Re: [PATCH RFC v2 1/8] drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support

From: Neil Armstrong
Date: Tue Dec 18 2018 - 08:17:33 EST

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In reply to: Andrzej Hajda: "Re: [PATCH RFC v2 1/8] drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support"
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On 18/12/2018 13:25, Andrzej Hajda wrote:
> Hi Neil,
>
>
> On 30.11.2018 14:42, Neil Armstrong wrote:
>> 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@60/50 modes.
>>
>> These changes were based on work done by Huicong Xu <xhc@xxxxxxxxxxxxxx>
>> and Nickey Yang <nickey.yang@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>
>> Cc: Huicong Xu <xhc@xxxxxxxxxxxxxx>
>> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>> ---
>> 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,
>
>
> Are you sure you need casting to u8?

Not sure, it's already casted in dw_hdmi_clear_overflow() :

...
hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ, HDMI_MC_SWRSTZ);
...

I'll check if it's really needed.

>
>
>> + 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);
>
> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>

Thanks,
Neil

>
> Â--
> Regards
> Andrzej
>
>
>

Next message: Jarkko Sakkinen: "Re: [PATCH v17 18/23] platform/x86: Intel SGX driver"
Previous message: YueHaibing: "Re: [PATCH -next] staging: fbtft: use strcmp() instead of strncmp() for subsystem lookup"
In reply to: Andrzej Hajda: "Re: [PATCH RFC v2 1/8] drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support"
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