[PATCH v6, 3/4] drm/mediatek: keep dsi as LP00 before dcs cmds transfer

[xinlei.lee]

On Wed, 2022-05-18 at 11:55 +0800, CK Hu wrote:
> Hi, Xinlei:
> 
> On Thu, 2022-05-12 at 14:30 +0800, xinlei.lee at mediatek.com wrote:
> > From: Jitao Shi <jitao.shi at mediatek.com>
> > 
> > To comply with the panel sequence, hold the mipi signal to LP00
> > before the dcs cmds transmission,
> > and pull the mipi signal high from LP00 to LP11 until the start of
> > the dcs cmds transmission.
> > The normal panel timing is :
> > (1) pp1800 DC pull up
> > (2) avdd & avee AC pull high
> > (3) lcm_reset pull high -> pull low -> pull high
> > (4) Pull MIPI signal high (LP11) -> initial code -> send video
> > data(HS mode)
> > The power-off sequence is reversed.
> > If dsi is not in cmd mode, then dsi will pull the mipi signal high
> > in
> > the mtk_output_dsi_enable function.
> > The delay in lane_ready func is the reaction time of dsi_rx after
> > pulling up the mipi signal.
> > 
> > Fixes: 2dd8075d2185 ("drm/mediatek: mtk_dsi: Use the
> > drm_panel_bridge
> > API")
> > 
> > Cc: <stable at vger.kernel.org> # 6.6.x: b255d51e3967: sched: Modify
> > dsi
> > funcs to atomic operations
> > Cc: <stable at vger.kernel.org> # 6.6.x: 72c69c977502: sched: Separate
> > poweron/poweroff from enable/disable and define new funcs
> > Cc: <stable at vger.kernel.org> # 6.6.x
> 
> This patch looks good to me, but do you want to 'back' port this
> patch
> to Linux version 6.6?
> 
> Regards,
> CK
> 
> > Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
> > Signed-off-by: Xinlei Lee <xinlei.lee at mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno at collabora.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dsi.c | 28 +++++++++++++++++++++-----
> > --
> >  1 file changed, 21 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index d9a6b928dba8..25e84d9426bf 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -203,6 +203,7 @@ struct mtk_dsi {
> >  	struct mtk_phy_timing phy_timing;
> >  	int refcount;
> >  	bool enabled;
> > +	bool lanes_ready;
> >  	u32 irq_data;
> >  	wait_queue_head_t irq_wait_queue;
> >  	const struct mtk_dsi_driver_data *driver_data;
> > @@ -661,18 +662,11 @@ static int mtk_dsi_poweron(struct mtk_dsi
> > *dsi)
> >  	mtk_dsi_reset_engine(dsi);
> >  	mtk_dsi_phy_timconfig(dsi);
> >  
> > -	mtk_dsi_rxtx_control(dsi);
> > -	usleep_range(30, 100);
> > -	mtk_dsi_reset_dphy(dsi);
> >  	mtk_dsi_ps_control_vact(dsi);
> >  	mtk_dsi_set_vm_cmd(dsi);
> >  	mtk_dsi_config_vdo_timing(dsi);
> >  	mtk_dsi_set_interrupt_enable(dsi);
> >  
> > -	mtk_dsi_clk_ulp_mode_leave(dsi);
> > -	mtk_dsi_lane0_ulp_mode_leave(dsi);
> > -	mtk_dsi_clk_hs_mode(dsi, 0);
> > -
> >  	return 0;
> >  err_disable_engine_clk:
> >  	clk_disable_unprepare(dsi->engine_clk);
> > @@ -701,6 +695,23 @@ static void mtk_dsi_poweroff(struct mtk_dsi
> > *dsi)
> >  	clk_disable_unprepare(dsi->digital_clk);
> >  
> >  	phy_power_off(dsi->phy);
> > +
> > +	dsi->lanes_ready = false;
> > +}
> > +
> > +static void mtk_dsi_lane_ready(struct mtk_dsi *dsi)
> > +{
> > +	if (!dsi->lanes_ready) {
> > +		dsi->lanes_ready = true;
> > +		mtk_dsi_rxtx_control(dsi);
> > +		usleep_range(30, 100);
> > +		mtk_dsi_reset_dphy(dsi);
> > +		mtk_dsi_clk_ulp_mode_leave(dsi);
> > +		mtk_dsi_lane0_ulp_mode_leave(dsi);
> > +		mtk_dsi_clk_hs_mode(dsi, 0);
> > +		msleep(20);
> > +		/* The reaction time after pulling up the mipi signal
> > for dsi_rx */
> > +	}
> >  }
> >  
> >  static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
> > @@ -708,6 +719,7 @@ static void mtk_output_dsi_enable(struct
> > mtk_dsi
> > *dsi)
> >  	if (dsi->enabled)
> >  		return;
> >  
> > +	mtk_dsi_lane_ready(dsi);
> >  	mtk_dsi_set_mode(dsi);
> >  	mtk_dsi_clk_hs_mode(dsi, 1);
> >  
> > @@ -1017,6 +1029,8 @@ static ssize_t mtk_dsi_host_transfer(struct
> > mipi_dsi_host *host,
> >  	if (MTK_DSI_HOST_IS_READ(msg->type))
> >  		irq_flag |= LPRX_RD_RDY_INT_FLAG;
> >  
> > +	mtk_dsi_lane_ready(dsi);
> > +
> >  	ret = mtk_dsi_host_send_cmd(dsi, msg, irq_flag);
> >  	if (ret)
> >  		goto restore_dsi_mode;
> 
> 

Hi CK:

Thanks for your review.
I had some misunderstandings before, and I will modify the back version
to 5.10.x in the next version.

Best Regards!
xinlei