drivers/leds/leds-powernv.c - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * PowerNV LED Driver
  *
  * Copyright IBM Corp. 2015
  *
  * Author: Vasant Hegde <[email protected]>
  * Author: Anshuman Khandual <[email protected]>
  */

 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/types.h>

 #include <asm/opal.h>

 /* Map LED type to description. */
 struct led_type_map {
 	const int	type;
 	const char	*desc;
 };
 static const struct led_type_map led_type_map[] = {
 	{OPAL_SLOT_LED_TYPE_ID,		"identify"},
 	{OPAL_SLOT_LED_TYPE_FAULT,	"fault"},
 	{OPAL_SLOT_LED_TYPE_ATTN,	"attention"},
 	{-1,				NULL},
 };

 struct powernv_led_common {
 	/*
 	 * By default unload path resets all the LEDs. But on PowerNV
 	 * platform we want to retain LED state across reboot as these
 	 * are controlled by firmware. Also service processor can modify
 	 * the LEDs independent of OS. Hence avoid resetting LEDs in
 	 * unload path.
 	 */
 	bool		led_disabled;

 	/* Max supported LED type */
 	__be64		max_led_type;

 	/* glabal lock */
 	struct mutex	lock;
 };

 /* PowerNV LED data */
 struct powernv_led_data {
 	struct led_classdev	cdev;
 	char			*loc_code;	/* LED location code */
 	int			led_type;	/* OPAL_SLOT_LED_TYPE_* */

 	struct powernv_led_common *common;
 };


 /* Returns OPAL_SLOT_LED_TYPE_* for given led type string */
 static int powernv_get_led_type(const char *led_type_desc)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(led_type_map); i++)
 		if (!strcmp(led_type_map[i].desc, led_type_desc))
 			return led_type_map[i].type;

 	return -1;
 }

 /*
  * This commits the state change of the requested LED through an OPAL call.
  * This function is called from work queue task context when ever it gets
  * scheduled. This function can sleep at opal_async_wait_response call.
  */
 static int powernv_led_set(struct powernv_led_data *powernv_led,
 			    enum led_brightness value)
 {
 	int rc, token;
 	u64 led_mask, led_value = 0;
 	__be64 max_type;
 	struct opal_msg msg;
 	struct device *dev = powernv_led->cdev.dev;
 	struct powernv_led_common *powernv_led_common = powernv_led->common;

 	/* Prepare for the OPAL call */
 	max_type = powernv_led_common->max_led_type;
 	led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type;
 	if (value)
 		led_value = led_mask;

 	/* OPAL async call */
 	token = opal_async_get_token_interruptible();
 	if (token < 0) {
 		if (token != -ERESTARTSYS)
 			dev_err(dev, "%s: Couldn't get OPAL async token\n",
 				__func__);
 		return token;
 	}

 	rc = opal_leds_set_ind(token, powernv_led->loc_code,
 			       led_mask, led_value, &max_type);
 	if (rc != OPAL_ASYNC_COMPLETION) {
 		dev_err(dev, "%s: OPAL set LED call failed for %s [rc=%d]\n",
 			__func__, powernv_led->loc_code, rc);
 		goto out_token;
 	}

 	rc = opal_async_wait_response(token, &msg);
 	if (rc) {
 		dev_err(dev,
 			"%s: Failed to wait for the async response [rc=%d]\n",
 			__func__, rc);
 		goto out_token;
 	}

 	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS)
 		dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n",
 			__func__, rc);

 out_token:
 	opal_async_release_token(token);
 	return rc;
 }

 /*
  * This function fetches the LED state for a given LED type for
  * mentioned LED classdev structure.
  */
 static enum led_brightness powernv_led_get(struct powernv_led_data *powernv_led)
 {
 	int rc;
 	__be64 mask, value, max_type;
 	u64 led_mask, led_value;
 	struct device *dev = powernv_led->cdev.dev;
 	struct powernv_led_common *powernv_led_common = powernv_led->common;

