[PATCH V3 8/9] thermal: da9062/61: Thermal junction temperature monitoring driver

Steve Twiss
2016-10-31T16:02:05Z

From: Steve Twiss <stwiss.opensource@diasemi.com>

Add junction temperature monitoring supervisor device driver, compatible
with the DA9062 and DA9061 PMICs. A MODULE_DEVICE_TABLE() macro is added.

If the PMIC's internal junction temperature rises above TEMP_WARN (125
degC) an interrupt is issued. This TEMP_WARN level is defined as the
THERMAL_TRIP_HOT trip-wire inside the device driver.

The thermal triggering mechanism is interrupt based and happens when the
temperature rises above a given threshold level. The component cannot
return an exact temperature, it only has knowledge if the temperature is
above or below a given threshold value. A status bit must be polled to
detect when the temperature falls below that threshold level again. A
kernel work queue is configured to repeatedly poll and detect when the
temperature falls below this trip-wire, between 1 and 10 second intervals
(defaulting at 3 seconds).

This first level of temperature supervision is intended for non-invasive
temperature control, where the necessary measures for cooling the system
down are left to the host software.

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>

---
This patch applies against linux-next and v4.8

v2 -> v3
- Patch renamed from [PATCH V2 09/10] to [PATCH V3 8/9]
- Addition of MODULE_DEVICE_TABLE macro to allow modinfo additions

v1 -> v2
- Patch renamed from [PATCH V1 05/10] to [PATCH V2 09/10] -- these
changes were made to fix checkpatch warnings caused by the patch
set dependency order
- List the header files in alphabetical order
- Remove "GPL v2" and replace with MODULE_LICENSE("GPL") to match the
copyright "GNU Public License v2 or later" option in the header
comment for this file. See the allowed identifiers in the file
include/linux/module.h +170
- Remove notify function "da9062_thermal_notify" function.
- MODULE_AUTHOR() macros removes Company Name and just gives Name in
accordance with include/linux/module.h +200
- Remove the compatible "dlg,da9061-thermal" option in the of_device_id
struct table. This patch now assumes the use of a DA9062 fallback
compatible string in the DTS when using the DA9061 thermal component
of the DA9061 device.
- Re-ordered some assignments earlier in the probe() for thermal->hw,
thermal->polling_period, thermal->mode, thermal->dev
- Added further information in the patch description to explain the use
of the device driver's built-in work-queue.

Regards,
Steve Twiss, Dialog Semiconductor Ltd.

drivers/thermal/Kconfig | 10 ++
drivers/thermal/Makefile | 1 +
drivers/thermal/da9062-thermal.c | 291 +++++++++++++++++++++++++++++++++++++++
3 files changed, 302 insertions(+)
create mode 100644 drivers/thermal/da9062-thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2d702ca..da58e54 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -272,6 +272,16 @@ config DB8500_CPUFREQ_COOLING
bound cpufreq cooling device turns active to set CPU frequency low to
cool down the CPU.

