Re: [PATCH v1 1/2] drm/msm/dp: Add support for SC7280 eDP

From: Stephen Boyd
Date: Wed Aug 11 2021 - 20:41:51 EST


Quoting Sankeerth Billakanti (2021-08-11 17:08:01)
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> index b131fd37..1096c44 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> @@ -856,9 +856,9 @@ static const struct dpu_intf_cfg sm8150_intf[] = {
> };
>
> static const struct dpu_intf_cfg sc7280_intf[] = {
> - INTF_BLK("intf_0", INTF_0, 0x34000, INTF_DP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 24, 25),
> + INTF_BLK("intf_0", INTF_0, 0x34000, INTF_DP, 1, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 24, 25),
> INTF_BLK("intf_1", INTF_1, 0x35000, INTF_DSI, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 26, 27),
> - INTF_BLK("intf_5", INTF_5, 0x39000, INTF_EDP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 22, 23),
> + INTF_BLK("intf_5", INTF_5, 0x39000, INTF_DP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 22, 23),
> };
>
> /*************************************************************
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index d2569da..06d5a2d 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -1244,7 +1244,9 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl,
> struct dp_cr_status *cr, int *training_step)
> {
> int ret = 0;
> + u8 *dpcd = ctrl->panel->dpcd;
> u8 encoding = DP_SET_ANSI_8B10B;
> + u8 ssc = 0, assr = 0;

Please don't initialize to zero and then overwrite it before using it.
It hides usage before actual initialization bugs.

> struct dp_link_info link_info = {0};
>
> dp_ctrl_config_ctrl(ctrl);
> @@ -1254,9 +1256,21 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl,
> link_info.capabilities = DP_LINK_CAP_ENHANCED_FRAMING;
>
> dp_aux_link_configure(ctrl->aux, &link_info);
> +
> + if (dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5) {
> + ssc = DP_SPREAD_AMP_0_5;
> + drm_dp_dpcd_write(ctrl->aux, DP_DOWNSPREAD_CTRL, &ssc, 1);
> + }
> +
> drm_dp_dpcd_write(ctrl->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
> &encoding, 1);
>
> + if (dpcd[DP_EDP_CONFIGURATION_CAP] & DP_ALTERNATE_SCRAMBLER_RESET_CAP) {
> + assr = DP_ALTERNATE_SCRAMBLER_RESET_ENABLE;
> + drm_dp_dpcd_write(ctrl->aux, DP_EDP_CONFIGURATION_SET,
> + &assr, 1);
> + }
> +
> ret = dp_ctrl_link_train_1(ctrl, cr, training_step);
> if (ret) {
> DRM_ERROR("link training #1 failed. ret=%d\n", ret);
> @@ -1328,9 +1342,11 @@ static int dp_ctrl_enable_mainlink_clocks(struct dp_ctrl_private *ctrl)
> struct dp_io *dp_io = &ctrl->parser->io;
> struct phy *phy = dp_io->phy;
> struct phy_configure_opts_dp *opts_dp = &dp_io->phy_opts.dp;
> + u8 *dpcd = ctrl->panel->dpcd;

const?

>
> opts_dp->lanes = ctrl->link->link_params.num_lanes;
> opts_dp->link_rate = ctrl->link->link_params.rate / 100;
> + opts_dp->ssc = dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
> dp_ctrl_set_clock_rate(ctrl, DP_CTRL_PM, "ctrl_link",
> ctrl->link->link_params.rate * 1000);
>
> @@ -1760,6 +1776,9 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
> ctrl->link->link_params.num_lanes = ctrl->panel->link_info.num_lanes;
> ctrl->dp_ctrl.pixel_rate = ctrl->panel->dp_mode.drm_mode.clock;
>
> + if (ctrl->dp_ctrl.pixel_rate == 0)
> + return -EINVAL;
> +

Why are we enabling the stream with a zero pixel clk?

