diff mbox

add omap34xx temperature monitoring support

Message ID 20141226102933.GA28778@amd (mailing list archive)
State New, archived
Headers show

Commit Message

Pavel Machek Dec. 26, 2014, 10:29 a.m. UTC 
Signed-off-by: Pavel Machek <pavel@ucw.cz>

Comments

Sebastian Reichel Dec. 26, 2014, 12:34 p.m. UTC | #1 
Hi,

I've prepared an updated variant of the omap34xx temperature monitor driver.
It's based on the N9 driver instead of the N900 driver (and thus has omap36xx
support).

The differences compared to the original driver are:

 * DT based
 * No includes from arch, instead uses syscon DT node + regmap
 * Removed support for raw temperature reading
  - I assume this was used for debugging and regmap can be used
    instead with newer kernels.
 * Introduction of managed resources where possible
 * Usage of module_platform_driver() macro
 * Added some comments referencing the TRM

So far the patchset is _compile-tested only_. I will test it on my N900 in
the next days.

-- Sebastian

Sebastian Reichel (3):
  DT Binding for omap3 temperature sensor
  hwmon: Driver for OMAP3 temperature sensor
  ARM: dts: OMAP34xx/36xx: Add temperature sensor

 .../bindings/hwmon/omap3-temperature.txt           |  25 ++
 arch/arm/boot/dts/omap34xx.dtsi                    |   7 +
 arch/arm/boot/dts/omap36xx.dtsi                    |   7 +
 drivers/hwmon/Kconfig                              |   8 +
 drivers/hwmon/Makefile                             |   1 +
 drivers/hwmon/omap3-temp.c                         | 307 +++++++++++++++++++++
 6 files changed, 355 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/omap3-temperature.txt
 create mode 100644 drivers/hwmon/omap3-temp.c
Tony Lindgren Dec. 26, 2014, 3:54 p.m. UTC | #2 
* Pavel Machek <pavel@ucw.cz> [141226 02:32]:
> --- /dev/null
> +++ b/drivers/hwmon/omap34xx_temp.c
> @@ -0,0 +1,263 @@
> +/*
> + * omap34xx_temp.c - Linux kernel module for OMAP34xx hardware monitoring
> + *
> + * Copyright (C) 2008 Nokia Corporation
> + *
> + * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
> + *
> + * Inspired by k8temp.c
> + *
> + * This file is subject to the terms and conditions of the GNU General
> + * Public License. See the file "COPYING" in the main directory of this
> + * archive for more details.
> + *
> + * 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/hrtimer.h>
> +#include <linux/module.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +
> +#include "../../arch/arm/mach-omap2/control.h"

No need to do this, you can use syscon here like pbias-regulator.c
is doing.

Regards,

Tony
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Tony Lindgren Dec. 26, 2014, 4:17 p.m. UTC | #3 
* Tony Lindgren <tony@atomide.com> [141226 07:57]:
> * Pavel Machek <pavel@ucw.cz> [141226 02:32]:
> > --- /dev/null
> > +++ b/drivers/hwmon/omap34xx_temp.c
> > @@ -0,0 +1,263 @@
> > +/*
> > + * omap34xx_temp.c - Linux kernel module for OMAP34xx hardware monitoring
> > + *
> > + * Copyright (C) 2008 Nokia Corporation
> > + *
> > + * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
> > + *
> > + * Inspired by k8temp.c
> > + *
> > + * This file is subject to the terms and conditions of the GNU General
> > + * Public License. See the file "COPYING" in the main directory of this
> > + * archive for more details.
> > + *
> > + * 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/hrtimer.h>
> > +#include <linux/module.h>
> > +#include <linux/hwmon.h>
> > +#include <linux/hwmon-sysfs.h>
> > +#include <linux/err.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/io.h>
> > +#include <linux/slab.h>
> > +
> > +#include "../../arch/arm/mach-omap2/control.h"
> 
> No need to do this, you can use syscon here like pbias-regulator.c
> is doing.

Oh looks like you're already using syscon, nice. What defines do you
need from control.h?

Those should be in the driver if private to the driver, or else we
should have some minimal header in include/linux somewhere if some
control.h defines really need to be exposed.

