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* [PATCH V5 0/6] thermal: bcm2835: add thermal driver
@ 2016-09-13  9:34 ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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

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                            |   5 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/bcm2835_thermal.c                  | 327 +++++++++++++++++++++
 10 files changed, 378 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
 create mode 100644 drivers/thermal/bcm2835_thermal.c

--
2.1.4

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 0/6] thermal: bcm2835: add thermal driver
@ 2016-09-13  9:34 ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-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

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                            |   5 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/bcm2835_thermal.c                  | 327 +++++++++++++++++++++
 10 files changed, 378 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
 create mode 100644 drivers/thermal/bcm2835_thermal.c

--
2.1.4

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 1/6] dt: bindings: add thermal device driver for bcm2835
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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


^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 1/6] dt: bindings: add thermal device driver for bcm2835
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-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 at 7e212000 {
+	compatible = "brcm,bcm2835-thermal";
+	reg = <0x7e212000 0x8>;
+	clocks = <&clocks BCM2835_CLOCK_TSENS>;
+};
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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>

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)
---
 drivers/thermal/Kconfig           |   5 +
 drivers/thermal/Makefile          |   1 +
 drivers/thermal/bcm2835_thermal.c | 327 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 333 insertions(+)
 create mode 100644 drivers/thermal/bcm2835_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2d702ca..5e3e4e4 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -399,4 +399,9 @@ 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"
+       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..6fa972e
--- /dev/null
+++ b/drivers/thermal/bcm2835_thermal.c
@@ -0,0 +1,327 @@
+/*
+ * 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_RSTDELAY_DEFAULT	14
+#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;
+
+	/* mask the relevant bits */
+	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;
+
+	/* get registers */
+	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;
+	}
+
+	/* get clock */
+	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;
+	}
+
+	/* set up registers if not already done by the fw */
+	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 */
+		val |= (BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT <<
+			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);
+	}
+
+	/* enable clock and check rate */
+	clk_prepare_enable(data->clk);
+	rate = clk_get_rate(data->clk);
+	if ((rate < 1920000) || (rate > 5000000)) {
+		dev_warn(&pdev->dev,
+			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range of 1.9 to 5.0 MHz\n",
+			 data->clk, data->clk);
+	}
+
+	/* 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);
+
+	return 0;
+}
+
+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


^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-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>

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)
---
 drivers/thermal/Kconfig           |   5 +
 drivers/thermal/Makefile          |   1 +
 drivers/thermal/bcm2835_thermal.c | 327 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 333 insertions(+)
 create mode 100644 drivers/thermal/bcm2835_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2d702ca..5e3e4e4 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -399,4 +399,9 @@ 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"
+       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..6fa972e
--- /dev/null
+++ b/drivers/thermal/bcm2835_thermal.c
@@ -0,0 +1,327 @@
+/*
+ * 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_RSTDELAY_DEFAULT	14
+#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;
+
+	/* mask the relevant bits */
+	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;
+
+	/* get registers */
+	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;
+	}
+
+	/* get clock */
+	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;
+	}
+
+	/* set up registers if not already done by the fw */
+	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 */
+		val |= (BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT <<
+			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);
+	}
+
+	/* enable clock and check rate */
+	clk_prepare_enable(data->clk);
+	rate = clk_get_rate(data->clk);
+	if ((rate < 1920000) || (rate > 5000000)) {
+		dev_warn(&pdev->dev,
+			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range of 1.9 to 5.0 MHz\n",
+			 data->clk, data->clk);
+	}
+
+	/* 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);
+
+	return 0;
+}
+
+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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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

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

Signed-off-by: Martin Sperl <kernel@martin.sperl.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

Note: there is no arm/boot/dts/bcm2837.dtsi as of now,
      so there is no support for bcm2837 in 32 bit mode.
---
 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(+)

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..2cc4847 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@0x7e212000 {
+			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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-kernel

