Subject: [PATCH v5 1/4] leds: netxbig: add device tree binding

From: [email-masked] (Jacek Anaszewski)
Date: Thu, 24 Sep 2015 14:19:56 +0200

Hi Simon,

On 09/22/2015 10:24 AM, Simon Guinot wrote:
> This patch adds device tree support for the netxbig LEDs.
>
> This also introduces a additionnal DT binding for the GPIO extension bus
> (netxbig-gpio-ext) used to configure the LEDs. Since this bus could also
> be used to control other devices, then it seems more suitable to have it
> in a separate DT binding.
>
> Signed-off-by: Simon Guinot <[email-masked]>
> Acked-by: Linus Walleij <[email-masked]>
> ---
>   .../devicetree/bindings/gpio/netxbig-gpio-ext.txt  |  22 ++
>   .../devicetree/bindings/leds/leds-netxbig.txt      |  92 +++++++
>   drivers/leds/leds-netxbig.c                        | 265 +++++++++++++++++++--
>   include/dt-bindings/leds/leds-netxbig.h            |  18 ++
>   .../linux/platform_data/leds-kirkwood-netxbig.h    |   1 +
>   5 files changed, 376 insertions(+), 22 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt
>   create mode 100644 Documentation/devicetree/bindings/leds/leds-netxbig.txt
>   create mode 100644 include/dt-bindings/leds/leds-netxbig.h
>
> Changes for v2:
> - Check timer mode value retrieved from DT.
> - In netxbig_leds_get_of_pdata, don't use unsigned long variables to get
>    timer delay values from DT with function of_property_read_u32_index.
>    Instead, use a temporary u32 variable. This allows to silence a static
>    checker warning.
> - Make timer property optional in the binding documentation. It is now
>    aligned with the driver code.
>
> Changes for v3:
> - Fix pointer usage with the temporary u32 variable while calling
>    of_property_read_u32_index.
>
> Changes for v4:
> - In DT binding document netxbig-gpio-ext.txt, detail byte order for
>    registers and latch mechanism for "enable-gpio".
> - In leds-netxbig.c, add some error messages.
> - In leds-netxbig.c, fix some "sizeof" style issues.
> - In leds-netxbig.c, in netxbig_leds_get_of_pdata(), move the
>    of_property_read_string() calls after the error-prone checks.
> - Add some Acked-by.
>
> Changes for v5:
> - Rename DT property "bright-max" into the more common "max-brightness".
> - Make use of the "max-brightness" DT property. Instead of counting the
>    data pins of the GPIO extension bus, use "max-brightness" to get the
>    maximum brightness level.
>
> diff --git a/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt b/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt
> new file mode 100644
> index 000000000000..50ec2e690701
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/netxbig-gpio-ext.txt
> @@ -0,0 +1,22 @@
> +Binding for the GPIO extension bus found on some LaCie/Seagate boards
> +(Example: 2Big/5Big Network v2, 2Big NAS).
> +
> +Required properties:
> +- compatible: "lacie,netxbig-gpio-ext".
> +- addr-gpios: GPIOs representing the address register (LSB -> MSB).
> +- data-gpios: GPIOs representing the data register (LSB -> MSB).
> +- enable-gpio: latches the new configuration (address, data) on raising edge.
> +
> +Example:
> +
> +netxbig_gpio_ext: netxbig-gpio-ext {
> +	compatible = "lacie,netxbig-gpio-ext";
> +
> +	addr-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH
> +		      &gpio1 16 GPIO_ACTIVE_HIGH
> +		      &gpio1 17 GPIO_ACTIVE_HIGH>;
> +	data-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH
> +		      &gpio1 13 GPIO_ACTIVE_HIGH
> +		      &gpio1 14 GPIO_ACTIVE_HIGH>;
> +	enable-gpio = <&gpio0 29 GPIO_ACTIVE_HIGH>;
> +};
> diff --git a/Documentation/devicetree/bindings/leds/leds-netxbig.txt b/Documentation/devicetree/bindings/leds/leds-netxbig.txt
> new file mode 100644
> index 000000000000..5ef92a26d768
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-netxbig.txt
> @@ -0,0 +1,92 @@
> +Binding for the CPLD LEDs (GPIO extension bus) found on some LaCie/Seagate
> +boards (Example: 2Big/5Big Network v2, 2Big NAS).
> +
> +Required properties:
> +- compatible: "lacie,netxbig-leds".
> +- gpio-ext: Phandle for the gpio-ext bus.
> +
> +Optional properties:
