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Properly implement backlighting on Onda VX7x7 (using PWM).

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21235 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Maurus Cuelenaere 2009-06-09 17:19:43 +00:00
parent a7621fcb8b
commit b91ebdd600
2 changed files with 36 additions and 74 deletions
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97
firmware/target/mips/ingenic_jz47xx/onda_vx747/backlight-onda_vx7X7.c
View file

@ -27,84 +27,50 @@
#define BACKLIGHT_GPIO (32*3+31)
#define BACKLIGHT_PWM 7
/* TODO: use HW PWM */
#define SW_PWM 1
#if SW_PWM
static bool backlight_on;
static void set_backlight(int val)
{
(void)val;
}
bool _backlight_init(void)
{
__gpio_as_output(BACKLIGHT_GPIO);
__gpio_set_pin(BACKLIGHT_GPIO);
backlight_on = true;
return true;
}
void _backlight_on(void)
{
if(!backlight_on)
__gpio_set_pin(BACKLIGHT_GPIO);
backlight_on = true;
}
void _backlight_off(void)
{
if(backlight_on)
__gpio_clear_pin(BACKLIGHT_GPIO);
backlight_on = false;
}
#else
/* PWM counter (PWM INITL = 0):
* [0, PWM half rate[ -> backlight off
* [PWM half rate, PWM full rate[ -> backlight on
* [PWM full rate, PWM full rate] -> counter reset to 0
*/
static int old_val;
static void set_backlight(int val)
{
if(val == old_val)
return;
/* Taken from the OF */
int tmp;
tmp = (val/2 + __cpm_get_rtcclk()) / val;
if(tmp > 0xFFFF)
tmp = 0xFFFF;
__tcu_set_half_data(BACKLIGHT_PWM, (tmp * val * 1374389535) >> 5);
__tcu_set_full_data(BACKLIGHT_PWM, tmp);
/* The pulse repetition frequency should be greater than 100Hz so
the flickering is not perceptible to the human eye but
not greater than about 1kHz. */
/* Clock = 8192 Hz */
/* 1 <= val <= 30 */
int cycle = (MAX_BRIGHTNESS_SETTING - val + 1);
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_stop_counter(BACKLIGHT_PWM);
__tcu_set_count(BACKLIGHT_PWM, 0);
__tcu_set_half_data(BACKLIGHT_PWM, cycle-1);
__tcu_set_full_data(BACKLIGHT_PWM, cycle);
__tcu_start_counter(BACKLIGHT_PWM);
__tcu_enable_pwm_output(BACKLIGHT_PWM);
old_val = val;
}
static void set_backlight_on(void)
{
if(old_val == MAX_BRIGHTNESS_SETTING)
return;
__tcu_start_timer_clock(BACKLIGHT_PWM);
set_backlight(MAX_BRIGHTNESS_SETTING);
__tcu_set_count(BACKLIGHT_PWM, 0);
__tcu_start_counter(BACKLIGHT_PWM);
set_backlight(old_val);
__tcu_enable_pwm_output(BACKLIGHT_PWM);
__tcu_start_counter(BACKLIGHT_PWM);
}
static void set_backlight_off(void)
{
__tcu_stop_counter(BACKLIGHT_PWM);
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_stop_timer_clock(BACKLIGHT_PWM);
old_val = -1;
}
bool _backlight_init(void)
@ -113,17 +79,17 @@ bool _backlight_init(void)
__tcu_start_timer_clock(BACKLIGHT_PWM);
__tcu_stop_counter(BACKLIGHT_PWM);
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_init_pwm_output_low(BACKLIGHT_PWM);
__tcu_select_rtcclk(BACKLIGHT_PWM);
__tcu_select_clk_div1(BACKLIGHT_PWM);
__tcu_set_pwm_output_shutdown_graceful(BACKLIGHT_PWM);
__tcu_enable_pwm_output(BACKLIGHT_PWM);
__tcu_select_rtcclk(BACKLIGHT_PWM); /* 32.768 kHz */
__tcu_select_clk_div1(BACKLIGHT_PWM); /* 8.192 kHz */
__tcu_mask_half_match_irq(BACKLIGHT_PWM);
__tcu_mask_full_match_irq(BACKLIGHT_PWM);
old_val = -1;
old_val = MAX_BRIGHTNESS_SETTING;
set_backlight_on();
return true;
@ -138,7 +104,6 @@ void _backlight_off(void)
{
set_backlight_off();
}
#endif /* !SW_PWM */
#ifdef HAVE_BACKLIGHT_BRIGHTNESS
void _backlight_set_brightness(int brightness)