rgb_lcd: workaround pclk polarity bug by setting mo>=2

This commit is contained in:
morris 2022-07-15 18:07:52 +08:00
parent a149afb0c0
commit 454d658309
3 changed files with 20 additions and 6 deletions

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@ -95,6 +95,7 @@ struct esp_rgb_panel_t {
int x_gap; // Extra gap in x coordinate, it's used when calculate the flush window
int y_gap; // Extra gap in y coordinate, it's used when calculate the flush window
portMUX_TYPE spinlock; // to protect panel specific resource from concurrent access (e.g. between task and ISR)
int lcd_clk_flags; // LCD clock calculation flags
struct {
uint32_t disp_en_level: 1; // The level which can turn on the screen by `disp_gpio_num`
uint32_t stream_mode: 1; // If set, the LCD transfers data continuously, otherwise, it stops refreshing the LCD when transaction done
@ -259,6 +260,11 @@ esp_err_t esp_lcd_new_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_conf
// set clock source
ret = lcd_rgb_panel_select_clock_src(rgb_panel, rgb_panel_config->clk_src);
ESP_GOTO_ON_ERROR(ret, err, TAG, "set source clock failed");
// set minimal PCLK divider
// A limitation in the hardware, if the LCD_PCLK == LCD_CLK, then the PCLK polarity can't be adjustable
if (!(rgb_panel_config->timings.flags.pclk_active_neg || rgb_panel_config->timings.flags.pclk_idle_high)) {
rgb_panel->lcd_clk_flags |= LCD_HAL_PCLK_FLAG_ALLOW_EQUAL_SYSCLK;
}
// install interrupt service, (LCD peripheral shares the interrupt source with Camera by different mask)
int isr_flags = LCD_RGB_INTR_ALLOC_FLAGS | ESP_INTR_FLAG_SHARED;
ret = esp_intr_alloc_intrstatus(lcd_periph_signals.panels[panel_id].irq_id, isr_flags,
@ -391,7 +397,7 @@ static esp_err_t rgb_panel_init(esp_lcd_panel_t *panel)
esp_err_t ret = ESP_OK;
esp_rgb_panel_t *rgb_panel = __containerof(panel, esp_rgb_panel_t, base);
// set pixel clock frequency
rgb_panel->timings.pclk_hz = lcd_hal_cal_pclk_freq(&rgb_panel->hal, rgb_panel->src_clk_hz, rgb_panel->timings.pclk_hz);
rgb_panel->timings.pclk_hz = lcd_hal_cal_pclk_freq(&rgb_panel->hal, rgb_panel->src_clk_hz, rgb_panel->timings.pclk_hz, rgb_panel->lcd_clk_flags);
// pixel clock phase and polarity
lcd_ll_set_clock_idle_level(rgb_panel->hal.dev, rgb_panel->timings.flags.pclk_idle_high);
lcd_ll_set_pixel_clock_edge(rgb_panel->hal.dev, rgb_panel->timings.flags.pclk_active_neg);
@ -795,7 +801,7 @@ IRAM_ATTR static void lcd_rgb_panel_try_update_pclk(esp_rgb_panel_t *rgb_panel)
portENTER_CRITICAL_ISR(&rgb_panel->spinlock);
if (unlikely(rgb_panel->flags.need_update_pclk)) {
rgb_panel->flags.need_update_pclk = false;
rgb_panel->timings.pclk_hz = lcd_hal_cal_pclk_freq(&rgb_panel->hal, rgb_panel->src_clk_hz, rgb_panel->timings.pclk_hz);
rgb_panel->timings.pclk_hz = lcd_hal_cal_pclk_freq(&rgb_panel->hal, rgb_panel->src_clk_hz, rgb_panel->timings.pclk_hz, rgb_panel->lcd_clk_flags);
}
portEXIT_CRITICAL_ISR(&rgb_panel->spinlock);
}

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@ -7,6 +7,7 @@
#pragma once
#include <stdint.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
@ -32,6 +33,8 @@ typedef struct {
*/
void lcd_hal_init(lcd_hal_context_t *hal, int id);
#define LCD_HAL_PCLK_FLAG_ALLOW_EQUAL_SYSCLK (1 << 0)
/**
* @brief LCD PCLK clock calculation
* @note Currently this function is only used by RGB LCD driver, I80 driver still uses a fixed clock division
@ -39,9 +42,10 @@ void lcd_hal_init(lcd_hal_context_t *hal, int id);
* @param hal LCD HAL layer context
* @param src_freq_hz LCD source clock frequency in Hz
* @param expect_pclk_freq_hz Expected LCD PCLK frequency in Hz
* @param lcd_clk_flags Extra flags to control LCD PCLK clock calculation, supported flags are prefixed with LCD_HAL_PCLK_FLAG_
* @return Actual LCD PCLK frequency in Hz
*/
uint32_t lcd_hal_cal_pclk_freq(lcd_hal_context_t *hal, uint32_t src_freq_hz, uint32_t expect_pclk_freq_hz);
uint32_t lcd_hal_cal_pclk_freq(lcd_hal_context_t *hal, uint32_t src_freq_hz, uint32_t expect_pclk_freq_hz, int lcd_clk_flags);
#ifdef __cplusplus
}

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@ -20,6 +20,7 @@ void lcd_hal_init(lcd_hal_context_t *hal, int id)
* @param b smaller value
* @return result of gcd(a, b)
*/
__attribute__((always_inline))
static inline uint32_t _gcd(uint32_t a, uint32_t b)
{
uint32_t c = a % b;
@ -31,16 +32,19 @@ static inline uint32_t _gcd(uint32_t a, uint32_t b)
return b;
}
uint32_t lcd_hal_cal_pclk_freq(lcd_hal_context_t *hal, uint32_t src_freq_hz, uint32_t expect_pclk_freq_hz)
uint32_t lcd_hal_cal_pclk_freq(lcd_hal_context_t *hal, uint32_t src_freq_hz, uint32_t expect_pclk_freq_hz, int lcd_clk_flags)
{
// lcd_clk = module_clock_src / (n + b / a)
// pixel_clk = lcd_clk / mo
uint32_t mo = src_freq_hz / expect_pclk_freq_hz / LCD_LL_CLK_FRAC_DIV_N_MAX + 1;
if (mo == 1 && !(lcd_clk_flags & LCD_HAL_PCLK_FLAG_ALLOW_EQUAL_SYSCLK)) {
mo = 2;
}
uint32_t n = src_freq_hz / expect_pclk_freq_hz / mo;
uint32_t a = 0;
uint32_t b = 0;
// delta_hz / expect_pclk_freq_hz <==> b / a
uint32_t delta_hz = src_freq_hz - expect_pclk_freq_hz * mo * n;
uint32_t delta_hz = src_freq_hz / mo - expect_pclk_freq_hz * n;
// fractional divider
if (delta_hz) {
uint32_t gcd = _gcd(expect_pclk_freq_hz, delta_hz);
@ -52,7 +56,7 @@ uint32_t lcd_hal_cal_pclk_freq(lcd_hal_context_t *hal, uint32_t src_freq_hz, uin
b /= d;
}
HAL_LOGD("lcd_hal", "n=%d,a=%d,b=%d,mo=%d", n, a, b, mo);
HAL_EARLY_LOGD("lcd_hal", "n=%d,a=%d,b=%d,mo=%d", n, a, b, mo);
lcd_ll_set_group_clock_coeff(hal->dev, n, a, b);
lcd_ll_set_pixel_clock_prescale(hal->dev, mo);