target/linux/xburst/files-2.6.32/drivers/video/backlight/gpm940b0.c

   1 /*
   2  *  Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.de>
   3  *      JZ4720/JZ4740 SoC LCD framebuffer driver
   4  *
   5  *  This program is free software; you can redistribute  it and/or modify it
   6  *  under  the terms of  the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the  License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the  GNU General Public License along
  11  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/spi/spi.h>
  18 #include <linux/lcd.h>
  19 #include <linux/backlight.h>
  20 #include <linux/delay.h>
  21
  22 struct gpm940b0 {
  23         struct spi_device *spi;
  24         struct lcd_device *lcd;
  25         struct backlight_device *bl;
  26         unsigned enabled:1;
  27 };
  28
  29 static int gpm940b0_write_reg(struct spi_device *spi, uint8_t reg,
  30                                 uint8_t data)
  31 {
  32         uint8_t buf[2];
  33         buf[0] = ((reg & 0x40) << 1) | (reg & 0x3f);
  34         buf[1] = data;
  35
  36         return spi_write(spi, buf, sizeof(buf));
  37 }
  38
  39 static void gpm940b0_power_disable(struct gpm940b0 *gpm940b0)
  40 {
  41         int ret = gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc6) ;
  42         if (ret < 0)
  43                 printk("Failed to disable power: %d\n", ret);
  44 }
  45
  46 static void gpm940b0_power_enable(struct gpm940b0 *gpm940b0)
  47 {
  48         gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc7);
  49 }
  50
  51
  52 static int gpm940b0_set_power(struct lcd_device *lcd, int power)
  53 {
  54         struct gpm940b0 *gpm940b0 = lcd_get_data(lcd);
  55
  56         switch (power) {
  57         case FB_BLANK_UNBLANK:
  58                 mdelay(20);
  59                 gpm940b0->enabled = 1;
  60                 gpm940b0_power_enable(gpm940b0);
  61                 break;
  62         default:
  63                 gpm940b0->enabled = 0;
  64                 gpm940b0_power_disable(gpm940b0);
  65                 mdelay(20);
  66                 break;
  67         }
  68         return 0;
  69 }
  70
  71 static int gpm940b0_set_contrast(struct lcd_device *lcd, int contrast)
  72 {
  73         struct gpm940b0 *gpm940b0 = lcd_get_data(lcd);
  74         gpm940b0_write_reg(gpm940b0->spi, 0x0d, contrast);
  75         return 0;
  76 }
  77
  78 static int gpm940b0_set_mode(struct lcd_device *lcd, struct fb_videomode *mode)
  79 {
  80         if (mode->xres != 320 && mode->yres != 240)
  81                 return -EINVAL;
  82
  83         return 0;
  84 }
  85
  86 /*
  87 int gpm940b0_bl_update_status(struct backlight_device *bl)
  88 {
  89         struct gpm940b0 *gpm940b0 = bl_get_data(bl);
  90
  91         gpm940b0->reg5 &= ~0x38;
  92         gpm940b0->reg5 |= ((bl->props.brightness << 3) & 0x38);
  93
  94         gpm940b0_write_reg(gpm940b0->spi, 0x5, gpm940b0->reg5);
  95
  96         return 0;
  97 }*/
  98
  99 static ssize_t reg_write(struct device *dev, struct device_attribute *attr,
 100                                                 const char *buf, size_t count)
 101 {
 102         char *buf2;
 103         uint32_t reg = simple_strtoul(buf, &buf2, 10);
 104         uint32_t val = simple_strtoul(buf2 + 1, NULL, 10);
 105         struct gpm940b0 *gpm940b0 = dev_get_drvdata(dev);
 106
 107         if (reg < 0 || val < 0)
 108                 return -EINVAL;
 109
 110         gpm940b0_write_reg(gpm940b0->spi, reg, val);
 111         return count;
 112 }
 113
 114 static DEVICE_ATTR(reg, 0644, NULL, reg_write);
 115
 116 static struct lcd_ops gpm940b0_lcd_ops = {
 117         .set_power = gpm940b0_set_power,
 118         .set_contrast = gpm940b0_set_contrast,
 119         .set_mode = gpm940b0_set_mode,
 120 };
 121
 122 #if 0
 123 static struct backlight_ops gpm940b0_bl_ops = {
 124 /*      .get_brightness = gpm940b0_bl_get_brightness,*/
 125         .update_status  = gpm940b0_bl_update_status,
 126 };
 127 #endif
 128
 129 static int __devinit gpm940b0_probe(struct spi_device *spi)
