25000, -24600, -24200, -23800, -23400, -23000,
+	-22600, -22200, -21800, -21400, -21000, -20500, -19900, -19400, -19000,
+	-18600, -18200, -17800, -17400, -17000, -16600, -16200, -15800, -15400,
+	-15000, -14600, -14200, -13800, -13400, -13000, -12500, -11900, -11400,
+	-11000, -10600, -10200, -9800, -9400, -9000, -8600, -8200, -7800, -7400,
+	-7000, -6600, -6200, -5800, -5400, -5000, -4500, -3900, -3400, -3000,
+	-2600, -2200, -1800, -1400, -1000, -600, -200, 200, 600, 1000, 1400,
+	1800, 2200, 2600, 3000, 3400, 3900, 4500, 5000, 5400, 5800, 6200, 6600,
+	7000, 7400, 7800, 8200, 8600, 9000, 9400, 9800, 10200, 10600, 11000,
+	11400, 11800, 12200, 12700, 13300, 13800, 14200, 14600, 15000, 15400,
+	15800, 16200, 16600, 17000, 17400, 17800, 18200, 18600, 19000, 19400,
+	19800, 20200, 20600, 21000, 21400, 21900, 22500, 23000, 23400, 23800,
+	24200, 24600, 25000, 25400, 25800, 26200, 26600, 27000, 27400, 27800,
+	28200, 28600, 29000, 29400, 29800, 30200, 30600, 31000, 31400, 31900,
+	32500, 33000, 33400, 33800, 34200, 34600, 35000, 35400, 35800, 36200,
+	36600, 37000, 37400, 37800, 38200, 38600, 39000, 39400, 39800, 40200,
+	40600, 41000, 41400, 41800, 42200, 42600, 43100, 43700, 44200, 44600,
+	45000, 45400, 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600,
+	49000, 49400, 49800, 50200, 50600, 51000, 51400, 51800, 52200, 52600,
+	53000, 53400, 53800, 54200, 54600, 55000, 55400, 55900, 56500, 57000,
+	57400, 57800, 58200, 58600, 59000, 59400, 59800, 60200, 60600, 61000,
+	61400, 61800, 62200, 62600, 63000, 63400, 63800, 64200, 64600, 65000,
+	65400, 65800, 66200, 66600, 67000, 67400, 67800, 68200, 68600, 69000,
+	69400, 69800, 70200, 70600, 71000, 71500, 72100, 72600, 73000, 73400,
+	73800, 74200, 74600, 75000, 75400, 75800, 76200, 76600, 77000, 77400,
+	77800, 78200, 78600, 79000, 79400, 79800, 80200, 80600, 81000, 81400,
+	81800, 82200, 82600, 83000, 83400, 83800, 84200, 84600, 85000, 85400,
+	85800, 86200, 86600, 87000, 87400, 87800, 88200, 88600, 89000, 89400,
+	89800, 90200, 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400,
+	93800, 94200, 94600, 95000, 95400, 95800, 96200, 96600, 97000, 97500,
+	98100, 98600, 99000, 99400, 99800, 100200, 100600, 101000, 101400,
+	101800, 102200, 102600, 103000, 103400, 103800, 104200, 104600, 105000,
+	105400, 105800, 106200, 106600, 107000, 107400, 107800, 108200, 108600,
+	109000, 109400, 109800, 110200, 110600, 111000, 111400, 111800, 112200,
+	112600, 113000, 113400, 113800, 114200, 114600, 115000, 115400, 115800,
+	116200, 116600, 117000, 117400, 117800, 118200, 118600, 119000, 119400,
+	119800, 120200, 120600, 121000, 121400, 121800, 122200, 122600, 123000,
+	123400, 123800, 124200, 124600, 124900, 125000,
+};
+
+struct k3_thermal_data;
+
+struct k3_bandgap {
+	struct device *dev;
+	void __iomem *base;
+	const struct k3_bandgap_data *conf;
+	spinlock_t lock; /* shields this struct */
+	int ts_cnt;
+	u32 errata;
