Mark Brown | 0081e80 | 2008-12-04 16:52:33 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * LED driver for WM8350 driven LEDS. |
| 3 | * |
| 4 | * Copyright(C) 2007, 2008 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> |
| 15 | #include <linux/leds.h> |
| 16 | #include <linux/err.h> |
| 17 | #include <linux/mfd/wm8350/pmic.h> |
| 18 | #include <linux/regulator/consumer.h> |
| 19 | |
| 20 | /* Microamps */ |
| 21 | static const int isink_cur[] = { |
| 22 | 4, |
| 23 | 5, |
| 24 | 6, |
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| 84 | 187681, |
| 85 | 223191 |
| 86 | }; |
| 87 | |
| 88 | #define to_wm8350_led(led_cdev) \ |
| 89 | container_of(led_cdev, struct wm8350_led, cdev) |
| 90 | |
| 91 | static void wm8350_led_enable(struct wm8350_led *led) |
| 92 | { |
| 93 | int ret; |
| 94 | |
| 95 | if (led->enabled) |
| 96 | return; |
| 97 | |
| 98 | ret = regulator_enable(led->isink); |
| 99 | if (ret != 0) { |
| 100 | dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret); |
| 101 | return; |
| 102 | } |
| 103 | |
| 104 | ret = regulator_enable(led->dcdc); |
| 105 | if (ret != 0) { |
| 106 | dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret); |
| 107 | regulator_disable(led->isink); |
| 108 | return; |
| 109 | } |
| 110 | |
| 111 | led->enabled = 1; |
| 112 | } |
| 113 | |
| 114 | static void wm8350_led_disable(struct wm8350_led *led) |
| 115 | { |
| 116 | int ret; |
| 117 | |
| 118 | if (!led->enabled) |
| 119 | return; |
| 120 | |
| 121 | ret = regulator_disable(led->dcdc); |
| 122 | if (ret != 0) { |
| 123 | dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret); |
| 124 | return; |
| 125 | } |
| 126 | |
| 127 | ret = regulator_disable(led->isink); |
| 128 | if (ret != 0) { |
| 129 | dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret); |
| 130 | regulator_enable(led->dcdc); |
| 131 | return; |
| 132 | } |
| 133 | |
| 134 | led->enabled = 0; |
| 135 | } |
| 136 | |
| 137 | static void led_work(struct work_struct *work) |
| 138 | { |
| 139 | struct wm8350_led *led = container_of(work, struct wm8350_led, work); |
| 140 | int ret; |
| 141 | int uA; |
| 142 | unsigned long flags; |
| 143 | |
| 144 | mutex_lock(&led->mutex); |
| 145 | |
| 146 | spin_lock_irqsave(&led->value_lock, flags); |
| 147 | |
| 148 | if (led->value == LED_OFF) { |
| 149 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 150 | wm8350_led_disable(led); |
| 151 | goto out; |
| 152 | } |
| 153 | |
| 154 | /* This scales linearly into the index of valid current |
| 155 | * settings which results in a linear scaling of perceived |
| 156 | * brightness due to the non-linear current settings provided |
| 157 | * by the hardware. |
| 158 | */ |
| 159 | uA = (led->max_uA_index * led->value) / LED_FULL; |
| 160 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 161 | BUG_ON(uA >= ARRAY_SIZE(isink_cur)); |
| 162 | |
| 163 | ret = regulator_set_current_limit(led->isink, isink_cur[uA], |
| 164 | isink_cur[uA]); |
| 165 | if (ret != 0) |
| 166 | dev_err(led->cdev.dev, "Failed to set %duA: %d\n", |
| 167 | isink_cur[uA], ret); |
| 168 | |
| 169 | wm8350_led_enable(led); |
| 170 | |
| 171 | out: |
| 172 | mutex_unlock(&led->mutex); |
| 173 | } |
| 174 | |
| 175 | static void wm8350_led_set(struct led_classdev *led_cdev, |
| 176 | enum led_brightness value) |
| 177 | { |
| 178 | struct wm8350_led *led = to_wm8350_led(led_cdev); |
| 179 | unsigned long flags; |
| 180 | |
| 181 | spin_lock_irqsave(&led->value_lock, flags); |
| 182 | led->value = value; |
| 183 | schedule_work(&led->work); |
| 184 | spin_unlock_irqrestore(&led->value_lock, flags); |
| 185 | } |
| 186 | |
| 187 | #ifdef CONFIG_PM |
| 188 | static int wm8350_led_suspend(struct platform_device *pdev, pm_message_t state) |
| 189 | { |
| 190 | struct wm8350_led *led = platform_get_drvdata(pdev); |
| 191 | |
| 192 | led_classdev_suspend(&led->cdev); |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | static int wm8350_led_resume(struct platform_device *pdev) |
| 197 | { |
| 198 | struct wm8350_led *led = platform_get_drvdata(pdev); |
| 199 | |
| 200 | led_classdev_resume(&led->cdev); |
| 201 | return 0; |
