Hi, Bo-Chen:
On Fri, 2022-06-10 at 18:55 +0800, Bo-Chen Chen wrote:
From: Markus Schneider-Pargmann msp@baylibre.com
This patch adds a embedded displayport driver for the MediaTek mt8195 SoC.
It supports the MT8195, the embedded DisplayPort units. It offers DisplayPort 1.4 with up to 4 lanes.
The driver creates a child device for the phy. The child device will never exist without the parent being active. As they are sharing a register range, the parent passes a regmap pointer to the child so that both can work with the same register range. The phy driver sets device data that is read by the parent to get the phy device that can be used to control the phy properties.
This driver is based on an initial version by Jitao shi jitao.shi@mediatek.com
Signed-off-by: Markus Schneider-Pargmann msp@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com [Bo-Chen: Cleanup the drivers and modify comments from reviewers] Signed-off-by: Bo-Chen Chen rex-bc.chen@mediatek.com
[snip]
+static int mtk_dp_parse_capabilities(struct mtk_dp *mtk_dp) +{
- u8 val;
- struct mtk_dp_train_info *train_info = &mtk_dp->train_info;
- drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
DP_SET_POWER_D0);
- usleep_range(2000, 5000);
- drm_dp_read_dpcd_caps(&mtk_dp->aux, mtk_dp->rx_cap);
- mtk_dp->rx_cap[DP_TRAINING_AUX_RD_INTERVAL] &=
DP_TRAINING_AUX_RD_MASK;
- train_info->link_rate = min_t(int, mtk_dp->max_linkrate,
mtk_dp->rx_cap[mtk_dp-max_linkrate]);
- train_info->lane_count = min_t(int, mtk_dp->max_lanes,
drm_dp_max_lane_count(mtk_dp-rx_cap));
- train_info->tps3 = drm_dp_tps3_supported(mtk_dp->rx_cap);
- train_info->tps4 = drm_dp_tps4_supported(mtk_dp->rx_cap);
- train_info->sink_ssc = !!(mtk_dp->rx_cap[DP_MAX_DOWNSPREAD] &
DP_MAX_DOWNSPREAD_0_5);
I think this is redundant because next statement would set sink_scc to false.
Regards, CK
- train_info->sink_ssc = false;
- drm_dp_dpcd_readb(&mtk_dp->aux, DP_MSTM_CAP, &val);
- if (val & DP_MST_CAP) {
/* Clear DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 */drm_dp_dpcd_readb(&mtk_dp->aux,DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0,&val);
if (val)drm_dp_dpcd_writeb(&mtk_dp->aux,DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0,
val);- }
- return 0;
+}