drm/rcar-du: Add internal LVDS encoder support

The R8A7790 includes two internal LVDS encoders. Support them in the DU
driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

drivers/gpu/drm/rcar-du/Kconfig

@@ -7,3 +7,10 @@ config DRM_RCAR_DU
 	help
 	  Choose this option if you have an R-Car chipset.
 	  If M is selected the module will be called rcar-du-drm.
+
+config DRM_RCAR_LVDS
+	bool "R-Car DU LVDS Encoder Support"
+	depends on DRM_RCAR_DU
+	help
+	  Enable support the R-Car Display Unit embedded LVDS encoders
+	  (currently only on R8A7790).

drivers/gpu/drm/rcar-du/Makefile

@@ -7,4 +7,6 @@ rcar-du-drm-y := rcar_du_crtc.o \
 		 rcar_du_plane.o \
 		 rcar_du_vgacon.o
 
-obj-$(CONFIG_DRM_RCAR_DU)	+= rcar-du-drm.o
+rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS)	+= rcar_du_lvdsenc.o
+
+obj-$(CONFIG_DRM_RCAR_DU)		+= rcar-du-drm.o

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

@@ -26,8 +26,6 @@
 #include "rcar_du_plane.h"
 #include "rcar_du_regs.h"
 
-#define to_rcar_crtc(c)	container_of(c, struct rcar_du_crtc, crtc)
-
 static u32 rcar_du_crtc_read(struct rcar_du_crtc *rcrtc, u32 reg)
 {
 	struct rcar_du_device *rcdu = rcrtc->group->dev;

drivers/gpu/drm/rcar-du/rcar_du_crtc.h

@@ -39,6 +39,8 @@ struct rcar_du_crtc {
 	struct rcar_du_plane *plane;
 };
 
+#define to_rcar_crtc(c)	container_of(c, struct rcar_du_crtc, crtc)
+
 int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index);
 void rcar_du_crtc_enable_vblank(struct rcar_du_crtc *rcrtc, bool enable);
 void rcar_du_crtc_cancel_page_flip(struct rcar_du_crtc *rcrtc,

drivers/gpu/drm/rcar-du/rcar_du_drv.c

@@ -232,6 +232,7 @@ static const struct rcar_du_device_info rcar_du_r8a7779_info = {
 			.encoder_type = DRM_MODE_ENCODER_NONE,
 		},
 	},
+	.num_lvds = 0,
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7790_info = {
@@ -255,6 +256,7 @@ static const struct rcar_du_device_info rcar_du_r8a7790_info = {
 			.encoder_type = DRM_MODE_ENCODER_LVDS,
 		},
 	},
+	.num_lvds = 2,
 };
 
 static const struct platform_device_id rcar_du_id_table[] = {

drivers/gpu/drm/rcar-du/rcar_du_drv.h

@@ -24,6 +24,7 @@ struct clk;
 struct device;
 struct drm_device;
 struct rcar_du_device;
+struct rcar_du_lvdsenc;
 
 #define RCAR_DU_FEATURE_CRTC_IRQ_CLOCK	(1 << 0)	/* Per-CRTC IRQ and clock */
 #define RCAR_DU_FEATURE_ALIGN_128B	(1 << 1)	/* Align pitches to 128 bytes */
@@ -48,11 +49,13 @@ struct rcar_du_output_routing {
  * @features: device features (RCAR_DU_FEATURE_*)
  * @num_crtcs: total number of CRTCs
  * @routes: array of CRTC to output routes, indexed by output (RCAR_DU_OUTPUT_*)
+ * @num_lvds: number of internal LVDS encoders
  */
 struct rcar_du_device_info {
 	unsigned int features;
 	unsigned int num_crtcs;
 	struct rcar_du_output_routing routes[RCAR_DU_OUTPUT_MAX];
+	unsigned int num_lvds;
 };
 
 struct rcar_du_device {
@@ -70,6 +73,7 @@ struct rcar_du_device {
 	struct rcar_du_group groups[2];
 
 	unsigned int dpad0_source;
+	struct rcar_du_lvdsenc *lvds[2];
 };
 
 static inline bool rcar_du_has(struct rcar_du_device *rcdu,

drivers/gpu/drm/rcar-du/rcar_du_encoder.c

@@ -11,6 +11,8 @@
  * (at your option) any later version.
  */
 
+#include <linux/export.h>
+
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
@@ -19,6 +21,7 @@
 #include "rcar_du_encoder.h"
 #include "rcar_du_kms.h"
 #include "rcar_du_lvdscon.h"
+#include "rcar_du_lvdsenc.h"
 #include "rcar_du_vgacon.h"
 