Regards,

Tony
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Pali Rohár Dec. 26, 2014, 4:26 p.m. UTC | #4 
On Friday 26 December 2014 17:17:57 Tony Lindgren wrote:
> * Tony Lindgren <tony@atomide.com> [141226 07:57]:
> > * Pavel Machek <pavel@ucw.cz> [141226 02:32]:
> > > --- /dev/null
> > > +++ b/drivers/hwmon/omap34xx_temp.c
> > > @@ -0,0 +1,263 @@
> > > +/*
> > > + * omap34xx_temp.c - Linux kernel module for OMAP34xx
> > > hardware monitoring + *
> > > + * Copyright (C) 2008 Nokia Corporation
> > > + *
> > > + * Written by Peter De Schrijver
> > > <peter.de-schrijver@nokia.com> + *
> > > + * Inspired by k8temp.c
> > > + *
> > > + * This file is subject to the terms and conditions of
> > > the GNU General + * Public License. See the file
> > > "COPYING" in the main directory of this + * archive for
> > > more details.
> > > + *
> > > + * 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/hrtimer.h>
> > > +#include <linux/module.h>
> > > +#include <linux/hwmon.h>
> > > +#include <linux/hwmon-sysfs.h>
> > > +#include <linux/err.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/io.h>
> > > +#include <linux/slab.h>
> > > +
> > > +#include "../../arch/arm/mach-omap2/control.h"
> > 
> > No need to do this, you can use syscon here like
> > pbias-regulator.c is doing.
> 
> Oh looks like you're already using syscon, nice. What defines
> do you need from control.h?
> 
> Those should be in the driver if private to the driver, or
> else we should have some minimal header in include/linux
> somewhere if some control.h defines really need to be
> exposed.
> 
> Regards,
> 
> Tony

Hi Tony,

Sebastian Reichel has already sent new version of temperature 
driver. See email thread with subject:

[PATCH 0/3] OMAP3 temperature sensor
Tony Lindgren Dec. 26, 2014, 4:31 p.m. UTC | #5 
* Pali Rohár <pali.rohar@gmail.com> [141226 08:29]:
> On Friday 26 December 2014 17:17:57 Tony Lindgren wrote:
> > > > +
> > > > +#include "../../arch/arm/mach-omap2/control.h"
> > > 
> > > No need to do this, you can use syscon here like
> > > pbias-regulator.c is doing.
> > 
> > Oh looks like you're already using syscon, nice. What defines
> > do you need from control.h?
> > 
> > Those should be in the driver if private to the driver, or
> > else we should have some minimal header in include/linux
> > somewhere if some control.h defines really need to be
> > exposed.
> > 
> > Regards,
> > 
> > Tony
> 
> Hi Tony,
> 
> Sebastian Reichel has already sent new version of temperature 
> driver. See email thread with subject:
> 
> [PATCH 0/3] OMAP3 temperature sensor

Yeah great, looks like I was also reading Sebastian's patch
with the syscon comments above :)

Regards,

Tony
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diff mbox

Patch

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 6529c09..9007ca9 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -28,6 +28,10 @@  config HWMON_VID
 	tristate
 	default n
 
