RE: [RFC 03/13] drm/dp_helper: Add FRL training support for a DP-HDMI2.1 PCON

-----Original Message----- From: Nautiyal, Ankit K ankit.k.nautiyal@intel.com Sent: Thursday, October 15, 2020 4:23 PM To: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org; Shankar, Uma uma.shankar@intel.com; Kulkarni, Vandita vandita.kulkarni@intel.com; ville.syrjala@linux.intel.com; Sharma, Swati2 swati2.sharma@intel.com Subject: [RFC 03/13] drm/dp_helper: Add FRL training support for a DP-HDMI2.1 PCON

You can name this patch as "Add Helpers for FRL Link Training support for DP-HDMI2.1 PCON"

This patch adds support for configuring a PCON device, connected as a DP branched device to enable FRL Link training with a HDMI2.1 + sink.

v2: Minor changes: -removed unnecessary argument supplied to a drm helper function. -fixed return value for max frl read from pcon.

Signed-off-by: Ankit Nautiyal ankit.k.nautiyal@intel.com

drivers/gpu/drm/drm_dp_helper.c | 305 ++++++++++++++++++++++++++++++++ include/drm/drm_dp_helper.h | 80 +++++++++ 2 files changed, 385 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 14ddf28ecac0..df858533dbf7 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -2591,3 +2591,308 @@ void drm_dp_vsc_sdp_log(const char *level, struct device *dev, #undef DP_SDP_LOG } EXPORT_SYMBOL(drm_dp_vsc_sdp_log);

+/**

• • drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON
• • @dpcd: DisplayPort configuration data
• • @port_cap: port capabilities
• • Returns maximum frl bandwidth supported by PCON in GBPS,
• • returns 0 if not supported.
• **/

+int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],

• 	       const u8 port_cap[4])
  

+{

• int bw;
• u8 buf;
• buf = port_cap[2];
• bw = buf & DP_PCON_MAX_FRL_BW;
• switch (bw) {
• case DP_PCON_MAX_9GBPS:

• return 9;
  

• case DP_PCON_MAX_18GBPS:

• return 18;
  

• case DP_PCON_MAX_24GBPS:

• return 24;
  

• case DP_PCON_MAX_32GBPS:

• return 32;
  

• case DP_PCON_MAX_40GBPS:

• return 40;
  

• case DP_PCON_MAX_48GBPS:

• return 48;
  

• case DP_PCON_MAX_0GBPS:
• default:

• return 0;
  

• }
• return 0;

+} +EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw);

+/**

• • drm_dp_get_hdmi_max_frl_bw() - maximum frl supported by HDMI Sink
• • @aux: DisplayPort AUX channel
• • Returns maximum frl bandwidth supported by HDMI in Gbps on success,
• • returns 0, if not supported.
• **/

+int drm_dp_get_hdmi_max_frl_bw(struct drm_dp_aux *aux) {

s/hdmi/hdmi_sink/ will make it clear that we are referring to sink here.

• u8 buf;
• int bw, ret;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_SINK, &buf);
• if (ret < 0)

• return 0;
  

• bw = buf & DP_HDMI_SINK_LINK_BW;
• switch (bw) {
• case DP_HDMI_SINK_BW_9GBPS:

• return 9;
  

• case DP_HDMI_SINK_BW_18GBPS:

• return 18;
  

• case DP_HDMI_SINK_BW_24GBPS:

• return 24;
  

• case DP_HDMI_SINK_BW_32GBPS:

• return 32;
  

• case DP_HDMI_SINK_BW_40GBPS:

• return 40;
  

• case DP_HDMI_SINK_BW_48GBPS:

• return 48;
  

• case DP_HDMI_SINK_BW_0GBPS:
• default:

• return 0;
  

• }
• return 0;

+} +EXPORT_SYMBOL(drm_dp_get_hdmi_max_frl_bw);

+/**

• • drm_dp_pcon_frl_prepare() - Prepare PCON for FRL.
• • @aux: DisplayPort AUX channel
• • Returns 0 if success, else returns negative error code.
• **/