> +- timers: Timer array. Each timer entry is represented by three integers:
> +  Mode (gpio-ext bus), delay_on and delay_off.
> +
> +Each LED is represented as a sub-node of the netxbig-leds device.
> +
> +Required sub-node properties:
> +- mode-addr: Mode register address on gpio-ext bus.
> +- mode-val: Mode to value mapping. Each entry is represented by two integers:
> +  A mode and the corresponding value on the gpio-ext bus.
> +- bright-addr: Brightness register address on gpio-ext bus.
> +- max-brightness: Maximum brightness value.
> +
> +Optional sub-node properties:
> +- label: Name for this LED. If omitted, the label is taken from the node name.
> +- linux,default-trigger: Trigger assigned to the LED.
> +
> +Example:
> +
> +netxbig-leds {
> +	compatible = "lacie,netxbig-leds";
> +
> +	gpio-ext = &gpio_ext;
> +
> +	timers = <NETXBIG_LED_TIMER1 500 500
> +		  NETXBIG_LED_TIMER2 500 1000>;
> +
> +	blue-power {
> +		label = "netxbig:blue:power";
> +		mode-addr = <0>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 1
> +			    NETXBIG_LED_TIMER1 3
> +			    NETXBIG_LED_TIMER2 7>;
> +		bright-addr = <1>;
> +		max-brightness = <7>;
> +	};
> +	red-power {
> +		label = "netxbig:red:power";
> +		mode-addr = <0>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 2
> +			    NETXBIG_LED_TIMER1 4>;
> +		bright-addr = <1>;
> +		max-brightness = <7>;
> +	};
> +	blue-sata0 {
> +		label = "netxbig:blue:sata0";
> +		mode-addr = <3>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 7
> +			    NETXBIG_LED_SATA 1
> +			    NETXBIG_LED_TIMER1 3>;
> +		bright-addr = <2>;
> +		max-brightness = <7>;
> +	};
> +	red-sata0 {
> +		label = "netxbig:red:sata0";
> +		mode-addr = <3>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 2
> +			    NETXBIG_LED_TIMER1 4>;
> +		bright-addr = <2>;
> +		max-brightness = <7>;
> +	};
> +	blue-sata1 {
> +		label = "netxbig:blue:sata1";
> +		mode-addr = <4>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 7
> +			    NETXBIG_LED_SATA 1
> +			    NETXBIG_LED_TIMER1 3>;
> +		bright-addr = <2>;
> +		max-brightness = <7>;
> +	};
> +	red-sata1 {
> +		label = "netxbig:red:sata1";
> +		mode-addr = <4>;
> +		mode-val = <NETXBIG_LED_OFF 0
> +			    NETXBIG_LED_ON 2
> +			    NETXBIG_LED_TIMER1 4>;
> +		bright-addr = <2>;
> +		max-brightness = <7>;
> +	};
> +};
> diff --git a/drivers/leds/leds-netxbig.c b/drivers/leds/leds-netxbig.c
> index 25e419752a7b..19dac94b0364 100644
> --- a/drivers/leds/leds-netxbig.c
> +++ b/drivers/leds/leds-netxbig.c
> @@ -26,6 +26,7 @@
>   #include <linux/spinlock.h>
>   #include <linux/platform_device.h>
>   #include <linux/gpio.h>
> +#include <linux/of_gpio.h>
>   #include <linux/leds.h>
>   #include <linux/platform_data/leds-kirkwood-netxbig.h>
>
> @@ -140,6 +141,11 @@ struct netxbig_led_data {
>   	spinlock_t		lock;
>   };
>
> +struct netxbig_led_priv {
> +	struct netxbig_led_platform_data *pdata;
> +	struct netxbig_led_data leds_data[];
> +};
> +
>   static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
>   				      unsigned long delay_on,
>   				      unsigned long delay_off,
> @@ -304,12 +310,12 @@ static void delete_netxbig_led(struct netxbig_led_data *led_dat)
>   	led_classdev_unregister(&led_dat->cdev);
>   }
>
> -static int
> -create_netxbig_led(struct platform_device *pdev,
> -		   struct netxbig_led_data *led_dat,
> -		   const struct netxbig_led *template)
> +static int create_netxbig_led(struct platform_device *pdev, int led,
> +			      struct netxbig_led_priv *priv)
>   {
> -	struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
> +	struct netxbig_led_platform_data *pdata = priv->pdata;
> +	struct netxbig_led_data *led_dat = &priv->leds_data[led];
> +	const struct netxbig_led *template = &priv->pdata->leds[led];
>
>   	spin_lock_init(&led_dat->lock);
>   	led_dat->gpio_ext = pdata->gpio_ext;
> @@ -333,7 +339,7 @@ create_netxbig_led(struct platform_device *pdev,
>   	led_dat->mode_addr = template->mode_addr;
>   	led_dat->mode_val = template->mode_val;
>   	led_dat->bright_addr = template->bright_addr;
> -	led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
> +	led_dat->bright_max = template->bright_max;

