drm/i915/dsi: call dpi_send_cmd() for each dsi port at a higher level

Instead of having the for each dsi port loop within dpi_send_cmd(), add
a port parameter to the function and call it for each port instead.

This is a rewrite of

commit 4510cd779e5897eeb8691aecbd639bb62ec27d55
Author: Gaurav K Singh <gaurav.k.singh@intel.com>
Date:   Thu Dec 4 10:58:51 2014 +0530

    drm/i915: Dual link needs Shutdown and Turn on packet for both ports

to add more flexibility in using dpi_send_cmd() for just one port as
necessary. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-By: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dsi.c

@@ -207,7 +207,8 @@ static void intel_dsi_enable(struct intel_encoder *encoder)
 		I915_WRITE(MIPI_MAX_RETURN_PKT_SIZE(port), 8 * 4);
 	else {
 		msleep(20); /* XXX */
-		dpi_send_cmd(intel_dsi, TURN_ON, DPI_LP_MODE_EN);
+		for_each_dsi_port(port, intel_dsi->ports)
+			dpi_send_cmd(intel_dsi, TURN_ON, DPI_LP_MODE_EN, port);
 		msleep(100);
 
 		if (intel_dsi->dev.dev_ops->enable)
@@ -275,12 +276,14 @@ static void intel_dsi_enable_nop(struct intel_encoder *encoder)
 static void intel_dsi_pre_disable(struct intel_encoder *encoder)
 {
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
+	enum port port;
 
 	DRM_DEBUG_KMS("\n");
 
 	if (is_vid_mode(intel_dsi)) {
 		/* Send Shutdown command to the panel in LP mode */
-		dpi_send_cmd(intel_dsi, SHUTDOWN, DPI_LP_MODE_EN);
+		for_each_dsi_port(port, intel_dsi->ports)
+			dpi_send_cmd(intel_dsi, SHUTDOWN, DPI_LP_MODE_EN, port);
 		msleep(10);
 	}
 }

drivers/gpu/drm/i915/intel_dsi_cmd.c

@@ -380,12 +380,11 @@ int dsi_vc_generic_read(struct intel_dsi *intel_dsi, int channel,
  *
  * XXX: commands with data in MIPI_DPI_DATA?
  */
-int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs)
+int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs, enum port port)
 {
 	struct drm_encoder *encoder = &intel_dsi->base.base;
 	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	enum port port;
 	u32 mask;
 
 	/* XXX: pipe, hs */
@@ -394,23 +393,18 @@ int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs)
 	else
 		cmd |= DPI_LP_MODE;
 
-	for_each_dsi_port(port, intel_dsi->ports) {
-		/* clear bit */
-		I915_WRITE(MIPI_INTR_STAT(port), SPL_PKT_SENT_INTERRUPT);
+	/* clear bit */
+	I915_WRITE(MIPI_INTR_STAT(port), SPL_PKT_SENT_INTERRUPT);
 
-		/* XXX: old code skips write if control unchanged */
-		if (cmd == I915_READ(MIPI_DPI_CONTROL(port)))
-			DRM_ERROR("Same special packet %02x twice in a row.\n",
-									cmd);
+	/* XXX: old code skips write if control unchanged */
+	if (cmd == I915_READ(MIPI_DPI_CONTROL(port)))
+		DRM_ERROR("Same special packet %02x twice in a row.\n", cmd);
 
-		I915_WRITE(MIPI_DPI_CONTROL(port), cmd);
+	I915_WRITE(MIPI_DPI_CONTROL(port), cmd);
 
-		mask = SPL_PKT_SENT_INTERRUPT;
-		if (wait_for((I915_READ(MIPI_INTR_STAT(port)) & mask) == mask,
-									100))
-			DRM_ERROR("Video mode command 0x%08x send failed.\n",
-									cmd);
-	}
+	mask = SPL_PKT_SENT_INTERRUPT;
+	if (wait_for((I915_READ(MIPI_INTR_STAT(port)) & mask) == mask, 100))
+		DRM_ERROR("Video mode command 0x%08x send failed.\n", cmd);
 
 	return 0;
 }

drivers/gpu/drm/i915/intel_dsi_cmd.h

@@ -51,7 +51,7 @@ int dsi_vc_dcs_read(struct intel_dsi *intel_dsi, int channel, u8 dcs_cmd,
 int dsi_vc_generic_read(struct intel_dsi *intel_dsi, int channel,
 		u8 *reqdata, int reqlen, u8 *buf, int buflen, enum port port);
 
-int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs);
+int dpi_send_cmd(struct intel_dsi *intel_dsi, u32 cmd, bool hs, enum port port);
 void wait_for_dsi_fifo_empty(struct intel_dsi *intel_dsi);
 
 /* XXX: questionable write helpers */