drivers/video/backlight/wm831x_bl.c

   1 /*
   2  * Backlight driver for Wolfson Microelectronics WM831x PMICs
   3  *
   4  * Copyright 2009 Wolfson Microelectonics 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 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/fb.h>
  15 #include <linux/backlight.h>
  16 #include <linux/slab.h>
  17
  18 #include <linux/mfd/wm831x/core.h>
  19 #include <linux/mfd/wm831x/pdata.h>
  20 #include <linux/mfd/wm831x/regulator.h>
  21 #ifdef CONFIG_HAS_EARLYSUSPEND
  22 #include <linux/earlysuspend.h>
  23 #endif
  24 #include <linux/delay.h>
  25 #include <linux/ktime.h>
  26 #define BL_SET   255
  27 struct wm831x_backlight_data {
  28         struct wm831x *wm831x;
  29         int isink_reg;
  30         int current_brightness;
  31 #ifdef CONFIG_HAS_EARLYSUSPEND
  32         struct  early_suspend early_suspend;
  33         struct delayed_work work;
  34         int suspend_flag;
  35 #endif
  36 };
  37 #define TS_POLL_DELAY (10000*1000*1000)
  38 int wm831x_bright = 0;
  39 int max_tp = 0;
  40 #ifdef CONFIG_HAS_EARLYSUSPEND
  41 static struct backlight_device *gwm831x_bl;
  42 static struct wm831x_backlight_data *gwm831x_data;
  43 #endif
  44 static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
  45 {
  46         struct wm831x_backlight_data *data = bl_get_data(bl);
  47         struct wm831x *wm831x = data->wm831x;
  48 //      int power_up = !data->current_brightness && brightness;
  49 //      int power_down = data->current_brightness && !brightness;
  50         int power_up;
  51         int power_down;
  52         int ret;
  53         int bright_tp;
  54
  55         bright_tp =( max_tp*brightness)/BL_SET;
  56         power_up =!data->current_brightness && bright_tp;
  57         power_down = data->current_brightness && !bright_tp;
  58         if (power_up) {
  59                 /* Enable the ISINK */
  60                 ret = wm831x_set_bits(wm831x, data->isink_reg,
  61                                       WM831X_CS1_ENA, WM831X_CS1_ENA);
  62                 if (ret < 0)
  63                         goto err;
  64
  65                 /* Enable the DC-DC */
  66                 ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
  67                                       WM831X_DC4_ENA, WM831X_DC4_ENA);
  68                 if (ret < 0)
  69                         goto err;
  70         }
  71
  72         if (power_down) {
  73                 /* DCDC first */
  74                 ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
  75                                       WM831X_DC4_ENA, 0);
  76                 if (ret < 0)
  77                         goto err;
  78
  79                 /* ISINK */
  80                 ret = wm831x_set_bits(wm831x, data->isink_reg,
  81                                       WM831X_CS1_DRIVE | WM831X_CS1_ENA, 0);
  82                 if (ret < 0)
  83                         goto err;
  84         }
  85
  86         /* Set the new brightness */
  87         ret = wm831x_set_bits(wm831x, data->isink_reg,
  88                               WM831X_CS1_ISEL_MASK, bright_tp);
  89         if (ret < 0)
  90                 goto err;
  91
  92         if (power_up) {
  93                 /* Drive current through the ISINK */
  94                 ret = wm831x_set_bits(wm831x, data->isink_reg,
  95                                       WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
  96                 if (ret < 0)
  97                         return ret;
  98         }
  99
 100         data->current_brightness = brightness;
 101
 102         return 0;
 103
 104 err:
 105         /* If we were in the middle of a power transition always shut down
 106          * for safety.
 107          */
 108         if (power_up || power_down) {
 109                 wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
 110                 wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
 111         }
 112
 113         return ret;
 114 }
 115
 116 static int wm831x_backlight_update_status(struct backlight_device *bl)
 117 {
 118         int brightness = bl->props.brightness;
 119
 120         if(gwm831x_data->suspend_flag == 1)
 121                 brightness = 0;
 122
 123         if (bl->props.power != FB_BLANK_UNBLANK)
 124                 brightness = 0;
 125
 126         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
 127                 brightness = 0;
 128
 129         if (bl->props.state & BL_CORE_SUSPENDED)
 130                 brightness = 0;
 131
 132         printk("backlight brightness=%d\n", brightness);
 133
 134         return wm831x_backlight_set(bl, brightness);
 135 }
 136
 137 static int wm831x_backlight_get_brightness(struct backlight_device *bl)
 138 {
 139         struct wm831x_backlight_data *data = bl_get_data(bl);
 140         return data->current_brightness;
 141 }
 142
 143 static struct backlight_ops wm831x_backlight_ops = {
 144         .options = BL_CORE_SUSPENDRESUME,
 145         .update_status  = wm831x_backlight_update_status,
 146         .get_brightness = wm831x_backlight_get_brightness,
 147 };
 148 #ifdef CONFIG_HAS_EARLYSUSPEND
 149 static void wm831x_bl_work(struct work_struct *work)
 150 {
 151         //struct wm831x_backlight_data *wm831x_data = container_of(work, struct wm831x_backlight_data,
 152                                                    //work.work);
 153         backlight_update_status(gwm831x_bl);
 154 }
 155
 156 static void wm831x_bl_suspend(struct early_suspend *h)
 157 {
 158         struct wm831x_backlight_data *wm831x_data;
 159         wm831x_data = container_of(h, struct wm831x_backlight_data, early_suspend);
 160         wm831x_data->suspend_flag = 1;
 161