+int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool +enable_frl_ready_hpd) {

• int ret;
• u8 buf = DP_PCON_ENABLE_SOURCE_CTL_MODE |

•  DP_PCON_ENABLE_LINK_FRL_MODE;
  

• if (enable_frl_ready_hpd)

• buf |= DP_PCON_ENABLE_HPD_READY;
  

• ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
• return ret;

+} +EXPORT_SYMBOL(drm_dp_pcon_frl_prepare);

+/**

• • drm_dp_pcon_is_frl_ready() - Is PCON ready for FRL
• • @aux: DisplayPort AUX channel
• • Returns true if success, else returns false.
• **/

+bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux) {

• int ret;
• u8 buf;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf);
• if (ret < 0)

• return false;
  

• if (buf & DP_PCON_FRL_READY)

• return true;
  

• return false;

+} +EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready);

+/**

• • drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1
• • @aux: DisplayPort AUX channel
• • max_frl_mask: mask for selecting the bandwidths supported by source,

@missing from variable and its not a mask here but an absolute value.

• • to be tried by Pcon f/w.
• • @concurrent_mode: true if concurrent mode or operation is required,
• • false otherwise.
• • Returns 0 if success, else returns negative error code.
• **/

+int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,

• 		bool concurrent_mode)
  

+{

• int ret;
• u8 buf;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf);
• if (ret < 0)

• return ret;
  

• if (concurrent_mode)

• buf |= DP_PCON_ENABLE_CONCURRENT_LINK;
  

• else

• buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK;
  

• switch (max_frl_gbps) {
• case 9:

• buf |=  DP_PCON_ENABLE_MAX_BW_9GBPS;
  

• break;
  

• case 18:

• buf |=  DP_PCON_ENABLE_MAX_BW_18GBPS;
  

• break;
  

• case 24:

• buf |=  DP_PCON_ENABLE_MAX_BW_24GBPS;
  

• break;
  

• case 32:

• buf |=  DP_PCON_ENABLE_MAX_BW_32GBPS;
  

• break;
  

• case 40:

• buf |=  DP_PCON_ENABLE_MAX_BW_40GBPS;
  

• break;
  

• case 48:

• buf |=  DP_PCON_ENABLE_MAX_BW_48GBPS;
  

• break;
  

• case 0:

• buf |=  DP_PCON_ENABLE_MAX_BW_0GBPS;
  

• break;
  

• default:

• return -EINVAL;
  

• }
• ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
• if (ret < 0)

• return ret;
  

• return 0;

+} +EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1);

+/**

• • drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2
• • @aux: DisplayPort AUX channel
• • @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink
• • @extended_train_mode : true for Extended Mode, false for Normal Mode.
• • In Normal mode, the PCON tries each frl bw from the max_frl_mask

+starting

• • from min, and stops when link training is successful. In Extended

+mode, all

• • frl bw selected in the mask are trained by the PCON.
• • Returns 0 if success, else returns negative error code.
• **/

+int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,

• 		bool extended_train_mode)
  

+{

• int ret;
• u8 buf = 0;
• buf |= max_frl_mask;

Can just initialize buf to max _frl_mask.

• if (extended_train_mode)

• buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED;
  

• ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf);
• if (ret < 0)

• return ret;
  

• return 0;

+} +EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2);

+/**

• • drm_dp_pcon_reset_frl_config() - Re-Set HDMI Link configuration.
• • @aux: DisplayPort AUX channel
• • Returns 0 if success, else returns negative error code.
• **/

+int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux) {

• int ret;
• ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0);
• if (ret < 0)

• return ret;
  

• return 0;

+} +EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config);

+/**

• • drm_dp_pcon_frl_enable() - Enable HDMI link through FRL
• • @aux: DisplayPort AUX channel
• • Returns 0 if success, else returns negative error code.
• **/

+int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux) {

• int ret;
• u8 buf = 0;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf);
• if (ret < 0)

• return ret;
  

• if (!(buf & DP_PCON_ENABLE_SOURCE_CTL_MODE)) {

• DRM_DEBUG_KMS("PCON in Autonomous mode, can't enable
  

FRL\n");

• return -EINVAL;
  

• }
• buf |= DP_PCON_ENABLE_HDMI_LINK;
• ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
• if (ret < 0)

• return ret;
  

• return 0;

+} +EXPORT_SYMBOL(drm_dp_pcon_frl_enable);

+/**

• • drm_dp_pcon_hdmi_link_active() - check if the PCON HDMI LINK status is

active.