 	/* Fetch all LED status */
 	mask = cpu_to_be64(0);
 	value = cpu_to_be64(0);
 	max_type = powernv_led_common->max_led_type;

 	rc = opal_leds_get_ind(powernv_led->loc_code,
 			       &mask, &value, &max_type);
 	if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
 		dev_err(dev, "%s: OPAL get led call failed [rc=%d]\n",
 			__func__, rc);
 		return LED_OFF;
 	}

 	led_mask = be64_to_cpu(mask);
 	led_value = be64_to_cpu(value);

 	/* LED status available */
 	if (!((led_mask >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)) {
 		dev_err(dev, "%s: LED status not available for %s\n",
 			__func__, powernv_led->cdev.name);
 		return LED_OFF;
 	}

 	/* LED status value */
 	if ((led_value >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)
 		return LED_FULL;

 	return LED_OFF;
 }

 /*
  * LED classdev 'brightness_get' function. This schedules work
  * to update LED state.
  */
 static int powernv_brightness_set(struct led_classdev *led_cdev,
 				   enum led_brightness value)
 {
 	struct powernv_led_data *powernv_led =
 		container_of(led_cdev, struct powernv_led_data, cdev);
 	struct powernv_led_common *powernv_led_common = powernv_led->common;
 	int rc;

 	/* Do not modify LED in unload path */
 	if (powernv_led_common->led_disabled)
 		return 0;

 	mutex_lock(&powernv_led_common->lock);
 	rc = powernv_led_set(powernv_led, value);
 	mutex_unlock(&powernv_led_common->lock);

 	return rc;
 }

 /* LED classdev 'brightness_get' function */
 static enum led_brightness powernv_brightness_get(struct led_classdev *led_cdev)
 {
 	struct powernv_led_data *powernv_led =
 		container_of(led_cdev, struct powernv_led_data, cdev);

 	return powernv_led_get(powernv_led);
 }

 /*
  * This function registers classdev structure for any given type of LED on
  * a given child LED device node.
  */
 static int powernv_led_create(struct device *dev,
 			      struct powernv_led_data *powernv_led,
 			      const char *led_type_desc)
 {
 	int rc;

 	/* Make sure LED type is supported */
 	powernv_led->led_type = powernv_get_led_type(led_type_desc);
 	if (powernv_led->led_type == -1) {
 		dev_warn(dev, "%s: No support for led type : %s\n",
 			 __func__, led_type_desc);
 		return -EINVAL;
 	}

 	/* Create the name for classdev */
 	powernv_led->cdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
 						powernv_led->loc_code,
 						led_type_desc);
 	if (!powernv_led->cdev.name)
 		return -ENOMEM;

 	powernv_led->cdev.brightness_set_blocking = powernv_brightness_set;
 	powernv_led->cdev.brightness_get = powernv_brightness_get;
 	powernv_led->cdev.brightness = LED_OFF;
 	powernv_led->cdev.max_brightness = LED_FULL;

 	/* Register the classdev */
 	rc = devm_led_classdev_register(dev, &powernv_led->cdev);
 	if (rc) {
 		dev_err(dev, "%s: Classdev registration failed for %s\n",
 			__func__, powernv_led->cdev.name);
 	}

 	return rc;
 }

 /* Go through LED device tree node and register LED classdev structure */
 static int powernv_led_classdev(struct platform_device *pdev,
 				struct device_node *led_node,
 				struct powernv_led_common *powernv_led_common)
 {
 	const char *cur = NULL;
 	int rc = -1;
 	struct property *p;
 	struct device_node *np;
 	struct powernv_led_data *powernv_led;
 	struct device *dev = &pdev->dev;

 	for_each_available_child_of_node(led_node, np) {
 		p = of_find_property(np, "led-types", NULL);

 		while ((cur = of_prop_next_string(p, cur)) != NULL) {
 			powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
 						   GFP_KERNEL);
 			if (!powernv_led) {
 				of_node_put(np);
 				return -ENOMEM;
 			}

