drm/msm/disp/dpu1: Add support for DSC in encoder

We need to configure the encoder for DSC configuration and calculate DSC
parameters for the given timing so this patch adds that support by
adding dpu_encoder_prep_dsc() which is invoked when DSC is enabled.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/480920/
Link: https://lore.kernel.org/r/20220406094031.1027376-8-vkoul@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c

@@ -21,6 +21,7 @@
 #include "dpu_hw_intf.h"
 #include "dpu_hw_ctl.h"
 #include "dpu_hw_dspp.h"
+#include "dpu_hw_dsc.h"
 #include "dpu_formats.h"
 #include "dpu_encoder_phys.h"
 #include "dpu_crtc.h"
@@ -135,6 +136,8 @@ enum dpu_enc_rc_states {
  * @cur_slave:		As above but for the slave encoder.
  * @hw_pp:		Handle to the pingpong blocks used for the display. No.
  *			pingpong blocks can be different than num_phys_encs.
+ * @hw_dsc:		Handle to the DSC blocks used for the display.
+ * @dsc_mask:		Bitmask of used DSC blocks.
  * @intfs_swapped:	Whether or not the phys_enc interfaces have been swapped
  *			for partial update right-only cases, such as pingpong
  *			split where virtual pingpong does not generate IRQs
@@ -168,6 +171,7 @@ enum dpu_enc_rc_states {
  * @vsync_event_work:		worker to handle vsync event for autorefresh
  * @topology:                   topology of the display
  * @idle_timeout:		idle timeout duration in milliseconds
+ * @dsc:			msm_display_dsc_config pointer, for DSC-enabled encoders
  */
 struct dpu_encoder_virt {
 	struct drm_encoder base;
@@ -180,6 +184,9 @@ struct dpu_encoder_virt {
 	struct dpu_encoder_phys *cur_master;
 	struct dpu_encoder_phys *cur_slave;
 	struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
+	struct dpu_hw_dsc *hw_dsc[MAX_CHANNELS_PER_ENC];
+
+	unsigned int dsc_mask;
 
 	bool intfs_swapped;
 
@@ -208,6 +215,9 @@ struct dpu_encoder_virt {
 	u32 idle_timeout;
 
 	bool wide_bus_en;
+
+	/* DSC configuration */
+	struct msm_display_dsc_config *dsc;
 };
 
 #define to_dpu_encoder_virt(x) container_of(x, struct dpu_encoder_virt, base)
@@ -952,7 +962,9 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
 	struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC];
 	struct dpu_hw_blk *hw_lm[MAX_CHANNELS_PER_ENC];
 	struct dpu_hw_blk *hw_dspp[MAX_CHANNELS_PER_ENC] = { NULL };
-	int num_lm, num_ctl, num_pp;
+	struct dpu_hw_blk *hw_dsc[MAX_CHANNELS_PER_ENC];
+	int num_lm, num_ctl, num_pp, num_dsc;
+	unsigned int dsc_mask = 0;
 	int i;
 
 	if (!drm_enc) {
@@ -990,6 +1002,18 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
 		dpu_enc->hw_pp[i] = i < num_pp ? to_dpu_hw_pingpong(hw_pp[i])
 						: NULL;
 
+	if (dpu_enc->dsc) {
+		num_dsc = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
+							drm_enc->base.id, DPU_HW_BLK_DSC,
+							hw_dsc, ARRAY_SIZE(hw_dsc));
+		for (i = 0; i < num_dsc; i++) {
+			dpu_enc->hw_dsc[i] = to_dpu_hw_dsc(hw_dsc[i]);
+			dsc_mask |= BIT(dpu_enc->hw_dsc[i]->idx - DSC_0);
+		}
+	}
+
+	dpu_enc->dsc_mask = dsc_mask;
+
 	cstate = to_dpu_crtc_state(crtc_state);
 
 	for (i = 0; i < num_lm; i++) {
@@ -1687,6 +1711,95 @@ static void dpu_encoder_vsync_event_work_handler(struct kthread_work *work)
 			nsecs_to_jiffies(ktime_to_ns(wakeup_time)));
 }
 
