[PATCH V6 0/6] thermal: bcm2835: add thermal driver

[PATCH V6 0/6] thermal: bcm2835: add thermal driver

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add a thermal driver for the TSENSE device of the bcm2835/6/7 SOC.

If the firmware enables the HW, then the configuration is not touched.
In case the firmware has not enabled the device, then we try to set
it up correctly (which unfortunately can not get tested).

It exposes temperature and a critical trip point
(using a hardcoded default of 80C or the temperature configured
in the control register by the firmware, which reads as
407C currently)

The calibrations are (potentially) different for bcm2835, bcm2836
and bcm2837 and can get selected by the compatible property
in the device tree.

The driver also exposes the registers via debugfs.

Possible future enhancements:
* the device has the ability to trigger interrupts on reaching
  the programmed critical temperature.
  I have no knowledge which interrupt could be responsible
  for this on the ARM side, so if we get to know which irq
  it is we can implement that.
  Instead the driver right now implements polling in 1 second intervals
* the device can also reset the HW after the trip point
  has been reached (also with some delay, so that corrective
  actions can get taken) - this is currently not enabled by the
  firmware, but could.
* we could define more trip points for THERMAL_TRIP_HOT
* make the trip point limits modifiable (ops.set_trip_temp)

Note:
  No support for 32-bit arm bcm2837, as there is no
  arch/arm/boot/dts/bcm2836.dtsi upstream as of now.
  64-bit arm support is not tested

Changelog:
 V1 -> V2: renamed dt-binding documentation file
       	   added specific settings depending on compatible
	   added trip point based on register
	   setting up ctrl-register if HW is not enabled by firmware
	     as per recommendation of Eric (untested)
	   check that clock frequency is in range
	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
 	   added driver to multi_v7_defconfig
 V2 -> V3: made a module in multi_v7_defconfig
           fixed typo in dt-binding document
 V3 -> V4: moved driver back to thermal (not using bcm sub-directory)
       	   set polling interval to 1second (was 0ms, so interrupt driven)
 V4 -> V5: use correct compatiblity for different soc versions in dt
       	   support ARM64 for bcm2837 in devicetree and defconfig
 V5 -> V6: incorporated changes recommended by Stefan Wahren

Martin Sperl (6):
  dt: bindings: add thermal device driver for bcm2835
  thermal: bcm2835: add thermal driver for bcm2835 soc
  ARM: bcm2835: dts: add thermal node to device-tree of bcm283x
  ARM64: bcm2835: dts: add thermal node to device-tree of bcm2837
  ARM: bcm2835: add thermal driver to default_config
  ARM64: bcm2835: add thermal driver to default_config

 .../bindings/thermal/brcm,bcm2835-thermal.txt      |  17 ++
 arch/arm/boot/dts/bcm2835.dtsi                     |   6 +
 arch/arm/boot/dts/bcm2836.dtsi                     |   6 +
 arch/arm/boot/dts/bcm283x.dtsi                     |   7 +
 arch/arm/configs/bcm2835_defconfig                 |   2 +
 arch/arm64/boot/dts/broadcom/bcm2837.dtsi          |   6 +
 arch/arm64/configs/defconfig                       |   1 +
 drivers/thermal/Kconfig                            |   8 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/bcm2835_thermal.c                  | 340 +++++++++++++++++++++
 10 files changed, 394 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
 create mode 100644 drivers/thermal/bcm2835_thermal.c

--
2.1.4

[PATCH V6 1/6] dt: bindings: add thermal device driver for bcm2835

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add dt-binding documentation for bcm2835 SOC thermal sensor.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>