+config SENSORS_OMAP34XX
+	bool "TI OMAP34xx internal temperature sensor"
+	depends on ARCH_OMAP3 && HIGH_RES_TIMERS
+
 config HWMON_DEBUG_CHIP
 	bool "Hardware Monitoring Chip debugging messages"
 	default n
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 6728064..5c3b5d1 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -120,6 +120,7 @@  obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
 obj-$(CONFIG_SENSORS_NCT7802)	+= nct7802.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
+obj-$(CONFIG_SENSORS_OMAP34XX)  += omap34xx_temp.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
diff --git a/drivers/hwmon/omap34xx_temp.c b/drivers/hwmon/omap34xx_temp.c
new file mode 100644
index 0000000..bc7a72f
--- /dev/null
+++ b/drivers/hwmon/omap34xx_temp.c
@@ -0,0 +1,263 @@ 
+/*
+ * omap34xx_temp.c - Linux kernel module for OMAP34xx hardware monitoring
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
+ *
+ * Inspired by k8temp.c
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * 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/hrtimer.h>
+#include <linux/module.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include "../../arch/arm/mach-omap2/control.h"
+
+#define TEMP_SENSOR_SOC BIT(8)
+#define TEMP_SENSOR_EOCZ BIT(7)
+
+/* minimum delay for EOCZ rise after SOC rise is
+ * 11 cycles of the 32.768Khz clock */
+#define EOCZ_MIN_RISING_DELAY (11 * 30518)
+
+/* maximum delay for EOCZ rise after SOC rise is
+ * 14 cycles of the 32.768Khz clock */
+#define EOCZ_MAX_RISING_DELAY (14 * 30518)
+
+/* minimum delay for EOCZ falling is
+ * 36 cycles of the 32.768Khz clock */
+#define EOCZ_MIN_FALLING_DELAY (36 * 30518)
+
+/* maximum delay for EOCZ falling is
+ * 40 cycles of the 32.768Khz clock */
+#define EOCZ_MAX_FALLING_DELAY (40 * 30518)
+
+struct omap34xx_data {
+	struct device *hwmon_dev;
+	struct clk *clk_32k;
+	struct mutex update_lock;
+	const char *name;
+	char valid;
+	unsigned long last_updated;
+	u32 temp;
+};
+
+static struct platform_device omap34xx_temp_device = {
+	.name	= "omap34xx_temp",
+	.id	= -1,
+};
+
+static int adc_to_temp[] = {
+	-40, -40, -40, -40, -40, -39, -38, -36, -34, -32, -31, -29, -28, -26,
+	-25, -24, -22, -21, -19, -18, -17, -15, -14, -12, -11, -9, -8, -7, -5,
+	-4, -2, -1, 0, 1, 3, 4, 5, 7, 8, 10, 11, 13, 14, 15, 17, 18, 20, 21,
+	22, 24, 25, 27, 28, 30, 31, 32, 34, 35, 37, 38, 39, 41, 42, 44, 45,
+	47, 48, 49, 51, 52, 53, 55, 56, 58, 59, 60, 62, 63, 65, 66, 67, 69,
+	70, 72, 73, 74, 76, 77, 79, 80, 81, 83, 84, 85, 87, 88, 89, 91, 92,
+	94, 95, 96, 98, 99, 100, 102, 103, 105, 106, 107, 109, 110, 111, 113,
+	114, 116, 117, 118, 120, 121, 122, 124, 124, 125, 125, 125, 125, 125};
+
+static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level)
+{
+	struct timespec timeout;
+	ktime_t expire;
+	u32 temp_sensor_reg;
+
+	level &= 1;
+	level *= TEMP_SENSOR_EOCZ;
+
+	expire = ktime_add_ns(ktime_get(), max_delay);
+	timeout = ns_to_timespec(min_delay);
+	hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	do {
+		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
+		if ((temp_sensor_reg & TEMP_SENSOR_EOCZ) == level)
+			break;
+	} while (ktime_us_delta(expire, ktime_get()) > 0);
+
+	return (temp_sensor_reg & TEMP_SENSOR_EOCZ) == level;
+}
+
+static void omap34xx_update(struct omap34xx_data *data)
+{
+	u32 temp_sensor_reg;
+
+	mutex_lock(&data->update_lock);
+
+	if (!data->valid
+	    || time_after(jiffies, data->last_updated + HZ)) {
+		clk_prepare_enable(data->clk_32k);
+
+		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
+		temp_sensor_reg |= TEMP_SENSOR_SOC;
+		omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR);
+
+		if (!wait_for_eocz(EOCZ_MIN_RISING_DELAY,
+					EOCZ_MAX_RISING_DELAY, 1))