 130 {
 131         int ret;
 132         struct gpm940b0 *gpm940b0;
 133
 134         gpm940b0 = kmalloc(sizeof(*gpm940b0), GFP_KERNEL);
 135
 136         spi->bits_per_word = 8;
 137
 138         ret = spi_setup(spi);
 139         if (ret) {
 140                 dev_err(&spi->dev, "Failed to setup spi\n");
 141                 goto err_free_gpm940b0;
 142         }
 143
 144         gpm940b0->spi = spi;
 145
 146         gpm940b0->lcd = lcd_device_register("gpm940b0-lcd", &spi->dev, gpm940b0,
 147                                                 &gpm940b0_lcd_ops);
 148
 149         if (IS_ERR(gpm940b0->lcd)) {
 150                 ret = PTR_ERR(gpm940b0->lcd);
 151                 dev_err(&spi->dev, "Failed to register lcd device: %d\n", ret);
 152                 goto err_free_gpm940b0;
 153         }
 154
 155         gpm940b0->lcd->props.max_contrast = 255;
 156
 157 #if 0
 158         gpm940b0->bl = backlight_device_register("gpm940b0-bl", &spi->dev, gpm940b0,
 159                                                  &gpm940b0_bl_ops);
 160
 161         if (IS_ERR(gpm940b0->bl)) {
 162                 ret = PTR_ERR(gpm940b0->bl);
 163                 dev_err(&spi->dev, "Failed to register backlight device: %d\n", ret);
 164                 gpm940b0->bl = NULL;
 165         } else {
 166                 gpm940b0->bl->props.max_brightness = 8;
 167                 gpm940b0->bl->props.brightness = 0;
 168                 gpm940b0->bl->props.power = FB_BLANK_UNBLANK;
 169         }
 170 #endif
 171
 172         ret = device_create_file(&spi->dev, &dev_attr_reg);
 173         if (ret)
 174                 goto err_unregister_lcd;
 175
 176         gpm940b0->enabled = 1;
 177         dev_set_drvdata(&spi->dev, gpm940b0);
 178
 179         gpm940b0_write_reg(spi, 0x13, 0x01);
 180         gpm940b0_write_reg(spi, 0x5, 0xc7);
 181         return 0;
 182 err_unregister_lcd:
 183         lcd_device_unregister(gpm940b0->lcd);
 184 err_free_gpm940b0:
 185         kfree(gpm940b0);
 186         return ret;
 187 }
 188
 189 static int __devexit gpm940b0_remove(struct spi_device *spi)
 190 {
 191         struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
 192 #if 0
 193         if (gpm940b0->bl)
 194                 backlight_device_unregister(gpm940b0->bl);
 195 #endif
 196
 197         lcd_device_unregister(gpm940b0->lcd);
 198
 199         spi_set_drvdata(spi, NULL);
 200         kfree(gpm940b0);
 201         return 0;
 202 }
 203
 204 #ifdef CONFIG_PM
 205
 206 static int gpm940b0_suspend(struct spi_device *spi, pm_message_t state)
 207 {
 208         struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
 209         if (gpm940b0->enabled) {
 210                 gpm940b0_power_disable(gpm940b0);
 211                 mdelay(10);
 212         }
 213         return 0;
 214 }
 215
 216 static int gpm940b0_resume(struct spi_device *spi)
 217 {
 218         struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi);
 219         if (gpm940b0->enabled)
 220                 gpm940b0_power_enable(gpm940b0);
 221         return 0;
 222 }
 223
 224 #else
 225 #define gpm940b0_suspend NULL
 226 #define gpm940b0_resume NULL
 227 #endif
 228
 229 static struct spi_driver gpm940b0_driver = {
 230         .driver = {
 231                 .name = "gpm940b0",
 232                 .owner = THIS_MODULE,
 233         },
 234         .probe = gpm940b0_probe,
 235         .remove = __devexit_p(gpm940b0_remove),
 236         .suspend = gpm940b0_suspend,
 237         .resume = gpm940b0_resume,
 238 };
 239
 240 static int __init gpm940b0_init(void)
 241 {
 242         return spi_register_driver(&gpm940b0_driver);
 243 }
 244 module_init(gpm940b0_init);
 245
 246 static void __exit gpm940b0_exit(void)
 247 {
 248         return spi_unregister_driver(&gpm940b0_driver);
 249 }
 250 module_exit(gpm940b0_exit)
 251
 252 MODULE_AUTHOR("Lars-Peter Clausen");
 253 MODULE_LICENSE("GPL v2");
 254 MODULE_DESCRIPTION("LCD and backlight controll for Giantplus GPM940B0");
 255 MODULE_ALIAS("spi:gpm940b0");