 			powernv_led->common = powernv_led_common;
 			powernv_led->loc_code = (char *)np->name;

 			rc = powernv_led_create(dev, powernv_led, cur);
 			if (rc) {
 				of_node_put(np);
 				return rc;
 			}
 		} /* while end */
 	}

 	return rc;
 }

 /* Platform driver probe */
 static int powernv_led_probe(struct platform_device *pdev)
 {
 	struct device_node *led_node;
 	struct powernv_led_common *powernv_led_common;
 	struct device *dev = &pdev->dev;
 	int rc;

 	led_node = of_find_node_by_path("/ibm,opal/leds");
 	if (!led_node) {
 		dev_err(dev, "%s: LED parent device node not found\n",
 			__func__);
 		return -EINVAL;
 	}

 	powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common),
 					  GFP_KERNEL);
 	if (!powernv_led_common) {
 		rc = -ENOMEM;
 		goto out;
 	}

 	mutex_init(&powernv_led_common->lock);
 	powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);

 	platform_set_drvdata(pdev, powernv_led_common);

 	rc = powernv_led_classdev(pdev, led_node, powernv_led_common);
 out:
 	of_node_put(led_node);
 	return rc;
 }

 /* Platform driver remove */
 static int powernv_led_remove(struct platform_device *pdev)
 {
 	struct powernv_led_common *powernv_led_common;

 	/* Disable LED operation */
 	powernv_led_common = platform_get_drvdata(pdev);
 	powernv_led_common->led_disabled = true;

 	/* Destroy lock */
 	mutex_destroy(&powernv_led_common->lock);

 	dev_info(&pdev->dev, "PowerNV led module unregistered\n");
 	return 0;
 }

 /* Platform driver property match */
 static const struct of_device_id powernv_led_match[] = {
 	{
 		.compatible	= "ibm,opal-v3-led",
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, powernv_led_match);

 static struct platform_driver powernv_led_driver = {
 	.probe	= powernv_led_probe,
 	.remove = powernv_led_remove,
 	.driver = {
 		.name = "powernv-led-driver",
 		.of_match_table = powernv_led_match,
 	},
 };

 module_platform_driver(powernv_led_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("PowerNV LED driver");
 MODULE_AUTHOR("Vasant Hegde <[email protected]>");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* PowerNV LED Driver
	*
	* Copyright IBM Corp. 2015
	*
	* Author: Vasant Hegde <[email protected]>
	* Author: Anshuman Khandual <[email protected]>
	*/

	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/types.h>

	#include <asm/opal.h>

	/* Map LED type to description. */
	struct led_type_map {
	const int type;
	const char *desc;
	};
	static const struct led_type_map led_type_map[] = {
	{OPAL_SLOT_LED_TYPE_ID, "identify"},
	{OPAL_SLOT_LED_TYPE_FAULT, "fault"},
	{OPAL_SLOT_LED_TYPE_ATTN, "attention"},
	{-1, NULL},
	};

	struct powernv_led_common {
	/*
	* By default unload path resets all the LEDs. But on PowerNV
	* platform we want to retain LED state across reboot as these
	* are controlled by firmware. Also service processor can modify
	* the LEDs independent of OS. Hence avoid resetting LEDs in
	* unload path.
	*/
	bool led_disabled;

	/* Max supported LED type */
	__be64 max_led_type;

	/* glabal lock */
	struct mutex lock;
	};

	/* PowerNV LED data */
	struct powernv_led_data {
	struct led_classdev cdev;
	char loc_code; / LED location code */
	int led_type; /* OPAL_SLOT_LED_TYPE_* */

	struct powernv_led_common *common;
	};