Changelog:
 V1 -> V2: renamed file to follow naming conventions
 V2 -> V3: removed 0x in node name
---
 .../bindings/thermal/brcm,bcm2835-thermal.txt           | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt

diff --git a/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt b/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
new file mode 100644
index 0000000..474531d
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
@@ -0,0 +1,17 @@
+Binding for Thermal Sensor driver for BCM2835 SoCs.
+
+Required parameters:
+-------------------
+
+compatible: 	should be one of: "brcm,bcm2835-thermal",
+		"brcm,bcm2836-thermal" or "brcm,bcm2837-thermal"
+reg:		Address range of the thermal registers.
+clocks: 	Phandle of the clock used by the thermal sensor.
+
+Example:
+
+thermal: thermal@7e212000 {
+	compatible = "brcm,bcm2835-thermal";
+	reg = <0x7e212000 0x8>;
+	clocks = <&clocks BCM2835_CLOCK_TSENS>;
+};
-- 
2.1.4

[PATCH V6 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add basic thermal driver for bcm2835 SOC.

This driver currently relies on the firmware setting up the
tsense HW block and does not set it up itself.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Eric Anholt <eric@anholt.net>

ChangeLog:
 V1 -> V2: added specific settings depending on compatiblity
	   added trip point based on register
	   setting up ctrl-register if HW is not enabled by firmware
	     as per recommendation of Eric (untested)
	   check that clock frequency is in range
	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
 V2 -> V4: moved back to thermal (not using bcm sub-directory)
       	   set polling interval to 1second (was 0ms, so interrupt driven)
 V5 -> V6: added correct depends in KConfig
	   removed defined default for RESET_DELAY
	   removed obvious comments
	   clarify HW setup comments if not set up by FW already
	   move clk_prepare_enable to an earlier stage and add error handling
	   clarify warning when TS-clock runs out of recommended range
	   clk_disable_unprepare added in bcm2835_thermal_remove
	   added comment on recommended temperature ranges for SOC
---
 drivers/thermal/Kconfig           |   8 +
 drivers/thermal/Makefile          |   1 +
 drivers/thermal/bcm2835_thermal.c | 340 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 349 insertions(+)
 create mode 100644 drivers/thermal/bcm2835_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2d702ca..6489723 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -399,4 +399,12 @@ config GENERIC_ADC_THERMAL
 	  to this driver. This driver reports the temperature by reading ADC
 	  channel and converts it to temperature based on lookup table.
 
