> -----Original Message-----
> From: Nautiyal, Ankit K <ankit.k.nautiyal@xxxxxxxxx>
> Sent: Thursday, October 15, 2020 4:23 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; Shankar, Uma <uma.shankar@xxxxxxxxx>;
> Kulkarni, Vandita <vandita.kulkarni@xxxxxxxxx>; ville.syrjala@xxxxxxxxxxxxxxx;
> Sharma, Swati2 <swati2.sharma@xxxxxxxxx>
> 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@xxxxxxxxx>
> ---
> 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
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