| Message ID | 20230427142934.55435-7-francesco@dolcini.it (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: tc358768: various fixes on PLL calculation and DSI timings | expand |
On Thu, Apr 27, 2023 at 4:33 PM Francesco Dolcini <francesco@dolcini.it> wrote: > > From: Francesco Dolcini <francesco.dolcini@toradex.com> > > Correct computation of THS_ZEROCNT register. > > This register must be set to a value that ensure that > THS_PREPARE + THS_ZERO > 145ns + 10*UI > > with the actual value of (THS_PREPARE + THS_ZERO) being > > ((1 to 2) + 1 + (TCLK_ZEROCNT + 1) + (3 to 4)) x ByteClk cycle + > + HSByteClk x (2 + (1 to 2)) + (PHY delay) > > with PHY delay being about > > (8 + (5 to 6)) x MIPIBitClk cycle in the BitClk conversion. > > Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver") > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com> > --- > drivers/gpu/drm/bridge/tc358768.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c > index 360c7c65f8c4..36e33cba59a2 100644 > --- a/drivers/gpu/drm/bridge/tc358768.c > +++ b/drivers/gpu/drm/bridge/tc358768.c > @@ -760,9 +760,10 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) > /* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */ > val = 50 + tc358768_to_ns(4 * ui_nsk); > val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1; > - /* THS_ZERO > 145ns + 10*UI */ > - val2 = tc358768_ns_to_cnt(145 - tc358768_to_ns(ui_nsk), dsibclk_nsk); > - val |= (val2 - tc358768_to_ns(phy_delay_nsk)) << 8; > + /* THS_PREPARE + THS_ZERO > 145ns + 10*UI */ > + raw_val = tc358768_ns_to_cnt(145 - tc358768_to_ns(3 * ui_nsk), dsibclk_nsk) - 10; > + val2 = clamp(raw_val, 0, 127); > + val |= val2 << 8; > dev_dbg(priv->dev, "THS_HEADERCNT: 0x%x\n", val); > tc358768_write(priv, TC358768_THS_HEADERCNT, val); > > -- > 2.25.1 > Reviewed-by: Robert Foss <rfoss@kernel.org>
diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index 360c7c65f8c4..36e33cba59a2 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -760,9 +760,10 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) /* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */ val = 50 + tc358768_to_ns(4 * ui_nsk); val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1; - /* THS_ZERO > 145ns + 10*UI */ - val2 = tc358768_ns_to_cnt(145 - tc358768_to_ns(ui_nsk), dsibclk_nsk); - val |= (val2 - tc358768_to_ns(phy_delay_nsk)) << 8; + /* THS_PREPARE + THS_ZERO > 145ns + 10*UI */ + raw_val = tc358768_ns_to_cnt(145 - tc358768_to_ns(3 * ui_nsk), dsibclk_nsk) - 10; + val2 = clamp(raw_val, 0, 127); + val |= val2 << 8; dev_dbg(priv->dev, "THS_HEADERCNT: 0x%x\n", val); tc358768_write(priv, TC358768_THS_HEADERCNT, val);