• • @aux: DisplayPort AUX channel
• • Returns true if link is active else returns false.
• **/

+bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux) {

• u8 buf;
• int ret;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf);
• if (ret < 0)

• return false;
  

• return buf & DP_PCON_HDMI_TX_LINK_ACTIVE; }

+EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_active);

+/**

• • drm_dp_pcon_hdmi_link_mode() - get the PCON HDMI LINK MODE
• • @aux: DisplayPort AUX channel
• • @frl_trained_mask: pointer to store bitmask of the trained bw configuration.
• • Valid only if the MODE returned is FRL. For Normal Link training

+mode

• • only 1 of the bits will be set, but in case of Extended mode, more

+than

• • one bits can be set.
• • Returns the link mode : TMDS or FRL on success, else retunes

Typo in returns

+negative error

• • code.
• **/

+int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 +*frl_trained_mask) {

• u8 buf;
• int mode;
• int ret;
• ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_POST_FRL_STATUS,

&buf);

• if (ret < 0)

• return ret;
  

• mode = buf & DP_PCON_HDMI_LINK_MODE;
• if (frl_trained_mask && DP_PCON_HDMI_MODE_FRL == mode)

Should be bitwise and not logical and right ?. Also this mask is a bit ambigious, we could just use absolute bandwidth which would be more clear.

• *frl_trained_mask = (buf & DP_PCON_HDMI_FRL_TRAINED_BW)
  

...

...

1;

• return mode;

+} +EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_mode); diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index f55a9d1320ca..d6f79b2d1287 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -411,6 +411,17 @@ struct drm_device; # define DP_DS_10BPC 1 # define DP_DS_12BPC 2 # define DP_DS_16BPC 3 +/* HDMI2.1 PCON FRL CONFIGURATION */ +# define DP_PCON_MAX_FRL_BW (7 << 2) +# define DP_PCON_MAX_0GBPS (0 << 2) +# define DP_PCON_MAX_9GBPS (1 << 2) +# define DP_PCON_MAX_18GBPS (2 << 2) +# define DP_PCON_MAX_24GBPS (3 << 2) +# define DP_PCON_MAX_32GBPS (4 << 2) +# define DP_PCON_MAX_40GBPS (5 << 2) +# define DP_PCON_MAX_48GBPS (6 << 2) +# define DP_PCON_SOURCE_CTL_MODE (1 << 5)

/* offset 3 for DVI */ # define DP_DS_DVI_DUAL_LINK (1 << 1) # define DP_DS_DVI_HIGH_COLOR_DEPTH (1 << 2) @@ -1053,6 +1064,61 @@ struct drm_device; #define DP_CEC_RX_MESSAGE_BUFFER 0x3010 #define DP_CEC_TX_MESSAGE_BUFFER 0x3020 #define DP_CEC_MESSAGE_BUFFER_LENGTH 0x10 +/* PROTOCOL CONVERSION HDMI SINK */ +#define DP_PCON_HDMI_SINK 0x3035 +# define DP_HDMI_SINK_LINK_BW (7 << 0) +# define DP_HDMI_SINK_BW_0GBPS 0 +# define DP_HDMI_SINK_BW_9GBPS 1 +# define DP_HDMI_SINK_BW_18GBPS 2 +# define DP_HDMI_SINK_BW_24GBPS 3 +# define DP_HDMI_SINK_BW_32GBPS 4 +# define DP_HDMI_SINK_BW_40GBPS 5 +# define DP_HDMI_SINK_BW_48GBPS 6

