board/spreadtrum/sp9820ea/sprd_bl.c

   1 #include <common.h>
   2 #include <asm/arch/hardware.h>
   3 #include <asm/io.h>
   4 #include <asm/arch/sprd_reg.h>
   5 #include <asm/arch/sprd_reg_base.h>
   6
   7 #define PWM_INDEX 2
   8
   9 #define PWM_PRESCALE (0x0000)
  10 #define PWM_CNT (0x0004)
  11 #define PWM_PAT_LOW (0x000C)
  12 #define PWM_PAT_HIG (0x0010)
  13
  14 #define PWM_ENABLE (1 << 8)
  15 #define PWM2_SCALE 0x0
  16 #define PWM_REG_MSK 0xffff
  17 #define PWM_MOD_MAX 0xff
  18
  19
  20 static inline uint32_t pwm_read(int index, uint32_t reg)
  21 {
  22         return __raw_readl(CTL_BASE_PWM + index * 0x20 + reg);
  23 }
  24
  25 static void pwm_write(int index, uint32_t value, uint32_t reg)
  26 {
  27         __raw_writel(value, CTL_BASE_PWM + index * 0x20 + reg);
  28 }
  29
  30 void set_backlight(uint32_t brightness)
  31 {
  32         int index = PWM_INDEX;
  33
  34         __raw_bits_or((0x1 << 0), REG_AON_CLK_PWM0_CFG + index * 4);//ext_26m select
  35
  36         if (0 == brightness) {
  37                 pwm_write(index, 0, PWM_PRESCALE);
  38                 printf("sprd backlight power off. pwm_index=%d  brightness=%d\n", index, brightness);
  39         } else {
  40                 __raw_bits_or((0x1 << (index+4)), REG_AON_APB_APB_EB0); //PWMx EN
  41
  42                 pwm_write(index, PWM2_SCALE, PWM_PRESCALE);
  43                 pwm_write(index, (brightness << 8) | PWM_MOD_MAX, PWM_CNT);
  44                 pwm_write(index, PWM_REG_MSK, PWM_PAT_LOW);
  45                 pwm_write(index, PWM_REG_MSK, PWM_PAT_HIG);
  46                 pwm_write(index, PWM_ENABLE, PWM_PRESCALE);
  47                 printf("sprd backlight power on. pwm_index=%d  brightness=%d\n", index, brightness);
  48         }
  49
  50         return;
  51 }