Could you explain please, why in netxbig_led_set() led_dat->bright_max
is multiplied by the brightness value to be set as shown below?

void netxbig_led_set(struct led_classdev *led_cdev,
                      enum led_brightness value)
{
...
         if (set_brightness) {
                 bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
                                           LED_FULL);
                 gpio_ext_set_value(led_dat->gpio_ext,
                                    led_dat->bright_addr, bright_val);
         }
...
}

>   	led_dat->timer = pdata->timer;
>   	led_dat->num_timer = pdata->num_timer;
>   	/*
> @@ -346,38 +352,254 @@ create_netxbig_led(struct platform_device *pdev,
>   	return led_classdev_register(&pdev->dev, &led_dat->cdev);
>   }
>
> +#ifdef CONFIG_OF_GPIO
> +static int gpio_ext_get_of_pdata(struct device *dev, struct device_node *np,
> +				 struct netxbig_gpio_ext *gpio_ext)
> +{
> +	int *addr, *data;
> +	int num_addr, num_data;
> +	int ret;
> +	int i;
> +
> +	ret = of_gpio_named_count(np, "addr-gpios");
> +	if (ret < 0) {
> +		dev_err(dev,
> +			"Failed to count GPIOs in DT property addr-gpios\n");
> +		return ret;
> +	}
> +	num_addr = ret;
> +	addr = devm_kzalloc(dev, num_addr * sizeof(*addr), GFP_KERNEL);
> +	if (!addr)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_addr; i++) {
> +		ret = of_get_named_gpio(np, "addr-gpios", i);
> +		if (ret < 0)
> +			return ret;
> +		addr[i] = ret;
> +	}
> +	gpio_ext->addr = addr;
> +	gpio_ext->num_addr = num_addr;
> +
> +	ret = of_gpio_named_count(np, "data-gpios");
> +	if (ret < 0) {
> +		dev_err(dev,
> +			"Failed to count GPIOs in DT property data-gpios\n");
> +		return ret;
> +	}
> +	num_data = ret;
> +	data = devm_kzalloc(dev, num_data * sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_data; i++) {
> +		ret = of_get_named_gpio(np, "data-gpios", i);
> +		if (ret < 0)
> +			return ret;
> +		data[i] = ret;
> +	}
> +	gpio_ext->data = data;
> +	gpio_ext->num_data = num_data;
> +
> +	ret = of_get_named_gpio(np, "enable-gpio", 0);
> +	if (ret < 0) {
> +		dev_err(dev,
> +			"Failed to get GPIO from DT property enable-gpio\n");
> +		return ret;
> +	}
> +	gpio_ext->enable = ret;
> +
> +	return 0;
> +}
> +
> +static int netxbig_leds_get_of_pdata(struct device *dev,
> +				     struct netxbig_led_platform_data *pdata)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct device_node *gpio_ext_np;
> +	struct device_node *child;
> +	struct netxbig_gpio_ext *gpio_ext;
> +	struct netxbig_led_timer *timers;
> +	struct netxbig_led *leds, *led;
> +	int num_timers;
> +	int num_leds = 0;
> +	int ret;
> +	int i;
> +
> +	/* GPIO extension */
> +	gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
> +	if (!gpio_ext_np) {
> +		dev_err(dev, "Failed to get DT handle gpio-ext\n");
> +		return -EINVAL;
> +	}
> +
> +	gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
> +	if (!gpio_ext)
> +		return -ENOMEM;
> +	ret = gpio_ext_get_of_pdata(dev, gpio_ext_np, gpio_ext);
> +	if (ret)
> +		return ret;
> +	of_node_put(gpio_ext_np);
> +	pdata->gpio_ext = gpio_ext;
> +
> +	/* Timers (optional) */
> +	ret = of_property_count_u32_elems(np, "timers");
> +	if (ret > 0) {
> +		if (ret % 3)
> +			return -EINVAL;
> +		num_timers = ret / 3;
> +		timers = devm_kzalloc(dev, num_timers * sizeof(*timers),
> +				      GFP_KERNEL);
> +		if (!timers)
> +			return -ENOMEM;
> +		for (i = 0; i < num_timers; i++) {
> +			u32 tmp;
> +
> +			of_property_read_u32_index(np, "timers", 3 * i,
> +						   &timers[i].mode);
> +			if (timers[i].mode >= NETXBIG_LED_MODE_NUM)
> +				return -EINVAL;
> +			of_property_read_u32_index(np, "timers",
> +						   3 * i + 1, &tmp);
> +			timers[i].delay_on = tmp;
> +			of_property_read_u32_index(np, "timers",
> +						   3 * i + 2, &tmp);
> +			timers[i].delay_off = tmp;
> +		}
> +		pdata->timer = timers;
> +		pdata->num_timer = num_timers;
> +	}
> +
> +	/* LEDs */
> +	num_leds = of_get_child_count(np);
> +	if (!num_leds) {
> +		dev_err(dev, "No LED subnodes found in DT\n");
> +		return -ENODEV;
> +	}
> +
> +	leds = devm_kzalloc(dev, num_leds * sizeof(*leds), GFP_KERNEL);
> +	if (!leds)
> +		return -ENOMEM;
> +
> +	led = leds;
> +	for_each_child_of_node(np, child) {
> +		const char *string;
> +		int *mode_val;
> +		int num_modes;
> +
> +		if (of_property_read_u32(child, "mode-addr",
> +					 &led->mode_addr))
> +			return -EINVAL;

