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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * LED driver for WM831x status LEDs4 *5 * Copyright(C) 2009 Wolfson Microelectronics PLC.6 */7 8#include <linux/kernel.h>9#include <linux/platform_device.h>10#include <linux/slab.h>11#include <linux/leds.h>12#include <linux/err.h>13#include <linux/mfd/wm831x/core.h>14#include <linux/mfd/wm831x/pdata.h>15#include <linux/mfd/wm831x/status.h>16#include <linux/module.h>17 18 19struct wm831x_status {20 struct led_classdev cdev;21 struct wm831x *wm831x;22 struct mutex mutex;23 24 spinlock_t value_lock;25 int reg; /* Control register */26 int reg_val; /* Control register value */27 28 int blink;29 int blink_time;30 int blink_cyc;31 int src;32 enum led_brightness brightness;33};34 35#define to_wm831x_status(led_cdev) \36 container_of(led_cdev, struct wm831x_status, cdev)37 38static void wm831x_status_set(struct wm831x_status *led)39{40 unsigned long flags;41 42 mutex_lock(&led->mutex);43 44 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |45 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);46 47 spin_lock_irqsave(&led->value_lock, flags);48 49 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;50 if (led->blink) {51 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;52 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;53 led->reg_val |= led->blink_cyc;54 } else {55 if (led->brightness != LED_OFF)56 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;57 }58 59 spin_unlock_irqrestore(&led->value_lock, flags);60 61 wm831x_reg_write(led->wm831x, led->reg, led->reg_val);62 63 mutex_unlock(&led->mutex);64}65 66static int wm831x_status_brightness_set(struct led_classdev *led_cdev,67 enum led_brightness value)68{69 struct wm831x_status *led = to_wm831x_status(led_cdev);70 unsigned long flags;71 72 spin_lock_irqsave(&led->value_lock, flags);73 led->brightness = value;74 if (value == LED_OFF)75 led->blink = 0;76 spin_unlock_irqrestore(&led->value_lock, flags);77 wm831x_status_set(led);78 79 return 0;80}81 82static int wm831x_status_blink_set(struct led_classdev *led_cdev,83 unsigned long *delay_on,84 unsigned long *delay_off)85{86 struct wm831x_status *led = to_wm831x_status(led_cdev);87 unsigned long flags;88 int ret = 0;89 90 /* Pick some defaults if we've not been given times */91 if (*delay_on == 0 && *delay_off == 0) {92 *delay_on = 250;93 *delay_off = 250;94 }95 96 spin_lock_irqsave(&led->value_lock, flags);97 98 /* We only have a limited selection of settings, see if we can99 * support the configuration we're being given */100 switch (*delay_on) {101 case 1000:102 led->blink_time = 0;103 break;104 case 250:105 led->blink_time = 1;106 break;107 case 125:108 led->blink_time = 2;109 break;110 case 62:111 case 63:112 /* Actually 62.5ms */113 led->blink_time = 3;114 break;115 default:116 ret = -EINVAL;117 break;118 }119 120 if (ret == 0) {121 switch (*delay_off / *delay_on) {122 case 1:123 led->blink_cyc = 0;124 break;125 case 3:126 led->blink_cyc = 1;127 break;128 case 4:129 led->blink_cyc = 2;130 break;131 case 8:132 led->blink_cyc = 3;133 break;134 default:135 ret = -EINVAL;136 break;137 }138 }139 140 if (ret == 0)141 led->blink = 1;142 else143 led->blink = 0;144 145 spin_unlock_irqrestore(&led->value_lock, flags);146 wm831x_status_set(led);147 148 return ret;149}150 151static const char * const led_src_texts[] = {152 "otp",153 "power",154 "charger",155 "soft",156};157 158static ssize_t src_show(struct device *dev,159 struct device_attribute *attr, char *buf)160{161 struct led_classdev *led_cdev = dev_get_drvdata(dev);162 struct wm831x_status *led = to_wm831x_status(led_cdev);163 int i;164 ssize_t ret = 0;165 166 