Date:	Wed, 06 Jan 2016 18:12:33 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Laxman Dewangan <ldewangan@...dia.com>,
	Mark Brown <broonie@...nel.org>
Cc:	linux-kernel@...r.kernel.org
Subject: Applied "regulator: max8973: add support for junction thermal warning" to the regulator tree

The patch

   regulator: max8973: add support for junction thermal warning

has been applied to the regulator tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 1b7a4c6a9eeaa2d44186da98270d325a3857b88b Mon Sep 17 00:00:00 2001
From: Laxman Dewangan <ldewangan@...dia.com>
Date: Wed, 6 Jan 2016 21:37:20 +0530
Subject: [PATCH] regulator: max8973: add support for junction thermal warning

The driver MAX8973 supports the driver for Maxim PMIC MAX77621.
MAX77621 supports the  junction temp warning at 120 degC and
140 degC which is configurable. It generates alert signal when
junction temperature crosses these threshold.

MAX77621 does not support the continuous temp monitoring of
junction temperature. It just report whether junction temperature
crossed the threshold or not.

Add support to
- Configure junction temp warning threshold via DT property
  to generate alert when it crosses the threshold.
- Add support to interrupt the host from this device when alert
  occurred.
- read the junction temp via thermal framework.

Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
Signed-off-by: Mark Brown <broonie@...nel.org>
---
 .../bindings/regulator/max8973-regulator.txt       |   5 +
 drivers/regulator/max8973-regulator.c              | 140 ++++++++++++++++++++-
 include/linux/regulator/max8973-regulator.h        |   4 +
 3 files changed, 147 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/regulator/max8973-regulator.txt b/Documentation/devicetree/bindings/regulator/max8973-regulator.txt
index f80ea2fe27e6..93f9939115af 100644
--- a/Documentation/devicetree/bindings/regulator/max8973-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/max8973-regulator.txt
@@ -31,6 +31,11 @@ Optional properties:
 		property is available then etr will be enable default.
 
 Enhanced transient response (ETR) will affect the configuration of CKADV.
+-maxim,junction-temp-warning: Junction temp warning on which device generates
+		warning interrupts. This is in millicelcius.
+
+Please note that thermal functionality is only supported on MAX77621. The
+threshold warning supported by MAX77621 are 120 degC and 140 degC.
 
 Example:
 
diff --git a/drivers/regulator/max8973-regulator.c b/drivers/regulator/max8973-regulator.c
index 5b75b7c2e3ea..4640d1b85b35 100644
--- a/drivers/regulator/max8973-regulator.c
+++ b/drivers/regulator/max8973-regulator.c
@@ -38,6 +38,9 @@
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/regmap.h>
+#include <linux/thermal.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
 
 /* Register definitions */
 #define MAX8973_VOUT					0x0
@@ -74,6 +77,7 @@
 #define MAX8973_WDTMR_ENABLE				BIT(6)
 #define MAX8973_DISCH_ENBABLE				BIT(5)
 #define MAX8973_FT_ENABLE				BIT(4)
+#define MAX77621_T_JUNCTION_120				BIT(7)
 
 #define MAX8973_CKKADV_TRIP_MASK			0xC
 #define MAX8973_CKKADV_TRIP_DISABLE			0xC
@@ -93,6 +97,13 @@
 #define MAX8973_VOLATGE_STEP				6250
 #define MAX8973_BUCK_N_VOLTAGE				0x80
 
+#define MAX77621_CHIPID_TJINT_S				BIT(0)
+
+#define MAX77621_NORMAL_OPERATING_TEMP			100000
+#define MAX77621_TJINT_WARNING_TEMP_120			120000
+#define MAX77621_TJINT_WARNING_TEMP_140			140000
+
+
 enum device_id {
 	MAX8973,
 	MAX77621
@@ -112,6 +123,9 @@ struct max8973_chip {
 	int curr_gpio_val;
 	struct regulator_ops ops;
 	enum device_id id;
+	int junction_temp_warning;
+	int irq;
+	struct thermal_zone_device *tz_device;
 };
 