+	struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
+};
+
+struct k3_vtm_driver_data {
+	u32 errata;
+};
+
+/* common data structures */
+struct k3_thermal_data {
+	struct thermal_zone_device *ti_thermal;
+	struct thermal_cooling_device *cool_dev;
+	struct k3_bandgap *bgp;
+	enum thermal_device_mode mode;
+	struct work_struct thermal_wq;
+	int sensor_id;
+	u32 ctrl_offset;
+	u32 stat_offset;
+	int prev_temp;
+};
+
+static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
+				       unsigned int s2)
+{
+	int d01 = abs(s0 - s1);
+	int d02 = abs(s0 - s2);
+	int d12 = abs(s1 - s2);
+
+	if (d01 <= d02 && d01 <= d12)
+		return (s0 + s1) / 2;
+
+	if (d02 <= d01 && d02 <= d12)
+		return (s0 + s2) / 2;
+
+	return (s1 + s2) / 2;
+}
+
+static int k3_bgp_read_temp(struct k3_thermal_data *devdata,
+			    int *temp)
+{
+	struct k3_bandgap *bgp;
+	unsigned int dtemp, s0, s1, s2;
+
+	bgp = devdata->bgp;
+	/**
+	 * Errata is applicable for am654 pg 1.0 silicon. There
+	 * is a variation of the order for 8-10 degree centigrade.
+	 * Work around that by getting the average of two closest
+	 * readings out of three readings everytime we want to
+	 * report temperatures.
+	 *
+	 * Errata workaround.
+	 */
+
+	if (bgp->errata) {
+		s0 = readl(bgp->base + devdata->stat_offset) &
+			K3_VTM_TS_STAT_DTEMP_MASK;
+		s1 = readl(bgp->base + devdata->stat_offset) &
+			K3_VTM_TS_STAT_DTEMP_MASK;
+		s2 = readl(bgp->base + devdata->stat_offset) &
+			K3_VTM_TS_STAT_DTEMP_MASK;
+		dtemp = vtm_get_best_value(s0, s1, s2);
+	} else {
+		dtemp = readl(bgp->base + devdata->stat_offset) &
+				K3_VTM_TS_STAT_DTEMP_MASK;
+	}
+
+	if (dtemp < K3_VTM_ADC_BEGIN_VAL || dtemp > K3_VTM_ADC_END_VAL)
+		return -EINVAL;
+
+	*temp = k3_adc_to_temp[dtemp - K3_VTM_ADC_BEGIN_VAL];
+
+	return 0;
+}
+
+/* thermal zone ops */
+/* Get temperature callback function for thermal zone */
+static int k3_thermal_get_temp(void *devdata, int *temp)
+{
+	struct k3_thermal_data *data = devdata;
+	int ret = 0;
+
+	ret = k3_bgp_read_temp(data, temp);
+	if (ret)
+		return ret;
+
+	data->prev_temp = *temp;
+
+	return ret;
+}
+
+static int k3_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
+{
+	struct k3_thermal_data *data = p;
+	struct k3_bandgap *bgp;
+	int ret = 0, temp = 0;
+
+	bgp = data->bgp;
+
+	ret = k3_bgp_read_temp(data, &temp);
+	if (ret)
+		return ret;
+
+	if (temp > data->prev_temp)
+		*trend = THERMAL_TREND_RAISING;
+	else if (temp < data->prev_temp)
+		*trend = THERMAL_TREND_DROPPING;
+	else
+		*trend = THERMAL_TREND_STABLE;
+
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
+	.get_temp = k3_thermal_get_temp,
+	.get_trend = k3_thermal_get_trend,
+};
+
+static void k3_thermal_work(struct work_struct *work)
+{
+	struct k3_thermal_data *data = container_of(work,
+					struct k3_thermal_data, thermal_wq);
+
+	thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
+
+	dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
+		data->ti_thermal->type);
