Mark Brown | c746b55 | 2009-09-05 14:09:21 +0100 | [diff] [blame] | 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/init.h> |
| 14 | #include <linux/platform_device.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 15 | #include <linux/slab.h> |
Mark Brown | c746b55 | 2009-09-05 14:09:21 +0100 | [diff] [blame] | 16 | #include <linux/leds.h> |
| 17 | #include <linux/err.h> |
| 18 | #include <linux/mfd/wm831x/core.h> |
| 19 | #include <linux/mfd/wm831x/pdata.h> |
| 20 | #include <linux/mfd/wm831x/status.h> |
Paul Gortmaker | 54f4ded | 2011-07-03 13:56:03 -0400 | [diff] [blame^] | 21 | #include <linux/module.h> |
Mark Brown | c746b55 | 2009-09-05 14:09:21 +0100 | [diff] [blame] | 22 | |
| 23 | |
| 24 | struct wm831x_status { |
| 25 | struct led_classdev cdev; |
| 26 | struct wm831x *wm831x; |
| 27 | struct work_struct work; |
| 28 | struct mutex mutex; |
| 29 | |
| 30 | spinlock_t value_lock; |
| 31 | int reg; /* Control register */ |
| 32 | int reg_val; /* Control register value */ |
| 33 | |
| 34 | int blink; |
| 35 | int blink_time; |
| 36 | int blink_cyc; |
| 37 | int src; |
| 38 | enum led_brightness brightness; |
| 39 | }; |
| 40 | |
| 41 | #define to_wm831x_status(led_cdev) \ |
| 42 | container_of(led_cdev, struct wm831x_status, cdev) |
| 43 | |
| 44 | static void wm831x_status_work(struct work_struct *work) |
| 45 | { |
| 46 | struct wm831x_status *led = container_of(work, struct wm831x_status, |
| 47 | work); |
| 48 | unsigned long flags; |
| 49 | |
| 50 | mutex_lock(&led->mutex); |
| 51 | |
| 52 | led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK | |
| 53 | WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK); |
| 54 | |
| 55 | spin_lock_irqsave(&led->value_lock, flags); |
| 56 | |
| 57 | led->reg_val |= led->src << WM831X_LED_SRC_SHIFT; |
| 58 | if (led->blink) { |
| 59 | led->reg_val |= 2 << WM831X_LED_MODE_SHIFT; |
| 60 | led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT; |
| 61 | led->reg_val |= led->blink_cyc; |
| 62 | } else { |
| 63 | if (led->brightness != LED_OFF) |
| 64 | led->reg_val |= 1 << WM831X_LED_MODE_SHIFT; |
| 65 | } |
| 66 | |
| 67 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 68 | |
| 69 | wm831x_reg_write(led->wm831x, led->reg, led->reg_val); |
| 70 | |
| 71 | mutex_unlock(&led->mutex); |
| 72 | } |
| 73 | |
| 74 | static void wm831x_status_set(struct led_classdev *led_cdev, |
| 75 | enum led_brightness value) |
| 76 | { |
| 77 | struct wm831x_status *led = to_wm831x_status(led_cdev); |
| 78 | unsigned long flags; |
| 79 | |
| 80 | spin_lock_irqsave(&led->value_lock, flags); |
| 81 | led->brightness = value; |
| 82 | if (value == LED_OFF) |
| 83 | led->blink = 0; |
| 84 | schedule_work(&led->work); |
| 85 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 86 | } |
| 87 | |
| 88 | static int wm831x_status_blink_set(struct led_classdev *led_cdev, |
| 89 | unsigned long *delay_on, |
| 90 | unsigned long *delay_off) |
| 91 | { |
| 92 | struct wm831x_status *led = to_wm831x_status(led_cdev); |
| 93 | unsigned long flags; |
| 94 | int ret = 0; |
| 95 | |
| 96 | /* Pick some defaults if we've not been given times */ |
| 97 | if (*delay_on == 0 && *delay_off == 0) { |
| 98 | *delay_on = 250; |
| 99 | *delay_off = 250; |
| 100 | } |
| 101 | |
| 102 | spin_lock_irqsave(&led->value_lock, flags); |
| 103 | |
| 104 | /* We only have a limited selection of settings, see if we can |
| 105 | * support the configuration we're being given */ |
| 106 | switch (*delay_on) { |
| 107 | case 1000: |
| 108 | led->blink_time = 0; |
| 109 | break; |
| 110 | case 250: |
| 111 | led->blink_time = 1; |
