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Commit e0986b0e authored by Tatenda Chipeperekwa's avatar Tatenda Chipeperekwa Committed by Ajay Singh Parmar
Browse files

msm: mdss: dp: restrict Vx and Px to within allowable range 



Restrict the combinations of voltage swing levels and
pre-emaphasis levels to within the allowable range as per
DP v1.3 specification. Furthermore, set the bits to indicate
the sink when the maximum voltage or pre-emaphasis level
supported has been reached.

CRs-Fixed: 1076516
Change-Id: Ibd5ccc5e24248780df70b5ac7ec7a82511abf688
Signed-off-by: default avatarTatenda Chipeperekwa <tatendac@codeaurora.org>
parent 596cb31b

drivers/video/fbdev/msm/mdss_dp.h

+13 −2
Original line number Diff line number Diff line
@@ -322,8 +322,19 @@ struct dp_statistic { 
	u32 aux_native_rx;

};



#define DPCD_LINK_VOLTAGE_MAX	4

#define DPCD_LINK_PRE_EMPHASIS_MAX	4

enum dpcd_link_voltage_level {

	DPCD_LINK_VOLTAGE_LEVEL_0	= 0,

	DPCD_LINK_VOLTAGE_LEVEL_1	= 1,

	DPCD_LINK_VOLTAGE_LEVEL_2	= 2,

	DPCD_LINK_VOLTAGE_MAX		= DPCD_LINK_VOLTAGE_LEVEL_2,

};



enum dpcd_link_preemaphasis_level {

	DPCD_LINK_PRE_EMPHASIS_LEVEL_0	= 0,

	DPCD_LINK_PRE_EMPHASIS_LEVEL_1	= 1,

	DPCD_LINK_PRE_EMPHASIS_LEVEL_2	= 2,

	DPCD_LINK_PRE_EMPHASIS_MAX	= DPCD_LINK_PRE_EMPHASIS_LEVEL_2,

};



struct dp_pinctrl_res {

	struct pinctrl *pinctrl;

drivers/video/fbdev/msm/mdss_dp_aux.c

+38 −5
Original line number Diff line number Diff line
@@ -1166,17 +1166,26 @@ static int dp_lane_set_write(struct mdss_dp_drv_pdata *ep, int voltage_level, 
{

	int i;

	char buf[4];

	u32 max_level_reached = 0;



	if (voltage_level >= DPCD_LINK_VOLTAGE_MAX)

		voltage_level |= 0x04;

	if (voltage_level == DPCD_LINK_VOLTAGE_MAX) {

		pr_debug("max. voltage swing level reached %d\n",

				voltage_level);

		max_level_reached |= BIT(2);

	}



	if (pre_emphasis_level == DPCD_LINK_PRE_EMPHASIS_MAX) {

		pr_debug("max. pre-emphasis level reached %d\n",

				pre_emphasis_level);

		max_level_reached  |= BIT(5);

	}



	if (pre_emphasis_level >= DPCD_LINK_PRE_EMPHASIS_MAX)

		pre_emphasis_level |= 0x04;

	pr_debug("max_level_reached = 0x%x\n", max_level_reached);



	pre_emphasis_level <<= 3;



	for (i = 0; i < 4; i++)

		buf[i] = voltage_level | pre_emphasis_level;

		buf[i] = voltage_level | pre_emphasis_level | max_level_reached;



	pr_debug("p|v=0x%x", voltage_level | pre_emphasis_level);

	return dp_aux_write_buf(ep, 0x103, buf, 4, 0);
@@ -1278,6 +1287,30 @@ void dp_sink_train_set_adjust(struct mdss_dp_drv_pdata *ep) 
	}



	ep->p_level = max;



	/**

	 * Adjust the voltage swing and pre-emphasis level combination to within

	 * the allowable range.

	 */

	if (ep->v_level > DPCD_LINK_VOLTAGE_MAX) {

		pr_debug("Requested vSwingLevel=%d, change to %d\n",

				ep->v_level, DPCD_LINK_VOLTAGE_MAX);

		ep->v_level = DPCD_LINK_VOLTAGE_MAX;

	}



	if (ep->p_level > DPCD_LINK_PRE_EMPHASIS_MAX) {

		pr_debug("Requested preEmphasisLevel=%d, change to %d\n",

				ep->p_level, DPCD_LINK_PRE_EMPHASIS_MAX);

		ep->p_level = DPCD_LINK_PRE_EMPHASIS_MAX;

	}



	if ((ep->p_level > DPCD_LINK_PRE_EMPHASIS_LEVEL_1)

			&& (ep->v_level == DPCD_LINK_VOLTAGE_LEVEL_2)) {

		pr_debug("Requested preEmphasisLevel=%d, change to %d\n",

				ep->p_level, DPCD_LINK_PRE_EMPHASIS_LEVEL_1);

		ep->p_level = DPCD_LINK_PRE_EMPHASIS_LEVEL_1;

	}



	pr_debug("v_level=%d, p_level=%d",

					ep->v_level, ep->p_level);

}