+}
+
+static const struct of_device_id of_k3_bandgap_match[];
+
+static int k3_bandgap_probe(struct platform_device *pdev)
+{
+	int ret = 0, cnt, val, id, reg_cnt = 0;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct k3_bandgap *bgp;
+	struct k3_thermal_data *data;
+	const struct k3_vtm_driver_data *drv_data;
+
+	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
+	if (!bgp)
+		return -ENOMEM;
+
+	drv_data = of_device_get_match_data(&pdev->dev);
+	if (drv_data)
+		bgp->errata = drv_data->errata;
+
+	bgp->dev = dev;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bgp->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(bgp->base))
+		return PTR_ERR(bgp->base);
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		pm_runtime_disable(dev);
+		return ret;
+	}
+
+	/* Get the sensor count in the VTM */
+	val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
+	cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
+	cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
+	bgp->ts_cnt = cnt;
+
+	data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	/* Register the thermal sensors */
+	for (id = 0; id < cnt; id++) {
+		data[id].sensor_id = id;
+		data[id].bgp = bgp;
+		data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET +
+					id * K3_VTM_REGS_PER_TS;
+		data[id].stat_offset = data[id].ctrl_offset + 0x8;
+		INIT_WORK(&data[id].thermal_wq, k3_thermal_work);
+
+		val = readl(data[id].bgp->base + data[id].ctrl_offset);
+		val |= (K3_VTM_TMPSENS_CTRL_SOC |
+			K3_VTM_TMPSENS_CTRL_CLRZ |
+			K3_VTM_TMPSENS_CTRL_CLKON_REQ);
+		val &= ~K3_VTM_TMPSENS_CTRL_CBIASSEL;
+		writel(val, data[id].bgp->base + data[id].ctrl_offset);
+
+		bgp->ts_data[id] = &data[id];
+		data[id].ti_thermal =
+		devm_thermal_zone_of_sensor_register(bgp->dev, id,
+						     &data[id],
+						     &k3_of_thermal_ops);
+		if (IS_ERR(data[id].ti_thermal)) {
+			dev_err(bgp->dev, "thermal zone device is NULL\n");
+			ret = PTR_ERR(data[id].ti_thermal);
+			goto err_alloc;
+		}
+
+		reg_cnt++;
+
+		/* Initialize Previous temp */
+		k3_thermal_get_temp(&data[id], &data[id].prev_temp);
+	}
+
+	platform_set_drvdata(pdev, bgp);
+
+	return 0;
+
+err_alloc:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int k3_bandgap_remove(struct platform_device *pdev)
+{
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct k3_vtm_driver_data am654_data = {
+	.errata = 1,
+};
+
+static const struct of_device_id of_k3_bandgap_match[] = {
+	{
+		.compatible = "ti,am654-vtm",
+		.data = &am654_data,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, of_k3_bandgap_match);
+
+static struct platform_driver k3_bandgap_sensor_driver = {
+	.probe = k3_bandgap_probe,
+	.remove = k3_bandgap_remove,
+	.driver = {
+		.name = "k3-soc-thermal",
+		.of_match_table	= of_k3_bandgap_match,
+	},
+};
+
+module_platform_driver(k3_bandgap_sensor_driver);
+
+MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
-- 
2.17.1

