1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LED driver for WM831x status LEDs 4 * 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 19 struct 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 38 static 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 66 static 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 82 static 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 can 99 * 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 else 143 led->blink = 0; 144 145 spin_unlock_irqrestore(&led->value_lock, flags); 146 wm831x_status_set(led); 147 148 return ret; 149 } 150 151 static const char * const led_src_texts[] = { 152 "otp", 153 "power", 154 "charger", 155 "soft", 156 }; 157 158 static 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 else 172 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 } 180 181 static 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 } 199 200 static DEVICE_ATTR_RW(src); 201 202 static struct attribute *wm831x_status_attrs[] = { 203 &dev_attr_src.attr, 204 NULL 205 }; 206 ATTRIBUTE_GROUPS(wm831x_status); 207 208 static 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 else 235 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 else 241 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 values 247 * 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 else 253 drvdata->brightness = LED_OFF; 254 255 /* Set a default source if configured, otherwise leave the 256 * 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 } 282 283 static int 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 return 0; 290 } 291 292 static struct platform_driver wm831x_status_driver = { 293 .driver = { 294 .name = "wm831x-status", 295 }, 296 .probe = wm831x_status_probe, 297 .remove = wm831x_status_remove, 298 }; 299 300 module_platform_driver(wm831x_status_driver); 301 302 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 303 MODULE_DESCRIPTION("WM831x status LED driver"); 304 MODULE_LICENSE("GPL"); 305 MODULE_ALIAS("platform:wm831x-status"); 306