> DRM_DEBUG_DP("rate=%d, num_lanes=%d, pixel_rate=%d\n",
> ctrl->link->link_params.rate,
> ctrl->link->link_params.num_lanes, ctrl->dp_ctrl.pixel_rate);
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index ee5bf64..a772290 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -117,8 +117,36 @@ struct dp_display_private {
> struct dp_audio *audio;
> };
>
> +struct msm_dp_config {
> + phys_addr_t io_start[3];
> + size_t num_dp;
> +};
> +
> +static const struct msm_dp_config sc7180_dp_cfg = {
> + .io_start = { 0x0ae90000 },
> + .num_dp = 1,
> +};
> +
> +static const struct msm_dp_config sc8180x_dp_cfg = {
> + .io_start = { 0xae90000, 0xae98000, 0 },
> + .num_dp = 3,
> +};
> +
> +static const struct msm_dp_config sc8180x_edp_cfg = {
> + .io_start = { 0, 0, 0xae9a000 },
> + .num_dp = 3,
> +};
> +
> +static const struct msm_dp_config sc7280_edp_cfg = {
> + .io_start = { 0xaea0000, 0 },
> + .num_dp = 2,
> +};

Are all of these supposed to be here?

> +
> static const struct of_device_id dp_dt_match[] = {
> - {.compatible = "qcom,sc7180-dp"},
> + { .compatible = "qcom,sc7180-dp", .data = &sc7180_dp_cfg },
> + { .compatible = "qcom,sc8180x-dp", .data = &sc8180x_dp_cfg },
> + { .compatible = "qcom,sc8180x-edp", .data = &sc8180x_edp_cfg },
> + { .compatible = "qcom,sc7280-edp", .data = &sc7280_edp_cfg },

Please sort alphabetically on compatible string, it helps avoid
conflicts in the future.

> {}
> };
>
> @@ -1408,7 +1436,7 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display)
>
> dp_hpd_event_setup(dp);
>
> - dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
> + dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 1);
> }
>
> void msm_dp_debugfs_init(struct msm_dp *dp_display, struct drm_minor *minor)
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
> index 0519dd3..c05fc0a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -248,6 +248,33 @@ static int dp_parser_clock(struct dp_parser *parser)
> return 0;
> }
>
> +static int dp_parser_gpio(struct dp_parser *parser)
> +{
> + struct device *dev = &parser->pdev->dev;
> + int ret;
> +
> + parser->panel_bklt_gpio = devm_gpiod_get(dev, "panel-bklt",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(parser->panel_bklt_gpio)) {
> + ret = PTR_ERR(parser->panel_bklt_gpio);
> + parser->panel_bklt_gpio = NULL;
> + DRM_ERROR("%s: cannot get panel-bklt gpio, %d\n", __func__, ret);
> + goto fail;
> + }
> +
> + parser->panel_pwm_gpio = devm_gpiod_get(dev, "panel-pwm", GPIOD_OUT_HIGH);
> + if (IS_ERR(parser->panel_pwm_gpio)) {
> + ret = PTR_ERR(parser->panel_pwm_gpio);
> + parser->panel_pwm_gpio = NULL;
> + DRM_ERROR("%s: cannot get panel-pwm gpio, %d\n", __func__, ret);
> + goto fail;
> + }
> +
> + DRM_INFO("gpio on");
> +fail:
> + return 0;
> +}

Don't we have pwm backlight drivers like
drivers/video/backlight/pwm_bl.c to support this? This sort of thing
doesn't belong in the dp driver.

> +
> static int dp_parser_parse(struct dp_parser *parser)
> {
> int rc = 0;
> @@ -269,6 +296,10 @@ static int dp_parser_parse(struct dp_parser *parser)
> if (rc)
> return rc;
>
> + rc = dp_parser_gpio(parser);
> + if (rc)
> + return rc;
> +
> /* Map the corresponding regulator information according to
> * version. Currently, since we only have one supported platform,
> * mapping the regulator directly.