 162         schedule_delayed_work(&wm831x_data->work, msecs_to_jiffies(100));
 163 }
 164
 165
 166 static void wm831x_bl_resume(struct early_suspend *h)
 167 {
 168         struct wm831x_backlight_data *wm831x_data;
 169         wm831x_data = container_of(h, struct wm831x_backlight_data, early_suspend);
 170         wm831x_data->suspend_flag = 0;
 171
 172         schedule_delayed_work(&wm831x_data->work, msecs_to_jiffies(100));
 173 }
 174
 175 #endif
 176 static int wm831x_backlight_probe(struct platform_device *pdev)
 177 {
 178         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 179         struct wm831x_pdata *wm831x_pdata;
 180         struct wm831x_backlight_pdata *pdata;
 181         struct wm831x_backlight_data *data;
 182         struct backlight_device *bl;
 183         struct backlight_properties props;
 184         int ret, i, max_isel, isink_reg, dcdc_cfg;
 185
 186         /* We need platform data */
 187         if (pdev->dev.parent->platform_data) {
 188                 wm831x_pdata = pdev->dev.parent->platform_data;
 189                 pdata = wm831x_pdata->backlight;
 190         } else {
 191                 pdata = NULL;
 192         }
 193
 194         if (!pdata) {
 195                 dev_err(&pdev->dev, "No platform data supplied\n");
 196                 return -EINVAL;
 197         }
 198
 199         /* Figure out the maximum current we can use */
 200         for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
 201                 if (wm831x_isinkv_values[i] > pdata->max_uA)
 202                         break;
 203         }
 204
 205         if (i == 0) {
 206                 dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
 207                 return -EINVAL;
 208         }
 209         max_isel = i - 1;
 210         max_tp = max_isel;
 211         if (pdata->max_uA != wm831x_isinkv_values[max_isel])
 212                 dev_warn(&pdev->dev,
 213                          "Maximum current is %duA not %duA as requested\n",
 214                          wm831x_isinkv_values[max_isel], pdata->max_uA);
 215
 216         switch (pdata->isink) {
 217         case 1:
 218                 isink_reg = WM831X_CURRENT_SINK_1;
 219                 dcdc_cfg = 0;
 220                 break;
 221         case 2:
 222                 isink_reg = WM831X_CURRENT_SINK_2;
 223                 dcdc_cfg = WM831X_DC4_FBSRC;
 224                 break;
 225         default:
 226                 dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
 227                 return -EINVAL;
 228         }
 229
 230         /* Configure the ISINK to use for feedback */
 231         ret = wm831x_reg_unlock(wm831x);
 232         if (ret < 0)
 233                 return ret;
 234
 235         ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
 236                               dcdc_cfg);
 237
 238         wm831x_reg_lock(wm831x);
 239         if (ret < 0)
 240                 return ret;
 241
 242         data = kzalloc(sizeof(*data), GFP_KERNEL);
 243         if (data == NULL)
 244                 return -ENOMEM;
 245
 246         data->wm831x = wm831x;
 247         data->current_brightness = 0;
 248         data->isink_reg = isink_reg;
 249
 250         props.max_brightness = max_isel;
 251         bl = backlight_device_register("wm831x", &pdev->dev, data,
 252                                        &wm831x_backlight_ops);
 253         if (IS_ERR(bl)) {
 254                 dev_err(&pdev->dev, "failed to register backlight\n");
 255                 kfree(data);
 256                 return PTR_ERR(bl);
 257         }
 258
 259         bl->props.brightness = BL_SET;
 260         bl->props.max_brightness= BL_SET;
 261
 262         platform_set_drvdata(pdev, bl);
 263
 264 #ifdef CONFIG_HAS_EARLYSUSPEND
 265         data->early_suspend.level = ~0x0;
 266         data->early_suspend.suspend = wm831x_bl_suspend;
 267         data->early_suspend.resume = wm831x_bl_resume;
 268         register_early_suspend(&data->early_suspend);
 269         INIT_DELAYED_WORK(&data->work, wm831x_bl_work);
 270         gwm831x_bl = bl;
 271         gwm831x_data = data;
 272 #endif
 273
 274
 275         /* Disable the DCDC if it was started so we can bootstrap */
 276         wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
 277
 278         //backlight_update_status(bl);
 279         schedule_delayed_work(&data->work, msecs_to_jiffies(100));
 280
 281         return 0;
 282 }
 283
 284 static int wm831x_backlight_remove(struct platform_device *pdev)
 285 {
 286         struct backlight_device *bl = platform_get_drvdata(pdev);
 287         struct wm831x_backlight_data *data = bl_get_data(bl);
 288
 289         backlight_device_unregister(bl);
 290 #ifdef CONFIG_HAS_EARLYSUSPEND
 291         unregister_early_suspend(&data->early_suspend);
 292 #endif
 293         kfree(data);
 294         return 0;
 295 }
 296
 297 static struct platform_driver wm831x_backlight_driver = {
 298         .driver         = {
 299                 .name   = "wm831x-backlight",
 300                 .owner  = THIS_MODULE,
 301         },
 302         .probe          = wm831x_backlight_probe,
 303         .remove         = wm831x_backlight_remove,
 304 };
 305
 306 static int __init wm831x_backlight_init(void)
 307 {
 308         return platform_driver_register(&wm831x_backlight_driver);
 309 }
 310 module_init(wm831x_backlight_init);
 311
 312 static void __exit wm831x_backlight_exit(void)
 313 {
 314         platform_driver_unregister(&wm831x_backlight_driver);
 315 }
 316 module_exit(wm831x_backlight_exit);
 317
 318 MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
 319 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
 320 MODULE_LICENSE("GPL");
 321 MODULE_ALIAS("platform:wm831x-backlight");