1 /* 2 * LED driver for WM831x status LEDs 3 * 4 * Copyright(C) 2009 Wolfson Microelectronics PLC. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/platform_device.h> 14 #include <linux/slab.h> 15 #include <linux/leds.h> 16 #include <linux/err.h> 17 #include <linux/mfd/wm831x/core.h> 18 #include <linux/mfd/wm831x/pdata.h> 19 #include <linux/mfd/wm831x/status.h> 20 #include <linux/module.h> 21 22 23 struct wm831x_status { 24 struct led_classdev cdev; 25 struct wm831x *wm831x; 26 struct mutex mutex; 27 28 spinlock_t value_lock; 29 int reg; /* Control register */ 30 int reg_val; /* Control register value */ 31 32 int blink; 33 int blink_time; 34 int blink_cyc; 35 int src; 36 enum led_brightness brightness; 37 }; 38 39 #define to_wm831x_status(led_cdev) \ 40 container_of(led_cdev, struct wm831x_status, cdev) 41 42 static void wm831x_status_set(struct wm831x_status *led) 43 { 44 unsigned long flags; 45 46 mutex_lock(&led->mutex); 47 48 led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK | 49 WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK); 50 51 spin_lock_irqsave(&led->value_lock, flags); 52 53 led->reg_val |= led->src << WM831X_LED_SRC_SHIFT; 54 if (led->blink) { 55 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT; 56 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT; 57 led->reg_val |= led->blink_cyc; 58 } else { 59 if (led->brightness != LED_OFF) 60 led->reg_val |= 1 << WM831X_LED_MODE_SHIFT; 61 } 62 63 spin_unlock_irqrestore(&led->value_lock, flags); 64 65 wm831x_reg_write(led->wm831x, led->reg, led->reg_val); 66 67 mutex_unlock(&led->mutex); 68 } 69 70 static int wm831x_status_brightness_set(struct led_classdev *led_cdev, 71 enum led_brightness value) 72 { 73 struct wm831x_status *led = to_wm831x_status(led_cdev); 74 unsigned long flags; 75 76 spin_lock_irqsave(&led->value_lock, flags); 77 led->brightness = value; 78 if (value == LED_OFF) 79 led->blink = 0; 80 spin_unlock_irqrestore(&led->value_lock, flags); 81 wm831x_status_set(led); 82 83 return 0; 84 } 85 86 static int wm831x_status_blink_set(struct led_classdev *led_cdev, 87 unsigned long *delay_on, 88 unsigned long *delay_off) 89 { 90 struct wm831x_status *led = to_wm831x_status(led_cdev); 91 unsigned long flags; 92 int ret = 0; 93 94 /* Pick some defaults if we've not been given times */ 95 if (*delay_on == 0 && *delay_off == 0) { 96 *delay_on = 250; 97 *delay_off = 250; 98 } 99 100 spin_lock_irqsave(&led->value_lock, flags); 101 102 /* We only have a limited selection of settings, see if we can 103 * support the configuration we're being given */ 104 switch (*delay_on) { 105 case 1000: 106 led->blink_time = 0; 107 break; 108 case 250: 109 led->blink_time = 1; 110 break; 111 case 125: 112 led->blink_time = 2; 113 break; 114 case 62: 115 case 63: 116 /* Actually 62.5ms */ 117 led->blink_time = 3; 118 break; 119 default: 120 ret = -EINVAL; 121 break; 122 } 123 124 if (ret == 0) { 125 switch (*delay_off / *delay_on) { 126 case 1: 127 led->blink_cyc = 0; 128 break; 129 case 3: 130 led->blink_cyc = 1; 131 break; 132 case 4: 133 led->blink_cyc = 2; 134 break; 135 case 8: 136 led->blink_cyc = 3; 137 break; 138 default: 139 ret = -EINVAL; 140 break; 141 } 142 } 143 144 if (ret == 0) 145 led->blink = 1; 146 else 147 led->blink = 0; 148 149 spin_unlock_irqrestore(&led->value_lock, flags); 150 wm831x_status_set(led); 151 152 return ret; 153 } 154 155 static const char * const led_src_texts[] = { 156 "otp", 157 "power", 158 "charger", 159 "soft", 160 }; 161 162 static ssize_t wm831x_status_src_show(struct device *dev, 163 struct device_attribute *attr, char *buf) 164 { 165 struct led_classdev *led_cdev = dev_get_drvdata(dev); 166 struct wm831x_status *led = to_wm831x_status(led_cdev); 167 int i; 168 ssize_t ret = 0; 169 170 mutex_lock(&led->mutex); 171 172 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) 173 if (i == led->src) 174 ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]); 175 else 176 ret += sprintf(&buf[ret], "%s ", led_src_texts[i]); 177 178 mutex_unlock(&led->mutex); 179 180 ret += sprintf(&buf[ret], "\n"); 181 182 return ret; 183 } 184 185 static ssize_t wm831x_status_src_store(struct device *dev, 186 struct device_attribute *attr, 187 const char *buf, size_t size) 188 { 189 struct led_classdev *led_cdev = dev_get_drvdata(dev); 190 struct wm831x_status *led = to_wm831x_status(led_cdev); 191 char name[20]; 192 int i; 193 size_t len; 194 195 name[sizeof(name) - 1] = '\0'; 196 strncpy(name, buf, sizeof(name) - 1); 197 len = strlen(name); 198 199 if (len && name[len - 1] == '\n') 200 name[len - 1] = '\0'; 201 202 for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) { 203 if (!strcmp(name, led_src_texts[i])) { 204 mutex_lock(&led->mutex); 205 led->src = i; 206 mutex_unlock(&led->mutex); 207 wm831x_status_set(led); 208 } 209 } 210 211 return size; 212 } 213 214 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store); 215 216 static struct attribute *wm831x_status_attrs[] = { 217 &dev_attr_src.attr, 218 NULL 219 }; 220 ATTRIBUTE_GROUPS(wm831x_status); 221 222 static int wm831x_status_probe(struct platform_device *pdev) 223 { 224 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 225 struct wm831x_pdata *chip_pdata; 226 struct wm831x_status_pdata pdata; 227 struct wm831x_status *drvdata; 228 struct resource *res; 229 int id = pdev->id % ARRAY_SIZE(chip_pdata->status); 230 int ret; 231 232 res = platform_get_resource(pdev, IORESOURCE_REG, 0); 233 if (res == NULL) { 234 dev_err(&pdev->dev, "No register resource\n"); 235 return -EINVAL; 236 } 237 238 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status), 239 GFP_KERNEL); 240 if (!drvdata) 241 return -ENOMEM; 242 platform_set_drvdata(pdev, drvdata); 243 244 drvdata->wm831x = wm831x; 245 drvdata->reg = res->start; 246 247 if (dev_get_platdata(wm831x->dev)) 248 chip_pdata = dev_get_platdata(wm831x->dev); 249 else 250 chip_pdata = NULL; 251 252 memset(&pdata, 0, sizeof(pdata)); 253 if (chip_pdata && chip_pdata->status[id]) 254 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata)); 255 else 256 pdata.name = dev_name(&pdev->dev); 257 258 mutex_init(&drvdata->mutex); 259 spin_lock_init(&drvdata->value_lock); 260 261 /* We cache the configuration register and read startup values 262 * from it. */ 263 drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg); 264 265 if (drvdata->reg_val & WM831X_LED_MODE_MASK) 266 drvdata->brightness = LED_FULL; 267 else 268 drvdata->brightness = LED_OFF; 269 270 /* Set a default source if configured, otherwise leave the 271 * current hardware setting. 272 */ 273 if (pdata.default_src == WM831X_STATUS_PRESERVE) { 274 drvdata->src = drvdata->reg_val; 275 drvdata->src &= WM831X_LED_SRC_MASK; 276 drvdata->src >>= WM831X_LED_SRC_SHIFT; 277 } else { 278 drvdata->src = pdata.default_src - 1; 279 } 280 281 drvdata->cdev.name = pdata.name; 282 drvdata->cdev.default_trigger = pdata.default_trigger; 283 drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set; 284 drvdata->cdev.blink_set = wm831x_status_blink_set; 285 drvdata->cdev.groups = wm831x_status_groups; 286 287 ret = led_classdev_register(wm831x->dev, &drvdata->cdev); 288 if (ret < 0) { 289 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret); 290 return ret; 291 } 292 293 return 0; 294 } 295 296 static int wm831x_status_remove(struct platform_device *pdev) 297 { 298 struct wm831x_status *drvdata = platform_get_drvdata(pdev); 299 300 led_classdev_unregister(&drvdata->cdev); 301 302 return 0; 303 } 304 305 static struct platform_driver wm831x_status_driver = { 306 .driver = { 307 .name = "wm831x-status", 308 }, 309 .probe = wm831x_status_probe, 310 .remove = wm831x_status_remove, 311 }; 312 313 module_platform_driver(wm831x_status_driver); 314 315 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 316 MODULE_DESCRIPTION("WM831x status LED driver"); 317 MODULE_LICENSE("GPL"); 318 MODULE_ALIAS("platform:wm831x-status"); 319