Re: [PATCH v2 4/5] regulator: adapt fixed regulator driver to dt

[Grant Likely]

On Mon, Oct 10, 2011 at 09:49:37PM +0530, Rajendra Nayak wrote:
> 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         |   25 +++++++++
>  drivers/regulator/fixed.c                          |   58 ++++++++++++++++++++
>  2 files changed, 83 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..049df3d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/fixed-regulator.txt
> @@ -0,0 +1,25 @@
> +Fixed Voltage regulators
> +
> +Required properties:
> +- compatible: Must be "regulator-fixed";
> +
> +Optional properties:
> +- regulator-fixed-supply: Name of the regulator supply
> +- regulator-fixed-microvolts: Output voltage of regulator
> +- regulator-fixed-gpio: gpio to use for enable control
> +- regulator-fixed-startup-delay: startup time in microseconds
> +- regulator-fixed-enable-high: Polarity of enable GPIO,
> +  1 = Active High, 0 = Active low
> +- regulator-fixed-enabled-at-boot: 1 = yes, 0 = no
> +
> +Example:
> +
> +	abc: fixedregulator@0 {
> +		compatible = "regulator-fixed";
> +		regulator-fixed-supply = "fixed-supply";
> +		regulator-fixed-microvolts = <1800000>;
> +		regulator-fixed-gpio = <43>;
> +		regulator-fixed-startup-delay = <70000>;
> +		regulator-fixed-enable-high;
> +		regulator-fixed-enabled-at-boot;
> +	};
> diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
> index 2fe9d99..eb37eb6 100644
> --- a/drivers/regulator/fixed.c
> +++ b/drivers/regulator/fixed.c
> @@ -23,9 +23,12 @@
>  #include <linux/platform_device.h>
>  #include <linux/regulator/driver.h>
>  #include <linux/regulator/fixed.h>
> +#include <linux/regulator/machine.h>
>  #include <linux/gpio.h>
>  #include <linux/delay.h>
>  #include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/regulator/of_regulator.h>
>  
>  struct fixed_voltage_data {
>  	struct regulator_desc desc;
> @@ -37,6 +40,47 @@ 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 *microvolts, *gpio, *delay;
> +
> +	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config), GFP_KERNEL);
> +	if (!config)
> +		return NULL;
> +
> +	config->supply_name = (char *)of_get_property(np,
> +					"regulator-fixed-supply", NULL);

of_get_property() returns a (const void *).  Casting drops the const
and should not be used.  Either make supply_name a (const char *), or
copy the string into a (char *) buffer.

> +	microvolts = of_get_property(np, "regulator-fixed-microvolts", NULL);
> +	if (microvolts)
> +		config->microvolts = be32_to_cpu(*microvolts);
> +	gpio = of_get_property(np, "regulator-fixed-gpio", NULL);
> +	if (gpio)
> +		config->gpio = be32_to_cpu(*gpio);

of_property_read_u32() may help here.

> +	delay = of_get_property(np, "regulator-fixed-startup-delay", NULL);
> +	if (delay)
> +		config->startup_delay = be32_to_cpu(*delay);
> +
> +	if (of_find_property(np, "regulator-fixed-enable-high", NULL))
> +		config->enable_high = true;
> +	if (of_find_property(np, "regulator-fixed-enabled-at-boot", NULL))
> +		config->enabled_at_boot = true;
> +
> +	config->init_data = of_get_regulator_init_data(dev);
> +
> +	return config;
> +}
> +
>  static int fixed_voltage_is_enabled(struct regulator_dev *dev)
>  {
>  	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
> @@ -108,6 +152,9 @@ 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");
> @@ -216,12 +263,23 @@ 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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