arch/arm/mach-pxa/htcsable/htcsable_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  * Copyright (C) 2006 Luke Kenneth Casson Leighton
   8  *
   9  * Based on code from older versions of h4000_lcd.c
  10  * Based on code from h4000_bl.c
  11  */
  12
  13 #include <linux/types.h>
  14 #include <asm/arch/hardware.h>  /* for pxa-regs.h (__REG) */
  15 #include <linux/platform_device.h>
  16 #include <asm/arch/pxa-regs.h>  /* LCCR[0,1,2,3]* */
  17 #include <asm/mach-types.h>     /* machine_is_htcsable */
  18 #include <linux/corgi_bl.h>
  19 #include <linux/err.h>
  20 #include <linux/delay.h>
  21
  22 #include <asm/arch/htcsable-gpio.h>
  23 #include <asm/arch/htcsable-asic.h>
  24 #include <asm/hardware/ipaq-asic3.h>
  25 #include <linux/soc/asic3_base.h>
  26
  27 #define HTCSABLE_MAX_INTENSITY 0x3ff
  28
  29 extern struct platform_device htcsable_asic3;
  30
  31 static void htcsable_set_bl_intensity(int intensity)
  32 {
  33   printk("htcsable_set_bl_intensity: %d\n", intensity);
  34
  35         /* LCD brightness is driven by PWM0.
  36          * We'll set the pre-scaler to 8, and the period to 1024, this
  37          * means the backlight refresh rate will be 3686400/(8*1024) =
  38          * 450 Hz which is quite enough.
  39          */
  40         PWM_CTRL0 = 7;            /* pre-scaler */
  41         PWM_PWDUTY0 = intensity; /* duty cycle */
  42         PWM_PERVAL0 = HTCSABLE_MAX_INTENSITY;      /* period */
  43
  44         if (intensity > 0) {
  45                 asic3_set_gpio_out_d(&htcsable_asic3.dev,
  46                         GPIOD_LCD_BACKLIGHT, GPIOD_LCD_BACKLIGHT);
  47     mdelay(15);
  48                 asic3_set_gpio_out_d(&htcsable_asic3.dev,
  49                         1<<14, 1<<14);
  50     mdelay(15);
  51                 pxa_set_cken(CKEN0_PWM0, 1);
  52         } else {
  53                 asic3_set_gpio_out_d(&htcsable_asic3.dev,
  54                         GPIOD_LCD_BACKLIGHT, 0);
  55     mdelay(15);
  56                 asic3_set_gpio_out_d(&htcsable_asic3.dev,
  57                         1<<14, 0);
  58     mdelay(15);
  59                 pxa_set_cken(CKEN0_PWM0, 0);
  60         }
  61 }
  62
  63
  64 static struct corgibl_machinfo htcsable_bl_machinfo = {
  65         .default_intensity = HTCSABLE_MAX_INTENSITY / 4,
  66         .limit_mask = 0xffff,
  67         .max_intensity = HTCSABLE_MAX_INTENSITY,
  68         .set_bl_intensity = htcsable_set_bl_intensity,
  69 };
  70
  71 struct platform_device htcsable_bl = {
  72         .name = "corgi-bl",
  73         .dev = {
  74                 .platform_data = &htcsable_bl_machinfo,
  75         },
  76 };
  77
  78 MODULE_AUTHOR("Paul Sokolovsky <pmiscml@gmail.com>, Luke Kenneth Casson Leighton");
  79 MODULE_DESCRIPTION("Backlight driver for iPAQ HTCSABLE");
  80 MODULE_LICENSE("GPL");
  81