Re: [PATCH v5 5/7] gpio: davinci: add OF support

[Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>]

On 11/08/2013 12:11 PM, Prabhakar Lad wrote:
> From: KV Sujith <sujithkv-l0cyMroinI0@public.gmane.org>
> 
> This patch adds OF parser support for davinci gpio
> driver and also appropriate documentation in gpio-davinci.txt
> located at Documentation/devicetree/bindings/gpio/.
> 
> Signed-off-by: KV Sujith <sujithkv-l0cyMroinI0@public.gmane.org>
> Signed-off-by: Philip Avinash <avinashphilip-l0cyMroinI0@public.gmane.org>
> [prabhakar.csengg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org: simplified the OF code, removed
> 		unnecessary DT property and also simplified
> 		the commit message]
> Signed-off-by: Lad, Prabhakar <prabhakar.csengg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>   .../devicetree/bindings/gpio/gpio-davinci.txt      |   39 ++++++++++++++
>   drivers/gpio/gpio-davinci.c                        |   54 ++++++++++++++++++--
>   2 files changed, 90 insertions(+), 3 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> 
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> new file mode 100644
> index 0000000..d677bbe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> @@ -0,0 +1,39 @@
> +Davinci GPIO controller bindings
> +
> +Required Properties:
> +- compatible: should be "ti,dm6441-gpio"
> +
> +- reg: Physical base address of the controller and the size of memory mapped
> +       registers.
> +
> +- gpio-controller : Marks the device node as a gpio controller.
> +
> +- interrupt-parent: phandle of the parent interrupt controller.
> +
> +- interrupts: Array of GPIO interrupt number. Only banked or unbanked IRQs are
> +	      supported at a time.
> +
> +- ti,ngpio: The number of GPIO pins supported.
> +
> +- ti,davinci-gpio-unbanked: The number of GPIOs that have an individual interrupt
> +		             line to processor.
> +
> +The GPIO controller also acts as an interrupt controller. It uses the default
> +two cells specifier as described in Documentation/devicetree/bindings/
> +interrupt-controller/interrupts.txt.
> +
> +Example:
> +
> +gpio: gpio@1e26000 {
> +	compatible = "ti,dm6441-gpio";
> +	gpio-controller;
> +	reg = <0x226000 0x1000>;
> +	interrupt-parent = <&intc>;
> +	interrupts = <42 IRQ_TYPE_EDGE_BOTH 43 IRQ_TYPE_EDGE_BOTH
> +		44 IRQ_TYPE_EDGE_BOTH 45 IRQ_TYPE_EDGE_BOTH
> +		46 IRQ_TYPE_EDGE_BOTH 47 IRQ_TYPE_EDGE_BOTH
> +		48 IRQ_TYPE_EDGE_BOTH 49 IRQ_TYPE_EDGE_BOTH
> +		50 IRQ_TYPE_EDGE_BOTH>;
> +	ti,ngpio = <144>;
> +	ti,davinci-gpio-unbanked = <0>;
> +};
> diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
> index b149239..ed04835 100644
> --- a/drivers/gpio/gpio-davinci.c
> +++ b/drivers/gpio/gpio-davinci.c
> @@ -17,6 +17,9 @@
>   #include <linux/io.h>
>   #include <linux/irq.h>
>   #include <linux/irqdomain.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>   #include <linux/platform_device.h>
>   #include <linux/platform_data/gpio-davinci.h>
>   
> @@ -134,6 +137,40 @@ davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
>   	writel((1 << offset), value ? &g->set_data : &g->clr_data);
>   }
>   
> +static struct davinci_gpio_platform_data *
> +davinci_gpio_get_pdata(struct platform_device *pdev)

Minor: usually such functions have "_of" in their names:
 davinci_gpio_of_get_pdata()

> +{
> +	struct device_node *dn = pdev->dev.of_node;
> +	struct davinci_gpio_platform_data *pdata;
> +	int ret;
> +	u32 val;
> +
> +	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
> +		return pdev->dev.platform_data;
> +
> +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		return NULL;
> +
> +	ret = of_property_read_u32(dn, "ti,ngpio", &val);
> +	if (ret)
> +		goto of_err;
> +
> +	pdata->ngpio = val;
> +
> +	ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
> +	if (ret)
> +		goto of_err;
> +
> +	pdata->gpio_unbanked = val;
> +
> +	return pdata;
> +
> +of_err:
> +	dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
> +	return NULL;
> +}
> +
>   static int davinci_gpio_probe(struct platform_device *pdev)
>   {
>   	int i, base;
> @@ -144,12 +181,14 @@ static int davinci_gpio_probe(struct platform_device *pdev)
>   	struct device *dev = &pdev->dev;
>   	struct resource *res;
>   
> -	pdata = dev->platform_data;
> +	pdata = davinci_gpio_get_pdata(pdev);
>   	if (!pdata) {
>   		dev_err(dev, "No platform data found\n");
>   		return -EINVAL;
>   	}
>   
> +	dev->platform_data = pdata;
> +

Pls, add following code to GPIO chip initialization:

@@ -233,6 +245,9 @@ static int davinci_gpio_probe(struct platform_device *pdev)
                chips[i].chip.ngpio = ngpio - base;
                if (chips[i].chip.ngpio > 32)
                        chips[i].chip.ngpio = 32;
+#ifdef CONFIG_OF_GPIO
+               chips[i].chip.of_node = dev->of_node;
+#endif



>   	/*
>   	 * The gpio banks conceptually expose a segmented bitmap,
>   	 * and "ngpio" is one more than the largest zero-based
> @@ -496,11 +535,20 @@ done:
>   	return 0;
>   }
>   
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id davinci_gpio_ids[] = {
> +	{ .compatible = "ti,dm6441-gpio", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
> +#endif
> +
>   static struct platform_driver davinci_gpio_driver = {
>   	.probe		= davinci_gpio_probe,
>   	.driver		= {
> -		.name	= "davinci_gpio",
> -		.owner	= THIS_MODULE,
> +		.name		= "davinci_gpio",
> +		.owner		= THIS_MODULE,
> +		.of_match_table	= of_match_ptr(davinci_gpio_ids),
>   	},
>   };
>   
> 
Regards,
- grygorii