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

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

Signed-off-by: Martin Sperl <kernel@martin.sperl.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

Note: there is no arm/boot/dts/bcm2837.dtsi as of now,
      so there is no support for bcm2837 in 32 bit mode.
---
 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(+)

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..2cc4847 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 at 0x7e212000 {
+			compatible = "brcm,bcm2835-thermal";
+			reg = <0x7e212000 0x8>;
+			clocks = <&clocks BCM2835_CLOCK_TSENS>;
+			status = "disabled";
+		};
+
 		aux: aux at 0x7e215000 {
 			compatible = "brcm,bcm2835-aux";
 			#clock-cells = <1>;
--
2.1.4

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 4/6] ARM64: bcm2835: dts: add thermal node to device-tree of bcm2837
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 4/6] ARM64: bcm2835: dts: add thermal node to device-tree of bcm2837
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 5/6] ARM: bcm2835: add thermal driver to default_config
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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

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

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


^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 5/6] ARM: bcm2835: add thermal driver to default_config
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-kernel

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

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

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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 6/6] ARM64: bcm2835: add thermal driver to default_config
  2016-09-13  9:34 ` kernel at martin.sperl.org
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel @ 2016-09-13  9:34 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Eric Anholt, Russell King, Florian Fainelli,
	Catalin Marinas, Will Deacon, Stefan Wahren, linux-pm,
	devicetree, linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

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

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

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

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

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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* [PATCH V5 6/6] ARM64: bcm2835: add thermal driver to default_config
@ 2016-09-13  9:34   ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-13  9:34 UTC (permalink / raw)
  To: linux-arm-kernel

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

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

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

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

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

^ permalink raw reply related	[flat|nested] 22+ messages in thread

* Re: [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
  2016-09-13  9:34   ` kernel at martin.sperl.org
@ 2016-09-14  9:41     ` Eric Anholt
  -1 siblings, 0 replies; 22+ messages in thread
From: Eric Anholt @ 2016-09-14  9:41 UTC (permalink / raw)
  To: Zhang Rui, Rob Herring, Pawel Moll, Mark Rutland, Stephen Warren,
	Lee Jones, Russell King, Florian Fainelli, Catalin Marinas,
	Will Deacon, Stefan Wahren, linux-pm, devicetree,
	linux-rpi-kernel, linux-arm-kernel
  Cc: Martin Sperl

[-- Attachment #1: Type: text/plain, Size: 827 bytes --]

kernel@martin.sperl.org writes:

> 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>
>
> 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)

This is still:

Acked-by: Eric Anholt <eric@anholt.net>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 800 bytes --]

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
@ 2016-09-14  9:41     ` Eric Anholt
  0 siblings, 0 replies; 22+ messages in thread
From: Eric Anholt @ 2016-09-14  9:41 UTC (permalink / raw)
  To: linux-arm-kernel

kernel at martin.sperl.org writes:

> 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>
>
> 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)

This is still:

Acked-by: Eric Anholt <eric@anholt.net>
-------------- next part --------------
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^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
  2016-09-13  9:34   ` kernel at martin.sperl.org
@ 2016-09-18 11:31     ` Stefan Wahren
  -1 siblings, 0 replies; 22+ messages in thread
From: Stefan Wahren @ 2016-09-18 11:31 UTC (permalink / raw)
  To: kernel, Zhang Rui, Lee Jones, Eric Anholt, Stephen Warren, devicetree
  Cc: Will Deacon, Pawel Moll, linux-arm-kernel, Florian Fainelli,
	Rob Herring, Russell King, linux-pm, Mark Rutland,
	Catalin Marinas, linux-rpi-kernel

Hi Martin,

> kernel@martin.sperl.org hat am 13. September 2016 um 11:34 geschrieben:
> 
> 
> 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>
> 
> 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)
> ---
>  drivers/thermal/Kconfig           |   5 +
>  drivers/thermal/Makefile          |   1 +
>  drivers/thermal/bcm2835_thermal.c | 327
> ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 333 insertions(+)
>  create mode 100644 drivers/thermal/bcm2835_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 2d702ca..5e3e4e4 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -399,4 +399,9 @@ 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"

i'm not sure if "depends on ARCH_BCM2835 || COMPILE_TEST" is necessary here,
but the following is:

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
> ...
> +
> +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;
> +
> +	/* mask the relevant bits */

I think this is obvious and could be removed.

