linux/drivers/leds/leds-powernv.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

350 lines
8.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerNV LED Driver
*
* Copyright IBM Corp. 2015
*
* Author: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
* Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
*/
#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_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 <hegdevasant@linux.vnet.ibm.com>");