From b1388530046be8a912979594f9c43b47d6f242fe Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 8 Oct 2020 16:06:58 +0200
Subject: [PATCH] drm/vc4: hdmi: Enable the scrambler
The HDMI controller on the BCM2711 includes a scrambler in order to
reach the HDMI 2.0 modes that require it. Let's add the support for it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 64 +++++++++++++++++++++++++++++
drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 3 ++
2 files changed, 67 insertions(+)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -35,6 +35,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
+#include <drm/drm_scdc_helper.h>
#include <linux/clk.h>
#include <linux/component.h>
#include <linux/i2c.h>
@@ -77,6 +78,8 @@
#define VC5_HDMI_VERTB_VSPO_SHIFT 16
#define VC5_HDMI_VERTB_VSPO_MASK VC4_MASK(29, 16)
+#define VC5_HDMI_SCRAMBLER_CTL_ENABLE BIT(0)
+
#define VC5_HDMI_DEEP_COLOR_CONFIG_1_INIT_PACK_PHASE_SHIFT 8
#define VC5_HDMI_DEEP_COLOR_CONFIG_1_INIT_PACK_PHASE_MASK VC4_MASK(10, 8)
@@ -517,6 +520,64 @@ static void vc4_hdmi_set_infoframes(stru
vc4_hdmi_set_hdr_infoframe(encoder);
}
+static bool vc4_hdmi_supports_scrambling(struct drm_encoder *encoder,
+ struct drm_display_mode *mode)
+{
+ struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
+ struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+ struct drm_display_info *display = &vc4_hdmi->connector.display_info;
+
+ if (!vc4_encoder->hdmi_monitor)
+ return false;
+
+ if (!display->hdmi.scdc.supported ||
+ !display->hdmi.scdc.scrambling.supported)
+ return false;
+
+ return true;
+}
+
+static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
+{
+ struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
+ struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+
+ if (!vc4_hdmi_supports_scrambling(encoder, mode))
+ return;
+
+ if (!vc4_hdmi_mode_needs_scrambling(mode))
+ return;
+
+ drm_scdc_set_high_tmds_clock_ratio(vc4_hdmi->ddc, true);
+ drm_scdc_set_scrambling(vc4_hdmi->ddc, true);
+
+ HDMI_WRITE(HDMI_SCRAMBLER_CTL, HDMI_READ(HDMI_SCRAMBLER_CTL) |
+ VC5_HDMI_SCRAMBLER_CTL_ENABLE);
+}
+
+static void vc4_hdmi_disable_scrambling(struct drm_encoder *encoder)
+{
+ struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+ struct drm_crtc *crtc = encoder->crtc;
+
+ /*
+ * At boot, encoder->crtc will be NULL. Since we don't know the
+ * state of the scrambler and in order to avoid any
+ * inconsistency, let's disable it all the time.
+ */
+ if (crtc && !vc4_hdmi_supports_scrambling(encoder, &crtc->mode))
+ return;
+
+ if (crtc && !vc4_hdmi_mode_needs_scrambling(&crtc->mode))
+ return;
+
+ HDMI_WRITE(HDMI_SCRAMBLER_CTL, HDMI_READ(HDMI_SCRAMBLER_CTL) &
+ ~VC5_HDMI_SCRAMBLER_CTL_ENABLE);
+
+ drm_scdc_set_scrambling(vc4_hdmi->ddc, false);
+ drm_scdc_set_high_tmds_clock_ratio(vc4_hdmi->ddc, false);
+}
+
static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder,
struct drm_atomic_state *state)
{
@@ -529,6 +590,8 @@ static void vc4_hdmi_encoder_post_crtc_d
HDMI_WRITE(HDMI_VID_CTL,
HDMI_READ(HDMI_VID_CTL) | VC4_HD_VID_CTL_BLANKPIX);
+
+ vc4_hdmi_disable_scrambling(encoder);
}
static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder,
@@ -979,6 +1042,7 @@ static void vc4_hdmi_encoder_post_crtc_e
}
vc4_hdmi_recenter_fifo(vc4_hdmi);
+ vc4_hdmi_enable_scrambling(encoder);
}
static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
--- a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
@@ -100,6 +100,7 @@ enum vc4_hdmi_field {
HDMI_RM_FORMAT,
HDMI_RM_OFFSET,
HDMI_SCHEDULER_CONTROL,
+ HDMI_SCRAMBLER_CTL,
HDMI_SW_RESET_CONTROL,
HDMI_TX_PHY_CHANNEL_SWAP,
HDMI_TX_PHY_CLK_DIV,
@@ -238,6 +239,7 @@ static const struct vc4_hdmi_register vc
VC4_HDMI_REG(HDMI_GCP_CONFIG, 0x178),
VC4_HDMI_REG(HDMI_GCP_WORD_1, 0x17c),
VC4_HDMI_REG(HDMI_HOTPLUG, 0x1a8),
+ VC4_HDMI_REG(HDMI_SCRAMBLER_CTL, 0x1c4),
VC5_DVP_REG(HDMI_CLOCK_STOP, 0x0bc),
VC5_DVP_REG(HDMI_VEC_INTERFACE_XBAR, 0x0f0),
@@ -317,6 +319,7 @@ static const struct vc4_hdmi_register vc
VC4_HDMI_REG(HDMI_GCP_CONFIG, 0x178),
VC4_HDMI_REG(HDMI_GCP_WORD_1, 0x17c),
VC4_HDMI_REG(HDMI_HOTPLUG, 0x1a8),
+ VC4_HDMI_REG(HDMI_SCRAMBLER_CTL, 0x1c4),
VC5_DVP_REG(HDMI_CLOCK_STOP, 0x0bc),
VC5_DVP_REG(HDMI_VEC_INTERFACE_XBAR, 0x0f0),