drm/msm/dsi: Add a mdp4 encoder for DSI

Create an mdp4 incoder for DSI. Only DSI video mode is supported as of
now.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Vinay Simha BN <vinaysimha@inforcecomputing.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/Makefile

@@ -54,6 +54,7 @@ msm-$(CONFIG_DRM_FBDEV_EMULATION) += msm_fbdev.o
 msm-$(CONFIG_COMMON_CLK) += mdp/mdp4/mdp4_lvds_pll.o
 
 msm-$(CONFIG_DRM_MSM_DSI) += dsi/dsi.o \
+			mdp/mdp4/mdp4_dsi_encoder.o \
 			dsi/dsi_cfg.o \
 			dsi/dsi_host.o \
 			dsi/dsi_manager.o \

drivers/gpu/drm/msm/mdp/mdp4/mdp4_dsi_encoder.c

@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014, Inforce Computing. All rights reserved.
+ *
+ * Author: Vinay Simha <vinaysimha@inforcecomputing.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mdp4_kms.h"
+
+#include "drm_crtc.h"
+#include "drm_crtc_helper.h"
+
+struct mdp4_dsi_encoder {
+	struct drm_encoder base;
+	struct drm_panel *panel;
+	bool enabled;
+};
+#define to_mdp4_dsi_encoder(x) container_of(x, struct mdp4_dsi_encoder, base)
+
+static struct mdp4_kms *get_kms(struct drm_encoder *encoder)
+{
+	struct msm_drm_private *priv = encoder->dev->dev_private;
+	return to_mdp4_kms(to_mdp_kms(priv->kms));
+}
+
+static void mdp4_dsi_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);
+
+	drm_encoder_cleanup(encoder);
+	kfree(mdp4_dsi_encoder);
+}
+
+static const struct drm_encoder_funcs mdp4_dsi_encoder_funcs = {
+	.destroy = mdp4_dsi_encoder_destroy,
+};
+
+static bool mdp4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
+					const struct drm_display_mode *mode,
+					struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void mdp4_dsi_encoder_mode_set(struct drm_encoder *encoder,
+				      struct drm_display_mode *mode,
+				      struct drm_display_mode *adjusted_mode)
+{
+	struct mdp4_kms *mdp4_kms = get_kms(encoder);
+	uint32_t dsi_hsync_skew, vsync_period, vsync_len, ctrl_pol;
+	uint32_t display_v_start, display_v_end;
+	uint32_t hsync_start_x, hsync_end_x;
+
+	mode = adjusted_mode;
+
+	DBG("set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
+			mode->base.id, mode->name,
+			mode->vrefresh, mode->clock,
+			mode->hdisplay, mode->hsync_start,
+			mode->hsync_end, mode->htotal,
+			mode->vdisplay, mode->vsync_start,
+			mode->vsync_end, mode->vtotal,
+			mode->type, mode->flags);
+
+	ctrl_pol = 0;
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+		ctrl_pol |= MDP4_DSI_CTRL_POLARITY_HSYNC_LOW;
+	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+		ctrl_pol |= MDP4_DSI_CTRL_POLARITY_VSYNC_LOW;
+	/* probably need to get DATA_EN polarity from panel.. */
+
+	dsi_hsync_skew = 0;  /* get this from panel? */
+
+	hsync_start_x = (mode->htotal - mode->hsync_start);
+	hsync_end_x = mode->htotal - (mode->hsync_start - mode->hdisplay) - 1;
+
+	vsync_period = mode->vtotal * mode->htotal;
+	vsync_len = (mode->vsync_end - mode->vsync_start) * mode->htotal;
+	display_v_start = (mode->vtotal - mode->vsync_start) * mode->htotal + dsi_hsync_skew;
+	display_v_end = vsync_period - ((mode->vsync_start - mode->vdisplay) * mode->htotal) + dsi_hsync_skew - 1;
+
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_HSYNC_CTRL,
+			MDP4_DSI_HSYNC_CTRL_PULSEW(mode->hsync_end - mode->hsync_start) |
+			MDP4_DSI_HSYNC_CTRL_PERIOD(mode->htotal));
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_VSYNC_PERIOD, vsync_period);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_VSYNC_LEN, vsync_len);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_HCTRL,
+			MDP4_DSI_DISPLAY_HCTRL_START(hsync_start_x) |
+			MDP4_DSI_DISPLAY_HCTRL_END(hsync_end_x));
