On 2014년 11월 13일 18:54, YoungJun Cho wrote:
Hi Inki,
On 11/13/2014 06:12 PM, Inki Dae wrote:
On 2014년 10월 01일 15:19, YoungJun Cho wrote:
The I80 interface uses SYS_WE and SYS_CS to process 1 pixel data, so it requires the twice faster clock than the pixel clock. And the frame done interrupt should occurr prior to the next TE signal, H/W guy recommends to use as 1.73 times faster clock frequency.
Signed-off-by: YoungJun Cho yj44.cho@samsung.com Acked-by: Inki Dae inki.dae@samsung.com Acked-by: Kyungmin Park kyungmin.park@samsung.com
drivers/gpu/drm/exynos/exynos_drm_fimd.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index b2f6007..05c2a97a 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -81,6 +81,11 @@ #define LCD_WR_HOLD(x) ((x) << 4) #define I80IFEN_ENABLE (1 << 0)
+/* I80 interface clock */ +#define I80_DATA_SAMPLING_CYCLE 2 +#define I80_TE_PERIOD_US 1667 +#define I80_DATA_TRANSACTION_TIME_US 964
- /* FIMD has totally five hardware windows. */ #define WINDOWS_NR 5
@@ -303,16 +308,25 @@ static void fimd_mgr_remove(struct exynos_drm_manager *mgr) static u32 fimd_calc_clkdiv(struct fimd_context *ctx, const struct drm_display_mode *mode) {
- unsigned long ideal_clk = mode->htotal * mode->vtotal *
mode->vrefresh;
unsigned long ideal_clk; u32 clkdiv;
if (ctx->i80_if) { /*
* The frame done interrupt should be occurred prior to the* next TE signal.
* The I80 interface uses SYS_WE and SYS_CS to process 1 pixel* data, so it requires the twice faster clock than the pixel* clock[I80_DATA_SAMPLING_CYCLE].* And the frame done interrupt should occurr prior to the next* TE signal, H/W guy recommends to use as 1.73 times faster* frequency[I80_TE_PERIOD_US / I80_DATA_TRANSACTION_TIME_US]. */
ideal_clk *= 2;- }
ideal_clk = mode->hdisplay * mode->vdisplay *I80_DATA_SAMPLING_CYCLE *I80_TE_PERIOD_US / I80_DATA_TRANSACTION_TIME_US;How about using one constant directly?
I.e., #define RECOMMENDED_VAR 1.73
... I80_DATA_SAMPLING_CYCLE * RECOMMENDED_VAR
Is there any case that the te period and data transaction time should be changed?
At first time, I did.
But it made following build break : drivers/built-in.o: In function `fimd_commit': exynos_adc.c:(.text+0x878bc): undefined reference to `__aeabi_ui2d' exynos_adc.c:(.text+0x878d0): undefined reference to `__aeabi_dmul' exynos_adc.c:(.text+0x878d4): undefined reference to `__aeabi_d2uiz' make: *** [vmlinux] Error 1
It came from using floating point value. So I changed it.
Ah, sorry. I missed it. I think there would be better idea. Let's try to find the idea.
Thanks, Inki Dae
Do you have any good idea ?
Thank you. Best regards YJ
Thanks, Inki Dae
} else
ideal_clk = mode->htotal * mode->vtotal;ideal_clk *= mode->vrefresh;
/* Find the clock divider value that gets us closest to
ideal_clk */ clkdiv = DIV_ROUND_UP(clk_get_rate(ctx->lcd_clk), ideal_clk); @@ -431,7 +445,7 @@ static void fimd_commit(struct exynos_drm_manager *mgr) val |= VIDCON0_CLKSEL_LCD;
clkdiv = fimd_calc_clkdiv(ctx, mode);
- if (clkdiv > 1)
if (clkdiv >= 1) val |= VIDCON0_CLKVAL_F(clkdiv - 1) | VIDCON0_CLKDIR;
writel(val, ctx->regs + VIDCON0);