+/* PCON CONFIGURE-1 FRL FOR HDMI SINK */ +#define DP_PCON_HDMI_LINK_CONFIG_1 0x305A +# define DP_PCON_ENABLE_MAX_FRL_BW (7 << 0) +# define DP_PCON_ENABLE_MAX_BW_0GBPS 0 +# define DP_PCON_ENABLE_MAX_BW_9GBPS 1 +# define DP_PCON_ENABLE_MAX_BW_18GBPS 2 +# define DP_PCON_ENABLE_MAX_BW_24GBPS 3 +# define DP_PCON_ENABLE_MAX_BW_32GBPS 4 +# define DP_PCON_ENABLE_MAX_BW_40GBPS 5 +# define DP_PCON_ENABLE_MAX_BW_48GBPS 6 +# define DP_PCON_ENABLE_SOURCE_CTL_MODE (1 << 3) +# define DP_PCON_ENABLE_CONCURRENT_LINK (1 << 4) +# define DP_PCON_ENABLE_LINK_FRL_MODE (1 << 5) +# define DP_PCON_ENABLE_HPD_READY (1 << 6) +# define DP_PCON_ENABLE_HDMI_LINK (1 << 7)

+/* PCON CONFIGURE-2 FRL FOR HDMI SINK */ +#define DP_PCON_HDMI_LINK_CONFIG_2 0x305B +# define DP_PCON_MAX_LINK_BW_MASK (0x3F << 0) +# define DP_PCON_FRL_BW_MASK_9GBPS (1 << 0) +# define DP_PCON_FRL_BW_MASK_18GBPS (1 << 1) +# define DP_PCON_FRL_BW_MASK_24GBPS (1 << 2) +# define DP_PCON_FRL_BW_MASK_32GBPS (1 << 3) +# define DP_PCON_FRL_BW_MASK_40GBPS (1 << 4) +# define DP_PCON_FRL_BW_MASK_48GBPS (1 << 5) +# define DP_PCON_FRL_LINK_TRAIN_EXTENDED (1 << 6)

+/* PCON HDMI LINK STATUS */ +#define DP_PCON_HDMI_TX_LINK_STATUS 0x303B +# define DP_PCON_HDMI_TX_LINK_ACTIVE (1 << 0) +# define DP_PCON_FRL_READY (1 << 1)

+/* PCON HDMI POST FRL STATUS */ +#define DP_PCON_HDMI_POST_FRL_STATUS 0x3036 +# define DP_PCON_HDMI_LINK_MODE (1 << 0) +# define DP_PCON_HDMI_MODE_TMDS 0 +# define DP_PCON_HDMI_MODE_FRL 1 +# define DP_PCON_HDMI_FRL_TRAINED_BW (0x3F << 1)

This should be 0x3 < 1

+# define DP_PCON_FRL_TRAINED_BW_9GBPS (1 << 1) +# define DP_PCON_FRL_TRAINED_BW_18GBPS (1 << 2) +# define DP_PCON_FRL_TRAINED_BW_24GBPS (1 << 3) +# define DP_PCON_FRL_TRAINED_BW_32GBPS (1 << 4) +# define DP_PCON_FRL_TRAINED_BW_40GBPS (1 << 5) +# define DP_PCON_FRL_TRAINED_BW_48GBPS (1 << 6)

#define DP_PROTOCOL_CONVERTER_CONTROL_0 0x3050 /* DP 1.3 */ # define DP_HDMI_DVI_OUTPUT_CONFIG (1 << 0) /* DP 1.3 */ @@ -1967,4 +2033,18 @@ int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux, struct drm_dp_phy_test_params *data); int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux, struct drm_dp_phy_test_params *data, u8 dp_rev); +int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],

• 	       const u8 port_cap[4]);
  

+int drm_dp_get_hdmi_max_frl_bw(struct drm_dp_aux *aux); int +drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool +enable_frl_ready_hpd); bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux +*aux); int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,

• 		bool concurrent_mode);
  

+int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,

• 		bool extended_train_mode);
  

+int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux); int +drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);

+bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux); int +drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 +*frl_trained_mask);

Leave a blank line here.

#endif /* _DRM_DP_HELPER_H_ */

2.17.1