drm/msm/mdss: Handle the reg bus ICC path

Apart from the already handled data bus (MAS_MDP_Pn<->DDR), there's
another path that needs to be handled to ensure MDSS functions properly,
namely the "reg bus", a.k.a the CPU-MDSS interconnect.

Gating that path may have a variety of effects, from none to otherwise
inexplicable DSI timeouts.

Provide a way for MDSS driver to vote on this bus.

A note regarding vote values. Newer platforms have corresponding
bandwidth values in the vendor DT files. For the older platforms there
was a static vote in the mdss_mdp and rotator drivers. I choose to be
conservative here and choose this value as a default.

Co-developed-by: Konrad Dybcio <[email protected]>
Signed-off-by: Konrad Dybcio <[email protected]>
Signed-off-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/570164/
Link: https://lore.kernel.org/r/[email protected]

Author: lumag

drivers/gpu/drm/msm/msm_mdss.c

@@ -28,6 +28,8 @@
 
 #define MIN_IB_BW	400000000UL /* Min ib vote 400MB */
 
+#define DEFAULT_REG_BW	153600 /* Used in mdss fbdev driver */
+
 struct msm_mdss {
 	struct device *dev;
 
@@ -42,13 +44,15 @@ struct msm_mdss {
 	const struct msm_mdss_data *mdss_data;
 	struct icc_path *mdp_path[2];
 	u32 num_mdp_paths;
+	struct icc_path *reg_bus_path;
 };
 
 static int msm_mdss_parse_data_bus_icc_path(struct device *dev,
 					    struct msm_mdss *msm_mdss)
 {
 	struct icc_path *path0;
 	struct icc_path *path1;
+	struct icc_path *reg_bus_path;
 
 	path0 = devm_of_icc_get(dev, "mdp0-mem");
 	if (IS_ERR_OR_NULL(path0))
@@ -63,6 +67,10 @@ static int msm_mdss_parse_data_bus_icc_path(struct device *dev,
 		msm_mdss->num_mdp_paths++;
 	}
 
+	reg_bus_path = of_icc_get(dev, "cpu-cfg");
+	if (!IS_ERR_OR_NULL(reg_bus_path))
+		msm_mdss->reg_bus_path = reg_bus_path;
+
 	return 0;
 }
 
@@ -229,6 +237,13 @@ static int msm_mdss_enable(struct msm_mdss *msm_mdss)
 	for (i = 0; i < msm_mdss->num_mdp_paths; i++)
 		icc_set_bw(msm_mdss->mdp_path[i], 0, Bps_to_icc(MIN_IB_BW));
 
+	if (msm_mdss->mdss_data && msm_mdss->mdss_data->reg_bus_bw)
+		icc_set_bw(msm_mdss->reg_bus_path, 0,
+			   msm_mdss->mdss_data->reg_bus_bw);
+	else
+		icc_set_bw(msm_mdss->reg_bus_path, 0,
+			   DEFAULT_REG_BW);
+
 	ret = clk_bulk_prepare_enable(msm_mdss->num_clocks, msm_mdss->clocks);
 	if (ret) {
 		dev_err(msm_mdss->dev, "clock enable failed, ret:%d\n", ret);
@@ -286,6 +301,9 @@ static int msm_mdss_disable(struct msm_mdss *msm_mdss)
 	for (i = 0; i < msm_mdss->num_mdp_paths; i++)
 		icc_set_bw(msm_mdss->mdp_path[i], 0, 0);
 
+	if (msm_mdss->reg_bus_path)
+		icc_set_bw(msm_mdss->reg_bus_path, 0, 0);
+
 	return 0;
 }
 
@@ -372,6 +390,8 @@ static struct msm_mdss *msm_mdss_init(struct platform_device *pdev, bool is_mdp5
 	if (!msm_mdss)
 		return ERR_PTR(-ENOMEM);
 
+	msm_mdss->mdss_data = of_device_get_match_data(&pdev->dev);
+
 	msm_mdss->mmio = devm_platform_ioremap_resource_byname(pdev, is_mdp5 ? "mdss_phys" : "mdss");
 	if (IS_ERR(msm_mdss->mmio))
 		return ERR_CAST(msm_mdss->mmio);
@@ -462,8 +482,6 @@ static int mdss_probe(struct platform_device *pdev)
 	if (IS_ERR(mdss))
 		return PTR_ERR(mdss);
 
-	mdss->mdss_data = of_device_get_match_data(&pdev->dev);
-
 	platform_set_drvdata(pdev, mdss);
 
