drm/i915/bxt: DSI prepare changes for BXT

This patch modifies dsi_prepare() function to support the same
modeset prepare sequence for BXT also. Main changes are:
1. BXT port control register is different than VLV.
2. BXT modeset sequence needs vdisplay and hdisplay programmed
   for transcoder.
3. BXT can select PIPE for MIPI transcoders.
4. BXT needs to program register MIPI_INIT_COUNT for both the ports,
   even if only one is being used.

v2: Fixed Jani's review comments. Rectified the DSI Macros to get
    proper register offsets using _MIPI_PORT instead of _TRANSCODER

v3: Rebased on latest drm-nightly branch. Fixed Jani's review comments.
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -7507,6 +7507,22 @@ enum skl_disp_power_wells {
 
 #define _MIPI_PORT(port, a, c)	_PORT3(port, a, 0, c)	/* ports A and C only */
 
+/* BXT MIPI mode configure */
+#define  _BXT_MIPIA_TRANS_HACTIVE			0x6B0F8
+#define  _BXT_MIPIC_TRANS_HACTIVE			0x6B8F8
+#define  BXT_MIPI_TRANS_HACTIVE(tc)	_MIPI_PORT(tc, \
+		_BXT_MIPIA_TRANS_HACTIVE, _BXT_MIPIC_TRANS_HACTIVE)
+
+#define  _BXT_MIPIA_TRANS_VACTIVE			0x6B0FC
+#define  _BXT_MIPIC_TRANS_VACTIVE			0x6B8FC
+#define  BXT_MIPI_TRANS_VACTIVE(tc)	_MIPI_PORT(tc, \
+		_BXT_MIPIA_TRANS_VACTIVE, _BXT_MIPIC_TRANS_VACTIVE)
+
+#define  _BXT_MIPIA_TRANS_VTOTAL			0x6B100
+#define  _BXT_MIPIC_TRANS_VTOTAL			0x6B900
+#define  BXT_MIPI_TRANS_VTOTAL(tc)	_MIPI_PORT(tc, \
+		_BXT_MIPIA_TRANS_VTOTAL, _BXT_MIPIC_TRANS_VTOTAL)
+
 #define BXT_DSI_PLL_CTL			0x161000
 #define  BXT_DSI_PLL_PVD_RATIO_SHIFT	16
 #define  BXT_DSI_PLL_PVD_RATIO_MASK	(3 << BXT_DSI_PLL_PVD_RATIO_SHIFT)
@@ -7942,6 +7958,11 @@ enum skl_disp_power_wells {
 #define  READ_REQUEST_PRIORITY_HIGH			(3 << 3)
 #define  RGB_FLIP_TO_BGR				(1 << 2)
 
+#define  BXT_PIPE_SELECT_MASK				(7 << 7)
+#define  BXT_PIPE_SELECT_C				(2 << 7)
+#define  BXT_PIPE_SELECT_B				(1 << 7)
+#define  BXT_PIPE_SELECT_A				(0 << 7)
+
 #define _MIPIA_DATA_ADDRESS		(dev_priv->mipi_mmio_base + 0xb108)
 #define _MIPIC_DATA_ADDRESS		(dev_priv->mipi_mmio_base + 0xb908)
 #define MIPI_DATA_ADDRESS(port)		_MIPI_PORT(port, _MIPIA_DATA_ADDRESS, \

drivers/gpu/drm/i915/intel_dsi.c

@@ -737,6 +737,21 @@ static void set_dsi_timings(struct drm_encoder *encoder,
 	hbp = txbyteclkhs(hbp, bpp, lane_count, intel_dsi->burst_mode_ratio);
 
 	for_each_dsi_port(port, intel_dsi->ports) {
+		if (IS_BROXTON(dev)) {
+			/*
+			 * Program hdisplay and vdisplay on MIPI transcoder.
+			 * This is different from calculated hactive and
+			 * vactive, as they are calculated per channel basis,
+			 * whereas these values should be based on resolution.
+			 */
+			I915_WRITE(BXT_MIPI_TRANS_HACTIVE(port),
+					mode->hdisplay);
+			I915_WRITE(BXT_MIPI_TRANS_VACTIVE(port),
+					mode->vdisplay);
+			I915_WRITE(BXT_MIPI_TRANS_VTOTAL(port),
+					mode->vtotal);
+		}
+
 		I915_WRITE(MIPI_HACTIVE_AREA_COUNT(port), hactive);
 		I915_WRITE(MIPI_HFP_COUNT(port), hfp);
 
@@ -777,16 +792,39 @@ static void intel_dsi_prepare(struct intel_encoder *intel_encoder)
 	}
 
 	for_each_dsi_port(port, intel_dsi->ports) {
-		/* escape clock divider, 20MHz, shared for A and C.
-		 * device ready must be off when doing this! txclkesc? */
+		if (IS_VALLEYVIEW(dev)) {
+			/*
+			 * escape clock divider, 20MHz, shared for A and C.
+			 * device ready must be off when doing this! txclkesc?
+			 */
 			tmp = I915_READ(MIPI_CTRL(PORT_A));
 			tmp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
-		I915_WRITE(MIPI_CTRL(PORT_A), tmp | ESCAPE_CLOCK_DIVIDER_1);
+			I915_WRITE(MIPI_CTRL(PORT_A), tmp |
+					ESCAPE_CLOCK_DIVIDER_1);
 
 			/* read request priority is per pipe */
 			tmp = I915_READ(MIPI_CTRL(port));
 			tmp &= ~READ_REQUEST_PRIORITY_MASK;
-		I915_WRITE(MIPI_CTRL(port), tmp | READ_REQUEST_PRIORITY_HIGH);
+			I915_WRITE(MIPI_CTRL(port), tmp |
+					READ_REQUEST_PRIORITY_HIGH);
+		} else if (IS_BROXTON(dev)) {
+			/*
+			 * FIXME:
+			 * BXT can connect any PIPE to any MIPI port.
+			 * Select the pipe based on the MIPI port read from
+			 * VBT for now. Pick PIPE A for MIPI port A and C
+			 * for port C.
+			 */
+			tmp = I915_READ(MIPI_CTRL(port));
+			tmp &= ~BXT_PIPE_SELECT_MASK;
+
+			if (port == PORT_A)
+				tmp |= BXT_PIPE_SELECT_A;
+			else if (port == PORT_C)
+				tmp |= BXT_PIPE_SELECT_C;
+
+			I915_WRITE(MIPI_CTRL(port), tmp);
+		}
 
 		/* XXX: why here, why like this? handling in irq handler?! */
 		I915_WRITE(MIPI_INTR_STAT(port), 0xffffffff);
@@ -863,6 +901,17 @@ static void intel_dsi_prepare(struct intel_encoder *intel_encoder)
 		I915_WRITE(MIPI_INIT_COUNT(port),
 				txclkesc(intel_dsi->escape_clk_div, 100));
 
+		if (IS_BROXTON(dev) && (!intel_dsi->dual_link)) {
+			/*
+			 * BXT spec says write MIPI_INIT_COUNT for
+			 * both the ports, even if only one is
+			 * getting used. So write the other port
+			 * if not in dual link mode.
+			 */
+			I915_WRITE(MIPI_INIT_COUNT(port ==
+						PORT_A ? PORT_C : PORT_A),
+					intel_dsi->init_count);
+		}
 
 		/* recovery disables */
 		I915_WRITE(MIPI_EOT_DISABLE(port), tmp);