From: Axel Haslam <ahaslam@xxxxxxxxxxxx>
Some regulator supplies have an over-current pin that is
activated when the hw detects an over current condition.
When this happens, the hardware enters a current limited
mode.
Extend the fixed regulator driver with the ability
to handle irq's from the over-current pin and report
an over current event to the consumers via a regulator
notifier. Also, add device tree bindings to allow to
pass a gpio for over current monitoring.
Signed-off-by: Axel Haslam <ahaslam@xxxxxxxxxxxx>
---
.../bindings/regulator/fixed-regulator.txt | 4 ++
drivers/regulator/fixed.c | 64 ++++++++++++++++++++++
include/linux/regulator/consumer.h | 5 ++
include/linux/regulator/fixed.h | 3 +
4 files changed, 76 insertions(+)
diff --git a/Documentation/devicetree/bindings/regulator/fixed-regulator.txt b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
index 4fae41d..d20bf67 100644
--- a/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
@@ -11,6 +11,8 @@ If this property is missing, the default assumed is Active low.
- gpio-open-drain: GPIO is open drain type.
If this property is missing then default assumption is false.
-vin-supply: Input supply name.
+- oc-gpio: Input gpio that signals an over current condition
+- oc-active-high: The polarity of the over current pin is high
Any property defined as part of the core regulator
binding, defined in regulator.txt, can also be used.
@@ -26,9 +28,11 @@ Example:
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
gpio = <&gpio1 16 0>;
+ oc-gpio = <&gpio1 18 0>;
startup-delay-us = <70000>;
enable-active-high;
regulator-boot-on;
gpio-open-drain;
+ oc-active-high;
vin-supply = <&parent_reg>;
};
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index 988a747..e7964bb 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -30,10 +30,14 @@
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.h>
+#include <linux/interrupt.h>
struct fixed_voltage_data {
struct regulator_desc desc;
struct regulator_dev *dev;
+ int oc_gpio;
+ unsigned has_oc_gpio:1;
+ unsigned oc_high:1;
};
@@ -82,6 +86,14 @@ struct fixed_voltage_data {
if ((config->gpio < 0) && (config->gpio != -ENOENT))
return ERR_PTR(config->gpio);
+ config->oc_gpio = of_get_named_gpio(np, "oc-gpio", 0);
+ if (config->oc_gpio >= 0)
+ config->has_oc_gpio = true;
+ else if (config->oc_gpio != -ENOENT)
+ return ERR_PTR(config->oc_gpio);
+
+ config->oc_high = of_property_read_bool(np, "oc-active-high");
+
of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
config->enable_high = of_property_read_bool(np, "enable-active-high");
@@ -94,7 +106,34 @@ struct fixed_voltage_data {
return config;
}
+static irqreturn_t reg_fixed_overcurrent_irq(int irq, void *data)
+{
+ struct fixed_voltage_data *drvdata = data;
+
+ regulator_notifier_call_chain(drvdata->dev,
+ REGULATOR_EVENT_OVER_CURRENT, NULL);
+
+ return IRQ_HANDLED;
+}
+
+static unsigned int reg_fixed_get_mode(struct regulator_dev *rdev)
+{
+ struct fixed_voltage_data *drvdata = rdev_get_drvdata(rdev);
+ unsigned int ret = REGULATOR_MODE_NORMAL;
+ int oc_value;
+
+ if (!drvdata->has_oc_gpio)
+ return ret;
+
+ oc_value = gpio_get_value(drvdata->oc_gpio);
+ if ((oc_value && drvdata->oc_high) || (!oc_value && !drvdata->oc_high))
+ ret = REGULATOR_MODE_OVERCURRENT;
+
+ return ret;
+}
+
static struct regulator_ops fixed_voltage_ops = {
+ .get_mode = reg_fixed_get_mode,
};
static int reg_fixed_voltage_probe(struct platform_device *pdev)
@@ -175,6 +214,31 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
cfg.driver_data = drvdata;
cfg.of_node = pdev->dev.of_node;
+ if (config->has_oc_gpio && gpio_is_valid(config->oc_gpio)) {
+ ret = devm_gpio_request_one(&pdev->dev,
+ config->oc_gpio,
+ GPIOF_DIR_IN, "oc_gpio");
+ if (ret) {
+ pr_err("Failed to request gpio: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev,
+ gpio_to_irq(config->oc_gpio), NULL,
+ reg_fixed_overcurrent_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+ IRQF_ONESHOT,
+ "over_current", drvdata);
+ if (ret) {
+ pr_err("Failed to request irq: %d\n", ret);
+ return ret;
+ }
+
+ drvdata->oc_gpio = config->oc_gpio;
+ drvdata->oc_high = config->oc_high;
+ drvdata->has_oc_gpio = config->has_oc_gpio;
+ }
+
drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
&cfg);
if (IS_ERR(drvdata->dev)) {
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index 6921082..9269217 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -74,6 +74,10 @@
* the most noisy and may not be able to handle fast load
* switching.
*
+ * OVERCURRENT Regulator has detected an overcurrent condition, and
+ * may be limiting the supply output.
+ *
+ *
* NOTE: Most regulators will only support a subset of these modes. Some
* will only just support NORMAL.
*
@@ -84,6 +88,7 @@
#define REGULATOR_MODE_NORMAL 0x2
#define REGULATOR_MODE_IDLE 0x4
#define REGULATOR_MODE_STANDBY 0x8
+#define REGULATOR_MODE_OVERCURRENT 0x10
/*
* Regulator notifier events.
diff --git a/include/linux/regulator/fixed.h b/include/linux/regulator/fixed.h
index 48918be..79357be 100644
--- a/include/linux/regulator/fixed.h
+++ b/include/linux/regulator/fixed.h
@@ -50,10 +50,13 @@ struct fixed_voltage_config {
const char *input_supply;
int microvolts;
int gpio;
+ int oc_gpio;
unsigned startup_delay;
unsigned gpio_is_open_drain:1;
unsigned enable_high:1;
unsigned enabled_at_boot:1;
+ unsigned has_oc_gpio:1;
+ unsigned oc_high:1;
struct regulator_init_data *init_data;
};
--
1.9.1
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