 /* -----------------------------------------------------------------------------
@@ -39,12 +42,17 @@ rcar_du_connector_best_encoder(struct drm_connector *connector)
 
 static void rcar_du_encoder_dpms(struct drm_encoder *encoder, int mode)
 {
+	struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
+
+	if (renc->lvds)
+		rcar_du_lvdsenc_dpms(renc->lvds, encoder->crtc, mode);
 }
 
 static bool rcar_du_encoder_mode_fixup(struct drm_encoder *encoder,
 				       const struct drm_display_mode *mode,
 				       struct drm_display_mode *adjusted_mode)
 {
+	struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
 	const struct drm_display_mode *panel_mode;
 	struct drm_device *dev = encoder->dev;
 	struct drm_connector *connector;
@@ -82,15 +90,32 @@ static bool rcar_du_encoder_mode_fixup(struct drm_encoder *encoder,
 	/* The flat panel mode is fixed, just copy it to the adjusted mode. */
 	drm_mode_copy(adjusted_mode, panel_mode);
 
+	/* The internal LVDS encoder has a clock frequency operating range of
+	 * 30MHz to 150MHz. Clamp the clock accordingly.
+	 */
+	if (renc->lvds)
+		adjusted_mode->clock = clamp(adjusted_mode->clock,
+					     30000, 150000);
+
 	return true;
 }
 
 static void rcar_du_encoder_mode_prepare(struct drm_encoder *encoder)
 {
+	struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
+
+	if (renc->lvds)
+		rcar_du_lvdsenc_dpms(renc->lvds, encoder->crtc,
+				     DRM_MODE_DPMS_OFF);
 }
 
 static void rcar_du_encoder_mode_commit(struct drm_encoder *encoder)
 {
+	struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
+
+	if (renc->lvds)
+		rcar_du_lvdsenc_dpms(renc->lvds, encoder->crtc,
+				     DRM_MODE_DPMS_ON);
 }
 
 static void rcar_du_encoder_mode_set(struct drm_encoder *encoder,
@@ -129,6 +154,19 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 
 	renc->output = output;
 
+	switch (output) {
+	case RCAR_DU_OUTPUT_LVDS0:
+		renc->lvds = rcdu->lvds[0];
+		break;
+
+	case RCAR_DU_OUTPUT_LVDS1:
+		renc->lvds = rcdu->lvds[1];
+		break;
+
+	default:
+		break;
+	}
+
 	switch (type) {
 	case RCAR_DU_ENCODER_VGA:
 		encoder_type = DRM_MODE_ENCODER_DAC;

drivers/gpu/drm/rcar-du/rcar_du_encoder.h

@@ -19,10 +19,12 @@
 #include <drm/drm_crtc.h>
 
 struct rcar_du_device;
+struct rcar_du_lvdsenc;
 
 struct rcar_du_encoder {
 	struct drm_encoder encoder;
 	enum rcar_du_output output;
+	struct rcar_du_lvdsenc *lvds;
 };
 
 #define to_rcar_encoder(e) \

drivers/gpu/drm/rcar-du/rcar_du_kms.c

@@ -21,6 +21,7 @@
 #include "rcar_du_drv.h"
 #include "rcar_du_encoder.h"
 #include "rcar_du_kms.h"
+#include "rcar_du_lvdsenc.h"
 #include "rcar_du_regs.h"
 
 /* -----------------------------------------------------------------------------
@@ -217,6 +218,10 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 	}
 
 	/* Initialize the encoders. */
+	ret = rcar_du_lvdsenc_init(rcdu);
+	if (ret < 0)
+		return ret;
+
 	for (i = 0; i < rcdu->pdata->num_encoders; ++i) {
 		const struct rcar_du_encoder_data *pdata =
 			&rcdu->pdata->encoders[i];

drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c

@@ -0,0 +1,196 @@
+/*
+ * rcar_du_lvdsenc.c  --  R-Car Display Unit LVDS Encoder
+ *
+ * Copyright (C) 2013 Renesas Corporation
+ *
+ * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "rcar_du_drv.h"
+#include "rcar_du_encoder.h"
+#include "rcar_du_lvdsenc.h"
+#include "rcar_lvds_regs.h"
+
+struct rcar_du_lvdsenc {
+	struct rcar_du_device *dev;
+
+	unsigned int index;
+	void __iomem *mmio;
+	struct clk *clock;
+	int dpms;
+
+	enum rcar_lvds_input input;
+};
+
+static void rcar_lvds_write(struct rcar_du_lvdsenc *lvds, u32 reg, u32 data)
+{
+	iowrite32(data, lvds->mmio + reg);
+}
+
+static int rcar_du_lvdsenc_start(struct rcar_du_lvdsenc *lvds,
+				 struct rcar_du_crtc *rcrtc)
+{
+	const struct drm_display_mode *mode = &rcrtc->crtc.mode;
+	unsigned int freq = mode->clock;
+	u32 lvdcr0;
+	u32 pllcr;
+	int ret;
+
+	if (lvds->dpms == DRM_MODE_DPMS_ON)
+		return 0;
+
+	ret = clk_prepare_enable(lvds->clock);
+	if (ret < 0)
+		return ret;
+
+	/* PLL clock configuration */
+	if (freq <= 38000)
+		pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_38M;
+	else if (freq <= 60000)
+		pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_60M;
+	else if (freq <= 121000)
+		pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_121M;
+	else
+		pllcr = LVDPLLCR_PLLDLYCNT_150M;
+
+	rcar_lvds_write(lvds, LVDPLLCR, pllcr);
+
+	/* Hardcode the channels and control signals routing for now.
+	 *
+	 * HSYNC -> CTRL0
+	 * VSYNC -> CTRL1
+	 * DISP  -> CTRL2
+	 * 0     -> CTRL3
+	 *
+	 * Channels 1 and 3 are switched on ES1.
+	 */
+	rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
+			LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
+			LVDCTRCR_CTR0SEL_HSYNC);
+	rcar_lvds_write(lvds, LVDCHCR,
+			LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3) |
+			LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1));
+
+	/* Select the input, hardcode mode 0, enable LVDS operation and turn
+	 * bias circuitry on.
+	 */
+	lvdcr0 = LVDCR0_BEN | LVDCR0_LVEN;
+	if (rcrtc->index == 2)
+		lvdcr0 |= LVDCR0_DUSEL;
+	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
+	/* Turn all the channels on. */
+	rcar_lvds_write(lvds, LVDCR1, LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
+			LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
+
+	/* Turn the PLL on, wait for the startup delay, and turn the output
+	 * on.
+	 */
+	lvdcr0 |= LVDCR0_PLLEN;
+	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
+	usleep_range(100, 150);
+
+	lvdcr0 |= LVDCR0_LVRES;
+	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
+	lvds->dpms = DRM_MODE_DPMS_ON;
+	return 0;
+}
+
+static void rcar_du_lvdsenc_stop(struct rcar_du_lvdsenc *lvds)
+{
+	if (lvds->dpms == DRM_MODE_DPMS_OFF)
+		return;
+
+	rcar_lvds_write(lvds, LVDCR0, 0);
+	rcar_lvds_write(lvds, LVDCR1, 0);
+
+	clk_disable_unprepare(lvds->clock);
+
+	lvds->dpms = DRM_MODE_DPMS_OFF;
+}
+
+int rcar_du_lvdsenc_dpms(struct rcar_du_lvdsenc *lvds,
+			 struct drm_crtc *crtc, int mode)
+{
+	if (mode == DRM_MODE_DPMS_OFF) {
+		rcar_du_lvdsenc_stop(lvds);
+		return 0;
+	} else if (crtc) {
+		struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+		return rcar_du_lvdsenc_start(lvds, rcrtc);
+	} else
+		return -EINVAL;
+}
+
+static int rcar_du_lvdsenc_get_resources(struct rcar_du_lvdsenc *lvds,
+					 struct platform_device *pdev)
+{
+	struct resource *mem;
+	char name[7];
+
+	sprintf(name, "lvds.%u", lvds->index);
+
+	mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+	if (mem == NULL) {
+		dev_err(&pdev->dev, "failed to get memory resource for %s\n",
+			name);
+		return -EINVAL;
+	}
+
+	lvds->mmio = devm_ioremap_resource(&pdev->dev, mem);
+	if (lvds->mmio == NULL) {
+		dev_err(&pdev->dev, "failed to remap memory resource for %s\n",
+			name);
+		return -ENOMEM;
+	}
+
+	lvds->clock = devm_clk_get(&pdev->dev, name);
+	if (IS_ERR(lvds->clock)) {
+		dev_err(&pdev->dev, "failed to get clock for %s\n", name);
+		return PTR_ERR(lvds->clock);
+	}
+
+	return 0;
+}
+
+int rcar_du_lvdsenc_init(struct rcar_du_device *rcdu)
+{
+	struct platform_device *pdev = to_platform_device(rcdu->dev);
+	struct rcar_du_lvdsenc *lvds;
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < rcdu->info->num_lvds; ++i) {
+		lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
+		if (lvds == NULL) {
+			dev_err(&pdev->dev, "failed to allocate private data\n");
+			return -ENOMEM;
+		}
+
+		lvds->dev = rcdu;
+		lvds->index = i;
+		lvds->input = i ? RCAR_LVDS_INPUT_DU1 : RCAR_LVDS_INPUT_DU0;
+		lvds->dpms = DRM_MODE_DPMS_OFF;
+
+		ret = rcar_du_lvdsenc_get_resources(lvds, pdev);
+		if (ret < 0)
+			return ret;
+
+		rcdu->lvds[i] = lvds;
+	}
+
+	return 0;
+}