> +	val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
> +
> +	*temp = bcm2835_thermal_adc2temp(data->info, val);
> +
> +	return 0;
> +}
> +
> ...
> +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;
> +
> +	/* get registers */

ditto

> +	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;
> +	}
> +
> +	/* get clock */

ditto

> +	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;
> +	}
> +
> +	/* set up registers if not already done by the fw */
> +	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;

The comment above isn't helpful. Could you please write down the intension
behind this bit operation?

> +
> +		/* reset delay */

What is the unit of the delay (seconds, 1/10 seconds)?

> +		val |= (BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT <<

Instead of hiding the value behind a define, please use the number directly and
remove this define.

> +			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);
> +	}
> +
> +	/* enable clock and check rate */
> +	clk_prepare_enable(data->clk);

This could fail. So please check the result and move this call before the
register set up.

> +	rate = clk_get_rate(data->clk);
> +	if ((rate < 1920000) || (rate > 5000000)) {
> +		dev_warn(&pdev->dev,
> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range
> of 1.9 to 5.0 MHz\n",
> +			 data->clk, data->clk);

Instead of printing the clock name twice your intension would be to print the
actual clock rate?

Btw the message is very long. Could you please shorten it and make the lower
limit more precise 1.92 MHz?

> +	}
> +
> +	/* 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;
> +}
> +
> +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

Since the operating temperature of the bcm2835 is only available in the
Foundation FAQ. I would suggest to add the recommenend operating temperature
range ( -40 C to +85 C ) here as a comment.

Thanks
Stefan

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
@ 2016-09-18 11:31     ` Stefan Wahren
  0 siblings, 0 replies; 22+ messages in thread
From: Stefan Wahren @ 2016-09-18 11:31 UTC (permalink / raw)
  To: linux-arm-kernel

Hi Martin,

> kernel at martin.sperl.org hat am 13. September 2016 um 11:34 geschrieben:
> 
> 
> 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>
> 
> 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)
> ---
>  drivers/thermal/Kconfig           |   5 +
>  drivers/thermal/Makefile          |   1 +
>  drivers/thermal/bcm2835_thermal.c | 327
> ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 333 insertions(+)
>  create mode 100644 drivers/thermal/bcm2835_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 2d702ca..5e3e4e4 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -399,4 +399,9 @@ 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"

i'm not sure if "depends on ARCH_BCM2835 || COMPILE_TEST" is necessary here,
but the following is:

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
> ...
> +
> +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;
> +
> +	/* mask the relevant bits */

I think this is obvious and could be removed.

> +	val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
> +
> +	*temp = bcm2835_thermal_adc2temp(data->info, val);
> +
> +	return 0;
> +}
> +
> ...
> +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;
> +
> +	/* get registers */

ditto

> +	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;
> +	}
> +
> +	/* get clock */

ditto

> +	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;
> +	}
> +
> +	/* set up registers if not already done by the fw */
> +	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;

The comment above isn't helpful. Could you please write down the intension
behind this bit operation?

> +
> +		/* reset delay */

What is the unit of the delay (seconds, 1/10 seconds)?

> +		val |= (BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT <<

Instead of hiding the value behind a define, please use the number directly and
remove this define.

> +			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);
> +	}
> +
> +	/* enable clock and check rate */
> +	clk_prepare_enable(data->clk);

This could fail. So please check the result and move this call before the
register set up.

