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drm/mediatek: fixed the calc method of data rate per lane

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Tune dsi frame rate by pixel clock, dsi add some extra signal (i.e.
Tlpx, Ths-prepare, Ths-zero, Ths-trail,Ths-exit) when enter and exit LP
mode, those signals will cause h-time larger than normal and reduce FPS.
So need to multiply a coefficient to offset the extra signal's effect.
  coefficient = ((htotal*bpp/lane_number)+Tlpx+Ths_prep+Ths_zero+
		 Ths_trail+Ths_exit)/(htotal*bpp/lane_number)

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
This commit is contained in:
Jitao Shi 2016-11-16 11:20:54 +08:00 committed by CK Hu
parent 1ee6f347f8
commit f6c8723970
1 changed files with 50 additions and 18 deletions
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68
drivers/gpu/drm/mediatek/mtk_dsi.c
View file

@ -86,7 +86,7 @@
#define DSI_PHY_TIMECON0 0x110
#define LPX (0xff << 0)
#define HS_PRPR (0xff << 8)
#define HS_PREP (0xff << 8)
#define HS_ZERO (0xff << 16)
#define HS_TRAIL (0xff << 24)
@ -102,10 +102,16 @@
#define CLK_TRAIL (0xff << 24)
#define DSI_PHY_TIMECON3 0x11c
#define CLK_HS_PRPR (0xff << 0)
#define CLK_HS_PREP (0xff << 0)
#define CLK_HS_POST (0xff << 8)
#define CLK_HS_EXIT (0xff << 16)
#define T_LPX 5
#define T_HS_PREP 6
#define T_HS_TRAIL 8
#define T_HS_EXIT 7
#define T_HS_ZERO 10
#define NS_TO_CYCLE(n, c) ((n) / (c) + (((n) % (c)) ? 1 : 0))
struct phy;
@ -161,20 +167,18 @@ static void mtk_dsi_mask(struct mtk_dsi *dsi, u32 offset, u32 mask, u32 data)
static void dsi_phy_timconfig(struct mtk_dsi *dsi)
{
u32 timcon0, timcon1, timcon2, timcon3;
unsigned int ui, cycle_time;
unsigned int lpx;
u32 ui, cycle_time;
ui = 1000 / dsi->data_rate + 0x01;
cycle_time = 8000 / dsi->data_rate + 0x01;
lpx = 5;
timcon0 = (8 << 24) | (0xa << 16) | (0x6 << 8) | lpx;
timcon1 = (7 << 24) | (5 * lpx << 16) | ((3 * lpx) / 2) << 8 |
(4 * lpx);
timcon0 = T_LPX | T_HS_PREP << 8 | T_HS_ZERO << 16 | T_HS_TRAIL << 24;
timcon1 = 4 * T_LPX | (3 * T_LPX / 2) << 8 | 5 * T_LPX << 16 |
T_HS_EXIT << 24;
timcon2 = ((NS_TO_CYCLE(0x64, cycle_time) + 0xa) << 24) |
(NS_TO_CYCLE(0x150, cycle_time) << 16);
timcon3 = (2 * lpx) << 16 | NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8 |
NS_TO_CYCLE(0x40, cycle_time);
timcon3 = NS_TO_CYCLE(0x40, cycle_time) | (2 * T_LPX) << 16 |
NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8;
writel(timcon0, dsi->regs + DSI_PHY_TIMECON0);
writel(timcon1, dsi->regs + DSI_PHY_TIMECON1);
@ -202,19 +206,47 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
{
struct device *dev = dsi->dev;
int ret;
u64 pixel_clock, total_bits;
u32 htotal, htotal_bits, bit_per_pixel, overhead_cycles, overhead_bits;
if (++dsi->refcount != 1)
return 0;
/**
* data_rate = (pixel_clock / 1000) * pixel_dipth * mipi_ratio;
* pixel_clock unit is Khz, data_rata unit is MHz, so need divide 1000.
* mipi_ratio is mipi clk coefficient for balance the pixel clk in mipi.
* we set mipi_ratio is 1.05.
*/
dsi->data_rate = dsi->vm.pixelclock * 3 * 21 / (1 * 1000 * 10);
switch (dsi->format) {
case MIPI_DSI_FMT_RGB565:
bit_per_pixel = 16;
break;
case MIPI_DSI_FMT_RGB666_PACKED:
bit_per_pixel = 18;
break;
case MIPI_DSI_FMT_RGB666:
case MIPI_DSI_FMT_RGB888:
default:
bit_per_pixel = 24;
break;
}
ret = clk_set_rate(dsi->hs_clk, dsi->data_rate * 1000000);
/**
* vm.pixelclock is in kHz, pixel_clock unit is Hz, so multiply by 1000
* htotal_time = htotal * byte_per_pixel / num_lanes
* overhead_time = lpx + hs_prepare + hs_zero + hs_trail + hs_exit
* mipi_ratio = (htotal_time + overhead_time) / htotal_time
* data_rate = pixel_clock * bit_per_pixel * mipi_ratio / num_lanes;
*/
pixel_clock = dsi->vm.pixelclock * 1000;
htotal = dsi->vm.hactive + dsi->vm.hback_porch + dsi->vm.hfront_porch +
dsi->vm.hsync_len;
htotal_bits = htotal * bit_per_pixel;
overhead_cycles = T_LPX + T_HS_PREP + T_HS_ZERO + T_HS_TRAIL +
T_HS_EXIT;
overhead_bits = overhead_cycles * dsi->lanes * 8;
total_bits = htotal_bits + overhead_bits;
dsi->data_rate = DIV_ROUND_UP_ULL(pixel_clock * total_bits,
htotal * dsi->lanes);
ret = clk_set_rate(dsi->hs_clk, dsi->data_rate);
if (ret < 0) {
dev_err(dev, "Failed to set data rate: %d\n", ret);
goto err_refcount;