+			goto err;
+
+		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
+		temp_sensor_reg &= ~TEMP_SENSOR_SOC;
+		omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR);
+
+		if (!wait_for_eocz(EOCZ_MIN_FALLING_DELAY,
+					EOCZ_MAX_FALLING_DELAY, 0))
+			goto err;
+
+		data->temp = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR) &
+						((1<<7) - 1);
+		data->last_updated = jiffies;
+		data->valid = 1;
+
+err:
+		clk_disable_unprepare(data->clk_32k);
+	}
+
+	mutex_unlock(&data->update_lock);
+}
+
+static ssize_t show_name(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	struct omap34xx_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", data->name);
+}
+
+static ssize_t show_temp_raw(struct device *dev,
+			 struct device_attribute *devattr, char *buf)
+{
+	struct omap34xx_data *data = dev_get_drvdata(dev);
+
+	omap34xx_update(data);
+
+	return sprintf(buf, "%d\n", data->temp);
+}
+
+static ssize_t show_temp(struct device *dev,
+			 struct device_attribute *devattr, char *buf)
+{
+	struct omap34xx_data *data = dev_get_drvdata(dev);
+
+	omap34xx_update(data);
+
+	return sprintf(buf, "%d\n", adc_to_temp[data->temp]);
+}
+
+static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0);
+static SENSOR_DEVICE_ATTR_2(temp1_input_raw, S_IRUGO, show_temp_raw,
+				NULL, 0, 0);
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static int omap34xx_temp_probe(void)
+{
+	int err;
+	struct omap34xx_data *data;
+
+	err = platform_device_register(&omap34xx_temp_device);
+	if (err) {
+		pr_err("Unable to register omap34xx temperature device\n");
+		goto exit;
+	}
+
+	data = kzalloc(sizeof(struct omap34xx_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit_platform;
+	}
+
+	dev_set_drvdata(&omap34xx_temp_device.dev, data);
+	mutex_init(&data->update_lock);
+	data->name = "omap34xx_temp";
+
+	data->clk_32k = clk_get(&omap34xx_temp_device.dev, "ts_fck");
+	if (IS_ERR(data->clk_32k)) {
+		err = PTR_ERR(data->clk_32k);
+		goto exit_free;
+	}
+
+	err = device_create_file(&omap34xx_temp_device.dev,
+				 &sensor_dev_attr_temp1_input.dev_attr);
+	if (err)
+		goto clock_free;
+
+	err = device_create_file(&omap34xx_temp_device.dev,
+				 &sensor_dev_attr_temp1_input_raw.dev_attr);
+	if (err)
+		goto exit_remove;
+
+	err = device_create_file(&omap34xx_temp_device.dev, &dev_attr_name);
+	if (err)
+		goto exit_remove_raw;
+
+	data->hwmon_dev = hwmon_device_register(&omap34xx_temp_device.dev);
+
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove_all;
+	}
+
+	return 0;
+
+exit_remove_all:
+	device_remove_file(&omap34xx_temp_device.dev,
+			   &dev_attr_name);
+exit_remove_raw:
+	device_remove_file(&omap34xx_temp_device.dev,
+			   &sensor_dev_attr_temp1_input_raw.dev_attr);
+exit_remove:
+	device_remove_file(&omap34xx_temp_device.dev,
+			   &sensor_dev_attr_temp1_input.dev_attr);
+clock_free:
+	clk_put(data->clk_32k);
+
+exit_free:
+	kfree(data);
+exit_platform:
+	platform_device_unregister(&omap34xx_temp_device);
+exit:
+	return err;
+}
+
+static int __init omap34xx_temp_init(void)
+{
+	return omap34xx_temp_probe();
+}
+
+static void __exit omap34xx_temp_exit(void)
+{
+	struct omap34xx_data *data =
+			dev_get_drvdata(&omap34xx_temp_device.dev);
+
+	clk_put(data->clk_32k);
+	hwmon_device_unregister(data->hwmon_dev);
+	device_remove_file(&omap34xx_temp_device.dev,
+			   &sensor_dev_attr_temp1_input.dev_attr);
+	device_remove_file(&omap34xx_temp_device.dev, &dev_attr_name);
+	kfree(data);
+	platform_device_unregister(&omap34xx_temp_device);
+}
+
+MODULE_AUTHOR("Peter De Schrijver");
+MODULE_DESCRIPTION("Omap34xx temperature sensor");
+MODULE_LICENSE("GPL");
+
+module_init(omap34xx_temp_init)
+module_exit(omap34xx_temp_exit)
+