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authorLaxman Dewangan <ldewangan@nvidia.com>2016-04-13 15:29:45 +0530
committerMark Brown <broonie@kernel.org>2016-04-13 17:19:26 +0100
commitd2d5437bdfdde20a75bdf59db1c1a77721613b22 (patch)
tree6823866b13d70fc22ef7f3b8775b1a280fd84f81 /drivers/regulator
parent19dd159ce8086293b70bd8e1aeebe06aff8d7df8 (diff)
downloadlinux-d2d5437bdfdde20a75bdf59db1c1a77721613b22.tar.bz2
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@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/Kconfig1
-rw-r--r--drivers/regulator/max8973-regulator.c97
2 files changed, 98 insertions, 0 deletions
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index c77dc08b1202..129359f775d0 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -409,6 +409,7 @@ config REGULATOR_MAX8952
config REGULATOR_MAX8973
tristate "Maxim MAX8973 voltage regulator "
depends on I2C
+ depends on THERMAL && THERMAL_OF
select REGMAP_I2C
help
The MAXIM MAX8973 high-efficiency. three phase, DC-DC step-down
diff --git a/drivers/regulator/max8973-regulator.c b/drivers/regulator/max8973-regulator.c
index 5b75b7c2e3ea..08d2f13eca00 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 +97,12 @@
#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 +122,9 @@ 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 +404,10 @@ static int max8973_init_dcdc(struct max8973_chip *max,
if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
control1 |= MAX8973_FREQSHIFT_9PER;
+ if ((pdata->junction_temp_warning == MAX77621_TJINT_WARNING_TEMP_120) &&
+ (max->id == MAX77621))
+ control2 |= MAX77621_T_JUNCTION_120;
+
if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
control2 |= MAX8973_DISCH_ENBABLE;
@@ -457,6 +474,79 @@ static int max8973_init_dcdc(struct max8973_chip *max,
return ret;
}
+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, "Failed to read register CHIPID1, %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;
+
+ thermal_zone_device_update(mchip->tz_device);
+
+ 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 thermal_zone_device *tzd;
+ struct irq_data *irq_data;
+ unsigned long irq_flags = 0;
+ int ret;
+
+ if (mchip->id != MAX77621)
+ return 0;
+
+ tzd = devm_thermal_zone_of_sensor_register(mchip->dev, 0, mchip,
+ &max77621_tz_ops);
+ if (IS_ERR(tzd)) {
+ ret = PTR_ERR(tzd);
+ dev_err(mchip->dev, "Failed to register thermal sensor: %d\n",
+ ret);
+ 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 = devm_request_threaded_irq(mchip->dev, mchip->irq, NULL,
+ max8973_thermal_irq,
+ IRQF_ONESHOT | IRQF_SHARED | irq_flags,
+ dev_name(mchip->dev), mchip);
+ if (ret < 0) {
+ dev_err(mchip->dev, "Failed to request irq %d, %d\n",
+ mchip->irq, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
static const struct regmap_config max8973_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
@@ -521,6 +611,11 @@ static struct max8973_regulator_platform_data *max8973_parse_dt(
pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED;
}
+ pdata->junction_temp_warning = MAX77621_TJINT_WARNING_TEMP_140;
+ ret = of_property_read_u32(np, "junction-warn-millicelsius", &pval);
+ if (!ret && (pval <= MAX77621_TJINT_WARNING_TEMP_120))
+ pdata->junction_temp_warning = MAX77621_TJINT_WARNING_TEMP_120;
+
return pdata;
}
@@ -608,6 +703,7 @@ 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 +814,7 @@ static int max8973_probe(struct i2c_client *client,
return ret;
}
+ max8973_thermal_init(max);
return 0;
}