drm/i915/icl: Allocate DSI hosts and imlement host transfer

Allocate DSI host structure for each DSI port available on gen11 and
register them with DSI fwk of DRM. Some of the DSI host operations are
also registered as part of this.

Retrieves DSI pkt (from DSI msg) to be sent over DSI link using DRM DSI
exported functions. A wrapper function is also added as "DSI host
transfer" for sending DSI data/cmd. Add DSI packet payload to command
payload queue using credit based mechanism for *long* packets.

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

v3 by Jani:
 - Squash DSI host allocation and transfer patches together

Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/af4f168ed8737d44687d8b6f21ecaa7e805eb695.1543500286.git.jani.nikula@intel.com

drivers/gpu/drm/i915/icl_dsi.c

@@ -108,6 +108,90 @@ 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)
+{
+	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);
+	u32 tmp;
+	int free_credits;
+
+	/* check if header credit available */
+	free_credits = header_credits_available(dev_priv, dsi_trans);
+	if (free_credits < 1) {
+		DRM_ERROR("send pkt header failed, not enough hdr credits\n");
+		return -1;
+	}
+
+	tmp = I915_READ(DSI_CMD_TXHDR(dsi_trans));
+
+	if (pkt.payload)
+		tmp |= PAYLOAD_PRESENT;
+	else
+		tmp &= ~PAYLOAD_PRESENT;
+
+	tmp &= ~VBLANK_FENCE;
+
+	if (enable_lpdt)
+		tmp |= LP_DATA_TRANSFER;
+
+	tmp &= ~(PARAM_WC_MASK | VC_MASK | DT_MASK);
+	tmp |= ((pkt.header[0] & VC_MASK) << VC_SHIFT);
+	tmp |= ((pkt.header[0] & DT_MASK) << DT_SHIFT);
+	tmp |= (pkt.header[1] << PARAM_WC_LOWER_SHIFT);
+	tmp |= (pkt.header[2] << PARAM_WC_UPPER_SHIFT);
+	I915_WRITE(DSI_CMD_TXHDR(dsi_trans), tmp);
+
+	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);
@@ -1002,6 +1086,58 @@ static const struct drm_connector_helper_funcs gen11_dsi_connector_helper_funcs
 	.atomic_check = intel_digital_connector_atomic_check,
 };
 
+static int gen11_dsi_host_attach(struct mipi_dsi_host *host,
+				 struct mipi_dsi_device *dsi)
+{
+	return 0;
+}
+
+static int gen11_dsi_host_detach(struct mipi_dsi_host *host,
+				 struct mipi_dsi_device *dsi)
+{
+	return 0;
+}
+
+static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host,
+				       const struct mipi_dsi_msg *msg)
+{
+	struct intel_dsi_host *intel_dsi_host = to_intel_dsi_host(host);
+	struct mipi_dsi_packet dsi_pkt;
+	ssize_t ret;
+	bool enable_lpdt = false;
+
+	ret = mipi_dsi_create_packet(&dsi_pkt, msg);
+	if (ret < 0)
+		return ret;
+
+	if (msg->flags & MIPI_DSI_MSG_USE_LPM)
+		enable_lpdt = true;
+
+	/* send packet header */
+	ret  = dsi_send_pkt_hdr(intel_dsi_host, dsi_pkt, enable_lpdt);
+	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;
+}
+
+static const struct mipi_dsi_host_ops gen11_dsi_host_ops = {
+	.attach = gen11_dsi_host_attach,
+	.detach = gen11_dsi_host_detach,
+	.transfer = gen11_dsi_host_transfer,
+};
+
 void icl_dsi_init(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = &dev_priv->drm;
@@ -1074,6 +1210,7 @@ void icl_dsi_init(struct drm_i915_private *dev_priv)
 	intel_panel_init(&intel_connector->panel, fixed_mode, NULL);
 	intel_panel_setup_backlight(connector, INVALID_PIPE);
 
+
 	if (dev_priv->vbt.dsi.config->dual_link)
 		intel_dsi->ports = BIT(PORT_A) | BIT(PORT_B);
 	else
@@ -1082,6 +1219,16 @@ void icl_dsi_init(struct drm_i915_private *dev_priv)
 	intel_dsi->dcs_backlight_ports = dev_priv->vbt.dsi.bl_ports;
 	intel_dsi->dcs_cabc_ports = dev_priv->vbt.dsi.cabc_ports;
 
+	for_each_dsi_port(port, intel_dsi->ports) {
+		struct intel_dsi_host *host;
+
+		host = intel_dsi_host_init(intel_dsi, &gen11_dsi_host_ops, port);
+		if (!host)
+			goto err;
+
+		intel_dsi->dsi_hosts[port] = host;
+	}
+
 	if (!intel_dsi_vbt_init(intel_dsi, MIPI_DSI_GENERIC_PANEL_ID)) {
 		DRM_DEBUG_KMS("no device found\n");
 		goto err;