arch/arm/mach-pxa/h4000/h4000_bl.c

   1 /*
   2  * Use consistent with the GNU GPL is permitted,
   3  * provided that this copyright notice is
   4  * preserved in its entirety in all copies and derived works.
   5  *
   6  * Copyright (C) 2006 Paul Sokolosvky
   7  * Based on code from older versions of h4000_lcd.c
   8  *
   9  */
  10
  11 #include <linux/types.h>
  12 #include <asm/arch/hardware.h>  /* for pxa-regs.h (__REG) */
  13 #include <linux/platform_device.h>
  14 #include <asm/arch/pxa-regs.h>  /* LCCR[0,1,2,3]* */
  15 #include <asm/mach-types.h>     /* machine_is_h4000 */
  16 #include <linux/corgi_bl.h>
  17 #include <linux/err.h>
  18
  19 #include <asm/arch/h4000-gpio.h>
  20 #include <asm/arch/h4000-asic.h>
  21 #include <asm/hardware/ipaq-asic3.h>
  22 #include <linux/soc/asic3_base.h>
  23
  24 #define H4000_MAX_INTENSITY 0x3ff
  25
  26 extern struct platform_device h4000_asic3;
  27
  28 static void h4000_set_bl_intensity(int intensity)
  29 {
  30         /* LCD brightness is driven by PWM0.
  31          * We'll set the pre-scaler to 8, and the period to 1024, this
  32          * means the backlight refresh rate will be 3686400/(8*1024) =
  33          * 450 Hz which is quite enough.
  34          */
  35         PWM_CTRL0 = 7;            /* pre-scaler */
  36         PWM_PWDUTY0 = intensity; /* duty cycle */
  37         PWM_PERVAL0 = H4000_MAX_INTENSITY;      /* period */
  38
  39         if (intensity > 0) {
  40                 pxa_set_cken(CKEN0_PWM0, 1);
  41                 asic3_set_gpio_out_b(&h4000_asic3.dev,
  42                         GPIOB_BACKLIGHT_POWER_ON, GPIOB_BACKLIGHT_POWER_ON);
  43         } else {
  44                 pxa_set_cken(CKEN0_PWM0, 0);
  45                 asic3_set_gpio_out_b(&h4000_asic3.dev,
  46                         GPIOB_BACKLIGHT_POWER_ON, 0);
  47         }
  48 }
  49
  50
  51 static struct corgibl_machinfo h4000_bl_machinfo = {
  52         .default_intensity = H4000_MAX_INTENSITY / 4,
  53         .limit_mask = 0xffff,
  54         .max_intensity = H4000_MAX_INTENSITY,
  55         .set_bl_intensity = h4000_set_bl_intensity,
  56 };
  57
  58 struct platform_device h4000_bl = {
  59         .name = "corgi-bl",
  60         .dev = {
  61                 .platform_data = &h4000_bl_machinfo,
  62         },
  63 };
  64
  65 MODULE_AUTHOR("Paul Sokolovsky <pmiscml@gmail.com>");
  66 MODULE_DESCRIPTION("Backlight driver for iPAQ H4000");
  67 MODULE_LICENSE("GPL");
  68