+static u32
+dpu_encoder_dsc_initial_line_calc(struct msm_display_dsc_config *dsc,
+				  u32 enc_ip_width)
+{
+	int ssm_delay, total_pixels, soft_slice_per_enc;
+
+	soft_slice_per_enc = enc_ip_width / dsc->drm->slice_width;
+
+	/*
+	 * minimum number of initial line pixels is a sum of:
+	 * 1. sub-stream multiplexer delay (83 groups for 8bpc,
+	 *    91 for 10 bpc) * 3
+	 * 2. for two soft slice cases, add extra sub-stream multiplexer * 3
+	 * 3. the initial xmit delay
+	 * 4. total pipeline delay through the "lock step" of encoder (47)
+	 * 5. 6 additional pixels as the output of the rate buffer is
+	 *    48 bits wide
+	 */
+	ssm_delay = ((dsc->drm->bits_per_component < 10) ? 84 : 92);
+	total_pixels = ssm_delay * 3 + dsc->drm->initial_xmit_delay + 47;
+	if (soft_slice_per_enc > 1)
+		total_pixels += (ssm_delay * 3);
+	return DIV_ROUND_UP(total_pixels, dsc->drm->slice_width);
+}
+
+static void dpu_encoder_dsc_pipe_cfg(struct dpu_hw_dsc *hw_dsc,
+				     struct dpu_hw_pingpong *hw_pp,
+				     struct msm_display_dsc_config *dsc,
+				     u32 common_mode,
+				     u32 initial_lines)
+{
+	if (hw_dsc->ops.dsc_config)
+		hw_dsc->ops.dsc_config(hw_dsc, dsc, common_mode, initial_lines);
+
+	if (hw_dsc->ops.dsc_config_thresh)
+		hw_dsc->ops.dsc_config_thresh(hw_dsc, dsc);
+
+	if (hw_pp->ops.setup_dsc)
+		hw_pp->ops.setup_dsc(hw_pp);
+
+	if (hw_pp->ops.enable_dsc)
+		hw_pp->ops.enable_dsc(hw_pp);
+}
+
+static void dpu_encoder_prep_dsc(struct dpu_encoder_virt *dpu_enc,
+				 struct msm_display_dsc_config *dsc)
+{
+	/* coding only for 2LM, 2enc, 1 dsc config */
+	struct dpu_encoder_phys *enc_master = dpu_enc->cur_master;
+	struct dpu_hw_dsc *hw_dsc[MAX_CHANNELS_PER_ENC];
+	struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
+	int this_frame_slices;
+	int intf_ip_w, enc_ip_w;
+	int dsc_common_mode;
+	int pic_width;
+	u32 initial_lines;
+	int i;
+
+	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++) {
+		hw_pp[i] = dpu_enc->hw_pp[i];
+		hw_dsc[i] = dpu_enc->hw_dsc[i];
+
+		if (!hw_pp[i] || !hw_dsc[i]) {
+			DPU_ERROR_ENC(dpu_enc, "invalid params for DSC\n");
+			return;
+		}
+	}
+
+	dsc_common_mode = 0;
+	pic_width = dsc->drm->pic_width;
+
+	dsc_common_mode = DSC_MODE_MULTIPLEX | DSC_MODE_SPLIT_PANEL;
+	if (enc_master->intf_mode == INTF_MODE_VIDEO)
+		dsc_common_mode |= DSC_MODE_VIDEO;
+
+	this_frame_slices = pic_width / dsc->drm->slice_width;
+	intf_ip_w = this_frame_slices * dsc->drm->slice_width;
+
+	/*
+	 * dsc merge case: when using 2 encoders for the same stream,
+	 * no. of slices need to be same on both the encoders.
+	 */
+	enc_ip_w = intf_ip_w / 2;
+	initial_lines = dpu_encoder_dsc_initial_line_calc(dsc, enc_ip_w);
+
+	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++)
+		dpu_encoder_dsc_pipe_cfg(hw_dsc[i], hw_pp[i], dsc, dsc_common_mode, initial_lines);
+}
+
 void dpu_encoder_prepare_for_kickoff(struct drm_encoder *drm_enc)
 {
 	struct dpu_encoder_virt *dpu_enc;
@@ -1718,6 +1831,9 @@ void dpu_encoder_prepare_for_kickoff(struct drm_encoder *drm_enc)
 			dpu_encoder_helper_hw_reset(dpu_enc->phys_encs[i]);
 		}
 	}
+
+	if (dpu_enc->dsc)
+		dpu_encoder_prep_dsc(dpu_enc, dpu_enc->dsc);
 }
 
 void dpu_encoder_kickoff(struct drm_encoder *drm_enc)
@@ -1963,6 +2079,8 @@ static int dpu_encoder_setup_display(struct dpu_encoder_virt *dpu_enc,
 		dpu_enc->idle_pc_supported =
 				dpu_kms->catalog->caps->has_idle_pc;
 
+	dpu_enc->dsc = disp_info->dsc;
+
 	mutex_lock(&dpu_enc->enc_lock);
 	for (i = 0; i < disp_info->num_of_h_tiles && !ret; i++) {
 		/*
@@ -2193,3 +2311,11 @@ enum dpu_intf_mode dpu_encoder_get_intf_mode(struct drm_encoder *encoder)
 
 	return INTF_MODE_NONE;
 }
+
+unsigned int dpu_encoder_helper_get_dsc(struct dpu_encoder_phys *phys_enc)
+{
+	struct drm_encoder *encoder = phys_enc->parent;
+	struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(encoder);
+
+	return dpu_enc->dsc_mask;
+}

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h

@@ -321,6 +321,14 @@ static inline enum dpu_3d_blend_mode dpu_encoder_helper_get_3d_blend_mode(
 	return BLEND_3D_NONE;
 }
 
+/**
+ * dpu_encoder_helper_get_dsc - get DSC blocks mask for the DPU encoder
+ *   This helper function is used by physical encoder to get DSC blocks mask
+ *   used for this encoder.
+ * @phys_enc: Pointer to physical encoder structure
+ */
+unsigned int dpu_encoder_helper_get_dsc(struct dpu_encoder_phys *phys_enc);
+
 /**
  * dpu_encoder_helper_split_config - split display configuration helper function
  *	This helper function may be used by physical encoders to configure