Since for_each_child_of_node uses of_get_next_child underneath,
the user is responsible for releasing current child in case
they are going to break the iteration. In other words you
need to execute of_node_put(child) then. Assigning error codes
to ret and following it with "goto exit_for_each" would do here,
where exit_for_each is defined as follows:

exit_for_each:
	of_node_put(child);
	return ret;

> +
> +		if (of_property_read_u32(child, "bright-addr",
> +					 &led->bright_addr))
> +			return -EINVAL;
> +
> +		if (of_property_read_u32(child, "max-brightness",
> +					 &led->bright_max))
> +			return -EINVAL;
> +		mode_val =
> +			devm_kzalloc(dev,
> +				     NETXBIG_LED_MODE_NUM * sizeof(*mode_val),
> +				     GFP_KERNEL);
> +		if (!mode_val)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
> +			mode_val[i] = NETXBIG_LED_INVALID_MODE;
> +
> +		ret = of_property_count_u32_elems(child, "mode-val");
> +		if (ret < 0 || ret % 2)
> +			return -EINVAL;
> +		num_modes = ret / 2;
> +		if (num_modes > NETXBIG_LED_MODE_NUM)
> +			return -EINVAL;
> +
> +		for (i = 0; i < num_modes; i++) {
> +			int mode;
> +			int val;
> +
> +			of_property_read_u32_index(child,
> +						   "mode-val", 2 * i, &mode);
> +			of_property_read_u32_index(child,
> +						   "mode-val", 2 * i + 1, &val);
> +			if (mode >= NETXBIG_LED_MODE_NUM)
> +				return -EINVAL;
> +			mode_val[mode] = val;
> +		}
> +		led->mode_val = mode_val;
> +
> +		if (!of_property_read_string(child, "label", &string))
> +			led->name = string;
> +		else
> +			led->name = child->name;
> +
> +		if (!of_property_read_string(child,
> +					     "linux,default-trigger", &string))
> +			led->default_trigger = string;
> +
> +		led++;
> +	}
> +
> +	pdata->leds = leds;
> +	pdata->num_leds = num_leds;
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id of_netxbig_leds_match[] = {
> +	{ .compatible = "lacie,netxbig-leds", },
> +	{},
> +};
> +#else
> +static inline int
> +netxbig_leds_get_of_pdata(struct device *dev,
> +			  struct netxbig_led_platform_data *pdata)
> +{
> +	return -ENODEV;
> +}
> +#endif /* CONFIG_OF_GPIO */
> +
>   static int netxbig_led_probe(struct platform_device *pdev)
>   {
>   	struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
> -	struct netxbig_led_data *leds_data;
> +	struct netxbig_led_priv *priv;
>   	int i;
>   	int ret;
>
> -	if (!pdata)
> -		return -EINVAL;
> +	if (!pdata) {
> +		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> +		if (!pdata)
> +			return -ENOMEM;
> +		ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
> +		if (ret)
> +			return ret;
> +	}
>
> -	leds_data = devm_kzalloc(&pdev->dev,
> -		sizeof(struct netxbig_led_data) * pdata->num_leds, GFP_KERNEL);
> -	if (!leds_data)
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv) +
