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: Fixed typos and addressed other review comments from Uma Shankar.
-changed the commit message for better clarity (Uma Shankar)
-removed unnecessary argument supplied to a drm helper function.
-fixed return value for max frl read from pcon.
v3: Removed DPCD 0x3035 for MAX Sink FRL b/w as per new version of spec.
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
Reviewed-by: Uma Shankar <uma.shankar@xxxxxxxxx> (v2)
---
drivers/gpu/drm/drm_dp_helper.c | 263 ++++++++++++++++++++++++++++++++
include/drm/drm_dp_helper.h | 70 +++++++++
2 files changed, 333 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 5bd0934004e3..f501e3890921 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -2596,3 +2596,266 @@ 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_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_gbps: maximum frl bw to be configured between PCON and HDMI sink
+ * @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 = 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 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)
+ *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 6b40258927bf..c66f570eadc2 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)
@@ -1054,6 +1065,51 @@ struct drm_device;
#define DP_CEC_TX_MESSAGE_BUFFER 0x3020
#define DP_CEC_MESSAGE_BUFFER_LENGTH 0x10
+/* 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)
+# 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 */
#define DP_PROTOCOL_CONVERTER_CONTROL_1 0x3051 /* DP 1.3 */
@@ -1967,4 +2023,18 @@ 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_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);
+
#endif /* _DRM_DP_HELPER_H_ */
--
2.17.1
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