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

From: sbillaka
Date: Thu Aug 12 2021 - 20:28:59 EST


On 2021-08-12 06:11, Stephen Boyd wrote:
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.


Okay. I will change it.

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?


Okay. I will change to const u8 *dpcd at all the required places.


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?


This was an error condition I encountered while bringing up sc7280. HPD processing was delayed and I got a commit with pixel clock = 0. I will recheck why this is happening.

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?

No. I will remove them. Only sc7280_edp_cfg will be there.


+
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.

Okay


{}
};

@@ -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.

Okay. I will explore it.


+
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.

Thank you,
Sankeerth