| 202 | } |
| 203 | #else |
| 204 | #define wm8350_led_suspend NULL |
| 205 | #define wm8350_led_resume NULL |
| 206 | #endif |
| 207 | |
| 208 | static void wm8350_led_shutdown(struct platform_device *pdev) |
| 209 | { |
| 210 | struct wm8350_led *led = platform_get_drvdata(pdev); |
| 211 | |
| 212 | mutex_lock(&led->mutex); |
| 213 | led->value = LED_OFF; |
| 214 | wm8350_led_disable(led); |
| 215 | mutex_unlock(&led->mutex); |
| 216 | } |
| 217 | |
| 218 | static int wm8350_led_probe(struct platform_device *pdev) |
| 219 | { |
| 220 | struct regulator *isink, *dcdc; |
| 221 | struct wm8350_led *led; |
| 222 | struct wm8350_led_platform_data *pdata = pdev->dev.platform_data; |
| 223 | int ret, i; |
| 224 | |
| 225 | if (pdata == NULL) { |
| 226 | dev_err(&pdev->dev, "no platform data\n"); |
| 227 | return -ENODEV; |
| 228 | } |
| 229 | |
| 230 | if (pdata->max_uA < isink_cur[0]) { |
| 231 | dev_err(&pdev->dev, "Invalid maximum current %duA\n", |
| 232 | pdata->max_uA); |
| 233 | return -EINVAL; |
| 234 | } |
| 235 | |
| 236 | isink = regulator_get(&pdev->dev, "led_isink"); |
| 237 | if (IS_ERR(isink)) { |
| 238 | printk(KERN_ERR "%s: cant get ISINK\n", __func__); |
| 239 | return PTR_ERR(isink); |
| 240 | } |
| 241 | |
| 242 | dcdc = regulator_get(&pdev->dev, "led_vcc"); |
| 243 | if (IS_ERR(dcdc)) { |
| 244 | printk(KERN_ERR "%s: cant get DCDC\n", __func__); |
| 245 | ret = PTR_ERR(dcdc); |
| 246 | goto err_isink; |
| 247 | } |
| 248 | |
| 249 | led = kzalloc(sizeof(*led), GFP_KERNEL); |
| 250 | if (led == NULL) { |
| 251 | ret = -ENOMEM; |
| 252 | goto err_dcdc; |
| 253 | } |
| 254 | |
| 255 | led->cdev.brightness_set = wm8350_led_set; |
| 256 | led->cdev.default_trigger = pdata->default_trigger; |
| 257 | led->cdev.name = pdata->name; |
| 258 | led->enabled = regulator_is_enabled(isink); |
| 259 | led->isink = isink; |
| 260 | led->dcdc = dcdc; |
| 261 | |
| 262 | for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++) |
| 263 | if (isink_cur[i] >= pdata->max_uA) |
| 264 | break; |
| 265 | led->max_uA_index = i; |
| 266 | if (pdata->max_uA != isink_cur[i]) |
| 267 | dev_warn(&pdev->dev, |
| 268 | "Maximum current %duA is not directly supported," |
| 269 | " check platform data\n", |
| 270 | pdata->max_uA); |
| 271 | |
| 272 | spin_lock_init(&led->value_lock); |
| 273 | mutex_init(&led->mutex); |
| 274 | INIT_WORK(&led->work, led_work); |
| 275 | led->value = LED_OFF; |
| 276 | platform_set_drvdata(pdev, led); |
| 277 | |
| 278 | ret = led_classdev_register(&pdev->dev, &led->cdev); |
| 279 | if (ret < 0) |
| 280 | goto err_led; |
| 281 | |
| 282 | return 0; |
| 283 | |
| 284 | err_led: |
| 285 | kfree(led); |
| 286 | err_dcdc: |
| 287 | regulator_put(dcdc); |
| 288 | err_isink: |
| 289 | regulator_put(isink); |
| 290 | return ret; |
| 291 | } |
| 292 | |
| 293 | static int wm8350_led_remove(struct platform_device *pdev) |
| 294 | { |
| 295 | struct wm8350_led *led = platform_get_drvdata(pdev); |
| 296 | |
| 297 | led_classdev_unregister(&led->cdev); |
| 298 | flush_scheduled_work(); |
| 299 | wm8350_led_disable(led); |
| 300 | regulator_put(led->dcdc); |
| 301 | regulator_put(led->isink); |
| 302 | kfree(led); |
| 303 | return 0; |
| 304 | } |
| 305 | |
| 306 | static struct platform_driver wm8350_led_driver = { |
| 307 | .driver = { |
| 308 | .name = "wm8350-led", |
| 309 | .owner = THIS_MODULE, |
| 310 | }, |
| 311 | .probe = wm8350_led_probe, |
| 312 | .remove = wm8350_led_remove, |
| 313 | .shutdown = wm8350_led_shutdown, |
| 314 | .suspend = wm8350_led_suspend, |
| 315 | .resume = wm8350_led_resume, |
| 316 | }; |
| 317 | |
| 318 | static int __devinit wm8350_led_init(void) |
| 319 | { |
| 320 | return platform_driver_register(&wm8350_led_driver); |
| 321 | } |
| 322 | module_init(wm8350_led_init); |
| 323 | |
| 324 | static void wm8350_led_exit(void) |
| 325 | { |
| 326 | platform_driver_unregister(&wm8350_led_driver); |
| 327 | } |
| 328 | module_exit(wm8350_led_exit); |
| 329 | |
| 330 | MODULE_AUTHOR("Mark Brown"); |
| 331 | MODULE_DESCRIPTION("WM8350 LED driver"); |
| 332 | MODULE_LICENSE("GPL"); |
| 333 | MODULE_ALIAS("platform:wm8350-led"); |