mutex_lock(&led->mutex);167 168 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)169 if (i == led->src)170 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);171 else172 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);173 174 mutex_unlock(&led->mutex);175 176 ret += sprintf(&buf[ret], "\n");177 178 return ret;179}180 181static ssize_t src_store(struct device *dev,182 struct device_attribute *attr,183 const char *buf, size_t size)184{185 struct led_classdev *led_cdev = dev_get_drvdata(dev);186 struct wm831x_status *led = to_wm831x_status(led_cdev);187 int i;188 189 i = sysfs_match_string(led_src_texts, buf);190 if (i >= 0) {191 mutex_lock(&led->mutex);192 led->src = i;193 mutex_unlock(&led->mutex);194 wm831x_status_set(led);195 }196 197 return size;198}199 200static DEVICE_ATTR_RW(src);201 202static struct attribute *wm831x_status_attrs[] = {203 &dev_attr_src.attr,204 NULL205};206ATTRIBUTE_GROUPS(wm831x_status);207 208static int wm831x_status_probe(struct platform_device *pdev)209{210 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);211 struct wm831x_pdata *chip_pdata;212 struct wm831x_status_pdata pdata;213 struct wm831x_status *drvdata;214 struct resource *res;215 int id = pdev->id % ARRAY_SIZE(chip_pdata->status);216 int ret;217 218 res = platform_get_resource(pdev, IORESOURCE_REG, 0);219 if (res == NULL) {220 dev_err(&pdev->dev, "No register resource\n");221 return -EINVAL;222 }223 224 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status),225 GFP_KERNEL);226 if (!drvdata)227 return -ENOMEM;228 229 drvdata->wm831x = wm831x;230 drvdata->reg = res->start;231 232 if (dev_get_platdata(wm831x->dev))233 chip_pdata = dev_get_platdata(wm831x->dev);234 else235 chip_pdata = NULL;236 237 memset(&pdata, 0, sizeof(pdata));238 if (chip_pdata && chip_pdata->status[id])239 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));240 else241 pdata.name = dev_name(&pdev->dev);242 243 mutex_init(&drvdata->mutex);244 spin_lock_init(&drvdata->value_lock);245 246 /* We cache the configuration register and read startup values247 * from it. */248 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);249 250 if (drvdata->reg_val & WM831X_LED_MODE_MASK)251 drvdata->brightness = LED_FULL;252 else253 drvdata->brightness = LED_OFF;254 255 /* Set a default source if configured, otherwise leave the256 * current hardware setting.257 */258 if (pdata.default_src == WM831X_STATUS_PRESERVE) {259 drvdata->src = drvdata->reg_val;260 drvdata->src &= WM831X_LED_SRC_MASK;261 drvdata->src >>= WM831X_LED_SRC_SHIFT;262 } else {263 drvdata->src = pdata.default_src - 1;264 }265 266 drvdata->cdev.name = pdata.name;267 drvdata->cdev.default_trigger = pdata.default_trigger;268 drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set;269 drvdata->cdev.blink_set = wm831x_status_blink_set;270 drvdata->cdev.groups = wm831x_status_groups;271 272 ret = led_classdev_register(wm831x->dev, &drvdata->cdev);273 if (ret < 0) {274 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);275 return ret;276 }277 278 platform_set_drvdata(pdev, drvdata);279 280 return 0;281}282 283static void wm831x_status_remove(struct platform_device *pdev)284{285 struct wm831x_status *drvdata = platform_get_drvdata(pdev);286 287 led_classdev_unregister(&drvdata->cdev);288}289 290static struct platform_driver wm831x_status_driver = {291 .driver = {292 .name = "wm831x-status",293 },294 .probe = wm831x_status_probe,295 .remove_new = wm831x_status_remove,296};297 298module_platform_driver(wm831x_status_driver);299 300MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");301MODULE_DESCRIPTION("WM831x status LED driver");302MODULE_LICENSE("GPL");303MODULE_ALIAS("platform:wm831x-status");304