// 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 <[email protected]>
*
* Based on leds-gpio.c by Raphael Assenat <[email protected]>
*/
#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_kcalloc(dev, count, sizeof(*leds), 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 <[email protected]>");
MODULE_DESCRIPTION("Network Space v2 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-ns2");
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