+config BCM2835_THERMAL
+	tristate "Thermal sensors on bcm2835 SoC"
+	depends on ARCH_BCM2835 || ARCH_BCM2836 || ARCH_BCM2837 || COMPILE_TEST
+	depends on OF
+	depends on HAS_IOMEM
+	help
+	  Support for thermal sensors on Broadcom bcm2835 SoCs.
+
 endif
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 10b07c1..c26343e 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -51,3 +51,4 @@ obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra/
 obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
 obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
+obj-$(CONFIG_BCM2835_THERMAL)	+= bcm2835_thermal.o
diff --git a/drivers/thermal/bcm2835_thermal.c b/drivers/thermal/bcm2835_thermal.c
new file mode 100644
index 0000000..3468c7b
--- /dev/null
+++ b/drivers/thermal/bcm2835_thermal.c
@@ -0,0 +1,340 @@
+/*
+ * Driver for Broadcom BCM2835 soc temperature sensor
+ *
+ * Copyright (C) 2016 Martin Sperl
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#define BCM2835_TS_TSENSCTL			0x00
+#define BCM2835_TS_TSENSSTAT			0x04
+
+#define BCM2835_TS_TSENSCTL_PRWDW		BIT(0)
+#define BCM2835_TS_TSENSCTL_RSTB		BIT(1)
+#define BCM2835_TS_TSENSCTL_CTRL_BITS		3
+#define BCM2835_TS_TSENSCTL_CTRL_SHIFT		2
+#define BCM2835_TS_TSENSCTL_CTRL_MASK		    \
+	GENMASK(BCM2835_TS_TSENSCTL_CTRL_BITS +     \
+		BCM2835_TS_TSENSCTL_CTRL_SHIFT - 1, \
+		BCM2835_TS_TSENSCTL_CTRL_SHIFT)
+#define BCM2835_TS_TSENSCTL_CTRL_DEFAULT	1
+#define BCM2835_TS_TSENSCTL_EN_INT		BIT(5)
+#define BCM2835_TS_TSENSCTL_DIRECT		BIT(6)
+#define BCM2835_TS_TSENSCTL_CLR_INT		BIT(7)
+#define BCM2835_TS_TSENSCTL_THOLD_SHIFT		8
+#define BCM2835_TS_TSENSCTL_THOLD_BITS		10
+#define BCM2835_TS_TSENSCTL_THOLD_MASK		     \
+	GENMASK(BCM2835_TS_TSENSCTL_THOLD_BITS +     \
+		BCM2835_TS_TSENSCTL_THOLD_SHIFT - 1, \
+		BCM2835_TS_TSENSCTL_THOLD_SHIFT)
+#define BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT	18
+#define BCM2835_TS_TSENSCTL_RSTDELAY_BITS	8
+#define BCM2835_TS_TSENSCTL_REGULEN		BIT(26)
+
+#define BCM2835_TS_TSENSSTAT_DATA_BITS		10
+#define BCM2835_TS_TSENSSTAT_DATA_SHIFT		0
+#define BCM2835_TS_TSENSSTAT_DATA_MASK		     \
+	GENMASK(BCM2835_TS_TSENSSTAT_DATA_BITS +     \
+		BCM2835_TS_TSENSSTAT_DATA_SHIFT - 1, \
+		BCM2835_TS_TSENSSTAT_DATA_SHIFT)
+#define BCM2835_TS_TSENSSTAT_VALID		BIT(10)
+#define BCM2835_TS_TSENSSTAT_INTERRUPT		BIT(11)
+
+struct bcm2835_thermal_info {
+	int offset;
+	int slope;
+	int trip_temp;
+};
+
+struct bcm2835_thermal_data {
+	const struct bcm2835_thermal_info *info;
+	void __iomem *regs;
+	struct clk *clk;
+	struct dentry *debugfsdir;
+};
+
+static int bcm2835_thermal_adc2temp(
+	const struct bcm2835_thermal_info *info, u32 adc)
+{
+	return info->offset + (adc * info->slope);
+}
+
+static int bcm2835_thermal_temp2adc(
+	const struct bcm2835_thermal_info *info, int temp)
+{
+	temp -= info->offset;
+	temp /= info->slope;
+
+	if (temp < 0)
+		temp = 0;
+	if (temp >= BIT(BCM2835_TS_TSENSSTAT_DATA_BITS))
+		temp = BIT(BCM2835_TS_TSENSSTAT_DATA_BITS) - 1;
+
+	return temp;
+}
+
+static int bcm2835_thermal_get_trip_type(
+	struct thermal_zone_device *tz, int trip,
+	enum thermal_trip_type *type)
+{
+	*type = THERMAL_TRIP_CRITICAL;
+	return 0;
+}
+
+static int bcm2835_thermal_get_trip_temp(
+	struct thermal_zone_device *tz, int trip, int *temp)
+{
+	struct bcm2835_thermal_data *data = tz->devdata;
+	u32 val = readl(data->regs + BCM2835_TS_TSENSCTL);
+
+	/* get the THOLD bits */
+	val &= BCM2835_TS_TSENSCTL_THOLD_MASK;
+	val >>= BCM2835_TS_TSENSCTL_THOLD_SHIFT;
+
+	/* if it is zero then use the info value */
+	if (val)
+		*temp = bcm2835_thermal_adc2temp(data->info, val);
+	else
+		*temp = data->info->trip_temp;
+
+	return 0;
+}
+
+static int bcm2835_thermal_get_temp(struct thermal_zone_device *tz,
+				    int *temp)
+{
+	struct bcm2835_thermal_data *data = tz->devdata;
+	u32 val = readl(data->regs + BCM2835_TS_TSENSSTAT);
+
+	if (!(val & BCM2835_TS_TSENSSTAT_VALID))
+		return -EIO;
+
+	val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
+
+	*temp = bcm2835_thermal_adc2temp(data->info, val);
+
+	return 0;
+}
+
+static const struct debugfs_reg32 bcm2835_thermal_regs[] = {
+	{
+		.name = "ctl",
+		.offset = 0
+	},
+	{
+		.name = "stat",
+		.offset = 4
+	}
+};
+
+static void bcm2835_thermal_debugfs(struct platform_device *pdev)
+{
+	struct thermal_zone_device *tz = platform_get_drvdata(pdev);
+	struct bcm2835_thermal_data *data = tz->devdata;
+	struct debugfs_regset32 *regset;
+
+	data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL);
+	if (!data->debugfsdir)
+		return;
+
+	regset = devm_kzalloc(&pdev->dev, sizeof(*regset), GFP_KERNEL);
+	if (!regset)
+		return;
+
+	regset->regs = bcm2835_thermal_regs;
