[Intel-gfx] [PATCH v6 06/20] drm/i915/icl: Program DSI clock and data lane timing params

Chauhan, Madhav madhav.chauhan at intel.com
Wed Sep 26 13:08:09 UTC 2018


> -----Original Message-----
> From: Nikula, Jani
> Sent: Wednesday, September 26, 2018 6:29 PM
> To: Chauhan, Madhav <madhav.chauhan at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Kulkarni, Vandita <vandita.kulkarni at intel.com>; Vivi, Rodrigo
> <rodrigo.vivi at intel.com>; Rangappa, Komala B
> <komala.b.rangappa at intel.com>; Chauhan, Madhav
> <madhav.chauhan at intel.com>
> Subject: Re: [PATCH v6 06/20] drm/i915/icl: Program DSI clock and data lane
> timing params
> 
> On Sun, 16 Sep 2018, Madhav Chauhan <madhav.chauhan at intel.com>
> wrote:
> > This patch programs D-PHY timing parameters for the clock and data
> > lane (in escape clocks) of DSI controller (DSI port 0 and 1).
> > These programmed timings would be used by DSI Controller to calculate
> > link transition latencies of the data and clock lanes.
> >
> > v2: Use newly defined bitfields for data and clock lane
> 
> Ville's review [1] hasn't been addressed.

Oh..Overlooked the comments. My bad.
Will address them while publishing v7.

Regards,
Madhav

> 
> BR,
> Jani.
> 
> [1] http://mid.mail-archive.com/20180719161739.GC5565@intel.com
> 
> >
> > Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> > ---
> >  drivers/gpu/drm/i915/icl_dsi.c       |  18 ++++
> >  drivers/gpu/drm/i915/intel_dsi.h     |   3 +
> >  drivers/gpu/drm/i915/intel_dsi_vbt.c | 200
> > +++++++++++++++++++++++++----------
> >  3 files changed, 165 insertions(+), 56 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/icl_dsi.c
> > b/drivers/gpu/drm/i915/icl_dsi.c index ff5b285..9602b65 100644
> > --- a/drivers/gpu/drm/i915/icl_dsi.c
> > +++ b/drivers/gpu/drm/i915/icl_dsi.c
> > @@ -291,6 +291,24 @@ static void gen11_dsi_setup_dphy_timings(struct
> intel_encoder *encoder)
> >  		tmp |= intel_dsi->init_count;
> >  		I915_WRITE(ICL_DSI_T_INIT_MASTER(port), tmp);
> >  	}
> > +
> > +	/* Program DPHY clock lanes timings */
> > +	for_each_dsi_port(port, intel_dsi->ports) {
> > +		I915_WRITE(DPHY_CLK_TIMING_PARAM(port), intel_dsi-
> >dphy_reg);
> > +
> > +		/* shadow register inside display core */
> > +		I915_WRITE(DSI_CLK_TIMING_PARAM(port), intel_dsi-
> >dphy_reg);
> > +	}
> > +
> > +	/* Program DPHY data lanes timings */
> > +	for_each_dsi_port(port, intel_dsi->ports) {
> > +		I915_WRITE(DPHY_DATA_TIMING_PARAM(port),
> > +			   intel_dsi->dphy_data_lane_reg);
> > +
> > +		/* shadow register inside display core */
> > +		I915_WRITE(DSI_DATA_TIMING_PARAM(port),
> > +			   intel_dsi->dphy_data_lane_reg);
> > +	}
> >  }
> >