	/* Returns OPAL_SLOT_LED_TYPE_* for given led type string */
	static int powernv_get_led_type(const char *led_type_desc)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(led_type_map); i++)
	if (!strcmp(led_type_map[i].desc, led_type_desc))
	return led_type_map[i].type;

	return -1;
	}

	/*
	* This commits the state change of the requested LED through an OPAL call.
	* This function is called from work queue task context when ever it gets
	* scheduled. This function can sleep at opal_async_wait_response call.
	*/
	static int powernv_led_set(struct powernv_led_data *powernv_led,
	enum led_brightness value)
	{
	int rc, token;
	u64 led_mask, led_value = 0;
	__be64 max_type;
	struct opal_msg msg;
	struct device *dev = powernv_led->cdev.dev;
	struct powernv_led_common *powernv_led_common = powernv_led->common;

	/* Prepare for the OPAL call */
	max_type = powernv_led_common->max_led_type;
	led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type;
	if (value)
	led_value = led_mask;

	/* OPAL async call */
	token = opal_async_get_token_interruptible();
	if (token < 0) {
	if (token != -ERESTARTSYS)
	dev_err(dev, "%s: Couldn't get OPAL async token\n",
	__func__);
	return token;
	}

	rc = opal_leds_set_ind(token, powernv_led->loc_code,
	led_mask, led_value, &max_type);
	if (rc != OPAL_ASYNC_COMPLETION) {
	dev_err(dev, "%s: OPAL set LED call failed for %s [rc=%d]\n",
	__func__, powernv_led->loc_code, rc);
	goto out_token;
	}

	rc = opal_async_wait_response(token, &msg);
	if (rc) {
	dev_err(dev,
	"%s: Failed to wait for the async response [rc=%d]\n",
	__func__, rc);
	goto out_token;
	}

	rc = opal_get_async_rc(msg);
	if (rc != OPAL_SUCCESS)
	dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n",
	__func__, rc);

	out_token:
	opal_async_release_token(token);
	return rc;
	}

	/*
	* This function fetches the LED state for a given LED type for
	* mentioned LED classdev structure.
	*/
	static enum led_brightness powernv_led_get(struct powernv_led_data *powernv_led)
	{
	int rc;
	__be64 mask, value, max_type;
	u64 led_mask, led_value;
	struct device *dev = powernv_led->cdev.dev;
	struct powernv_led_common *powernv_led_common = powernv_led->common;

	/* Fetch all LED status */
	mask = cpu_to_be64(0);
	value = cpu_to_be64(0);
	max_type = powernv_led_common->max_led_type;

	rc = opal_leds_get_ind(powernv_led->loc_code,
	&mask, &value, &max_type);
	if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
	dev_err(dev, "%s: OPAL get led call failed [rc=%d]\n",
	__func__, rc);
	return LED_OFF;
	}

	led_mask = be64_to_cpu(mask);
	led_value = be64_to_cpu(value);

	/* LED status available */
	if (!((led_mask >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)) {
	dev_err(dev, "%s: LED status not available for %s\n",
	__func__, powernv_led->cdev.name);
	return LED_OFF;
	}

	/* LED status value */
	if ((led_value >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)
	return LED_FULL;

	return LED_OFF;
	}

	/*
	* LED classdev 'brightness_get' function. This schedules work
	* to update LED state.
	*/
	static int powernv_brightness_set(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	struct powernv_led_data *powernv_led =
	container_of(led_cdev, struct powernv_led_data, cdev);
	struct powernv_led_common *powernv_led_common = powernv_led->common;
	int rc;

	/* Do not modify LED in unload path */
	if (powernv_led_common->led_disabled)
	return 0;

	mutex_lock(&powernv_led_common->lock);
	rc = powernv_led_set(powernv_led, value);
	mutex_unlock(&powernv_led_common->lock);

	return rc;
	}

	/* LED classdev 'brightness_get' function */
	static enum led_brightness powernv_brightness_get(struct led_classdev *led_cdev)
	{
	struct powernv_led_data *powernv_led =
	container_of(led_cdev, struct powernv_led_data, cdev);

	return powernv_led_get(powernv_led);
	}

	/*
	* This function registers classdev structure for any given type of LED on
	* a given child LED device node.
	*/
	static int powernv_led_create(struct device *dev,
	struct powernv_led_data *powernv_led,
	const char *led_type_desc)
	{
	int rc;

