drivers/leds/leds-ns2.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
  *
  * Copyright (C) 2010 LaCie
  *
  * Author: Simon Guinot <sguinot@lacie.com>
  *
  * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
  */

 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/gpio/consumer.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include "leds.h"

 enum ns2_led_modes {
 	NS_V2_LED_OFF,
 	NS_V2_LED_ON,
 	NS_V2_LED_SATA,
 };

 /*
  * If the size of this structure or types of its members is changed,
  * the filling of array modval in function ns2_led_register must be changed
  * accordingly.
  */
 struct ns2_led_modval {
 	u32			mode;
 	u32			cmd_level;
 	u32			slow_level;
 } __packed;

 /*
  * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
  * modes are available: off, on and SATA activity blinking. The LED modes are
  * controlled through two GPIOs (command and slow): each combination of values
  * for the command/slow GPIOs corresponds to a LED mode.
  */

 struct ns2_led {
 	struct led_classdev	cdev;
 	struct gpio_desc	*cmd;
 	struct gpio_desc	*slow;
 	bool			can_sleep;
 	unsigned char		sata; /* True when SATA mode active. */
 	rwlock_t		rw_lock; /* Lock GPIOs. */
 	int			num_modes;
 	struct ns2_led_modval	*modval;
 };

 static int ns2_led_get_mode(struct ns2_led *led, enum ns2_led_modes *mode)
 {
 	int i;
 	int cmd_level;
 	int slow_level;

 	cmd_level = gpiod_get_value_cansleep(led->cmd);
 	slow_level = gpiod_get_value_cansleep(led->slow);

 	for (i = 0; i < led->num_modes; i++) {
 		if (cmd_level == led->modval[i].cmd_level &&
 		    slow_level == led->modval[i].slow_level) {
 			*mode = led->modval[i].mode;
 			return 0;
 		}
 	}

 	return -EINVAL;
 }

 static void ns2_led_set_mode(struct ns2_led *led, enum ns2_led_modes mode)
 {
 	int i;
 	unsigned long flags;

 	for (i = 0; i < led->num_modes; i++)
 		if (mode == led->modval[i].mode)
 			break;

 	if (i == led->num_modes)
 		return;

 	write_lock_irqsave(&led->rw_lock, flags);

 	if (!led->can_sleep) {
 		gpiod_set_value(led->cmd, led->modval[i].cmd_level);
 		gpiod_set_value(led->slow, led->modval[i].slow_level);
 		goto exit_unlock;
 	}

 	gpiod_set_value_cansleep(led->cmd, led->modval[i].cmd_level);
 	gpiod_set_value_cansleep(led->slow, led->modval[i].slow_level);

 exit_unlock:
 	write_unlock_irqrestore(&led->rw_lock, flags);
 }

 static void ns2_led_set(struct led_classdev *led_cdev,
 			enum led_brightness value)
 {
 	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
 	enum ns2_led_modes mode;

 	if (value == LED_OFF)
 		mode = NS_V2_LED_OFF;
 	else if (led->sata)
 		mode = NS_V2_LED_SATA;
 	else
 		mode = NS_V2_LED_ON;

 	ns2_led_set_mode(led, mode);
 }

 static int ns2_led_set_blocking(struct led_classdev *led_cdev,
 			enum led_brightness value)
 {
 	ns2_led_set(led_cdev, value);
 	return 0;
 }

 static ssize_t ns2_led_sata_store(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buff, size_t count)
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
 	int ret;
 	unsigned long enable;

 	ret = kstrtoul(buff, 10, &enable);
 	if (ret < 0)
 		return ret;

 	enable = !!enable;

 	if (led->sata == enable)
 		goto exit;

 	led->sata = enable;

 	if (!led_get_brightness(led_cdev))
 		goto exit;

 	if (enable)
 		ns2_led_set_mode(led, NS_V2_LED_SATA);
 	else
 		ns2_led_set_mode(led, NS_V2_LED_ON);

 exit:
 	return count;
 }

 static ssize_t ns2_led_sata_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);

 	return sprintf(buf, "%d\n", led->sata);
 }

 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);

 static struct attribute *ns2_led_attrs[] = {
 	&dev_attr_sata.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(ns2_led);

 static int ns2_led_register(struct device *dev, struct fwnode_handle *node,
 			    struct ns2_led *led)
 {
 	struct led_init_data init_data = {};
 	struct ns2_led_modval *modval;
 	enum ns2_led_modes mode;
 	int nmodes, ret;

 	led->cmd = devm_fwnode_gpiod_get_index(dev, node, "cmd", 0, GPIOD_ASIS,
 					       fwnode_get_name(node));
 	if (IS_ERR(led->cmd))
 		return PTR_ERR(led->cmd);

 	led->slow = devm_fwnode_gpiod_get_index(dev, node, "slow", 0,
 						GPIOD_ASIS,
 						fwnode_get_name(node));
 	if (IS_ERR(led->slow))
 		return PTR_ERR(led->slow);