[PATCH v3 3/4] arm64: dts: ti: am654: Add thermal zones

[Keerthy]

The am654 SoC has three thermal zones namely MPU0, MPU1 and MCU
zones

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 .../dts/ti/k3-am654-industrial-thermal.dtsi   | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 arch/arm64/boot/dts/ti/k3-am654-industrial-thermal.dtsi

diff --git a/arch/arm64/boot/dts/ti/k3-am654-industrial-thermal.dtsi b/arch/arm64/boot/dts/ti/k3-am654-industrial-thermal.dtsi
new file mode 100644
index 000000000000..cdc3d40c3f60
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am654-industrial-thermal.dtsi
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <dt-bindings/thermal/thermal.h>
+
+mpu0_thermal: mpu0_thermal {
+	polling-delay-passive = <250>; /* milliseconds */
+	polling-delay = <500>; /* milliseconds */
+	thermal-sensors = <&wkup_vtm0 0>;
+
+	trips {
+		mpu0_crit: mpu0_crit {
+			temperature = <125000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = "critical";
+		};
+	};
+};
+
+mpu1_thermal: mpu1_thermal {
+	polling-delay-passive = <250>; /* milliseconds */
+	polling-delay = <500>; /* milliseconds */
+	thermal-sensors = <&wkup_vtm0 1>;
+
+	trips {
+		mpu1_crit: mpu1_crit {
+			temperature = <125000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = "critical";
+		};
+	};
+};
+
+mcu_thermal: mcu_thermal {
+	polling-delay-passive = <250>; /* milliseconds */
+	polling-delay = <500>; /* milliseconds */
+	thermal-sensors = <&wkup_vtm0 2>;
+
+	trips {
+		mcu_crit: mcu_crit {
+			temperature = <125000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = "critical";
+		};
+	};
+};
-- 
2.17.1

[PATCH v3 4/4] arm64: dts: ti: am6: Add VTM node

[Keerthy]

VTM stands for voltage and thermal management. Add the vtm node and
the associated thermal zones on the SoC.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi
index f4227e2743f2..e7ef96b621b3 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-wakeup.dtsi
@@ -89,4 +89,15 @@
 		clocks = <&k3_clks 59 0>;
 		clock-names = "gpio";
 	};
+
+	wkup_vtm0: wkup_vtm0@42050000 {
+		compatible = "ti,am654-vtm";
+		reg = <0x42050000 0x25c>;
+		power-domains = <&k3_pds 80 TI_SCI_PD_EXCLUSIVE>;
+		#thermal-sensor-cells = <1>;
+	};
+
+	thermal_zones: thermal-zones {
+		#include "k3-am654-industrial-thermal.dtsi"
+	};
 };
-- 
2.17.1

Re: [PATCH v3 2/4] thermal: k3: Add support for bandgap sensors

[Randy Dunlap]

On 2/18/20 11:43 PM, Keerthy wrote:
> The bandgap provides current and voltage reference for its internal
> circuits and other analog IP blocks. The analog-to-digital
> converter (ADC) produces an output value that is proportional
> to the silicon temperature.
> 
> Currently reading temperatures and trend computing is supported
> as there are no active/passive cooling agent supported.
> 
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
>  drivers/thermal/Kconfig      |  12 ++
>  drivers/thermal/Makefile     |   1 +
>  drivers/thermal/k3_bandgap.c | 342 +++++++++++++++++++++++++++++++++++
>  3 files changed, 355 insertions(+)
>  create mode 100644 drivers/thermal/k3_bandgap.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 5a05db5438d6..fa598eddc7ac 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -251,6 +251,18 @@ config IMX_THERMAL
>  	  cpufreq is used as the cooling device to throttle CPUs when the
>  	  passive trip is crossed.
>  
> +config K3_THERMAL
> +	bool "Texas Instruments K3 thermal support"

Hi,
Why is this bool and not tristate?

