[PATCH RFC v2 1/8] drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support
Neil Armstrong
narmstrong at baylibre.com
Fri Nov 30 13:42:54 UTC 2018
Add support for SCDC Setup for TMDS Clock > 3.4GHz and enable TMDS
Scrambling when supported or mandatory.
This patch also adds an helper to setup the control bit to support
the high TMDS Bit Period/TMDS Clock-Period Ratio as required with
TMDS Clock > 3.4GHz for HDMI2.0 3840x2160 at 60/50 modes.
These changes were based on work done by Huicong Xu <xhc at rock-chips.com>
and Nickey Yang <nickey.yang at rock-chips.com> to support HDMI2.0 modes
on the Rockchip 4.4 BSP kernel at [1]
[1] https://github.com/rockchip-linux/kernel/tree/release-4.4
Cc: Nickey Yang <nickey.yang at rock-chips.com>
Cc: Huicong Xu <xhc at rock-chips.com>
Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 88 ++++++++++++++++++++++-
drivers/gpu/drm/bridge/synopsys/dw-hdmi.h | 1 +
include/drm/bridge/dw_hdmi.h | 1 +
3 files changed, 87 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 64c3cf027518..fcd941d52753 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -28,6 +28,7 @@
#include <drm/drm_crtc_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_encoder_slave.h>
+#include <drm/drm_scdc_helper.h>
#include <drm/bridge/dw_hdmi.h>
#include <uapi/linux/media-bus-format.h>
@@ -43,6 +44,11 @@
#define HDMI_EDID_LEN 512
+/* DW-HDMI Controller >= 0x200a are at least compliant with SCDC version 1 */
+#define SCDC_MIN_SOURCE_VERSION 0x1
+
+#define HDMI14_MAX_TMDSCLK 340000000
+
enum hdmi_datamap {
RGB444_8B = 0x01,
RGB444_10B = 0x03,
@@ -1015,6 +1021,33 @@ void dw_hdmi_phy_i2c_write(struct dw_hdmi *hdmi, unsigned short data,
}
EXPORT_SYMBOL_GPL(dw_hdmi_phy_i2c_write);
+/*
+ * HDMI2.0 Specifies the following procedure for High TMDS Bit Rates:
+ * - The Source shall suspend transmission of the TMDS clock and data
+ * - The Source shall write to the TMDS_Bit_Clock_Ratio bit to change it
+ * from a 0 to a 1 or from a 1 to a 0
+ * - The Source shall allow a minimum of 1 ms and a maximum of 100 ms from
+ * the time the TMDS_Bit_Clock_Ratio bit is written until resuming
+ * transmission of TMDS clock and data
+ *
+ * To respect the 100ms maximum delay, the dw_hdmi_set_high_tmds_clock_ratio()
+ * helper should called right before enabling the TMDS Clock and Data in
+ * the PHY configuration callback.
+ */
+void dw_hdmi_set_high_tmds_clock_ratio(struct dw_hdmi *hdmi)
+{
+ unsigned long mtmdsclock = hdmi->hdmi_data.video_mode.mpixelclock;
+
+ /* Control for TMDS Bit Period/TMDS Clock-Period Ratio */
+ if (hdmi->connector.display_info.hdmi.scdc.supported) {
+ if (mtmdsclock > HDMI14_MAX_TMDSCLK)
+ drm_scdc_set_high_tmds_clock_ratio(hdmi->ddc, 1);
+ else
+ drm_scdc_set_high_tmds_clock_ratio(hdmi->ddc, 0);
+ }
+}
+EXPORT_SYMBOL_GPL(dw_hdmi_set_high_tmds_clock_ratio);
+
static void dw_hdmi_phy_enable_powerdown(struct dw_hdmi *hdmi, bool enable)
{
hdmi_mask_writeb(hdmi, !enable, HDMI_PHY_CONF0,
@@ -1216,6 +1249,8 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi)
dw_hdmi_phy_power_off(hdmi);
+ dw_hdmi_set_high_tmds_clock_ratio(hdmi);
+
/* Leave low power consumption mode by asserting SVSRET. */
if (phy->has_svsret)
dw_hdmi_phy_enable_svsret(hdmi, 1);
@@ -1237,6 +1272,10 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi)
return ret;
}
+ /* Wait for resuming transmission of TMDS clock and data */
+ if (mpixelclock > HDMI14_MAX_TMDSCLK)
+ msleep(100);
+
return dw_hdmi_phy_power_on(hdmi);
}
@@ -1340,11 +1379,12 @@ static void hdmi_tx_hdcp_config(struct dw_hdmi *hdmi)
static void hdmi_config_AVI(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
{
+ bool is_hdmi2_sink = hdmi->connector.display_info.hdmi.scdc.supported;
struct hdmi_avi_infoframe frame;
u8 val;
/* Initialise info frame from DRM mode */
- drm_hdmi_avi_infoframe_from_display_mode(&frame, mode, false);
+ drm_hdmi_avi_infoframe_from_display_mode(&frame, mode, is_hdmi2_sink);
if (hdmi_bus_fmt_is_yuv444(hdmi->hdmi_data.enc_out_bus_format))
frame.colorspace = HDMI_COLORSPACE_YUV444;
@@ -1503,7 +1543,8 @@ static void hdmi_config_vendor_specific_infoframe(struct dw_hdmi *hdmi,
static void hdmi_av_composer(struct dw_hdmi *hdmi,
const struct drm_display_mode *mode)
{
- u8 inv_val;
+ u8 inv_val, bytes;
+ struct drm_hdmi_info *hdmi_info = &hdmi->connector.display_info.hdmi;
struct hdmi_vmode *vmode = &hdmi->hdmi_data.video_mode;
int hblank, vblank, h_de_hs, v_de_vs, hsync_len, vsync_len;
unsigned int vdisplay;
@@ -1513,7 +1554,9 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi,
dev_dbg(hdmi->dev, "final pixclk = %d\n", vmode->mpixelclock);
/* Set up HDMI_FC_INVIDCONF */
- inv_val = (hdmi->hdmi_data.hdcp_enable ?
