285 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED4 *5 * Copyright (C) 2010 LaCie6 *7 * Author: Simon Guinot <sguinot@lacie.com>8 *9 * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>10 */11 12#include <linux/kernel.h>13#include <linux/platform_device.h>14#include <linux/slab.h>15#include <linux/gpio/consumer.h>16#include <linux/leds.h>17#include <linux/module.h>18#include <linux/of.h>19#include "leds.h"20 21enum ns2_led_modes {22 NS_V2_LED_OFF,23 NS_V2_LED_ON,24 NS_V2_LED_SATA,25};26 27/*28 * If the size of this structure or types of its members is changed,29 * the filling of array modval in function ns2_led_register must be changed30 * accordingly.31 */32struct ns2_led_modval {33 u32 mode;34 u32 cmd_level;35 u32 slow_level;36} __packed;37 38/*39 * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED40 * modes are available: off, on and SATA activity blinking. The LED modes are41 * controlled through two GPIOs (command and slow): each combination of values42 * for the command/slow GPIOs corresponds to a LED mode.43 */44 45struct ns2_led {46 struct led_classdev cdev;47 struct gpio_desc *cmd;48 struct gpio_desc *slow;49 bool can_sleep;50 unsigned char sata; /* True when SATA mode active. */51 rwlock_t rw_lock; /* Lock GPIOs. */52 int num_modes;53 struct ns2_led_modval *modval;54};55 56static int ns2_led_get_mode(struct ns2_led *led, enum ns2_led_modes *mode)57{58 int i;59 int cmd_level;60 int slow_level;61 62 cmd_level = gpiod_get_value_cansleep(led->cmd);63 slow_level = gpiod_get_value_cansleep(led->slow);64 65 for (i = 0; i < led->num_modes; i++) {66 if (cmd_level == led->modval[i].cmd_level &&67 slow_level == led->modval[i].slow_level) {68 *mode = led->modval[i].mode;69 return 0;70 }71 }72 73 return -EINVAL;74}75 76static void ns2_led_set_mode(struct ns2_led *led, enum ns2_led_modes mode)77{78 int i;79 unsigned long flags;80 81 for (i = 0; i < led->num_modes; i++)82 if (mode == led->modval[i].mode)83 break;84 85 if (i == led->num_modes)86 return;87 88 write_lock_irqsave(&led->rw_lock, flags);89 90 if (!led->can_sleep) {91 gpiod_set_value(led->cmd, led->modval[i].cmd_level);92 gpiod_set_value(led->slow, led->modval[i].slow_level);93 goto exit_unlock;94 }95 96 gpiod_set_value_cansleep(led->cmd, led->modval[i].cmd_level);97 gpiod_set_value_cansleep(led->slow, led->modval[i].slow_level);98 99exit_unlock:100 write_unlock_irqrestore(&led->rw_lock, flags);101}102 103static void ns2_led_set(struct led_classdev *led_cdev,104 enum led_brightness value)105{106 struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);107 enum ns2_led_modes mode;108 109 if (value == LED_OFF)110 mode = NS_V2_LED_OFF;111 else if (led->sata)112 mode = NS_V2_LED_SATA;113 else114 mode = NS_V2_LED_ON;115 116 ns2_led_set_mode(led, mode);117}118 119static int ns2_led_set_blocking(struct led_classdev *led_cdev,120 enum led_brightness value)121{122 ns2_led_set(led_cdev, value);123 return 0;124}125 126static ssize_t ns2_led_sata_store(struct device *dev,127 struct device_attribute *attr,128 const char *buff, size_t count)129{130 struct led_classdev *led_cdev = dev_get_drvdata(dev);131 struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);132 int ret;133 unsigned long enable;134 135 ret = kstrtoul(buff, 10, &enable);136 if (ret < 0)137 return ret;138 139 enable = !!enable;140 141 if (led->sata == enable)142 goto exit;143 144 led->sata = enable;145 146 if (!led_get_brightness(led_cdev))147 goto exit;148 149 if (enable)150 ns2_led_set_mode(led, NS_V2_LED_SATA);151 