> >  static void gen11_dsi_enable_port_and_phy(struct intel_encoder
> > *encoder) diff --git a/drivers/gpu/drm/i915/intel_dsi.h
> > b/drivers/gpu/drm/i915/intel_dsi.h
> > index ad7c1cb..9fd8526 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi.h
> > +++ b/drivers/gpu/drm/i915/intel_dsi.h
> > @@ -85,6 +85,9 @@ struct intel_dsi {
> >  	u32 port_bits;
> >  	u32 bw_timer;
> >  	u32 dphy_reg;
> > +
> > +	/* data lanes dphy timing */
> > +	u32 dphy_data_lane_reg;
> >  	u32 video_frmt_cfg_bits;
> >  	u16 lp_byte_clk;
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > index ac83d6b..fbb159b 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > @@ -509,7 +509,9 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi,
> u16 panel_id)
> >  	u32 bpp;
> >  	u32 tlpx_ns, extra_byte_count, bitrate, tlpx_ui;
> >  	u32 ui_num, ui_den;
> > -	u32 prepare_cnt, exit_zero_cnt, clk_zero_cnt, trail_cnt;
> > +	u32 prepare_cnt, exit_zero_cnt, clk_zero_cnt, trail_cnt, hs_zero_cnt;
> > +	u32 tclk_pre_cnt, tclk_post_cnt;
> > +	u32 tclk_pre_ns, tclk_post_ns;
> >  	u32 ths_prepare_ns, tclk_trail_ns;
> >  	u32 tclk_prepare_clkzero, ths_prepare_hszero;
> >  	u32 lp_to_hs_switch, hs_to_lp_switch; @@ -624,76 +626,157 @@
> bool
> > intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
> >
> >  	tclk_prepare_clkzero = mipi_config->tclk_prepare_clkzero;
> >  	ths_prepare_hszero = mipi_config->ths_prepare_hszero;
> > -
> > +	tclk_trail_ns = max(mipi_config->tclk_trail, mipi_config->ths_trail);
> > +	ths_prepare_ns = max(mipi_config->ths_prepare,
> > +				mipi_config->tclk_prepare);
> >  	/*
> >  	 * B060
> >  	 * LP byte clock = TLPX/ (8UI)
> >  	 */
> >  	intel_dsi->lp_byte_clk = DIV_ROUND_UP(tlpx_ns * ui_den, 8 *
> ui_num);
> >
> > -	/* DDR clock period = 2 * UI
> > -	 * UI(sec) = 1/(bitrate * 10^3) (bitrate is in KHZ)
> > -	 * UI(nsec) = 10^6 / bitrate
> > -	 * DDR clock period (nsec) = 2 * UI = (2 * 10^6)/ bitrate
> > -	 * DDR clock count  = ns_value / DDR clock period
> > -	 *
> > +	/*
> >  	 * For GEMINILAKE dphy_param_reg will be programmed in terms of
> >  	 * HS byte clock count for other platform in HS ddr clock count
> >  	 */
> >  	mul = IS_GEMINILAKE(dev_priv) ? 8 : 2;
> > -	ths_prepare_ns = max(mipi_config->ths_prepare,
> > -			     mipi_config->tclk_prepare);
> >
> > -	/* prepare count */
> > -	prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * ui_den, ui_num *
> mul);
> > +	if (IS_ICELAKE(dev_priv)) {
> > +		/*
> > +		 * prepare cnt in escape clocks
> > +		 * this field represents a hexadecimal value with a precision
> > +		 * of 1.2 – i.e. the most significant bit is the integer
> > +		 * and the least significant 2 bits are fraction bits.