+	regset->nregs = ARRAY_SIZE(bcm2835_thermal_regs);
+	regset->base = data->regs;
+
+	debugfs_create_regset32("regset", S_IRUGO,
+				data->debugfsdir, regset);
+}
+
+static struct thermal_zone_device_ops bcm2835_thermal_ops  = {
+	.get_temp = bcm2835_thermal_get_temp,
+	.get_trip_temp = bcm2835_thermal_get_trip_temp,
+	.get_trip_type = bcm2835_thermal_get_trip_type,
+};
+
+static const struct of_device_id bcm2835_thermal_of_match_table[];
+static int bcm2835_thermal_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct thermal_zone_device *tz;
+	struct bcm2835_thermal_data *data;
+	struct resource *res;
+	int err;
+	u32 val;
+	unsigned long rate;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	match = of_match_device(bcm2835_thermal_of_match_table,
+				&pdev->dev);
+	if (!match)
+		return -EINVAL;
+	data->info = match->data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->regs)) {
+		err = PTR_ERR(data->regs);
+		dev_err(&pdev->dev, "Could not get registers: %d\n", err);
+		return err;
+	}
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(data->clk)) {
+		err = PTR_ERR(data->clk);
+		if (err != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Could not get clk: %d\n", err);
+		return err;
+	}
+
+	err = clk_prepare_enable(data->clk);
+	if (err)
+		return err;
+
+	rate = clk_get_rate(data->clk);
+	if ((rate < 1920000) || (rate > 5000000))
+		dev_warn(&pdev->dev,
+			 "Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92 to 5MHz\n",
+			 data->clk, data->clk);
+
+	/*
+	 * right now the FW does set up the HW-block, so we are not
+	 * touching the configuration registers.
+	 * But if the HW is not enabled, then set it up
+	 * using "sane" values used by the firmware right now.
+	 */
+	val = readl(data->regs + BCM2835_TS_TSENSCTL);
+	if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
+		/* the basic required flags */
+		val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
+		       BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
+		      BCM2835_TS_TSENSCTL_REGULEN;
+
+		/*
+		 * reset delay using the current firmware value of 14
+		 * - units of time are unknown.
+		 */
+		val |= (14 << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
+
+		/*  trip_adc value from info */
+		val |= bcm2835_thermal_temp2adc(data->info,
+						data->info->trip_temp) <<
+			BCM2835_TS_TSENSCTL_THOLD_SHIFT;
+
+		/* write the value back to the register as 2 steps */
+		writel(val, data->regs + BCM2835_TS_TSENSCTL);
+		val |= BCM2835_TS_TSENSCTL_RSTB;
+		writel(val, data->regs + BCM2835_TS_TSENSCTL);
+	}
+
+	/* register thermal zone with 1 trip point an 1s polling */
+	tz = thermal_zone_device_register("bcm2835_thermal",
+					  1, 0, data,
+					  &bcm2835_thermal_ops,
+					  NULL,
+					  0, 1000);
+	if (IS_ERR(tz)) {
+		clk_disable_unprepare(data->clk);
+		err = PTR_ERR(tz);
+		dev_err(&pdev->dev,
+			"Failed to register the thermal device: %d\n",
+			err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, tz);
+
+	bcm2835_thermal_debugfs(pdev);
+
+	return 0;
+}
+
+static int bcm2835_thermal_remove(struct platform_device *pdev)
+{
+	struct thermal_zone_device *tz = platform_get_drvdata(pdev);
+	struct bcm2835_thermal_data *data = tz->devdata;
+
+	debugfs_remove_recursive(data->debugfsdir);
+	thermal_zone_device_unregister(tz);
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+/*
+ * Note: as per Raspberry Foundation FAQ
+ * (https://www.raspberrypi.org/help/faqs/#performanceOperatingTemperature)
+ * the recommended temperature range for the SOC -40C to +85C
+ * so the trip limit is set to 80C.
+ * this applies to all the BCM283X SOC
+ */
+
+static const struct of_device_id bcm2835_thermal_of_match_table[] = {
+	{
+		.compatible = "brcm,bcm2835-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			.offset = 407000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{
+		.compatible = "brcm,bcm2836-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			.offset = 407000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{
+		.compatible = "brcm,bcm2837-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			/* the bcm2837 needs adjustment of +5C */
+			.offset = 407000 + 5000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
+
+static struct platform_driver bcm2835_thermal_driver = {
+	.probe = bcm2835_thermal_probe,
+	.remove = bcm2835_thermal_remove,
+	.driver = {
+		.name = "bcm2835_thermal",
+		.of_match_table = bcm2835_thermal_of_match_table,
+	},
+};
+module_platform_driver(bcm2835_thermal_driver);
+
+MODULE_AUTHOR("Martin Sperl");
+MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
+MODULE_LICENSE("GPL");
-- 
2.1.4