 	ret = fwnode_property_count_u32(node, "modes-map");
 	if (ret < 0 || ret % 3) {
 		dev_err(dev, "Missing or malformed modes-map for %pfw\n", node);
 		return -EINVAL;
 	}

 	nmodes = ret / 3;
 	modval = devm_kcalloc(dev, nmodes, sizeof(*modval), GFP_KERNEL);
 	if (!modval)
 		return -ENOMEM;

 	fwnode_property_read_u32_array(node, "modes-map", (void *)modval,
 				       nmodes * 3);

 	rwlock_init(&led->rw_lock);

 	led->cdev.blink_set = NULL;
 	led->cdev.flags |= LED_CORE_SUSPENDRESUME;
 	led->cdev.groups = ns2_led_groups;
 	led->can_sleep = gpiod_cansleep(led->cmd) || gpiod_cansleep(led->slow);
 	if (led->can_sleep)
 		led->cdev.brightness_set_blocking = ns2_led_set_blocking;
 	else
 		led->cdev.brightness_set = ns2_led_set;
 	led->num_modes = nmodes;
 	led->modval = modval;

 	ret = ns2_led_get_mode(led, &mode);
 	if (ret < 0)
 		return ret;

 	/* Set LED initial state. */
 	led->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 	led->cdev.brightness = (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;

 	init_data.fwnode = node;

 	ret = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
 	if (ret)
 		dev_err(dev, "Failed to register LED for node %pfw\n", node);

 	return ret;
 }

 static int ns2_led_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct fwnode_handle *child;
 	struct ns2_led *leds;
 	int count;
 	int ret;

 	count = device_get_child_node_count(dev);
 	if (!count)
 		return -ENODEV;

 	leds = devm_kzalloc(dev, array_size(sizeof(*leds), count), GFP_KERNEL);
 	if (!leds)
 		return -ENOMEM;

 	device_for_each_child_node(dev, child) {
 		ret = ns2_led_register(dev, child, leds++);
 		if (ret) {
 			fwnode_handle_put(child);
 			return ret;
 		}
 	}

 	return 0;
 }

 static const struct of_device_id of_ns2_leds_match[] = {
 	{ .compatible = "lacie,ns2-leds", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, of_ns2_leds_match);

 static struct platform_driver ns2_led_driver = {
 	.probe		= ns2_led_probe,
 	.driver		= {
 		.name		= "leds-ns2",
 		.of_match_table	= of_ns2_leds_match,
 	},
 };

 module_platform_driver(ns2_led_driver);

 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 MODULE_DESCRIPTION("Network Space v2 LED driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:leds-ns2");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
	*
	* Copyright (C) 2010 LaCie
	*
	* Author: Simon Guinot <sguinot@lacie.com>
	*
	* Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
	*/

	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/gpio/consumer.h>
	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include "leds.h"

	enum ns2_led_modes {
	NS_V2_LED_OFF,
	NS_V2_LED_ON,
	NS_V2_LED_SATA,
	};

	/*
	* If the size of this structure or types of its members is changed,
	* the filling of array modval in function ns2_led_register must be changed
	* accordingly.
	*/
	struct ns2_led_modval {
	u32 mode;
	u32 cmd_level;
	u32 slow_level;
	} __packed;

	/*
	* The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
	* modes are available: off, on and SATA activity blinking. The LED modes are
	* controlled through two GPIOs (command and slow): each combination of values
	* for the command/slow GPIOs corresponds to a LED mode.
	*/

	struct ns2_led {
	struct led_classdev cdev;
	struct gpio_desc *cmd;
	struct gpio_desc *slow;
	bool can_sleep;
	unsigned char sata; /* True when SATA mode active. */
	rwlock_t rw_lock; /* Lock GPIOs. */
	int num_modes;
	struct ns2_led_modval *modval;
	};

	static int ns2_led_get_mode(struct ns2_led led, enum ns2_led_modes mode)
	{
	int i;
	int cmd_level;
	int slow_level;

	cmd_level = gpiod_get_value_cansleep(led->cmd);
	slow_level = gpiod_get_value_cansleep(led->slow);

	for (i = 0; i < led->num_modes; i++) {
	if (cmd_level == led->modval[i].cmd_level &&
	slow_level == led->modval[i].slow_level) {
	*mode = led->modval[i].mode;
	return 0;
	}
	}

	return -EINVAL;
	}

	static void ns2_led_set_mode(struct ns2_led *led, enum ns2_led_modes mode)
	{
	int i;
	unsigned long flags;

	for (i = 0; i < led->num_modes; i++)
	if (mode == led->modval[i].mode)
	break;

	if (i == led->num_modes)
	return;

	write_lock_irqsave(&led->rw_lock, flags);

	if (!led->can_sleep) {
	gpiod_set_value(led->cmd, led->modval[i].cmd_level);
	gpiod_set_value(led->slow, led->modval[i].slow_level);
	goto exit_unlock;
	}