> > +		 * so, the field can represent a range of 0.25 to 1.75
> > +		 */
> > +		prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * 4, tlpx_ns);
> > +
> > +		/* clk zero count in escape clocks */
> > +		clk_zero_cnt = DIV_ROUND_UP(
> > +					(tclk_prepare_clkzero -
> ths_prepare_ns),
> > +					tlpx_ns);
> > +
> > +		/* trail cnt in escape clocks*/
> > +		trail_cnt = DIV_ROUND_UP(tclk_trail_ns, tlpx_ns);
> > +
> > +		/* tclk pre/post count in escape clocks */
> > +		tclk_post_ns = mipi_config->tclk_post;
> > +		tclk_pre_ns = mipi_config->tclk_pre;
> > +		tclk_pre_cnt = DIV_ROUND_UP(tclk_pre_ns, tlpx_ns);
> > +		tclk_post_cnt = DIV_ROUND_UP(tclk_post_ns, tlpx_ns);
> > +
> > +		/* hs zero cnt in escape clocks */
> > +		hs_zero_cnt = DIV_ROUND_UP(
> > +					(ths_prepare_hszero -
> ths_prepare_ns),
> > +					tlpx_ns);
> > +
> > +		/* hs exit zero cnt in escape clocks */
> > +		exit_zero_cnt = DIV_ROUND_UP(mipi_config->ths_exit,
> tlpx_ns);
> > +
> > +		if (prepare_cnt > 0x7 ||
> > +		    clk_zero_cnt > 0xF ||
> > +		    tclk_pre_cnt > 0x3 ||
> > +		    tclk_post_cnt > 0x7 ||
> > +		    trail_cnt > 0x7 ||
> > +		    hs_zero_cnt > 0xF ||
> > +		    exit_zero_cnt > 0x7) {
> > +			DRM_DEBUG_DRIVER("DPHY values crossing max
> limits,");
> > +			DRM_DEBUG_DRIVER("restricting to max values\n");
> > +		}
> > +
> > +		prepare_cnt = (prepare_cnt > 0x7) ? 0x7 : prepare_cnt;
> > +		clk_zero_cnt = (clk_zero_cnt > 0xF) ? 0xF : clk_zero_cnt;
> > +		tclk_pre_cnt = (tclk_pre_cnt > 0x3) ? 0x3 : tclk_pre_cnt;
> > +		tclk_post_cnt = (tclk_post_cnt > 0x7) ? 0x7 : tclk_post_cnt;
> > +		trail_cnt = (trail_cnt > 0x7) ? 0x7 : trail_cnt;
> > +		hs_zero_cnt = (hs_zero_cnt > 0xF) ? 0xF : hs_zero_cnt;
> > +		exit_zero_cnt = (exit_zero_cnt > 0x7) ? 0x7 : exit_zero_cnt;
> > +
> > +		/* clock lane dphy timings */
> > +		intel_dsi->dphy_reg |= (CLK_PREPARE_OVERRIDE |
> > +					CLK_PREPARE(prepare_cnt) |
> > +					CLK_ZERO_OVERRIDE |
> > +					CLK_ZERO(clk_zero_cnt) |
> > +					CLK_PRE_OVERRIDE |
> > +					CLK_PRE(tclk_pre_cnt) |
> > +					CLK_POST_OVERRIDE |
> > +					CLK_POST(tclk_post_cnt) |
> > +					CLK_TRAIL_OVERRIDE |
> > +					CLK_TRAIL(trail_cnt));
> > +
> > +		/* data lanes dphy timings */
> > +		intel_dsi->dphy_data_lane_reg = HS_PREPARE_OVERRIDE |
> > +						HS_PREPARE(prepare_cnt) |
> > +						HS_ZERO_OVERRIDE |
> > +						HS_ZERO(hs_zero_cnt) |
> > +						HS_TRAIL_OVERRIDE |
> > +						HS_TRAIL(trail_cnt) |
> > +						HS_EXIT_OVERRIDE |
> > +						HS_EXIT(exit_zero_cnt);
> > +	} else {
> > +		/*
> > +		 * DDR clock period = 2 * UI
> > +		 * UI(sec) = 1/(bitrate * 10^3) (bitrate is in KHZ)
> > +		 * UI(nsec) = 10^6 / bitrate
> > +		 * DDR clock period (nsec) = 2 * UI = (2 * 10^6)/ bitrate