[PATCH V6 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x

[kernel-TqfNSX0MhmxHKSADF0wUEw]

From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>

Add the node for the thermal sensor of the bcm2835-soc
to the device tree.

Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
Reviewed-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>
Acked-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>

Changelog:
V1 -> V5: generic settings is shared in bcm283x.dtsi, but disabled
	  moved the compatible string to the SOC specific dtsi
            for arm and arm64
V5 -> V6: removed 0x in node name

---
 arch/arm/boot/dts/bcm2835.dtsi | 6 ++++++
 arch/arm/boot/dts/bcm2836.dtsi | 6 ++++++
 arch/arm/boot/dts/bcm283x.dtsi | 7 +++++++
 3 files changed, 19 insertions(+)

Note: there is no arm/boot/dts/bcm2837.dtsi as of now,
      so the 32-bit rpi3 dt is not modified.

diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi
index a78759e..0890d97 100644
--- a/arch/arm/boot/dts/bcm2835.dtsi
+++ b/arch/arm/boot/dts/bcm2835.dtsi
@@ -23,3 +23,9 @@
 		};
 	};
 };
+
+/* enable thermal sensor with the correct compatible property set */
+&thermal {
+	compatible = "brcm,bcm2835-thermal";
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/bcm2836.dtsi b/arch/arm/boot/dts/bcm2836.dtsi
index 9d0651d..519a44f 100644
--- a/arch/arm/boot/dts/bcm2836.dtsi
+++ b/arch/arm/boot/dts/bcm2836.dtsi
@@ -76,3 +76,9 @@
 	interrupt-parent = <&local_intc>;
 	interrupts = <8>;
 };
+
+/* enable thermal sensor with the correct compatible property set */
+&thermal {
+	compatible = "brcm,bcm2836-thermal";
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index b982522..d9acf21 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -186,6 +186,13 @@
 			interrupts = <2 14>; /* pwa1 */
 		};
 
