Subject: [PATCH 2/3] wlcore/wl12xx: spi: add device tree support

From: [email-masked] (Grygorii Strashko)
Date: Wed, 23 Dec 2015 12:25:57 +0200

On 12/23/2015 10:35 AM, Uri Mashiach wrote:
> Add DT support for the wl1271 SPI WiFi.
> 
> Add documentation file for the wl1271 SPI WiFi.
> 
> Signed-off-by: Uri Mashiach <[email-masked]>
> Acked-by: Igor Grinberg <[email-masked]>
> ---
>   .../bindings/net/wireless/ti,wlcore,spi.txt        | 35 +++++++++++
>   drivers/net/wireless/ti/wlcore/spi.c               | 67 +++++++++++++++++++---
>   2 files changed, 95 insertions(+), 7 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/net/wireless/ti,wlcore,spi.txt
> 
> diff --git a/Documentation/devicetree/bindings/net/wireless/ti,wlcore,spi.txt b/Documentation/devicetree/bindings/net/wireless/ti,wlcore,spi.txt
> new file mode 100644
> index 0000000..a3e7eb7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/wireless/ti,wlcore,spi.txt
> @@ -0,0 +1,35 @@
> +* Texas Instruments wl1271 wireless lan controller
> +
> +The wl1271 chip can be connected via SPI or via SDIO. This
> +document describes the binding for the SPI connected chip.
> +
> +Required properties:
> +- compatible :          Should be "ti,wl1271"
> +- reg :                 Chip select address of device
> +- spi-max-frequency :   Maximum SPI clocking speed of device in Hz
> +- ref-clock-frequency : Reference clock frequency
> +- interrupts :          Should contain interrupt line and trigger type

It's good to describe here number of IRQ lines your device have and IRQ types (edge/level) 

> +- interrupt-parent :    Should be the phandle for the interrupt controller
interrupt-parent is not required (also interrupts-extended can be used)

> +                        that services interrupts for this device
> +- vwlan-supply :        Point the node of the regulator that controls the wl1271 chip WLAN_EN pin

Pls, use gpio if this is required just to toggle WLAN_EN pin.

[ti,] power-gpio or en-gpio

> +
> +Optional properties:
> +- clock-xtal :          boolean, clock is generated from XTAL
> +
> +- Please consult Documentation/devicetree/bindings/spi/spi-bus.txt
> +  for optional SPI connection related properties,just
> +
> +Examples:
> +
> +&spi1 {
> +	wl1271 at 1 {
> +		compatible = "ti,wl1271";
> +
> +		reg = <1>;
> +		spi-max-frequency = <48000000>;
> +		clock-xtal;
> +		interrupt-parent = <&gpio3>;
> +		interrupts = <8 IRQ_TYPE_LEVEL_HIGH>;
> +		wifi-supply = <&wifi_fixed>;
> +	};
> +};
> diff --git a/drivers/net/wireless/ti/wlcore/spi.c b/drivers/net/wireless/ti/wlcore/spi.c
> index d3a4bcb..7281f5a 100644
> --- a/drivers/net/wireless/ti/wlcore/spi.c
> +++ b/drivers/net/wireless/ti/wlcore/spi.c
> @@ -30,6 +30,7 @@
>   #include <linux/spi/spi.h>
>   #include <linux/wl12xx.h>
>   #include <linux/platform_device.h>
> +#include <linux/of_irq.h>
>   #include <linux/regulator/consumer.h>
>   
>   #include "wlcore.h"
> @@ -357,6 +358,54 @@ static struct wl1271_if_operations spi_ops = {
>   	.set_block_size = NULL,
>   };
>   
> +#ifdef CONFIG_OF
> +static const struct of_device_id wlcore_spi_of_match_table[] = {
> +	{ .compatible = "ti,wl1271" },
> +	{ }
> +};
> +
> +/**
> + * wlcore_probe_of - DT node parsing.
> + * @spi: SPI slave device parameters.
> + * @res: resource parameters.
> + * @glue: wl12xx SPI bus to slave device glue parameters.
> + * @pdev_data: wlcore device parameters
> + */
> +static int wlcore_probe_of(struct spi_device *spi, struct resource *res,
> +			   struct wl12xx_spi_glue *glue,
> +			   struct wlcore_platdev_data *pdev_data)
> +{
> +	struct device_node *dt_node = spi->dev.of_node;
> +	int ret;
> +
> +	ret = of_irq_to_resource(dt_node, 0, &res[0]);
> +	if (spi->irq != ret) {
> +		dev_err(glue->dev, "can't get interrupt resource\n");
> +		return -EINVAL;
> +	}

SPI core will parse IRQ for you (see below)

> +
> +	if (of_find_property(dt_node, "clock-xtal", NULL))
> +		pdev_data->ref_clock_xtal = true;
> +
> +	ret = of_property_read_u32(dt_node, "ref-clock-frequency",
> +				   &pdev_data->ref_clock_freq);
> +	if (IS_ERR_VALUE(ret)) {
> +		dev_err(glue->dev,
> +			"can't get reference clock frequency (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +#else /* CONFIG_OF */
> +static int wlcore_probe_of(struct spi_device *spi, struct resource *res,
> +			   struct wl12xx_spi_glue *glue,
> +			   struct wlcore_platdev_data *pdev_data)
> +{
> +	return -ENODATA;
> +}
> +#endif /* CONFIG_OF */
> +
>   static int wl1271_probe(struct spi_device *spi)
>   {
>   	struct wl12xx_spi_glue *glue;
> @@ -365,8 +414,7 @@ static int wl1271_probe(struct spi_device *spi)
>   	int ret;
>   
>   	memset(&pdev_data, 0x00, sizeof(pdev_data));
> -
> -	/* TODO: add DT parsing when needed */
> +	memset(res, 0x00, sizeof(res));
>   
>   	pdev_data.if_ops = &spi_ops;
>   
> @@ -390,6 +438,13 @@ static int wl1271_probe(struct spi_device *spi)
>   		return PTR_ERR(glue->reg);
>   	}
>   
> +	ret = wlcore_probe_of(spi, &res[0], glue, &pdev_data);
> +	if (IS_ERR_VALUE(ret)) {
> +		dev_err(glue->dev,
> +			"can't get device tree parameters (%d)\n", ret);
> +		return ret;

So, wl1271_probe will fail always if CONFIG_OF=n. Right?

> +	}
> +
>   	ret = spi_setup(spi);
>   	if (ret < 0) {
>   		dev_err(glue->dev, "spi_setup failed\n");
> @@ -404,10 +459,6 @@ static int wl1271_probe(struct spi_device *spi)
>   
>   	glue->core->dev.parent = &spi->dev;
>   
> -	memset(res, 0x00, sizeof(res));
> -
> -	res[0].start = spi->irq;
> -	res[0].flags = IORESOURCE_IRQ;
>   	res[0].name = "irq";

Above code might be left unchaenged.

>   
>   	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
> @@ -445,10 +496,12 @@ static int wl1271_remove(struct spi_device *spi)
>   	return 0;
>   }
>   
> -
>   static struct spi_driver wl1271_spi_driver = {
>   	.driver = {
>   		.name		= "wl1271_spi",
> +#ifdef CONFIG_OF
> +		.of_match_table = of_match_ptr(wlcore_spi_of_match_table),
> +#endif /* CONFIG_OF */

These ifdefs are not needed - see of_match_ptr() definition

>   	},
>   	.probe		= wl1271_probe,

-- 
regards,
-grygorii