+ inv_val = (hdmi->hdmi_data.hdcp_enable ||
+ vmode->mpixelclock > HDMI14_MAX_TMDSCLK ||
+ hdmi_info->scdc.scrambling.low_rates ?
HDMI_FC_INVIDCONF_HDCP_KEEPOUT_ACTIVE :
HDMI_FC_INVIDCONF_HDCP_KEEPOUT_INACTIVE);
@@ -1562,6 +1605,45 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi,
vsync_len /= 2;
}
+ /* Scrambling Control */
+ if (hdmi_info->scdc.supported) {
+ if (vmode->mpixelclock > HDMI14_MAX_TMDSCLK ||
+ hdmi_info->scdc.scrambling.low_rates) {
+ /*
+ * HDMI2.0 Specifies the following procedure:
+ * After the Source Device has determined that
+ * SCDC_Present is set (=1), the Source Device should
+ * write the accurate Version of the Source Device
+ * to the Source Version field in the SCDCS.
+ * Source Devices compliant shall set the
+ * Source Version = 1.
+ */
+ drm_scdc_readb(&hdmi->i2c->adap, SCDC_SINK_VERSION,
+ &bytes);
+ drm_scdc_writeb(&hdmi->i2c->adap, SCDC_SOURCE_VERSION,
+ min_t(u8, bytes, SCDC_MIN_SOURCE_VERSION));
+
+ /* Enabled Scrambling in the Sink */
+ drm_scdc_set_scrambling(&hdmi->i2c->adap, 1);
+
+ /*
+ * To activate the scrambler feature, you must ensure
+ * that the quasi-static configuration bit
+ * fc_invidconf.HDCP_keepout is set at configuration
+ * time, before the required mc_swrstzreq.tmdsswrst_req
+ * reset request is issued.
+ */
+ hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ,
+ HDMI_MC_SWRSTZ);
+ hdmi_writeb(hdmi, 1, HDMI_FC_SCRAMBLER_CTRL);
+ } else {
+ hdmi_writeb(hdmi, 0, HDMI_FC_SCRAMBLER_CTRL);
+ hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ,
+ HDMI_MC_SWRSTZ);
+ drm_scdc_set_scrambling(&hdmi->i2c->adap, 0);
+ }
+ }
+
/* Set up horizontal active pixel width */
hdmi_writeb(hdmi, mode->hdisplay >> 8, HDMI_FC_INHACTV1);
hdmi_writeb(hdmi, mode->hdisplay, HDMI_FC_INHACTV0);
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
index 9d90eb9c46e5..3f3c616eba97 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
@@ -255,6 +255,7 @@
#define HDMI_FC_MASK2 0x10DA
#define HDMI_FC_POL2 0x10DB
#define HDMI_FC_PRCONF 0x10E0
+#define HDMI_FC_SCRAMBLER_CTRL 0x10E1
#define HDMI_FC_GMD_STAT 0x1100
#define HDMI_FC_GMD_EN 0x1101
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 9c56412bb2cf..7a02744ce0bc 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -157,6 +157,7 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
+void dw_hdmi_set_high_tmds_clock_ratio(struct dw_hdmi *hdmi);
/* PHY configuration */
void dw_hdmi_phy_i2c_set_addr(struct dw_hdmi *hdmi, u8 address);
--
2.19.2
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