[Intel-gfx] [PATCH v8 22/38] drm/i915/icl: Load DSI packet payload to queue

[Jani Nikula]

This patch adds DSI packet payload to command payload
queue using credit based mechanism for *long* packets.

v2 by Jani:
 - Add intel_dsi local variable for better code flow
 - Use the new credit available helper
 - Use int for free_credits, i, and j

Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/icl_dsi.c | 57 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
index c7b77cd81e45..58774a1ac84b 100644
--- a/drivers/gpu/drm/i915/icl_dsi.c
+++ b/drivers/gpu/drm/i915/icl_dsi.c
@@ -107,6 +107,33 @@ static void wait_for_cmds_dispatched_to_panel(struct intel_encoder *encoder)
 	}
 }
 
+static bool add_payld_to_queue(struct intel_dsi_host *host, const u8 *data,
+			       u32 len)
+{
+	struct intel_dsi *intel_dsi = host->intel_dsi;
+	struct drm_i915_private *dev_priv = to_i915(intel_dsi->base.base.dev);
+	enum transcoder dsi_trans = dsi_port_to_transcoder(host->port);
+	int free_credits;
+	int i, j;
+
+	for (i = 0; i < len; i += 4) {
+		u32 tmp = 0;
+
+		free_credits = payload_credits_available(dev_priv, dsi_trans);
+		if (free_credits < 1) {
+			DRM_ERROR("Payload credit not available\n");
+			return false;
+		}
+
+		for (j = 0; j < min_t(u32, len - i, 4); j++)
+			tmp |= *data++ << 8 * j;
+
+		I915_WRITE(DSI_CMD_TXPYLD(dsi_trans), tmp);
+	}
+
+	return true;
+}
+
 static int dsi_send_pkt_hdr(struct intel_dsi_host *host,
 			    struct mipi_dsi_packet pkt, bool enable_lpdt)
 {
@@ -145,6 +172,25 @@ static int dsi_send_pkt_hdr(struct intel_dsi_host *host,
 	return 0;
 }
 
+static int dsi_send_pkt_payld(struct intel_dsi_host *host,
+			      struct mipi_dsi_packet pkt)
+{
+	/* payload queue can accept *256 bytes*, check limit */
+	if (pkt.payload_length > MAX_PLOAD_CREDIT * 4) {
+		DRM_ERROR("payload size exceeds max queue limit\n");
+		return -1;
+	}
+
+	/* load data into command payload queue */
+	if (!add_payld_to_queue(host, pkt.payload,
+				pkt.payload_length)) {
+		DRM_ERROR("adding payload to queue failed\n");
+		return -1;
+	}
+
+	return 0;
+}
+
 static void dsi_program_swing_and_deemphasis(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
@@ -1052,6 +1098,17 @@ static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host,
 	if (ret < 0)
 		return ret;
 
+	/* only long packet contains payload */
+	if (mipi_dsi_packet_format_is_long(msg->type)) {
+		ret = dsi_send_pkt_payld(intel_dsi_host, dsi_pkt);
+		if (ret < 0)
+			return ret;
+	}
+
+	//TODO: add payload receive code if needed
+
+	ret = sizeof(dsi_pkt.header) + dsi_pkt.payload_length;
+
 	return ret;
 }
 
-- 
2.11.0