+		thermal: thermal@7e212000 {
+			compatible = "brcm,bcm2835-thermal";
+			reg = <0x7e212000 0x8>;
+			clocks = <&clocks BCM2835_CLOCK_TSENS>;
+			status = "disabled";
+		};
+
 		aux: aux@0x7e215000 {
 			compatible = "brcm,bcm2835-aux";
 			#clock-cells = <1>;
-- 
2.1.4

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[PATCH V6 4/6] ARM64: bcm2835: dts: add thermal node to device-tree of bcm2837

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add the node for the thermal sensor of the bcm2837-soc
to the device tree.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
 arch/arm64/boot/dts/broadcom/bcm2837.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

Note: untested as I have no 64 bit test system.

diff --git a/arch/arm64/boot/dts/broadcom/bcm2837.dtsi b/arch/arm64/boot/dts/broadcom/bcm2837.dtsi
index f2a31d0..2b0cfc7 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2837.dtsi
+++ b/arch/arm64/boot/dts/broadcom/bcm2837.dtsi
@@ -74,3 +74,9 @@
 	interrupt-parent = <&local_intc>;
 	interrupts = <8>;
 };
+
+/* enable thermal sensor with the correct compatible property set */
+&thermal {
+	compatible = "brcm,bcm2837-thermal";
+	status = "okay";
+};
-- 
2.1.4

[PATCH V6 5/6] ARM: bcm2835: add thermal driver to default_config

[kernel-TqfNSX0MhmxHKSADF0wUEw]

From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>

Add the thermal driver to list of compiled modules
in the default config for bcm2835.

Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
Reviewed-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>
---
 arch/arm/configs/bcm2835_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig
index 79de828..4b89f4e 100644
--- a/arch/arm/configs/bcm2835_defconfig
+++ b/arch/arm/configs/bcm2835_defconfig
@@ -73,6 +73,8 @@ CONFIG_SPI_BCM2835=y
 CONFIG_SPI_BCM2835AUX=y
 CONFIG_GPIO_SYSFS=y
 # CONFIG_HWMON is not set
+CONFIG_THERMAL=y
+CONFIG_BCM2835_THERMAL=y
 CONFIG_WATCHDOG=y
 CONFIG_BCM2835_WDT=y
 CONFIG_DRM=y
-- 
2.1.4

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[PATCH V6 6/6] ARM64: bcm2835: add thermal driver to default_config

[kernel-TqfNSX0MhmxHKSADF0wUEw]

From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>

Add the thermal driver for bcm2837 to list of compiled modules
in the default config.

Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index eadf485..372f981 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -252,6 +252,7 @@ CONFIG_SENSORS_INA2XX=m
 CONFIG_SENSORS_ARM_SCPI=y
 CONFIG_THERMAL=y
 CONFIG_THERMAL_EMULATION=y
+CONFIG_BCM2835_THERMAL=y
 CONFIG_EXYNOS_THERMAL=y
 CONFIG_WATCHDOG=y
 CONFIG_RENESAS_WDT=y
-- 
2.1.4

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Re: [PATCH V6 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc

[Stefan Wahren]