> +	depends on THERMAL
> +	depends on ARCH_K3 || COMPILE_TEST
> +	help
> +	  If you say yes here you get thermal support for the Texas Instruments
> +	  K3 SoC family. The current chip supported is:
> +	   - AM654
> +
> +	  This includes temperature reading functionality and also trend
> +	  computation.
> +
>  config MAX77620_THERMAL
>  	tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
>  	depends on MFD_MAX77620

> diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c
> new file mode 100644
> index 000000000000..35d904eb9857
> --- /dev/null
> +++ b/drivers/thermal/k3_bandgap.c
> @@ -0,0 +1,342 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TI Bandgap temperature sensor driver for K3 SoC Family
> + *
> + * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
> + */

> +static int k3_bgp_read_temp(struct k3_thermal_data *devdata,
> +			    int *temp)
> +{
> +	struct k3_bandgap *bgp;
> +	unsigned int dtemp, s0, s1, s2;
> +
> +	bgp = devdata->bgp;
> +	/**

"/**" is used to indicate kernel-doc notation in the Linux kernel source files,
but this comment is not kernel-doc notation, so please just use "/*".

> +	 * Errata is applicable for am654 pg 1.0 silicon. There
> +	 * is a variation of the order for 8-10 degree centigrade.
> +	 * Work around that by getting the average of two closest
> +	 * readings out of three readings everytime we want to
> +	 * report temperatures.
> +	 *
> +	 * Errata workaround.
> +	 */
thanks.
-- 
~Randy

Re: [PATCH v3 2/4] thermal: k3: Add support for bandgap sensors

[Keerthy]

On 19/02/20 1:20 pm, Randy Dunlap wrote:
> On 2/18/20 11:43 PM, Keerthy wrote:
>> The bandgap provides current and voltage reference for its internal
>> circuits and other analog IP blocks. The analog-to-digital
>> converter (ADC) produces an output value that is proportional
>> to the silicon temperature.
>>
>> Currently reading temperatures and trend computing is supported
>> as there are no active/passive cooling agent supported.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> ---
>>   drivers/thermal/Kconfig      |  12 ++
>>   drivers/thermal/Makefile     |   1 +
>>   drivers/thermal/k3_bandgap.c | 342 +++++++++++++++++++++++++++++++++++
>>   3 files changed, 355 insertions(+)
>>   create mode 100644 drivers/thermal/k3_bandgap.c
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index 5a05db5438d6..fa598eddc7ac 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -251,6 +251,18 @@ config IMX_THERMAL
>>   	  cpufreq is used as the cooling device to throttle CPUs when the
>>   	  passive trip is crossed.
>>   
>> +config K3_THERMAL
>> +	bool "Texas Instruments K3 thermal support"
> 
> Hi,
> Why is this bool and not tristate?

Definitely can work as tristate. I will fix it next version.

> 
>> +	depends on THERMAL
>> +	depends on ARCH_K3 || COMPILE_TEST
>> +	help
>> +	  If you say yes here you get thermal support for the Texas Instruments
>> +	  K3 SoC family. The current chip supported is:
>> +	   - AM654
>> +
>> +	  This includes temperature reading functionality and also trend
>> +	  computation.
>> +
>>   config MAX77620_THERMAL
>>   	tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
>>   	depends on MFD_MAX77620
> 
>> diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c
>> new file mode 100644
>> index 000000000000..35d904eb9857
>> --- /dev/null
>> +++ b/drivers/thermal/k3_bandgap.c
>> @@ -0,0 +1,342 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * TI Bandgap temperature sensor driver for K3 SoC Family
>> + *
>> + * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
>> + */
> 
>> +static int k3_bgp_read_temp(struct k3_thermal_data *devdata,
>> +			    int *temp)
>> +{
>> +	struct k3_bandgap *bgp;
>> +	unsigned int dtemp, s0, s1, s2;
>> +
>> +	bgp = devdata->bgp;
>> +	/**
> 
> "/**" is used to indicate kernel-doc notation in the Linux kernel source files,
> but this comment is not kernel-doc notation, so please just use "/*".

Okay

> 
>> +	 * Errata is applicable for am654 pg 1.0 silicon. There
>> +	 * is a variation of the order for 8-10 degree centigrade.
>> +	 * Work around that by getting the average of two closest
>> +	 * readings out of three readings everytime we want to
>> +	 * report temperatures.
>> +	 *
>> +	 * Errata workaround.
>> +	 */
> thanks.