> > +		 * DDR clock count  = ns_value / DDR clock period
> > +		 */
> >
> > -	if (prepare_cnt > PREPARE_CNT_MAX) {
> > -		DRM_DEBUG_KMS("prepare count too high %u\n",
> prepare_cnt);
> > -		prepare_cnt = PREPARE_CNT_MAX;
> > -	}
> > +		/* prepare count */
> > +		prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * ui_den,
> > +							ui_num * mul);
> >
> > -	/* exit zero count */
> > -	exit_zero_cnt = DIV_ROUND_UP(
> > +		if (prepare_cnt > PREPARE_CNT_MAX) {
> > +			DRM_DEBUG_KMS("prepare count too high %u\n",
> > +								prepare_cnt);
> > +			prepare_cnt = PREPARE_CNT_MAX;
> > +		}
> > +
> > +		/* exit zero count */
> > +		exit_zero_cnt = DIV_ROUND_UP(
> >  				(ths_prepare_hszero - ths_prepare_ns) *
> ui_den,
> >  				ui_num * mul
> >  				);
> >
> > -	/*
> > -	 * Exit zero is unified val ths_zero and ths_exit
> > -	 * minimum value for ths_exit = 110ns
> > -	 * min (exit_zero_cnt * 2) = 110/UI
> > -	 * exit_zero_cnt = 55/UI
> > -	 */
> > -	if (exit_zero_cnt < (55 * ui_den / ui_num) && (55 * ui_den) %
> ui_num)
> > -		exit_zero_cnt += 1;
> > -
> > -	if (exit_zero_cnt > EXIT_ZERO_CNT_MAX) {
> > -		DRM_DEBUG_KMS("exit zero count too high %u\n",
> exit_zero_cnt);
> > -		exit_zero_cnt = EXIT_ZERO_CNT_MAX;
> > -	}
> > +		/*
> > +		 * Exit zero is unified val ths_zero and ths_exit
> > +		 * minimum value for ths_exit = 110ns
> > +		 * min (exit_zero_cnt * 2) = 110/UI
> > +		 * exit_zero_cnt = 55/UI
> > +		 */
> > +		if (exit_zero_cnt < (55 * ui_den / ui_num) &&
> > +					(55 * ui_den) % ui_num)
> > +			exit_zero_cnt += 1;
> > +
> > +		if (exit_zero_cnt > EXIT_ZERO_CNT_MAX) {
> > +			DRM_DEBUG_KMS("exit zero count too high %u\n",
> > +
> 	exit_zero_cnt);
> > +			exit_zero_cnt = EXIT_ZERO_CNT_MAX;
> > +		}
> >
> > -	/* clk zero count */
> > -	clk_zero_cnt = DIV_ROUND_UP(
> > -				(tclk_prepare_clkzero -	ths_prepare_ns)
> > -				* ui_den, ui_num * mul);
> > +		/* clk zero count */
> > +		clk_zero_cnt = DIV_ROUND_UP((tclk_prepare_clkzero -
> > +						ths_prepare_ns)
> > +						* ui_den, ui_num * mul);
> >
> > -	if (clk_zero_cnt > CLK_ZERO_CNT_MAX) {
> > -		DRM_DEBUG_KMS("clock zero count too high %u\n",
> clk_zero_cnt);
> > -		clk_zero_cnt = CLK_ZERO_CNT_MAX;
> > -	}
> > +		if (clk_zero_cnt > CLK_ZERO_CNT_MAX) {
> > +			DRM_DEBUG_KMS("clock zero count too high %u\n",
> > +								clk_zero_cnt);
> > +			clk_zero_cnt = CLK_ZERO_CNT_MAX;
> > +		}
> >
> > -	/* trail count */
> > -	tclk_trail_ns = max(mipi_config->tclk_trail, mipi_config->ths_trail);
> > -	trail_cnt = DIV_ROUND_UP(tclk_trail_ns * ui_den, ui_num * mul);
> > +		/* trail cnt */
> > +		trail_cnt = DIV_ROUND_UP(tclk_trail_ns * ui_den, ui_num *
> mul);
> >
> > -	if (trail_cnt > TRAIL_CNT_MAX) {
