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Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0588-drm-vc4-hdmi-Adjust-HSM-clock-rate-depending-on-pixe.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0588-drm-vc4-hdmi-Adjust-HSM-clock-rate-depending-on-pixe.patch163
1 files changed, 163 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0588-drm-vc4-hdmi-Adjust-HSM-clock-rate-depending-on-pixe.patch b/target/linux/bcm27xx/patches-5.4/950-0588-drm-vc4-hdmi-Adjust-HSM-clock-rate-depending-on-pixe.patch
new file mode 100644
index 0000000000..5b836f8bf8
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0588-drm-vc4-hdmi-Adjust-HSM-clock-rate-depending-on-pixe.patch
@@ -0,0 +1,163 @@
+From 3c33724058852d7c58d77d03e11ca545fb04256a Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Mon, 10 Feb 2020 15:23:06 +0100
+Subject: [PATCH] drm/vc4: hdmi: Adjust HSM clock rate depending on
+ pixel rate
+
+The HSM clock needs to be setup at around 110% of the pixel rate. This
+was done previously by setting the clock rate to 148.5MHz * 108% at
+probe time and only check in mode_valid whether the mode pixel clock was
+under 148.5MHz or not.
+
+However, with 4k we need to change that frequency to a higher frequency
+than 148.5MHz.
+
+Let's change that logic a bit by setting the clock rate of the HSM clock
+to the pixel rate at encoder_enable time. This would work for the
+BCM2711 that support 4k resolutions and has a clock that can provide it,
+but we still have to take care of a 4k panel plugged on a BCM283x SoCs
+that wouldn't be able to use those modes, so let's define the limit in
+the variant.
+
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_hdmi.c | 51 +++++++++++++++++-----------------
+ drivers/gpu/drm/vc4/vc4_hdmi.h | 3 ++
+ 2 files changed, 29 insertions(+), 25 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
+@@ -52,7 +52,6 @@
+ #include "vc4_hdmi_regs.h"
+ #include "vc4_regs.h"
+
+-#define HSM_CLOCK_FREQ 163682864
+ #define CEC_CLOCK_FREQ 40000
+
+ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused)
+@@ -329,6 +328,7 @@ static void vc4_hdmi_encoder_disable(str
+ HDMI_WRITE(HDMI_VID_CTL,
+ HDMI_READ(HDMI_VID_CTL) & ~VC4_HD_VID_CTL_ENABLE);
+
++ clk_disable_unprepare(vc4_hdmi->hsm_clock);
+ clk_disable_unprepare(vc4_hdmi->pixel_clock);
+
+ ret = pm_runtime_put(&vc4_hdmi->pdev->dev);
+@@ -426,6 +426,7 @@ static void vc4_hdmi_encoder_enable(stru
+ struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+ struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
+ bool debug_dump_regs = false;
++ unsigned long pixel_rate, hsm_rate;
+ int ret;
+
+ ret = pm_runtime_get_sync(&vc4_hdmi->pdev->dev);
+@@ -434,9 +435,8 @@ static void vc4_hdmi_encoder_enable(stru
+ return;
+ }
+
+- ret = clk_set_rate(vc4_hdmi->pixel_clock,
+- mode->clock * 1000 *
+- ((mode->flags & DRM_MODE_FLAG_DBLCLK) ? 2 : 1));
++ pixel_rate = mode->clock * 1000 * ((mode->flags & DRM_MODE_FLAG_DBLCLK) ? 2 : 1);
++ ret = clk_set_rate(vc4_hdmi->pixel_clock, pixel_rate);
+ if (ret) {
+ DRM_ERROR("Failed to set pixel clock rate: %d\n", ret);
+ return;
+@@ -448,6 +448,24 @@ static void vc4_hdmi_encoder_enable(stru
+ return;
+ }
+
++ /*
++ * The HSM rate needs to be at 108% of the pixel clock, with a
++ * minimum of 108MHz.
++ */
++ hsm_rate = max_t(unsigned long, 108000000, (pixel_rate / 100) * 108);
++ ret = clk_set_rate(vc4_hdmi->hsm_clock, hsm_rate);
++ if (ret) {
++ DRM_ERROR("Failed to set HSM clock rate: %d\n", ret);
++ return;
++ }
++
++ ret = clk_prepare_enable(vc4_hdmi->hsm_clock);
++ if (ret) {
++ DRM_ERROR("Failed to turn on HSM clock: %d\n", ret);
++ clk_disable_unprepare(vc4_hdmi->pixel_clock);
++ return;
++ }
++
+ if (vc4_hdmi->variant->reset)
+ vc4_hdmi->variant->reset(vc4_hdmi);
+
+@@ -578,7 +596,9 @@ vc4_hdmi_encoder_mode_valid(struct drm_e
+ * Additionally, the AXI clock needs to be at least 25% of
+ * pixel clock, but HSM ends up being the limiting factor.
+ */
+- if (mode->clock > HSM_CLOCK_FREQ / (1000 * 101 / 100))
++ struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
++
++ if ((mode->clock * 1000) > vc4_hdmi->variant->max_pixel_clock)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+@@ -1354,23 +1374,6 @@ static int vc4_hdmi_bind(struct device *
+ return -EPROBE_DEFER;
+ }
+
+- /* This is the rate that is set by the firmware. The number
+- * needs to be a bit higher than the pixel clock rate
+- * (generally 148.5Mhz).
+- */
+- ret = clk_set_rate(vc4_hdmi->hsm_clock, HSM_CLOCK_FREQ);
+- if (ret) {
+- DRM_ERROR("Failed to set HSM clock rate: %d\n", ret);
+- goto err_put_i2c;
+- }
+-
+- ret = clk_prepare_enable(vc4_hdmi->hsm_clock);
+- if (ret) {
+- DRM_ERROR("Failed to turn on HDMI state machine clock: %d\n",
+- ret);
+- goto err_put_i2c;
+- }
+-
+ /* Only use the GPIO HPD pin if present in the DT, otherwise
+ * we'll use the HDMI core's register.
+ */
+@@ -1428,9 +1431,7 @@ err_destroy_conn:
+ err_destroy_encoder:
+ vc4_hdmi_encoder_destroy(encoder);
+ err_unprepare_hsm:
+- clk_disable_unprepare(vc4_hdmi->hsm_clock);
+ pm_runtime_disable(dev);
+-err_put_i2c:
+ put_device(&vc4_hdmi->ddc->dev);
+
+ return ret;
+@@ -1453,7 +1454,6 @@ static void vc4_hdmi_unbind(struct devic
+ vc4_hdmi_connector_destroy(&vc4_hdmi->connector);
+ vc4_hdmi_encoder_destroy(&vc4_hdmi->encoder.base.base);
+
+- clk_disable_unprepare(vc4_hdmi->hsm_clock);
+ pm_runtime_disable(dev);
+
+ put_device(&vc4_hdmi->ddc->dev);
+@@ -1476,6 +1476,7 @@ static int vc4_hdmi_dev_remove(struct pl
+ }
+
+ static const struct vc4_hdmi_variant bcm2835_variant = {
++ .max_pixel_clock = 148500000,
+ .audio_available = true,
+ .cec_available = true,
+ .registers = vc4_hdmi_fields,
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
+@@ -38,6 +38,9 @@ struct vc4_hdmi_variant {
+ /* Set to true when the CEC support is available */
+ bool cec_available;
+
++ /* Maximum pixel clock supported by the controller (in Hz) */
++ unsigned long long max_pixel_clock;
++
+ /* List of the registers available on that variant */
+ const struct vc4_hdmi_register *registers;
+