| 112 | break; |
| 113 | case 125: |
| 114 | led->blink_time = 2; |
| 115 | break; |
| 116 | case 62: |
| 117 | case 63: |
| 118 | /* Actually 62.5ms */ |
| 119 | led->blink_time = 3; |
| 120 | break; |
| 121 | default: |
| 122 | ret = -EINVAL; |
| 123 | break; |
| 124 | } |
| 125 | |
| 126 | if (ret == 0) { |
| 127 | switch (*delay_off / *delay_on) { |
| 128 | case 1: |
| 129 | led->blink_cyc = 0; |
| 130 | break; |
| 131 | case 3: |
| 132 | led->blink_cyc = 1; |
| 133 | break; |
| 134 | case 4: |
| 135 | led->blink_cyc = 2; |
| 136 | break; |
| 137 | case 8: |
| 138 | led->blink_cyc = 3; |
| 139 | break; |
| 140 | default: |
| 141 | ret = -EINVAL; |
| 142 | break; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (ret == 0) |
| 147 | led->blink = 1; |
| 148 | else |
| 149 | led->blink = 0; |
| 150 | |
| 151 | /* Always update; if we fail turn off blinking since we expect |
| 152 | * a software fallback. */ |
| 153 | schedule_work(&led->work); |
| 154 | |
| 155 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 156 | |
| 157 | return ret; |
| 158 | } |
| 159 | |
| 160 | static const char *led_src_texts[] = { |
| 161 | "otp", |
| 162 | "power", |
| 163 | "charger", |
| 164 | "soft", |
| 165 | }; |
| 166 | |
| 167 | static ssize_t wm831x_status_src_show(struct device *dev, |
| 168 | struct device_attribute *attr, char *buf) |
| 169 | { |
| 170 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 171 | struct wm831x_status *led = to_wm831x_status(led_cdev); |
| 172 | int i; |
| 173 | ssize_t ret = 0; |
| 174 | |
| 175 | mutex_lock(&led->mutex); |
| 176 | |
| 177 | for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) |
| 178 | if (i == led->src) |
| 179 | ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]); |
| 180 | else |
| 181 | ret += sprintf(&buf[ret], "%s ", led_src_texts[i]); |
| 182 | |
| 183 | mutex_unlock(&led->mutex); |
| 184 | |
| 185 | ret += sprintf(&buf[ret], "\n"); |
| 186 | |
| 187 | return ret; |
| 188 | } |
| 189 | |
| 190 | static ssize_t wm831x_status_src_store(struct device *dev, |
| 191 | struct device_attribute *attr, |
| 192 | const char *buf, size_t size) |
| 193 | { |
| 194 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 195 | struct wm831x_status *led = to_wm831x_status(led_cdev); |
| 196 | char name[20]; |
| 197 | int i; |
| 198 | size_t len; |
| 199 | |
| 200 | name[sizeof(name) - 1] = '\0'; |
| 201 | strncpy(name, buf, sizeof(name) - 1); |
| 202 | len = strlen(name); |
| 203 | |
| 204 | if (len && name[len - 1] == '\n') |
| 205 | name[len - 1] = '\0'; |
| 206 | |
| 207 | for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) { |
| 208 | if (!strcmp(name, led_src_texts[i])) { |
| 209 | mutex_lock(&led->mutex); |
| 210 | |
| 211 | led->src = i; |
| 212 | schedule_work(&led->work); |
| 213 | |
| 214 | mutex_unlock(&led->mutex); |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | return size; |
| 219 | } |
| 220 | |
| 221 | static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store); |
| 222 | |
| 223 | static int wm831x_status_probe(struct platform_device *pdev) |
| 224 | { |
| 225 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); |
| 226 | struct wm831x_pdata *chip_pdata; |
| 227 | struct wm831x_status_pdata pdata; |
| 228 | struct wm831x_status *drvdata; |
| 229 | struct resource *res; |
| 230 | int id = pdev->id % ARRAY_SIZE(chip_pdata->status); |
| 231 | int ret; |
| 232 | |
| 233 | res = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| 234 | if (res == NULL) { |
| 235 | dev_err(&pdev->dev, "No I/O resource\n"); |
| 236 | ret = -EINVAL; |
| 237 | goto err; |