Thanks for the review.

- Keerthy
> 

Re: [PATCH v3 1/4] dt-bindings: thermal: k3: Add VTM bindings documentation

[Rob Herring]

On Wed, Feb 19, 2020 at 01:13:11PM +0530, Keerthy wrote:
> Add VTM bindings documentation. In the Voltage Thermal
> Management Module(VTM), K3 AM654 supplies a voltage
> reference and a temperature sensor feature that are gathered in the band
> gap voltage and temperature sensor (VBGAPTS) module. The band
> gap provides current and voltage reference for its internal
> circuits and other analog IP blocks. The analog-to-digital
> converter (ADC) produces an output value that is proportional
> to the silicon temperature.
> 
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
> 
> Changes in v3:
> 
>   * Fixed errors seen with:
>     dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> 
>  .../bindings/thermal/ti,am654-thermal.yaml    | 57 +++++++++++++++++++
>  1 file changed, 57 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> 
> diff --git a/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> new file mode 100644
> index 000000000000..b6dc95c3acab
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> @@ -0,0 +1,57 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/thermal/ti,am654-thermal.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments AM654 VTM (DTS) binding
> +
> +maintainers:
> +  - Keerthy <j-keerthy@ti.com>
> +
> +properties:
> +  compatible:
> +    const: ti,am654-vtm
> +
> +  reg:
> +    maxItems: 1
> +
> +  power-domains:
> +    maxItems: 1
> +    description: phandle to the associated power domain

No need to redefine a standard property description.

> +
> +  "#thermal-sensor-cells":
> +    const: 1
> +
> +required:
> +  - "#thermal-sensor-cells"
> +  - compatible
> +  - reg
> +  - power-domains
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/soc/ti,sci_pm_domain.h>
> +    vtm: wkup_vtm0@42050000 {

thermal-sensor@...

Use generic node names and don't use '_' in node names.

> +        compatible = "ti,am654-vtm";
> +        reg = <0x0 0x42050000 0x0 0x25c>;
> +        power-domains = <&k3_pds 80 TI_SCI_PD_EXCLUSIVE>;
> +        #thermal-sensor-cells = <1>;
> +    };
> +
> +    mpu0_thermal: mpu0_thermal {
> +        polling-delay-passive = <250>; /* milliseconds */
> +        polling-delay = <500>; /* milliseconds */
> +        thermal-sensors = <&vtm0 0>;
> +
> +        trips {
> +                mpu0_crit: mpu0_crit {
> +                        temperature = <125000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = "critical";
> +                };
> +        };
> +    };
> +...
> -- 
> 2.17.1
> 

Re: [PATCH v3 1/4] dt-bindings: thermal: k3: Add VTM bindings documentation

[Keerthy]

On 19/02/20 8:22 pm, Rob Herring wrote:
> On Wed, Feb 19, 2020 at 01:13:11PM +0530, Keerthy wrote:
>> Add VTM bindings documentation. In the Voltage Thermal
>> Management Module(VTM), K3 AM654 supplies a voltage
>> reference and a temperature sensor feature that are gathered in the band
>> gap voltage and temperature sensor (VBGAPTS) module. The band
>> gap provides current and voltage reference for its internal
>> circuits and other analog IP blocks. The analog-to-digital
>> converter (ADC) produces an output value that is proportional
>> to the silicon temperature.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> ---
>>
>> Changes in v3:
>>
>>    * Fixed errors seen with:
>>      dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>
>>   .../bindings/thermal/ti,am654-thermal.yaml    | 57 +++++++++++++++++++
>>   1 file changed, 57 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>> new file mode 100644
>> index 000000000000..b6dc95c3acab
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>> @@ -0,0 +1,57 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/thermal/ti,am654-thermal.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Texas Instruments AM654 VTM (DTS) binding
>> +
>> +maintainers:
>> +  - Keerthy <j-keerthy@ti.com>
>> +
>> +properties:
>> +  compatible:
>> +    const: ti,am654-vtm
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  power-domains:
>> +    maxItems: 1
>> +    description: phandle to the associated power domain
> 
> No need to redefine a standard property description.