 /*
@@ -391,6 +405,10 @@ static int max8973_init_dcdc(struct max8973_chip *max,
 	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
 		control1 |= MAX8973_FREQSHIFT_9PER;
 
+	if ((max->id == MAX77621) && (pdata->junction_temp_warning ==
+					MAX77621_TJINT_WARNING_TEMP_120))
+		control2 |=  MAX77621_T_JUNCTION_120;
+
 	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
 		control2 |= MAX8973_DISCH_ENBABLE;
 
@@ -457,6 +475,100 @@ static int max8973_init_dcdc(struct max8973_chip *max,
 	return ret;
 }
 
+#ifdef CONFIG_THERMAL_OF
+static int max8973_thermal_read_temp(void *data, int *temp)
+{
+	struct max8973_chip *mchip = data;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(mchip->regmap, MAX8973_CHIPID1, &val);
+	if (ret < 0) {
+		dev_err(mchip->dev, "register CHIPID1 read failed, %d", ret);
+		return ret;
+	}
+
+	/* +1 degC to trigger cool devive */
+	if (val & MAX77621_CHIPID_TJINT_S)
+		*temp = mchip->junction_temp_warning + 1000;
+	else
+		*temp = MAX77621_NORMAL_OPERATING_TEMP;
+
+	return 0;
+}
+
+static irqreturn_t max8973_thermal_irq(int irq, void *data)
+{
+	struct max8973_chip *mchip = data;
+
+	dev_info(mchip->dev, "Junction Temp warning occurred\n");
+	thermal_zone_device_update(mchip->tz_device,
+			THERMAL_DEVICE_EVENT_THRESHOLD);
+	return IRQ_HANDLED;
+}
+
+static const struct thermal_zone_of_device_ops max77621_tz_ops = {
+	.get_temp = max8973_thermal_read_temp,
+};
+
+static int max8973_thermal_init(struct max8973_chip *mchip)
+{
+	struct irq_data *irq_data;
+	unsigned long irq_flags = 0;
+	int ret;
+
+	if (mchip->id != MAX77621)
+		return 0;
+
+	mchip->tz_device = thermal_zone_of_sensor_register(mchip->dev, 0,
+					mchip, &max77621_tz_ops);
+	if (IS_ERR(mchip->tz_device)) {
+		ret = PTR_ERR(mchip->tz_device);
+		dev_err(mchip->dev,
+			"Device can not register as thermal sensor: %d\n", ret);
+		mchip->tz_device = NULL;
+		return ret;
+	}
+
+	if (mchip->irq <= 0)
+		return 0;
+
+	irq_data = irq_get_irq_data(mchip->irq);
+	if (irq_data)
+		irq_flags = irqd_get_trigger_type(irq_data);
+	ret = request_threaded_irq(mchip->irq, NULL, max8973_thermal_irq,
+			IRQF_ONESHOT | IRQF_SHARED | irq_flags,
+			dev_name(mchip->dev), mchip);
+	if (ret < 0) {
+		dev_err(mchip->dev, "request irq %d failed: %d\n",
+			mchip->irq, ret);
+		goto fail;
+	}
+	return 0;
+
+fail:
+	thermal_zone_of_sensor_unregister(mchip->dev, mchip->tz_device);
+	return ret;
+}
+
+static void max8973_thermal_deinit(struct max8973_chip *mchip)
+{
+	if ((mchip->id != MAX77621) || !mchip->tz_device)
+		return;
+
+	if (mchip->irq > 0)
+		free_irq(mchip->irq, mchip);
+
+	thermal_zone_of_sensor_unregister(mchip->dev, mchip->tz_device);
+}
+#else
+static int max8973_thermal_init(struct max8973_chip *mchip)
+{
+	return 0;
+}
+static void max8973_thermal_deinit(struct max8973_chip *mchip) { }
+#endif
+
 static const struct regmap_config max8973_regmap_config = {
 	.reg_bits		= 8,
 	.val_bits		= 8,
@@ -465,9 +577,10 @@ static const struct regmap_config max8973_regmap_config = {
 };
 
 static struct max8973_regulator_platform_data *max8973_parse_dt(
-		struct device *dev)
+		struct i2c_client *client)
 {
 	struct max8973_regulator_platform_data *pdata;
+	struct device *dev = &client->dev;
 	struct device_node *np = dev->of_node;
 	int ret;
 	u32 pval;
@@ -521,6 +634,13 @@ static struct max8973_regulator_platform_data *max8973_parse_dt(
 		pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED;
 	}
 
