Hi, Jitao:
Sorry for late reply.
Some comments inline.
On Fri, 2016-08-26 at 14:10 +0800, Jitao Shi wrote:
> 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, this
> signal will cause h-time larger than normal and reduce FPS.
> 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@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 111 ++++++++++++++++++++++--------------
> 1 file changed, 67 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 28b2044..506aa22 100644
[snip...]
>
> -static void dsi_phy_timconfig(struct mtk_dsi *dsi)
> +static void dsi_phy_timconfig(struct mtk_dsi *dsi, u32 phy_timing0,
> + u32 phy_timing1, u32 phy_timing2,
> + u32 phy_timing3)
> {
> - u32 timcon0, timcon1, timcon2, timcon3;
> - unsigned int ui, cycle_time;
> - unsigned int lpx;
> -
> - 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);
> - 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);
> -
> - writel(timcon0, dsi->regs + DSI_PHY_TIMECON0);
> - writel(timcon1, dsi->regs + DSI_PHY_TIMECON1);
> - writel(timcon2, dsi->regs + DSI_PHY_TIMECON2);
> - writel(timcon3, dsi->regs + DSI_PHY_TIMECON3);
> + writel(phy_timing0, dsi->regs + DSI_PHY_TIMECON0);
> + writel(phy_timing1, dsi->regs + DSI_PHY_TIMECON1);
> + writel(phy_timing2, dsi->regs + DSI_PHY_TIMECON2);
> + writel(phy_timing3, dsi->regs + DSI_PHY_TIMECON3);
> }
>
> static void mtk_dsi_enable(struct mtk_dsi *dsi)
> @@ -202,19 +186,57 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
> {
> struct device *dev = dsi->dev;
> int ret;
> + u64 bit_clock, total_bits;
> + u32 htotal, htotal_bits, bit_per_pixel, overhead_cycles, overhead_bits;
> + u32 phy_timing0, phy_timing1, phy_timing2, phy_timing3;
>
> if (++dsi->refcount != 1)
> return 0;
>
> + phy_timing0 = LPX(5) | HS_PRPR(6) | HS_ZERO(10) | HS_TRAIL(8);
> + phy_timing1 = TA_GO(20) | TA_SURE(7) | TA_GET(25) | DA_HS_EXIT(7);
> + phy_timing2 = CLK_ZERO(38) | CLK_TRAIL(22);
> + phy_timing3 = CLK_HS_PRPR(8) | CLK_HS_POST(21) | CLK_HS_EXIT(10);
The original phy_timing2 and phy_timing3 is defined as
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);
They are varied by cycle_time. I think you should not use a fixed value
for them.
> +
> + 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;
> + }
> /**
> - * 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.
> + * data_rate = (pixel_clock) * bit_per_pixel * mipi_ratio / lane_num;
> + * vm.pixelclock is Khz, data_rata unit is Hz, so need to multiply 1000
> + * mipi_ratio is (htotal * byte_per_pixel / lane_num + Tlpx + Ths_prep
> + * + Thstrail + Ths_exit + Ths_zero) /
> + * (htotal * byte_per_pixel /lane_number)
> */
> - dsi->data_rate = dsi->vm.pixelclock * 3 * 21 / (1 * 1000 * 10);
> + bit_clock = dsi->vm.pixelclock * 1000 * bit_per_pixel;
> + htotal = dsi->vm.hactive + dsi->vm.hback_porch + dsi->vm.hfront_porch +
> + dsi->vm.hsync_len;
> + htotal_bits = htotal * bit_per_pixel;
> +
> + /**
> + * overhead = lpx + hs_prepare + hs_zero + hs_trail + hs_exit
> + */
> + overhead_cycles = (phy_timing0 & 0xff) + (phy_timing0 >> 8 & 0xff) +
> + (phy_timing0 >> 16 & 0xff) +
> + (phy_timing0 >> 24 & 0xff) +
> + (phy_timing1 >> 24 & 0xff);
I think phy_timing0 and phy_timing1 is defined as
phy_timing0 = LPX(a) | HS_PRPR(b) | HS_ZERO(c) | HS_TRAIL(d);
phy_timing1 = TA_GO(e) | TA_SURE(f) | TA_GET(g) | DA_HS_EXIT(h);
So, it could be a more simple way to assign overhead_cycles like this
overhead_cycles = a + b + c + d + h;
Because these variable are constant, maybe you can define them as
symbols.
> + overhead_bits = overhead_cycles * dsi->lanes * 8;
> + total_bits = htotal_bits + overhead_bits;
> +
> + dsi->data_rate = DIV_ROUND_UP_ULL(bit_clock * total_bits,
> + htotal_bits * dsi->lanes);
>
> - ret = clk_set_rate(dsi->hs_clk, dsi->data_rate * 1000000);
> + 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;
> @@ -236,7 +258,8 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
>
> mtk_dsi_enable(dsi);
> mtk_dsi_reset(dsi);
> - dsi_phy_timconfig(dsi);
> + dsi_phy_timconfig(dsi, phy_timing0, phy_timing1, phy_timing2,
> + phy_timing3);
>
> return 0;
>
Regards,
CK
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