	gpiod_set_value_cansleep(led->cmd, led->modval[i].cmd_level);
	gpiod_set_value_cansleep(led->slow, led->modval[i].slow_level);

	exit_unlock:
	write_unlock_irqrestore(&led->rw_lock, flags);
	}

	static void ns2_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
	enum ns2_led_modes mode;

	if (value == LED_OFF)
	mode = NS_V2_LED_OFF;
	else if (led->sata)
	mode = NS_V2_LED_SATA;
	else
	mode = NS_V2_LED_ON;

	ns2_led_set_mode(led, mode);
	}

	static int ns2_led_set_blocking(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	ns2_led_set(led_cdev, value);
	return 0;
	}

	static ssize_t ns2_led_sata_store(struct device *dev,
	struct device_attribute *attr,
	const char *buff, size_t count)
	{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
	int ret;
	unsigned long enable;

	ret = kstrtoul(buff, 10, &enable);
	if (ret < 0)
	return ret;

	enable = !!enable;

	if (led->sata == enable)
	goto exit;

	led->sata = enable;

	if (!led_get_brightness(led_cdev))
	goto exit;

	if (enable)
	ns2_led_set_mode(led, NS_V2_LED_SATA);
	else
	ns2_led_set_mode(led, NS_V2_LED_ON);

	exit:
	return count;
	}

	static ssize_t ns2_led_sata_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);

	return sprintf(buf, "%d\n", led->sata);
	}

	static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);

	static struct attribute *ns2_led_attrs[] = {
	&dev_attr_sata.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(ns2_led);

	static int ns2_led_register(struct device dev, struct fwnode_handle node,
	struct ns2_led *led)
	{
	struct led_init_data init_data = {};
	struct ns2_led_modval *modval;
	enum ns2_led_modes mode;
	int nmodes, ret;

	led->cmd = devm_fwnode_gpiod_get_index(dev, node, "cmd", 0, GPIOD_ASIS,
	fwnode_get_name(node));
	if (IS_ERR(led->cmd))
	return PTR_ERR(led->cmd);

	led->slow = devm_fwnode_gpiod_get_index(dev, node, "slow", 0,
	GPIOD_ASIS,
	fwnode_get_name(node));
	if (IS_ERR(led->slow))
	return PTR_ERR(led->slow);

	ret = fwnode_property_count_u32(node, "modes-map");
	if (ret < 0 \|\| ret % 3) {
	dev_err(dev, "Missing or malformed modes-map for %pfw\n", node);
	return -EINVAL;
	}

	nmodes = ret / 3;
	modval = devm_kcalloc(dev, nmodes, sizeof(*modval), GFP_KERNEL);
	if (!modval)
	return -ENOMEM;

	fwnode_property_read_u32_array(node, "modes-map", (void *)modval,
	nmodes * 3);

	rwlock_init(&led->rw_lock);

	led->cdev.blink_set = NULL;
	led->cdev.flags \|= LED_CORE_SUSPENDRESUME;
	led->cdev.groups = ns2_led_groups;
	led->can_sleep = gpiod_cansleep(led->cmd) \|\| gpiod_cansleep(led->slow);
	if (led->can_sleep)
	led->cdev.brightness_set_blocking = ns2_led_set_blocking;
	else
	led->cdev.brightness_set = ns2_led_set;
	led->num_modes = nmodes;
	led->modval = modval;

	ret = ns2_led_get_mode(led, &mode);
	if (ret < 0)
	return ret;

	/* Set LED initial state. */
	led->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
	led->cdev.brightness = (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;

	init_data.fwnode = node;

	ret = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
	if (ret)
	dev_err(dev, "Failed to register LED for node %pfw\n", node);

	return ret;
	}

	static int ns2_led_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct fwnode_handle *child;
	struct ns2_led *leds;
	int count;
	int ret;

	count = device_get_child_node_count(dev);
	if (!count)
	return -ENODEV;

	leds = devm_kzalloc(dev, array_size(sizeof(*leds), count), GFP_KERNEL);
	if (!leds)
	return -ENOMEM;

	device_for_each_child_node(dev, child) {
	ret = ns2_led_register(dev, child, leds++);
	if (ret) {
	fwnode_handle_put(child);
	return ret;
	}
	}

	return 0;
	}

	static const struct of_device_id of_ns2_leds_match[] = {
	{ .compatible = "lacie,ns2-leds", },
	{},
	};
	MODULE_DEVICE_TABLE(of, of_ns2_leds_match);

	static struct platform_driver ns2_led_driver = {
	.probe = ns2_led_probe,
	.driver = {
	.name = "leds-ns2",
	.of_match_table = of_ns2_leds_match,
	},
	};

	module_platform_driver(ns2_led_driver);

	MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
	MODULE_DESCRIPTION("Network Space v2 LED driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:leds-ns2");