else152 ns2_led_set_mode(led, NS_V2_LED_ON);153 154exit:155 return count;156}157 158static ssize_t ns2_led_sata_show(struct device *dev,159 struct device_attribute *attr, char *buf)160{161 struct led_classdev *led_cdev = dev_get_drvdata(dev);162 struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);163 164 return sprintf(buf, "%d\n", led->sata);165}166 167static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);168 169static struct attribute *ns2_led_attrs[] = {170 &dev_attr_sata.attr,171 NULL172};173ATTRIBUTE_GROUPS(ns2_led);174 175static int ns2_led_register(struct device *dev, struct fwnode_handle *node,176 struct ns2_led *led)177{178 struct led_init_data init_data = {};179 struct ns2_led_modval *modval;180 enum ns2_led_modes mode;181 int nmodes, ret;182 183 led->cmd = devm_fwnode_gpiod_get_index(dev, node, "cmd", 0, GPIOD_ASIS,184 fwnode_get_name(node));185 if (IS_ERR(led->cmd))186 return PTR_ERR(led->cmd);187 188 led->slow = devm_fwnode_gpiod_get_index(dev, node, "slow", 0,189 GPIOD_ASIS,190 fwnode_get_name(node));191 if (IS_ERR(led->slow))192 return PTR_ERR(led->slow);193 194 ret = fwnode_property_count_u32(node, "modes-map");195 if (ret < 0 || ret % 3) {196 dev_err(dev, "Missing or malformed modes-map for %pfw\n", node);197 return -EINVAL;198 }199 200 nmodes = ret / 3;201 modval = devm_kcalloc(dev, nmodes, sizeof(*modval), GFP_KERNEL);202 if (!modval)203 return -ENOMEM;204 205 fwnode_property_read_u32_array(node, "modes-map", (void *)modval,206 nmodes * 3);207 208 rwlock_init(&led->rw_lock);209 210 led->cdev.blink_set = NULL;211 led->cdev.flags |= LED_CORE_SUSPENDRESUME;212 led->cdev.groups = ns2_led_groups;213 led->can_sleep = gpiod_cansleep(led->cmd) || gpiod_cansleep(led->slow);214 if (led->can_sleep)215 led->cdev.brightness_set_blocking = ns2_led_set_blocking;216 else217 led->cdev.brightness_set = ns2_led_set;218 led->num_modes = nmodes;219 led->modval = modval;220 221 ret = ns2_led_get_mode(led, &mode);222 if (ret < 0)223 return ret;224 225 /* Set LED initial state. */226 led->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;227 led->cdev.brightness = (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;228 229 init_data.fwnode = node;230 231 ret = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);232 if (ret)233 dev_err(dev, "Failed to register LED for node %pfw\n", node);234 235 return ret;236}237 238static int ns2_led_probe(struct platform_device *pdev)239{240 struct device *dev = &pdev->dev;241 struct fwnode_handle *child;242 struct ns2_led *leds;243 int count;244 int ret;245 246 count = device_get_child_node_count(dev);247 if (!count)248 return -ENODEV;249 250 leds = devm_kcalloc(dev, count, sizeof(*leds), GFP_KERNEL);251 if (!leds)252 return -ENOMEM;253 254 device_for_each_child_node(dev, child) {255 ret = ns2_led_register(dev, child, leds++);256 if (ret) {257 fwnode_handle_put(child);258 return ret;259 }260 }261 262 return 0;263}264 265static const struct of_device_id of_ns2_leds_match[] = {266 { .compatible = "lacie,ns2-leds", },267 {},268};269MODULE_DEVICE_TABLE(of, of_ns2_leds_match);270 271static struct platform_driver ns2_led_driver = {272 .probe = ns2_led_probe,273 .driver = {274 .name = "leds-ns2",275 .of_match_table = of_ns2_leds_match,276 },277};278 279module_platform_driver(ns2_led_driver);280 281MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");282MODULE_DESCRIPTION("Network Space v2 LED driver");283MODULE_LICENSE("GPL");284MODULE_ALIAS("platform:leds-ns2");285