+config DA9062_THERMAL
+ tristate "DA9062/DA9061 Dialog Semiconductor thermal driver"
+ depends on MFD_DA9062
+ depends on OF
+ help
+ Enable this for the Dialog Semiconductor thermal sensor driver.
+ This will report PMIC junction over-temperature for one thermal trip
+ zone.
+ Compatible with the DA9062 and DA9061 PMICs.
+
config INTEL_POWERCLAMP
tristate "Intel PowerClamp idle injection driver"
depends on THERMAL
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 10b07c1..0a2b3f2 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
obj-$(CONFIG_TANGO_THERMAL) += tango_thermal.o
obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o
+obj-$(CONFIG_DA9062_THERMAL) += da9062-thermal.o
obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o
obj-$(CONFIG_X86_PKG_TEMP_THERMAL) += x86_pkg_temp_thermal.o
obj-$(CONFIG_INTEL_SOC_DTS_IOSF_CORE) += intel_soc_dts_iosf.o
diff --git a/drivers/thermal/da9062-thermal.c b/drivers/thermal/da9062-thermal.c
new file mode 100644
index 0000000..1f0af22
--- /dev/null
+++ b/drivers/thermal/da9062-thermal.c
@@ -0,0 +1,291 @@
+/*
+ * Thermal device driver for DA9062 and DA9061
+ * Copyright (C) 2016 Dialog Semiconductor Ltd.
+ *
+ * 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/errno.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/da9062/core.h>
+#include <linux/mfd/da9062/registers.h>
+
+#define DA9062_DEFAULT_POLLING_MS_PERIOD 3000
+#define DA9062_MAX_POLLING_MS_PERIOD 10000
+#define DA9062_MIN_POLLING_MS_PERIOD 1000
+
+#define DA9062_MILLI_CELSIUS(t) ((t)*1000)
+
+struct da9062_thermal_config {
+ const char *name;
+};
+
+struct da9062_thermal {
+ struct da9062 *hw;
+ struct delayed_work work;
+ struct thermal_zone_device *zone;
+ enum thermal_device_mode mode;
+ unsigned int polling_period;
+ struct mutex lock;
+ int temperature;
+ int irq;
+ const struct da9062_thermal_config *config;
+ struct device *dev;
+};
+
+static void da9062_thermal_poll_on(struct work_struct *work)
+{
+ struct da9062_thermal *thermal = container_of(work,
+ struct da9062_thermal,
+ work.work);
+ unsigned int val;
+ int ret;
+
+ /* clear E_TEMP */
+ ret = regmap_write(thermal->hw->regmap,
+ DA9062AA_EVENT_B,
+ DA9062AA_E_TEMP_MASK);
+ if (ret < 0) {
+ dev_err(thermal->dev,
+ "Cannot clear the TJUNC temperature status\n");
+ goto err_enable_irq;
+ }
+
+ /* Now read E_TEMP again: it is acting like a status bit.
+ * If over-temperature, then this status will be true.
+ * If not over-temperature, this status will be false.
+ */
+ ret = regmap_read(thermal->hw->regmap,
+ DA9062AA_EVENT_B,
+ &val);
+ if (ret < 0) {
+ dev_err(thermal->dev,
+ "Cannot check the TJUNC temperature status\n");
+ goto err_enable_irq;
+ } else {
+ if (val & DA9062AA_E_TEMP_MASK) {
+ mutex_lock(&thermal->lock);
+ thermal->temperature = DA9062_MILLI_CELSIUS(125);
+ mutex_unlock(&thermal->lock);
+ thermal_zone_device_update(thermal->zone);
+
+ schedule_delayed_work(&thermal->work,
+ msecs_to_jiffies(thermal->polling_period));
+ return;
+ } else {
+ mutex_lock(&thermal->lock);
+ thermal->temperature = DA9062_MILLI_CELSIUS(0);
+ mutex_unlock(&thermal->lock);
+ thermal_zone_device_update(thermal->zone);
+ }
+ }
+
+err_enable_irq:
+ enable_irq(thermal->irq);
+}
+
+static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
+{
+ struct da9062_thermal *thermal = data;
+
+ disable_irq_nosync(thermal->irq);
+ schedule_delayed_work(&thermal->work, 0);
+
+ return IRQ_HANDLED;
+}
+
+static int da9062_thermal_get_mode(struct thermal_zone_device *z,
+ enum thermal_device_mode *mode)
+{
+ struct da9062_thermal *thermal = z->devdata;
+ *mode = thermal->mode;
+ return 0;
+}
+
+static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
+ int trip,
+ enum thermal_trip_type *type)
+{
+ struct da9062_thermal *thermal = z->devdata;
+
+ switch (trip) {
+ case 0:
+ *type = THERMAL_TRIP_HOT;
+ break;
+ default:
+ dev_err(thermal->dev,
+ "Driver does not support more than 1 trip-wire\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
+ int trip,
+ int *temp)
+{
+ struct da9062_thermal *thermal = z->devdata;
+
+ switch (trip) {
+ case 0:
+ *temp = DA9062_MILLI_CELSIUS(125);
+ break;
+ default:
+ dev_err(thermal->dev,
+ "Driver does not support more than 1 trip-wire\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int da9062_thermal_get_temp(struct thermal_zone_device *z,
+ int *temp)
+{
+ struct da9062_thermal *thermal = z->devdata;
+
+ mutex_lock(&thermal->lock);
+ *temp = thermal->temperature;
+ mutex_unlock(&thermal->lock);
+
+ return 0;
+}
+
+static struct thermal_zone_device_ops da9062_thermal_ops = {
+ .get_temp = da9062_thermal_get_temp,
+ .get_mode = da9062_thermal_get_mode,
+ .get_trip_type = da9062_thermal_get_trip_type,
+ .get_trip_temp = da9062_thermal_get_trip_temp,
+};
+
+static const struct da9062_thermal_config da9062_config = {
+ .name = "da9062-thermal",
+};
+
+static const struct of_device_id da9062_compatible_reg_id_table[] = {
+ { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
+
+static int da9062_thermal_probe(struct platform_device *pdev)
+{
+ struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
+ struct da9062_thermal *thermal;
+ unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+ const struct of_device_id *match;
+ int ret = 0;
+
+ match = of_match_node(da9062_compatible_reg_id_table,
+ pdev->dev.of_node);
+ if (!match)
+ return -ENXIO;
+
+ if (pdev->dev.of_node) {
+ if (!of_property_read_u32(pdev->dev.of_node,
+ "dlg,tjunc-temp-polling-period-ms",
+ &pp_tmp)) {
+ if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
+ pp_tmp > DA9062_MAX_POLLING_MS_PERIOD)
+ pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+ }
+
+ dev_dbg(&pdev->dev,
+ "TJUNC temp polling period set at %d ms\n",
+ pp_tmp);
+ }
+
+ thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
+ GFP_KERNEL);
+ if (!thermal) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ thermal->config = match->data;
+ thermal->hw = chip;
+ thermal->polling_period = pp_tmp;
+ thermal->mode = THERMAL_DEVICE_ENABLED;
+ thermal->dev = &pdev->dev;
+
+ INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
+ mutex_init(&thermal->lock);
+
+ thermal->zone = thermal_zone_device_register(thermal->config->name,
+ 1, 0, thermal,
+ &da9062_thermal_ops, NULL, 0,
+ 0);
+ if (IS_ERR(thermal->zone)) {
+ dev_err(&pdev->dev, "Cannot register thermal zone device\n");
+ ret = PTR_ERR(thermal->zone);
+ goto err;
+ }
+
+ ret = platform_get_irq_byname(pdev, "THERMAL");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
+ goto err_zone;
+ }
+ thermal->irq = ret;
+
+ ret = request_threaded_irq(thermal->irq, NULL,
+ da9062_thermal_irq_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "THERMAL", thermal);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to request thermal device IRQ.\n");
+ goto err_zone;
+ }
+
+ platform_set_drvdata(pdev, thermal);
+ return 0;
+
+err_zone:
+ thermal_zone_device_unregister(thermal->zone);
+err:
+ return ret;
+}
+
+static int da9062_thermal_remove(struct platform_device *pdev)
+{
+ struct da9062_thermal *thermal = platform_get_drvdata(pdev);
+
+ free_irq(thermal->irq, thermal);
+ thermal_zone_device_unregister(thermal->zone);
+ cancel_delayed_work_sync(&thermal->work);
+ return 0;
+}
+
+static struct platform_driver da9062_thermal_driver = {
+ .probe = da9062_thermal_probe,
+ .remove = da9062_thermal_remove,
+ .driver = {
+ .name = "da9062-thermal",
+ .of_match_table = da9062_compatible_reg_id_table,
+ },
+};
+
+module_platform_driver(da9062_thermal_driver);
+
+MODULE_AUTHOR("Steve Twiss");
+MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9062-thermal");
--
end-of-patch for PATCH V3