> +	rate = clk_get_rate(data->clk);
> +	if ((rate < 1920000) || (rate > 5000000)) {
> +		dev_warn(&pdev->dev,
> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range
> of 1.9 to 5.0 MHz\n",
> +			 data->clk, data->clk);

Instead of printing the clock name twice your intension would be to print the
actual clock rate?

Btw the message is very long. Could you please shorten it and make the lower
limit more precise 1.92 MHz?

> +	}
> +
> +	/* 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;
> +}
> +
> +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

Since the operating temperature of the bcm2835 is only available in the
Foundation FAQ. I would suggest to add the recommenend operating temperature
range ( -40 C to +85 C ) here as a comment.

Thanks
Stefan

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH V5 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x
  2016-09-13  9:34   ` kernel at martin.sperl.org
@ 2016-09-18 11:41     ` Stefan Wahren
  -1 siblings, 0 replies; 22+ messages in thread
From: Stefan Wahren @ 2016-09-18 11:41 UTC (permalink / raw)
  To: kernel, Eric Anholt, Zhang Rui, Stephen Warren, Lee Jones
  Cc: Will Deacon, Pawel Moll, linux-rpi-kernel, Rob Herring,
	Catalin Marinas, devicetree, Mark Rutland, linux-pm,
	linux-arm-kernel, Russell King, Florian Fainelli

> kernel@martin.sperl.org hat am 13. September 2016 um 11:34 geschrieben:
> 
> 
> From: Martin Sperl <kernel@martin.sperl.org>
> 
> Add the node for the thermal sensor of the bcm2835-soc
> to the device tree.
> 
> Signed-off-by: Martin Sperl <kernel@martin.sperl.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
> 
> Note: there is no arm/boot/dts/bcm2837.dtsi as of now,
>       so there is no support for bcm2837 in 32 bit mode.
> ---
>  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(+)
> 
> 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..2cc4847 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@0x7e212000 {

After removing 0x here like in the binding doc you can add:

Acked-by: Stefan Wahren <stefan.wahren@i2se.com>

> +			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
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x
@ 2016-09-18 11:41     ` Stefan Wahren
  0 siblings, 0 replies; 22+ messages in thread
From: Stefan Wahren @ 2016-09-18 11:41 UTC (permalink / raw)
  To: linux-arm-kernel

> kernel at martin.sperl.org hat am 13. September 2016 um 11:34 geschrieben:
> 
> 
> From: Martin Sperl <kernel@martin.sperl.org>
> 
> Add the node for the thermal sensor of the bcm2835-soc
> to the device tree.
> 
> Signed-off-by: Martin Sperl <kernel@martin.sperl.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
> 
> Note: there is no arm/boot/dts/bcm2837.dtsi as of now,
>       so there is no support for bcm2837 in 32 bit mode.
> ---
>  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(+)
> 
> 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..2cc4847 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 at 0x7e212000 {

After removing 0x here like in the binding doc you can add:

Acked-by: Stefan Wahren <stefan.wahren@i2se.com>

> +			compatible = "brcm,bcm2835-thermal";
> +			reg = <0x7e212000 0x8>;
> +			clocks = <&clocks BCM2835_CLOCK_TSENS>;
> +			status = "disabled";
> +		};
> +
>  		aux: aux at 0x7e215000 {
>  			compatible = "brcm,bcm2835-aux";
>  			#clock-cells = <1>;
> --
> 2.1.4
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
  2016-09-18 11:31     ` Stefan Wahren
@ 2016-09-18 16:05         ` kernel at martin.sperl.org
  -1 siblings, 0 replies; 22+ messages in thread
From: kernel-TqfNSX0MhmxHKSADF0wUEw @ 2016-09-18 16:05 UTC (permalink / raw)
  To: Stefan Wahren
  Cc: Zhang Rui, Lee Jones, Eric Anholt, Stephen Warren, devicetree,
	Will Deacon, Pawel Moll,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	Florian Fainelli, Rob Herring, Russell King,
	linux-pm-u79uwXL29TY76Z2rM5mHXA, Mark Rutland, Catalin Marinas,
	linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r

Hi Stefan!

