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Message-ID: <1477472832.7427.1.camel@mszsdhlt06>
Date: Wed, 26 Oct 2016 17:07:12 +0800
From: Jitao Shi <jitao.shi@...iatek.com>
To: CK Hu <ck.hu@...iatek.com>
CC: Philipp Zabel <p.zabel@...gutronix.de>,
Matthias Brugger <matthias.bgg@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>,
"Ajay Kumar" <ajaykumar.rs@...sung.com>,
Inki Dae <inki.dae@...sung.com>,
"Rahul Sharma" <rahul.sharma@...sung.com>,
Sean Paul <seanpaul@...omium.org>,
Vincent Palatin <vpalatin@...omium.org>,
Andy Yan <andy.yan@...k-chips.com>,
Russell King <rmk+kernel@....linux.org.uk>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<dri-devel@...ts.freedesktop.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>,
<srv_heupstream@...iatek.com>,
"Sascha Hauer" <kernel@...gutronix.de>,
<yingjoe.chen@...iatek.com>, <eddie.huang@...iatek.com>,
<cawa.cheng@...iatek.com>, <bibby.hsieh@...iatek.com>,
<stonea168@....com>
Subject: Re: [PATCH v2] drm/mediatek: fixed the calc method of data rate per
lane
On Wed, 2016-10-26 at 14:41 +0800, CK Hu wrote:
> Hi, Jitao:
>
> On Tue, 2016-10-25 at 13:40 +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@...iatek.com>
> > ---
> > Change since v1:
> > - phy_timing2 and phy_timing3 refer clock cycle time.
> > - define values of LPX HS_PRPR HS_ZERO HS_TRAIL TA_GO TA_SURE TA_GET DA_HS_EXIT
> > ---
> > drivers/gpu/drm/mediatek/mtk_dsi.c | 103 +++++++++++++++++++++++-------------
> > 1 file changed, 67 insertions(+), 36 deletions(-)
> >
>
> [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);
>
> Why do you move these calculation to mtk_dsi_poweron()? You can keep
> calculation here and just do some modification.
>
> Regards,
> CK
Thanks for your review. I'll fix it in next patchset.
Best Regards
jitao
>
> > + 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 +188,51 @@ 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;
> > + u32 ui, cycle_time;
> >
> > if (++dsi->refcount != 1)
> > return 0;
> >
> > + 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) * 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)
> > + */
> > + 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;
> > +
> > /**
> > - * 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.
> > + * overhead = lpx + hs_prepare + hs_zero + hs_trail + hs_exit
> > */
> > - dsi->data_rate = dsi->vm.pixelclock * 3 * 21 / (1 * 1000 * 10);
> > + overhead_cycles = LPX + (HS_PRPR >> 8) + (HS_ZERO >> 16) +
> > + (HS_TRAIL >> 24) + (DA_HS_EXIT >> 24);
> > + overhead_bits = overhead_cycles * dsi->lanes * 8;
> > + total_bits = htotal_bits + overhead_bits;
> >
> > - ret = clk_set_rate(dsi->hs_clk, dsi->data_rate * 1000000);
> > + 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);
> > if (ret < 0) {
> > dev_err(dev, "Failed to set data rate: %d\n", ret);
> > goto err_refcount;
> > @@ -236,7 +254,20 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
> >
> > mtk_dsi_enable(dsi);
> > mtk_dsi_reset(dsi);
> > - dsi_phy_timconfig(dsi);
> > +
> > + ui = 1000 / dsi->data_rate + 0x01;
> > + cycle_time = 8000 / dsi->data_rate + 0x01;
> > +
> > + phy_timing0 = LPX | HS_PRPR | HS_ZERO | HS_TRAIL;
> > + phy_timing1 = TA_GO | TA_SURE | TA_GET | DA_HS_EXIT;
> > + phy_timing2 = ((NS_TO_CYCLE(0x64, cycle_time) + 0xa) << 24) |
> > + (NS_TO_CYCLE(0x150, cycle_time) << 16);
> > + phy_timing3 = (2 * LPX) << 16 |
> > + NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8 |
> > + NS_TO_CYCLE(0x40, cycle_time);
> > +
> > + dsi_phy_timconfig(dsi, phy_timing0, phy_timing1, phy_timing2,
> > + phy_timing3);
> >
> > return 0;
> >
>
>
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