Hi Martin,

> kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org hat am 19. September 2016 um 10:59 geschrieben:
> 
> 
> From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
> 
> Add basic thermal driver for bcm2835 SOC.
> 
> This driver currently relies on the firmware setting up the
> tsense HW block and does not set it up itself.
> 
> Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
> Acked-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>
> 
> ChangeLog:
>  V1 -> V2: added specific settings depending on compatiblity
> 	   added trip point based on register
> 	   setting up ctrl-register if HW is not enabled by firmware
> 	     as per recommendation of Eric (untested)
> 	   check that clock frequency is in range
> 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
>  V2 -> V4: moved back to thermal (not using bcm sub-directory)
>        	   set polling interval to 1second (was 0ms, so interrupt driven)
>  V5 -> V6: added correct depends in KConfig
> 	   removed defined default for RESET_DELAY
> 	   removed obvious comments
> 	   clarify HW setup comments if not set up by FW already
> 	   move clk_prepare_enable to an earlier stage and add error handling
> 	   clarify warning when TS-clock runs out of recommended range
> 	   clk_disable_unprepare added in bcm2835_thermal_remove
> 	   added comment on recommended temperature ranges for SOC
> ---
>  drivers/thermal/Kconfig           |   8 +
>  drivers/thermal/Makefile          |   1 +
>  drivers/thermal/bcm2835_thermal.c | 340
> ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 349 insertions(+)
>  create mode 100644 drivers/thermal/bcm2835_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 2d702ca..6489723 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -399,4 +399,12 @@ config GENERIC_ADC_THERMAL
>  	  to this driver. This driver reports the temperature by reading ADC
>  	  channel and converts it to temperature based on lookup table.
>  
> +config BCM2835_THERMAL
> +	tristate "Thermal sensors on bcm2835 SoC"
> +	depends on ARCH_BCM2835 || ARCH_BCM2836 || ARCH_BCM2837 || COMPILE_TEST

AFAIK there are no ARCH_BCM2836 or ARCH_BCM2837

After fixing that, you can add my ACK.

> +	depends on OF
> +	depends on HAS_IOMEM
> +	help
> +	  Support for thermal sensors on Broadcom bcm2835 SoCs.
> +
> ...
> +
> +static const struct of_device_id bcm2835_thermal_of_match_table[];
> +static int bcm2835_thermal_probe(struct platform_device *pdev)
> +{
> +	const struct of_device_id *match;
> +	struct thermal_zone_device *tz;
> +	struct bcm2835_thermal_data *data;
> +	struct resource *res;
> +	int err;
> +	u32 val;
> +	unsigned long rate;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	match = of_match_device(bcm2835_thermal_of_match_table,
> +				&pdev->dev);
> +	if (!match)
> +		return -EINVAL;
> +	data->info = match->data;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	data->regs = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(data->regs)) {
> +		err = PTR_ERR(data->regs);
> +		dev_err(&pdev->dev, "Could not get registers: %d\n", err);
> +		return err;
> +	}
> +
> +	data->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(data->clk)) {
> +		err = PTR_ERR(data->clk);
> +		if (err != -EPROBE_DEFER)
> +			dev_err(&pdev->dev, "Could not get clk: %d\n", err);
> +		return err;
> +	}
> +
> +	err = clk_prepare_enable(data->clk);
> +	if (err)
> +		return err;
> +
> +	rate = clk_get_rate(data->clk);
> +	if ((rate < 1920000) || (rate > 5000000))
> +		dev_warn(&pdev->dev,
> +			 "Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92
> to 5MHz\n",
> +			 data->clk, data->clk);
> +
> +	/*
> +	 * right now the FW does set up the HW-block, so we are not
> +	 * touching the configuration registers.
> +	 * But if the HW is not enabled, then set it up
> +	 * using "sane" values used by the firmware right now.
> +	 */
> +	val = readl(data->regs + BCM2835_TS_TSENSCTL);
> +	if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
> +		/* the basic required flags */
> +		val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
> +		       BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
> +		      BCM2835_TS_TSENSCTL_REGULEN;
> +
> +		/*
> +		 * reset delay using the current firmware value of 14
> +		 * - units of time are unknown.
> +		 */

I've have open a thread in the Raspberry Pi Forum regards to this. If i get a
positive feedback then i will send an incremental patch.

Stefan

> +		val |= (14 << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
> +
> +		/*  trip_adc value from info */
> +		val |= bcm2835_thermal_temp2adc(data->info,
> +						data->info->trip_temp) <<
> +			BCM2835_TS_TSENSCTL_THOLD_SHIFT;
> +
> +		/* write the value back to the register as 2 steps */
> +		writel(val, data->regs + BCM2835_TS_TSENSCTL);
> +		val |= BCM2835_TS_TSENSCTL_RSTB;
> +		writel(val, data->regs + BCM2835_TS_TSENSCTL);
> +	}
> +
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