| 238 | } |
| 239 | |
| 240 | drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL); |
| 241 | if (!drvdata) |
| 242 | return -ENOMEM; |
| 243 | dev_set_drvdata(&pdev->dev, drvdata); |
| 244 | |
| 245 | drvdata->wm831x = wm831x; |
| 246 | drvdata->reg = res->start; |
| 247 | |
| 248 | if (wm831x->dev->platform_data) |
| 249 | chip_pdata = wm831x->dev->platform_data; |
| 250 | else |
| 251 | chip_pdata = NULL; |
| 252 | |
| 253 | memset(&pdata, 0, sizeof(pdata)); |
| 254 | if (chip_pdata && chip_pdata->status[id]) |
| 255 | memcpy(&pdata, chip_pdata->status[id], sizeof(pdata)); |
| 256 | else |
| 257 | pdata.name = dev_name(&pdev->dev); |
| 258 | |
| 259 | mutex_init(&drvdata->mutex); |
| 260 | INIT_WORK(&drvdata->work, wm831x_status_work); |
| 261 | spin_lock_init(&drvdata->value_lock); |
| 262 | |
| 263 | /* We cache the configuration register and read startup values |
| 264 | * from it. */ |
| 265 | drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg); |
| 266 | |
| 267 | if (drvdata->reg_val & WM831X_LED_MODE_MASK) |
| 268 | drvdata->brightness = LED_FULL; |
| 269 | else |
| 270 | drvdata->brightness = LED_OFF; |
| 271 | |
| 272 | /* Set a default source if configured, otherwise leave the |
| 273 | * current hardware setting. |
| 274 | */ |
| 275 | if (pdata.default_src == WM831X_STATUS_PRESERVE) { |
| 276 | drvdata->src = drvdata->reg_val; |
| 277 | drvdata->src &= WM831X_LED_SRC_MASK; |
| 278 | drvdata->src >>= WM831X_LED_SRC_SHIFT; |
| 279 | } else { |
| 280 | drvdata->src = pdata.default_src - 1; |
| 281 | } |
| 282 | |
| 283 | drvdata->cdev.name = pdata.name; |
| 284 | drvdata->cdev.default_trigger = pdata.default_trigger; |
| 285 | drvdata->cdev.brightness_set = wm831x_status_set; |
| 286 | drvdata->cdev.blink_set = wm831x_status_blink_set; |
| 287 | |
| 288 | ret = led_classdev_register(wm831x->dev, &drvdata->cdev); |
| 289 | if (ret < 0) { |
| 290 | dev_err(&pdev->dev, "Failed to register LED: %d\n", ret); |
| 291 | goto err_led; |
| 292 | } |
| 293 | |
| 294 | ret = device_create_file(drvdata->cdev.dev, &dev_attr_src); |
| 295 | if (ret != 0) |
| 296 | dev_err(&pdev->dev, |
| 297 | "No source control for LED: %d\n", ret); |
| 298 | |
| 299 | return 0; |
| 300 | |
| 301 | err_led: |
| 302 | led_classdev_unregister(&drvdata->cdev); |
| 303 | kfree(drvdata); |
| 304 | err: |
| 305 | return ret; |
| 306 | } |
| 307 | |
| 308 | static int wm831x_status_remove(struct platform_device *pdev) |
| 309 | { |
| 310 | struct wm831x_status *drvdata = platform_get_drvdata(pdev); |
| 311 | |
| 312 | device_remove_file(drvdata->cdev.dev, &dev_attr_src); |
| 313 | led_classdev_unregister(&drvdata->cdev); |
| 314 | kfree(drvdata); |
| 315 | |
| 316 | return 0; |
| 317 | } |
| 318 | |
| 319 | static struct platform_driver wm831x_status_driver = { |
| 320 | .driver = { |
| 321 | .name = "wm831x-status", |
| 322 | .owner = THIS_MODULE, |
| 323 | }, |
| 324 | .probe = wm831x_status_probe, |
| 325 | .remove = wm831x_status_remove, |
| 326 | }; |
| 327 | |
| 328 | static int __devinit wm831x_status_init(void) |
| 329 | { |
| 330 | return platform_driver_register(&wm831x_status_driver); |
| 331 | } |
| 332 | module_init(wm831x_status_init); |
| 333 | |
| 334 | static void wm831x_status_exit(void) |
| 335 | { |
| 336 | platform_driver_unregister(&wm831x_status_driver); |
| 337 | } |
| 338 | module_exit(wm831x_status_exit); |
| 339 | |
| 340 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); |
| 341 | MODULE_DESCRIPTION("WM831x status LED driver"); |
| 342 | MODULE_LICENSE("GPL"); |
| 343 | MODULE_ALIAS("platform:wm831x-status"); |