drm/tegra: dc: rgb: Allow changing PLLD rate on Tegra30+

Asus Transformer TF700T is a Tegra30 tablet device which uses RGB->DSI
bridge that requires a precise clock rate in order to operate properly.
Tegra30 has a dedicated PLL for each display controller, hence the PLL
rate can be changed freely. Allow PLL rate changes on Tegra30+ for RGB
output. Configure the clock rate before display controller is enabled
since DC itself may be running off this PLL and it's not okay to change
the rate of the active PLL that doesn't support dynamic frequency
switching since hardware will hang.

Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> #TF700T
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index e62b091b93f2..a457ee954a49 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1834,10 +1834,9 @@ int tegra_dc_state_setup_clock(struct tegra_dc *dc,
 	return 0;
 }
 
-static void tegra_dc_commit_state(struct tegra_dc *dc,
-				  struct tegra_dc_state *state)
+static void tegra_dc_set_clock_rate(struct tegra_dc *dc,
+				    struct tegra_dc_state *state)
 {
-	u32 value;
 	int err;
 
 	err = clk_set_parent(dc->clk, state->clk);
@@ -1868,11 +1867,6 @@ static void tegra_dc_commit_state(struct tegra_dc *dc,
 	DRM_DEBUG_KMS("rate: %lu, div: %u\n", clk_get_rate(dc->clk),
 		      state->div);
 	DRM_DEBUG_KMS("pclk: %lu\n", state->pclk);
-
-	if (!dc->soc->has_nvdisplay) {
-		value = SHIFT_CLK_DIVIDER(state->div) | PIXEL_CLK_DIVIDER_PCD1;
-		tegra_dc_writel(dc, value, DC_DISP_DISP_CLOCK_CONTROL);
-	}
 }
 
 static void tegra_dc_stop(struct tegra_dc *dc)
@@ -2074,6 +2068,9 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 	u32 value;
 	int err;
 
+	/* apply PLL changes */
+	tegra_dc_set_clock_rate(dc, crtc_state);
+
 	err = host1x_client_resume(&dc->client);
 	if (err < 0) {
 		dev_err(dc->dev, "failed to resume: %d\n", err);
@@ -2148,8 +2145,11 @@ static void tegra_crtc_atomic_enable(struct drm_crtc *crtc,
 	else
 		tegra_dc_writel(dc, 0, DC_DISP_BORDER_COLOR);
 
-	/* apply PLL and pixel clock changes */
-	tegra_dc_commit_state(dc, crtc_state);
+	/* apply pixel clock changes */
+	if (!dc->soc->has_nvdisplay) {
+		value = SHIFT_CLK_DIVIDER(crtc_state->div) | PIXEL_CLK_DIVIDER_PCD1;
+		tegra_dc_writel(dc, value, DC_DISP_DISP_CLOCK_CONTROL);
+	}
 
 	/* program display mode */
 	tegra_dc_set_timings(dc, mode);
@@ -2763,6 +2763,7 @@ static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
 	.has_win_b_vfilter_mem_client = true,
 	.has_win_c_without_vert_filter = true,
 	.plane_tiled_memory_bandwidth_x2 = false,
+	.has_pll_d2_out0 = false,
 };
 
 static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
@@ -2785,6 +2786,7 @@ static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
 	.has_win_b_vfilter_mem_client = true,
 	.has_win_c_without_vert_filter = false,
 	.plane_tiled_memory_bandwidth_x2 = true,
+	.has_pll_d2_out0 = true,
 };
 
 static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
@@ -2807,6 +2809,7 @@ static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
 	.has_win_b_vfilter_mem_client = false,
 	.has_win_c_without_vert_filter = false,
 	.plane_tiled_memory_bandwidth_x2 = true,
+	.has_pll_d2_out0 = true,
 };
 
 static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
@@ -2829,6 +2832,7 @@ static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
 	.has_win_b_vfilter_mem_client = false,
 	.has_win_c_without_vert_filter = false,
 	.plane_tiled_memory_bandwidth_x2 = false,
+	.has_pll_d2_out0 = true,
 };
 
 static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
@@ -2851,6 +2855,7 @@ static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
 	.has_win_b_vfilter_mem_client = false,
 	.has_win_c_without_vert_filter = false,
 	.plane_tiled_memory_bandwidth_x2 = false,
+	.has_pll_d2_out0 = true,
 };
 
 static const struct tegra_windowgroup_soc tegra186_dc_wgrps[] = {
@@ -2901,6 +2906,7 @@ static const struct tegra_dc_soc_info tegra186_dc_soc_info = {
 	.wgrps = tegra186_dc_wgrps,
 	.num_wgrps = ARRAY_SIZE(tegra186_dc_wgrps),
 	.plane_tiled_memory_bandwidth_x2 = false,
+	.has_pll_d2_out0 = false,
 };
 
 static const struct tegra_windowgroup_soc tegra194_dc_wgrps[] = {
@@ -2951,6 +2957,7 @@ static const struct tegra_dc_soc_info tegra194_dc_soc_info = {
 	.wgrps = tegra194_dc_wgrps,
 	.num_wgrps = ARRAY_SIZE(tegra194_dc_wgrps),
 	.plane_tiled_memory_bandwidth_x2 = false,
+	.has_pll_d2_out0 = false,
 };
 
 static const struct of_device_id tegra_dc_of_match[] = {