[PATCH v5 2/4] regulator: adapt fixed regulator driver to dt

From: Rajendra Nayak
Date: Fri Nov 18 2011 - 06:18:18 EST


The fixed regulator driver uses of_get_fixed_voltage_config()
to extract fixed_voltage_config structure contents from device tree.

Also add documenation for additional bindings for fixed
regulators that can be passed through dt.

Signed-off-by: Rajendra Nayak <rnayak@xxxxxx>
---
.../bindings/regulator/fixed-regulator.txt | 29 +++++++++
drivers/regulator/fixed.c | 65 ++++++++++++++++++++
2 files changed, 94 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/regulator/fixed-regulator.txt

diff --git a/Documentation/devicetree/bindings/regulator/fixed-regulator.txt b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
new file mode 100644
index 0000000..9cf57fd
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
@@ -0,0 +1,29 @@
+Fixed Voltage regulators
+
+Required properties:
+- compatible: Must be "regulator-fixed";
+
+Optional properties:
+- gpio: gpio to use for enable control
+- startup-delay-us: startup time in microseconds
+- enable-active-high: Polarity of GPIO is Active high
+If this property is missing, the default assumed is Active low.
+
+Any property defined as part of the core regulator
+binding, defined in regulator.txt, can also be used.
+However a fixed voltage regulator is expected to have the
+regulator-min-microvolt and regulator-max-microvolt
+to be the same.
+
+Example:
+
+ abc: fixedregulator@0 {
+ compatible = "regulator-fixed";
+ regulator-name = "fixed-supply";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ gpio = <&gpio1 16 0>;
+ startup-delay-us = <70000>;
+ enable-active-high;
+ regulator-boot-on
+ };
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index 21ecf21..0650856 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -27,6 +27,10 @@
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/regulator/machine.h>

struct fixed_voltage_data {
struct regulator_desc desc;
@@ -38,6 +42,53 @@ struct fixed_voltage_data {
bool is_enabled;
};

+
+/**
+ * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
+ * @dev: device requesting for fixed_voltage_config
+ *
+ * Populates fixed_voltage_config structure by extracting data from device
+ * tree node, returns a pointer to the populated structure of NULL if memory
+ * alloc fails.
+ */
+struct fixed_voltage_config *of_get_fixed_voltage_config(struct device *dev)
+{
+ struct fixed_voltage_config *config;
+ struct device_node *np = dev->of_node;
+ const __be32 *delay;
+ struct regulator_init_data *init_data;
+
+ config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
+ GFP_KERNEL);
+ if (!config)
+ return NULL;
+
+ config->init_data = of_get_regulator_init_data(dev);
+ init_data = config->init_data;
+
+ config->supply_name = init_data->constraints.name;
+ if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
+ config->microvolts = init_data->constraints.min_uV;
+ } else {
+ dev_err(dev,
+ "Fixed regulator specified with variable voltages\n");
+ return NULL;
+ }
+
+ if (init_data->constraints.boot_on)
+ config->enabled_at_boot = true;
+
+ config->gpio = of_get_named_gpio(np, "gpio", 0);
+ delay = of_get_property(np, "startup-delay-us", NULL);
+ if (delay)
+ config->startup_delay = be32_to_cpu(*delay);
+
+ if (of_find_property(np, "enable-active-high", NULL))
+ config->enable_high = true;
+
+ return config;
+}
+
static int fixed_voltage_is_enabled(struct regulator_dev *dev)
{
struct fixed_voltage_data *data = rdev_get_drvdata(dev);
@@ -109,6 +160,9 @@ static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
struct fixed_voltage_data *drvdata;
int ret;

+ if (pdev->dev.of_node)
+ config = of_get_fixed_voltage_config(&pdev->dev);
+
drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
if (drvdata == NULL) {
dev_err(&pdev->dev, "Failed to allocate device data\n");
@@ -217,12 +271,23 @@ static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
return 0;
}

+#if defined(CONFIG_OF)
+static const struct of_device_id fixed_of_match[] __devinitconst = {
+ { .compatible = "regulator-fixed", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, fixed_of_match);
+#else
+#define fixed_of_match NULL
+#endif
+
static struct platform_driver regulator_fixed_voltage_driver = {
.probe = reg_fixed_voltage_probe,
.remove = __devexit_p(reg_fixed_voltage_remove),
.driver = {
.name = "reg-fixed-voltage",
.owner = THIS_MODULE,
+ .of_match_table = fixed_of_match,
},
};

--
1.7.1

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