Okay.

> 
>> +
>> +  "#thermal-sensor-cells":
>> +    const: 1
>> +
>> +required:
>> +  - "#thermal-sensor-cells"
>> +  - compatible
>> +  - reg
>> +  - power-domains
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/soc/ti,sci_pm_domain.h>
>> +    vtm: wkup_vtm0@42050000 {
> 
> thermal-sensor@...
> 
> Use generic node names and don't use '_' in node names

vtm stands for voltage thermal manager and comprises of multiple 
sensors. This is similar to omap bandgap. Should i replace vtm with more 
generic name like thermal? as used in:

Documentation/devicetree/bindings/thermal/st,stm32-thermal.yaml

- Keerthy

> 
>> +        compatible = "ti,am654-vtm";
>> +        reg = <0x0 0x42050000 0x0 0x25c>;
>> +        power-domains = <&k3_pds 80 TI_SCI_PD_EXCLUSIVE>;
>> +        #thermal-sensor-cells = <1>;
>> +    };
>> +
>> +    mpu0_thermal: mpu0_thermal {
>> +        polling-delay-passive = <250>; /* milliseconds */
>> +        polling-delay = <500>; /* milliseconds */
>> +        thermal-sensors = <&vtm0 0>;
>> +
>> +        trips {
>> +                mpu0_crit: mpu0_crit {
>> +                        temperature = <125000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = "critical";
>> +                };
>> +        };
>> +    };
>> +...
>> -- 
>> 2.17.1
>>

Re: [PATCH v3 1/4] dt-bindings: thermal: k3: Add VTM bindings documentation

[Rob Herring]

On Wed, Feb 19, 2020 at 10:13 PM Keerthy <j-keerthy@ti.com> wrote:
>
>
>
> On 19/02/20 8:22 pm, Rob Herring wrote:
> > On Wed, Feb 19, 2020 at 01:13:11PM +0530, Keerthy wrote:
> >> Add VTM bindings documentation. In the Voltage Thermal
> >> Management Module(VTM), K3 AM654 supplies a voltage
> >> reference and a temperature sensor feature that are gathered in the band
> >> gap voltage and temperature sensor (VBGAPTS) module. The band
> >> gap provides current and voltage reference for its internal
> >> circuits and other analog IP blocks. The analog-to-digital
> >> converter (ADC) produces an output value that is proportional
> >> to the silicon temperature.
> >>
> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> >> ---
> >>
> >> Changes in v3:
> >>
> >>    * Fixed errors seen with:
> >>      dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> >>
> >>   .../bindings/thermal/ti,am654-thermal.yaml    | 57 +++++++++++++++++++
> >>   1 file changed, 57 insertions(+)
> >>   create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> >>
> >> diff --git a/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> >> new file mode 100644
> >> index 000000000000..b6dc95c3acab
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
> >> @@ -0,0 +1,57 @@
> >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >> +%YAML 1.2
> >> +---
> >> +$id: http://devicetree.org/schemas/thermal/ti,am654-thermal.yaml#
> >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >> +
> >> +title: Texas Instruments AM654 VTM (DTS) binding
> >> +
> >> +maintainers:
> >> +  - Keerthy <j-keerthy@ti.com>
> >> +
> >> +properties:
> >> +  compatible:
> >> +    const: ti,am654-vtm
> >> +
> >> +  reg:
> >> +    maxItems: 1
> >> +
> >> +  power-domains:
> >> +    maxItems: 1
> >> +    description: phandle to the associated power domain
> >
> > No need to redefine a standard property description.
>
> Okay.
>
> >
> >> +
> >> +  "#thermal-sensor-cells":
> >> +    const: 1
> >> +
> >> +required:
> >> +  - "#thermal-sensor-cells"
> >> +  - compatible
> >> +  - reg
> >> +  - power-domains
> >> +
> >> +additionalProperties: false
> >> +
> >> +examples:
> >> +  - |
> >> +    #include <dt-bindings/soc/ti,sci_pm_domain.h>
> >> +    vtm: wkup_vtm0@42050000 {
> >
> > thermal-sensor@...
> >
> > Use generic node names and don't use '_' in node names
>
> vtm stands for voltage thermal manager and comprises of multiple
> sensors. This is similar to omap bandgap. Should i replace vtm with more
> generic name like thermal? as used in:

'vtm' is a label and source construct only (until you do overlays), so
I don't care what you put really.

Rob

Re: [PATCH v3 1/4] dt-bindings: thermal: k3: Add VTM bindings documentation

[J, KEERTHY]

On 2/21/2020 1:10 AM, Rob Herring wrote:
> On Wed, Feb 19, 2020 at 10:13 PM Keerthy <j-keerthy@ti.com> wrote:
>>
>>
>>
>> On 19/02/20 8:22 pm, Rob Herring wrote:
>>> On Wed, Feb 19, 2020 at 01:13:11PM +0530, Keerthy wrote:
>>>> Add VTM bindings documentation. In the Voltage Thermal
>>>> Management Module(VTM), K3 AM654 supplies a voltage
>>>> reference and a temperature sensor feature that are gathered in the band
>>>> gap voltage and temperature sensor (VBGAPTS) module. The band
>>>> gap provides current and voltage reference for its internal
>>>> circuits and other analog IP blocks. The analog-to-digital
>>>> converter (ADC) produces an output value that is proportional
>>>> to the silicon temperature.
>>>>
>>>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>>>> ---
>>>>
>>>> Changes in v3:
>>>>
>>>>     * Fixed errors seen with:
>>>>       dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>>>
>>>>    .../bindings/thermal/ti,am654-thermal.yaml    | 57 +++++++++++++++++++
>>>>    1 file changed, 57 insertions(+)
>>>>    create mode 100644 Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>>> new file mode 100644
>>>> index 000000000000..b6dc95c3acab
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/thermal/ti,am654-thermal.yaml
>>>> @@ -0,0 +1,57 @@
>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/thermal/ti,am654-thermal.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: Texas Instruments AM654 VTM (DTS) binding
>>>> +
>>>> +maintainers:
>>>> +  - Keerthy <j-keerthy@ti.com>
>>>> +
>>>> +properties:
>>>> +  compatible:
>>>> +    const: ti,am654-vtm
>>>> +
>>>> +  reg:
>>>> +    maxItems: 1
>>>> +
>>>> +  power-domains:
>>>> +    maxItems: 1
>>>> +    description: phandle to the associated power domain
>>>
>>> No need to redefine a standard property description.
>>
>> Okay.
>>
>>>
>>>> +
>>>> +  "#thermal-sensor-cells":
>>>> +    const: 1
>>>> +
>>>> +required:
>>>> +  - "#thermal-sensor-cells"
>>>> +  - compatible
>>>> +  - reg
>>>> +  - power-domains
>>>> +
>>>> +additionalProperties: false
>>>> +
>>>> +examples:
>>>> +  - |
>>>> +    #include <dt-bindings/soc/ti,sci_pm_domain.h>
>>>> +    vtm: wkup_vtm0@42050000 {
>>>
>>> thermal-sensor@...
>>>
>>> Use generic node names and don't use '_' in node names
>>
>> vtm stands for voltage thermal manager and comprises of multiple
>> sensors. This is similar to omap bandgap. Should i replace vtm with more
>> generic name like thermal? as used in:
> 
> 'vtm' is a label and source construct only (until you do overlays), so
> I don't care what you put really.

Okay.

I will change in to:

vtm: thermal@42050000 {

Regards,
Keerthy

> 
> Rob
>