> +			    pdata->num_leds * sizeof(struct netxbig_led_data),
> +			    GFP_KERNEL);
> +	if (!priv)
>   		return -ENOMEM;
> +	priv->pdata = pdata;
>
>   	ret = gpio_ext_init(pdata->gpio_ext);
>   	if (ret < 0)
>   		return ret;
>
>   	for (i = 0; i < pdata->num_leds; i++) {
> -		ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
> +		ret = create_netxbig_led(pdev, i, priv);
>   		if (ret < 0)
>   			goto err_free_leds;
>   	}
> -
> -	platform_set_drvdata(pdev, leds_data);
> +	platform_set_drvdata(pdev, priv);
>
>   	return 0;
>
>   err_free_leds:
>   	for (i = i - 1; i >= 0; i--)
> -		delete_netxbig_led(&leds_data[i]);
> +		delete_netxbig_led(&priv->leds_data[i]);
>
>   	gpio_ext_free(pdata->gpio_ext);
>   	return ret;
> @@ -385,14 +607,12 @@ err_free_leds:
>
>   static int netxbig_led_remove(struct platform_device *pdev)
>   {
> -	struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
> -	struct netxbig_led_data *leds_data;
> +	struct netxbig_led_priv *priv = platform_get_drvdata(pdev);
> +	struct netxbig_led_platform_data *pdata = priv->pdata;
>   	int i;
>
> -	leds_data = platform_get_drvdata(pdev);
> -
>   	for (i = 0; i < pdata->num_leds; i++)
> -		delete_netxbig_led(&leds_data[i]);
> +		delete_netxbig_led(&priv->leds_data[i]);
>
>   	gpio_ext_free(pdata->gpio_ext);
>
> @@ -403,7 +623,8 @@ static struct platform_driver netxbig_led_driver = {
>   	.probe		= netxbig_led_probe,
>   	.remove		= netxbig_led_remove,
>   	.driver		= {
> -		.name	= "leds-netxbig",
> +		.name		= "leds-netxbig",
> +		.of_match_table	= of_match_ptr(of_netxbig_leds_match),
>   	},
>   };
>
> diff --git a/include/dt-bindings/leds/leds-netxbig.h b/include/dt-bindings/leds/leds-netxbig.h
> new file mode 100644
> index 000000000000..92658b0310b2
> --- /dev/null
> +++ b/include/dt-bindings/leds/leds-netxbig.h
> @@ -0,0 +1,18 @@
> +/*
> + * This header provides constants for netxbig LED bindings.
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2.  This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#ifndef _DT_BINDINGS_LEDS_NETXBIG_H
> +#define _DT_BINDINGS_LEDS_NETXBIG_H
> +
> +#define NETXBIG_LED_OFF		0
> +#define NETXBIG_LED_ON		1
> +#define NETXBIG_LED_SATA	2
> +#define NETXBIG_LED_TIMER1	3
> +#define NETXBIG_LED_TIMER2	4
> +
> +#endif /* _DT_BINDINGS_LEDS_NETXBIG_H */
> diff --git a/include/linux/platform_data/leds-kirkwood-netxbig.h b/include/linux/platform_data/leds-kirkwood-netxbig.h
> index d2be19a51acd..3c85a735c380 100644
> --- a/include/linux/platform_data/leds-kirkwood-netxbig.h
> +++ b/include/linux/platform_data/leds-kirkwood-netxbig.h
> @@ -40,6 +40,7 @@ struct netxbig_led {
>   	int		mode_addr;
>   	int		*mode_val;
>   	int		bright_addr;
> +	int		bright_max;
>   };
>
>   struct netxbig_led_platform_data {
>

-- 
Best Regards,
Jacek Anaszewski