> On 18.09.2016, at 13:31, Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org> wrote:
> 
>> +	rate = clk_get_rate(data->clk);
>> +	if ((rate < 1920000) || (rate > 5000000)) {
>> +		dev_warn(&pdev->dev,
>> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range
>> of 1.9 to 5.0 MHz\n",
>> +			 data->clk, data->clk);
> 
> Instead of printing the clock name twice your intension would be to print the
> actual clock rate?
%pCn (and %pC) prints the clock name
%pCr prints the clock rate - I guess I could use “%lu” and rate instead

So I do not see an issue here - I will reword the text to shorten it.

Everything else I will fix as mentioned.

Martin--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
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^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
@ 2016-09-18 16:05         ` kernel at martin.sperl.org
  0 siblings, 0 replies; 22+ messages in thread
From: kernel at martin.sperl.org @ 2016-09-18 16:05 UTC (permalink / raw)
  To: linux-arm-kernel

Hi Stefan!

> On 18.09.2016, at 13:31, Stefan Wahren <stefan.wahren@i2se.com> wrote:
> 
>> +	rate = clk_get_rate(data->clk);
>> +	if ((rate < 1920000) || (rate > 5000000)) {
>> +		dev_warn(&pdev->dev,
>> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range
>> of 1.9 to 5.0 MHz\n",
>> +			 data->clk, data->clk);
> 
> Instead of printing the clock name twice your intension would be to print the
> actual clock rate?
%pCn (and %pC) prints the clock name
%pCr prints the clock rate - I guess I could use ?%lu? and rate instead

So I do not see an issue here - I will reword the text to shorten it.

Everything else I will fix as mentioned.

Martin

^ permalink raw reply	[flat|nested] 22+ messages in thread

end of thread, other threads:[~2016-09-18 16:05 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-13  9:34 [PATCH V5 0/6] thermal: bcm2835: add thermal driver kernel
2016-09-13  9:34 ` kernel at martin.sperl.org
2016-09-13  9:34 ` [PATCH V5 1/6] dt: bindings: add thermal device driver for bcm2835 kernel
2016-09-13  9:34   ` kernel at martin.sperl.org
2016-09-13  9:34 ` [PATCH V5 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc kernel
2016-09-13  9:34   ` kernel at martin.sperl.org
2016-09-14  9:41   ` Eric Anholt
2016-09-14  9:41     ` Eric Anholt
2016-09-18 11:31   ` Stefan Wahren
2016-09-18 11:31     ` Stefan Wahren
     [not found]     ` <1999564031.209213.6508fbdb-00c5-486b-a34e-3d60ae68fe88.open-xchange-7tX72C7vayboQLBSYMtkGA@public.gmane.org>
2016-09-18 16:05       ` kernel-TqfNSX0MhmxHKSADF0wUEw
2016-09-18 16:05         ` kernel at martin.sperl.org
2016-09-13  9:34 ` [PATCH V5 3/6] ARM: bcm2835: dts: add thermal node to device-tree of bcm283x kernel
2016-09-13  9:34   ` kernel at martin.sperl.org
2016-09-18 11:41   ` Stefan Wahren
2016-09-18 11:41     ` Stefan Wahren
2016-09-13  9:34 ` [PATCH V5 4/6] ARM64: bcm2835: dts: add thermal node to device-tree of bcm2837 kernel
2016-09-13  9:34   ` kernel at martin.sperl.org
2016-09-13  9:34 ` [PATCH V5 5/6] ARM: bcm2835: add thermal driver to default_config kernel
2016-09-13  9:34   ` kernel at martin.sperl.org
2016-09-13  9:34 ` [PATCH V5 6/6] ARM64: " kernel
2016-09-13  9:34   ` kernel at martin.sperl.org

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