+	ret = of_property_read_u32(np, "maxim,junction-temp-warning", &pval);
+	if (!ret)
+		pdata->junction_temp_warning = pval;
+	pdata->junction_temp_warning = (pdata->junction_temp_warning <
+					MAX77621_TJINT_WARNING_TEMP_120) ?
+					MAX77621_TJINT_WARNING_TEMP_120 :
+					MAX77621_TJINT_WARNING_TEMP_140;
 	return pdata;
 }
 
@@ -546,7 +666,7 @@ static int max8973_probe(struct i2c_client *client,
 	pdata = dev_get_platdata(&client->dev);
 
 	if (!pdata && client->dev.of_node) {
-		pdata = max8973_parse_dt(&client->dev);
+		pdata = max8973_parse_dt(client);
 		pdata_from_dt = true;
 	}
 
@@ -592,6 +712,7 @@ static int max8973_probe(struct i2c_client *client,
 			(chip_id >> 4) & 0xF, (chip_id >> 1) & 0x7);
 
 	i2c_set_clientdata(client, max);
+	max->irq = client->irq;
 	max->ops = max8973_dcdc_ops;
 	max->dev = &client->dev;
 	max->desc.name = id->name;
@@ -608,6 +729,7 @@ static int max8973_probe(struct i2c_client *client,
 	max->enable_external_control = pdata->enable_ext_control;
 	max->curr_gpio_val = pdata->dvs_def_state;
 	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
+	max->junction_temp_warning = pdata->junction_temp_warning;
 
 	if (gpio_is_valid(max->enable_gpio))
 		max->enable_external_control = true;
@@ -718,6 +840,19 @@ static int max8973_probe(struct i2c_client *client,
 		return ret;
 	}
 
+	ret = max8973_thermal_init(max);
+	if (ret < 0)
+		dev_info(max->dev, "Juntion Thermal not initialised, %d\n",
+			ret);
+
+	return 0;
+}
+
+static int max8973_remove(struct i2c_client *i2c)
+{
+	struct max8973_chip *mchip = i2c_get_clientdata(i2c);
+
+	max8973_thermal_deinit(mchip);
 	return 0;
 }
 
@@ -734,6 +869,7 @@ static struct i2c_driver max8973_i2c_driver = {
 		.of_match_table = of_max8973_match_tbl,
 	},
 	.probe = max8973_probe,
+	.remove = max8973_remove,
 	.id_table = max8973_id,
 };
 
diff --git a/include/linux/regulator/max8973-regulator.h b/include/linux/regulator/max8973-regulator.h
index f6a8a16a0d4d..abde9c4941cf 100644
--- a/include/linux/regulator/max8973-regulator.h
+++ b/include/linux/regulator/max8973-regulator.h
@@ -54,6 +54,9 @@
  * @reg_init_data: The regulator init data.
  * @control_flags: Control flags which are ORed value of above flags to
  *		configure device.
+ * @junction_temp_warning: Junction temp in millicelcius on which warning need
+ *		to be set. Thermal functionality is only supported on MAX77621.
+ *		The threshold warning supported by MAX77621 are 120C and 140C.
  * @enable_ext_control: Enable the voltage enable/disable through external
  *		control signal from EN input pin. If it is false then
  *		voltage output will be enabled/disabled through EN bit of
@@ -67,6 +70,7 @@
 struct max8973_regulator_platform_data {
 	struct regulator_init_data *reg_init_data;
 	unsigned long control_flags;
+	int junction_temp_warning;
 	bool enable_ext_control;
 	int enable_gpio;
 	int dvs_gpio;
-- 
2.7.0.rc3

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