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_VSTART, display_v_start);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_VEND, display_v_end);
+
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_CTRL_POLARITY, ctrl_pol);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_UNDERFLOW_CLR,
+			MDP4_DSI_UNDERFLOW_CLR_ENABLE_RECOVERY |
+			MDP4_DSI_UNDERFLOW_CLR_COLOR(0xff));
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_HCTL,
+			MDP4_DSI_ACTIVE_HCTL_START(0) |
+			MDP4_DSI_ACTIVE_HCTL_END(0));
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_HSYNC_SKEW, dsi_hsync_skew);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_BORDER_CLR, 0);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_VSTART, 0);
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_VEND, 0);
+}
+
+static void mdp4_dsi_encoder_disable(struct drm_encoder *encoder)
+{
+	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);
+	struct mdp4_kms *mdp4_kms = get_kms(encoder);
+
+	if (!mdp4_dsi_encoder->enabled)
+		return;
+
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_ENABLE, 0);
+
+	/*
+	 * Wait for a vsync so we know the ENABLE=0 latched before
+	 * the (connector) source of the vsync's gets disabled,
+	 * otherwise we end up in a funny state if we re-enable
+	 * before the disable latches, which results that some of
+	 * the settings changes for the new modeset (like new
+	 * scanout buffer) don't latch properly..
+	 */
+	mdp_irq_wait(&mdp4_kms->base, MDP4_IRQ_PRIMARY_VSYNC);
+
+	mdp4_dsi_encoder->enabled = false;
+}
+
+static void mdp4_dsi_encoder_enable(struct drm_encoder *encoder)
+{
+	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);
+	struct mdp4_kms *mdp4_kms = get_kms(encoder);
+
+	if (mdp4_dsi_encoder->enabled)
+		return;
+
+	 mdp4_crtc_set_config(encoder->crtc,
+			MDP4_DMA_CONFIG_PACK_ALIGN_MSB |
+			MDP4_DMA_CONFIG_DEFLKR_EN |
+			MDP4_DMA_CONFIG_DITHER_EN |
+			MDP4_DMA_CONFIG_R_BPC(BPC8) |
+			MDP4_DMA_CONFIG_G_BPC(BPC8) |
+			MDP4_DMA_CONFIG_B_BPC(BPC8) |
+			MDP4_DMA_CONFIG_PACK(0x21));
+
+	mdp4_crtc_set_intf(encoder->crtc, INTF_DSI_VIDEO, 0);
+
+	mdp4_write(mdp4_kms, REG_MDP4_DSI_ENABLE, 1);
+
+	mdp4_dsi_encoder->enabled = true;
+}
+
+static const struct drm_encoder_helper_funcs mdp4_dsi_encoder_helper_funcs = {
+	.mode_fixup = mdp4_dsi_encoder_mode_fixup,
+	.mode_set = mdp4_dsi_encoder_mode_set,
+	.disable = mdp4_dsi_encoder_disable,
+	.enable = mdp4_dsi_encoder_enable,
+};
+
+/* initialize encoder */
+struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev)
+{
+	struct drm_encoder *encoder = NULL;
+	struct mdp4_dsi_encoder *mdp4_dsi_encoder;
+	int ret;
+
+	mdp4_dsi_encoder = kzalloc(sizeof(*mdp4_dsi_encoder), GFP_KERNEL);
+	if (!mdp4_dsi_encoder) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	encoder = &mdp4_dsi_encoder->base;
+
+	drm_encoder_init(dev, encoder, &mdp4_dsi_encoder_funcs,
+			 DRM_MODE_ENCODER_DSI);
+	drm_encoder_helper_add(encoder, &mdp4_dsi_encoder_helper_funcs);
+
+	return encoder;
+
+fail:
+	if (encoder)
+		mdp4_dsi_encoder_destroy(encoder);
+
+	return ERR_PTR(ret);
+}

drivers/gpu/drm/msm/mdp/mdp4/mdp4_kms.h

@@ -217,6 +217,15 @@ struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev,
 struct drm_connector *mdp4_lvds_connector_init(struct drm_device *dev,
 		struct device_node *panel_node, struct drm_encoder *encoder);
 
+#ifdef CONFIG_DRM_MSM_DSI
+struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev);
+#else
+static inline struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif
+
 #ifdef CONFIG_COMMON_CLK
 struct clk *mpd4_lvds_pll_init(struct drm_device *dev);
 #else