 	/*
@@ -495,18 +513,21 @@ static const struct msm_mdss_data msm8998_data = {
 	.ubwc_enc_version = UBWC_1_0,
 	.ubwc_dec_version = UBWC_1_0,
 	.highest_bank_bit = 2,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data qcm2290_data = {
 	/* no UBWC */
 	.highest_bank_bit = 0x2,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sc7180_data = {
 	.ubwc_enc_version = UBWC_2_0,
 	.ubwc_dec_version = UBWC_2_0,
 	.ubwc_static = 0x1e,
 	.highest_bank_bit = 0x3,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sc7280_data = {
@@ -516,13 +537,15 @@ static const struct msm_mdss_data sc7280_data = {
 	.ubwc_static = 1,
 	.highest_bank_bit = 1,
 	.macrotile_mode = 1,
+	.reg_bus_bw = 74000,
 };
 
 static const struct msm_mdss_data sc8180x_data = {
 	.ubwc_enc_version = UBWC_3_0,
 	.ubwc_dec_version = UBWC_3_0,
 	.highest_bank_bit = 3,
 	.macrotile_mode = 1,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sc8280xp_data = {
@@ -532,6 +555,7 @@ static const struct msm_mdss_data sc8280xp_data = {
 	.ubwc_static = 1,
 	.highest_bank_bit = 3,
 	.macrotile_mode = 1,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sdm670_data = {
@@ -544,6 +568,7 @@ static const struct msm_mdss_data sdm845_data = {
 	.ubwc_enc_version = UBWC_2_0,
 	.ubwc_dec_version = UBWC_2_0,
 	.highest_bank_bit = 2,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sm6350_data = {
@@ -552,12 +577,14 @@ static const struct msm_mdss_data sm6350_data = {
 	.ubwc_swizzle = 6,
 	.ubwc_static = 0x1e,
 	.highest_bank_bit = 1,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sm8150_data = {
 	.ubwc_enc_version = UBWC_3_0,
 	.ubwc_dec_version = UBWC_3_0,
 	.highest_bank_bit = 2,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sm6115_data = {
@@ -566,6 +593,7 @@ static const struct msm_mdss_data sm6115_data = {
 	.ubwc_swizzle = 7,
 	.ubwc_static = 0x11f,
 	.highest_bank_bit = 0x1,
+	.reg_bus_bw = 76800,
 };
 
 static const struct msm_mdss_data sm6125_data = {
@@ -583,6 +611,18 @@ static const struct msm_mdss_data sm8250_data = {
 	/* TODO: highest_bank_bit = 2 for LP_DDR4 */
 	.highest_bank_bit = 3,
 	.macrotile_mode = 1,
+	.reg_bus_bw = 76800,
+};
+
+static const struct msm_mdss_data sm8350_data = {
+	.ubwc_enc_version = UBWC_4_0,
+	.ubwc_dec_version = UBWC_4_0,
+	.ubwc_swizzle = 6,
+	.ubwc_static = 1,
+	/* TODO: highest_bank_bit = 2 for LP_DDR4 */
+	.highest_bank_bit = 3,
+	.macrotile_mode = 1,
+	.reg_bus_bw = 74000,
 };
 
 static const struct msm_mdss_data sm8550_data = {
@@ -593,6 +633,7 @@ static const struct msm_mdss_data sm8550_data = {
 	/* TODO: highest_bank_bit = 2 for LP_DDR4 */
 	.highest_bank_bit = 3,
 	.macrotile_mode = 1,
+	.reg_bus_bw = 57000,
 };
 static const struct of_device_id mdss_dt_match[] = {
 	{ .compatible = "qcom,mdss" },
@@ -610,8 +651,8 @@ static const struct of_device_id mdss_dt_match[] = {
 	{ .compatible = "qcom,sm6375-mdss", .data = &sm6350_data },
 	{ .compatible = "qcom,sm8150-mdss", .data = &sm8150_data },
 	{ .compatible = "qcom,sm8250-mdss", .data = &sm8250_data },
-	{ .compatible = "qcom,sm8350-mdss", .data = &sm8250_data },
-	{ .compatible = "qcom,sm8450-mdss", .data = &sm8250_data },
+	{ .compatible = "qcom,sm8350-mdss", .data = &sm8350_data },
+	{ .compatible = "qcom,sm8450-mdss", .data = &sm8350_data },
 	{ .compatible = "qcom,sm8550-mdss", .data = &sm8550_data },
 	{ .compatible = "qcom,sm8650-mdss", .data = &sm8550_data},
 	{}

drivers/gpu/drm/msm/msm_mdss.h

@@ -14,6 +14,7 @@ struct msm_mdss_data {
 	u32 ubwc_static;
 	u32 highest_bank_bit;
 	u32 macrotile_mode;
+	u32 reg_bus_bw;
 };
 
 #define UBWC_1_0 0x10000000