	/* Make sure LED type is supported */
	powernv_led->led_type = powernv_get_led_type(led_type_desc);
	if (powernv_led->led_type == -1) {
	dev_warn(dev, "%s: No support for led type : %s\n",
	__func__, led_type_desc);
	return -EINVAL;
	}

	/* Create the name for classdev */
	powernv_led->cdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
	powernv_led->loc_code,
	led_type_desc);
	if (!powernv_led->cdev.name)
	return -ENOMEM;

	powernv_led->cdev.brightness_set_blocking = powernv_brightness_set;
	powernv_led->cdev.brightness_get = powernv_brightness_get;
	powernv_led->cdev.brightness = LED_OFF;
	powernv_led->cdev.max_brightness = LED_FULL;

	/* Register the classdev */
	rc = devm_led_classdev_register(dev, &powernv_led->cdev);
	if (rc) {
	dev_err(dev, "%s: Classdev registration failed for %s\n",
	__func__, powernv_led->cdev.name);
	}

	return rc;
	}

	/* Go through LED device tree node and register LED classdev structure */
	static int powernv_led_classdev(struct platform_device *pdev,
	struct device_node *led_node,
	struct powernv_led_common *powernv_led_common)
	{
	const char *cur = NULL;
	int rc = -1;
	struct property *p;
	struct device_node *np;
	struct powernv_led_data *powernv_led;
	struct device *dev = &pdev->dev;

	for_each_available_child_of_node(led_node, np) {
	p = of_find_property(np, "led-types", NULL);

	while ((cur = of_prop_next_string(p, cur)) != NULL) {
	powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
	GFP_KERNEL);
	if (!powernv_led) {
	of_node_put(np);
	return -ENOMEM;
	}

	powernv_led->common = powernv_led_common;
	powernv_led->loc_code = (char *)np->name;

	rc = powernv_led_create(dev, powernv_led, cur);
	if (rc) {
	of_node_put(np);
	return rc;
	}
	} /* while end */
	}

	return rc;
	}

	/* Platform driver probe */
	static int powernv_led_probe(struct platform_device *pdev)
	{
	struct device_node *led_node;
	struct powernv_led_common *powernv_led_common;
	struct device *dev = &pdev->dev;
	int rc;

	led_node = of_find_node_by_path("/ibm,opal/leds");
	if (!led_node) {
	dev_err(dev, "%s: LED parent device node not found\n",
	__func__);
	return -EINVAL;
	}

	powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common),
	GFP_KERNEL);
	if (!powernv_led_common) {
	rc = -ENOMEM;
	goto out;
	}

	mutex_init(&powernv_led_common->lock);
	powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);

	platform_set_drvdata(pdev, powernv_led_common);

	rc = powernv_led_classdev(pdev, led_node, powernv_led_common);
	out:
	of_node_put(led_node);
	return rc;
	}

	/* Platform driver remove */
	static int powernv_led_remove(struct platform_device *pdev)
	{
	struct powernv_led_common *powernv_led_common;

	/* Disable LED operation */
	powernv_led_common = platform_get_drvdata(pdev);
	powernv_led_common->led_disabled = true;

	/* Destroy lock */
	mutex_destroy(&powernv_led_common->lock);

	dev_info(&pdev->dev, "PowerNV led module unregistered\n");
	return 0;
	}

	/* Platform driver property match */
	static const struct of_device_id powernv_led_match[] = {
	{
	.compatible = "ibm,opal-v3-led",
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, powernv_led_match);

	static struct platform_driver powernv_led_driver = {
	.probe = powernv_led_probe,
	.remove = powernv_led_remove,
	.driver = {
	.name = "powernv-led-driver",
	.of_match_table = powernv_led_match,
	},
	};

	module_platform_driver(powernv_led_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("PowerNV LED driver");
	MODULE_AUTHOR("Vasant Hegde <[email protected]>");