> > -		DRM_DEBUG_KMS("trail count too high %u\n", trail_cnt);
> > -		trail_cnt = TRAIL_CNT_MAX;
> > -	}
> > +		if (trail_cnt > TRAIL_CNT_MAX) {
> > +			DRM_DEBUG_KMS("trail count too high %u\n",
> trail_cnt);
> > +			trail_cnt = TRAIL_CNT_MAX;
> > +		}
> >
> > -	/* B080 */
> > -	intel_dsi->dphy_reg = exit_zero_cnt << 24 | trail_cnt << 16 |
> > +		/* B080 */
> > +		intel_dsi->dphy_reg = exit_zero_cnt << 24 | trail_cnt << 16 |
> >  						clk_zero_cnt << 8 |
> prepare_cnt;
> > +	}
> >
> >  	/*
> >  	 * LP to HS switch count = 4TLPX + PREP_COUNT * mul +
> > EXIT_ZERO_COUNT * @@ -707,9 +790,10 @@ bool intel_dsi_vbt_init(struct
> intel_dsi *intel_dsi, u16 panel_id)
> >  	 */
> >  	tlpx_ui = DIV_ROUND_UP(tlpx_ns * ui_den, ui_num);
> >
> > -	/* B044 */
> > -	/* FIXME:
> > -	 * The comment above does not match with the code */
> > +	/*
> > +	 * B044
> > +	 * FIXME: comment above does not match with the code
> > +	 */
> >  	lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * mul +
> >  						exit_zero_cnt * mul + 10, 8);
> >
> > @@ -718,8 +802,9 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi,
> u16 panel_id)
> >  	intel_dsi->hs_to_lp_count = max(lp_to_hs_switch, hs_to_lp_switch);
> >  	intel_dsi->hs_to_lp_count += extra_byte_count;
> >
> > -	/* B088 */
> > -	/* LP -> HS for clock lanes
> > +	/*
> > +	 * B088
> > +	 * LP -> HS for clock lanes
> >  	 * LP clk sync + LP11 + LP01 + tclk_prepare + tclk_zero +
> >  	 *						extra byte count
> >  	 * 2TPLX + 1TLPX + 1 TPLX(in ns) + prepare_cnt * 2 + clk_zero_cnt *
> > @@ -735,7 +820,8 @@ bool intel_dsi_vbt_init(struct intel_dsi
> > *intel_dsi, u16 panel_id)
> >
> >  	intel_dsi->clk_lp_to_hs_count += extra_byte_count;
> >
> > -	/* HS->LP for Clock Lanes
> > +	/*
> > +	 * HS->LP for Clock Lanes
> >  	 * Low Power clock synchronisations + 1Tx byteclk + tclk_trail +
> >  	 *						Extra byte count
> >  	 * 2TLPX + 8UI + (trail_count*2)(in UI) + Extra byte count @@ -782,9
> > +868,11 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16
> panel_id)
> >  	DRM_DEBUG_KMS("BTA %s\n",
> >  			enableddisabled(!(intel_dsi->video_frmt_cfg_bits &
> > DISABLE_VIDEO_BTA)));
> >
> > -	/* delays in VBT are in unit of 100us, so need to convert
> > +	/*
> > +	 * delays in VBT are in unit of 100us, so need to convert
> >  	 * here in ms
> > -	 * Delay (100us) * 100 /1000 = Delay / 10 (ms) */
> > +	 * Delay (100us) * 100 /1000 = Delay / 10 (ms)
> > +	 */
> >  	intel_dsi->backlight_off_delay = pps->bl_disable_delay / 10;
> >  	intel_dsi->backlight_on_delay = pps->bl_enable_delay / 10;
> >  	intel_dsi->panel_on_delay = pps->panel_on_delay / 10;
> 
> --
> Jani Nikula, Intel Open Source Graphics Center


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