Re: [PATCH v3 2/4] regulator: adapt fixed regulator driver to dt

From: Olof Johansson
Date: Fri Nov 04 2011 - 16:34:09 EST


On Thu, Oct 27, 2011 at 01:26:23PM +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>

Shouldn't a fixed regulator just be a subset of a fixed one? If so, should the
binding be merged with that one?

> ---
> .../bindings/regulator/fixed-regulator.txt | 25 +++++++++
> drivers/regulator/fixed.c | 57 ++++++++++++++++++++
> 2 files changed, 82 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

Other regulator binding usese uV, here it's microvolts. Pick one, microvolts
has the benefit of not needing caps. :)

> +- regulator-fixed-gpio: gpio to use for enable control
> +- regulator-fixed-startup-delay: startup time in microseconds

startup-delay-ms ?

> +- regulator-fixed-enable-high: Polarity of enable GPIO,
> + 1 = Active High, 0 = Active low

Some gpio specifiers allow you to specify active high or low flags, but either
way something like "enable-active-low" as a property (with active high as
default if property is missing) is a more devicetreey convention.

> +- regulator-fixed-enabled-at-boot: 1 = yes, 0 = no

Same here, you can drop the prefix. Also, the regular regulators use
"regulator-name" for the supply name, it would make sense to reuse the same
naming here, right?

> +
> +Example:
> +
> + abc: fixedregulator@0 {
> + compatible = "regulator-fixed";
> + regulator-fixed-supply = "fixed-supply";
> + regulator-fixed-microvolts = <1800000>;
> + regulator-fixed-gpio = <43>;

This is not a valid gpio specifier.

> + 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..9851b42 100644
> --- a/drivers/regulator/fixed.c
> +++ b/drivers/regulator/fixed.c
> @@ -26,6 +26,9 @@
> #include <linux/gpio.h>
> #include <linux/delay.h>
> #include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/regulator/of_regulator.h>
> +#include <linux/regulator/machine.h>
>
> struct fixed_voltage_data {
> struct regulator_desc desc;
> @@ -37,6 +40,46 @@ 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 = of_get_property(np, "regulator-fixed-supply", NULL);
> + 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);

This needs to be fixed to parse a gpio properly instead.



-Olof
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