drm/sun4i: Tie the DSI controller in the TCON

The DSI controller needs a particular interface (CPU aka 8080) with some
modifications from the TCON in order to run.

Make sure the TCON is able to provide it when we are using the DSI output.
Reviewed-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/129f5928113d2ca865bf5269047c2e4ba6fed5e6.1522835818.git-series.maxime.ripard@bootlin.com

drivers/gpu/drm/sun4i/sun4i_tcon.c

@@ -35,6 +35,7 @@
 #include "sun4i_lvds.h"
 #include "sun4i_rgb.h"
 #include "sun4i_tcon.h"
+#include "sun6i_mipi_dsi.h"
 #include "sunxi_engine.h"
 
 static struct drm_connector *sun4i_tcon_get_connector(const struct drm_encoder *encoder)
@@ -169,6 +170,7 @@ void sun4i_tcon_set_status(struct sun4i_tcon *tcon,
 	case DRM_MODE_ENCODER_LVDS:
 		is_lvds = true;
 		/* Fallthrough */
+	case DRM_MODE_ENCODER_DSI:
 	case DRM_MODE_ENCODER_NONE:
 		channel = 0;
 		break;
@@ -274,6 +276,71 @@ static void sun4i_tcon0_mode_set_common(struct sun4i_tcon *tcon,
 		     SUN4I_TCON0_BASIC0_Y(mode->crtc_vdisplay));
 }
 
+static void sun4i_tcon0_mode_set_cpu(struct sun4i_tcon *tcon,
+				     struct mipi_dsi_device *device,
+				     const struct drm_display_mode *mode)
+{
+	u8 bpp = mipi_dsi_pixel_format_to_bpp(device->format);
+	u8 lanes = device->lanes;
+	u32 block_space, start_delay;
+	u32 tcon_div;
+
+	tcon->dclk_min_div = 4;
+	tcon->dclk_max_div = 127;
+
+	sun4i_tcon0_mode_set_common(tcon, mode);
+
+	regmap_update_bits(tcon->regs, SUN4I_TCON0_CTL_REG,
+			   SUN4I_TCON0_CTL_IF_MASK,
+			   SUN4I_TCON0_CTL_IF_8080);
+
+	regmap_write(tcon->regs, SUN4I_TCON_ECC_FIFO_REG,
+		     SUN4I_TCON_ECC_FIFO_EN);
+
+	regmap_write(tcon->regs, SUN4I_TCON0_CPU_IF_REG,
+		     SUN4I_TCON0_CPU_IF_MODE_DSI |
+		     SUN4I_TCON0_CPU_IF_TRI_FIFO_FLUSH |
+		     SUN4I_TCON0_CPU_IF_TRI_FIFO_EN |
+		     SUN4I_TCON0_CPU_IF_TRI_EN);
+
+	/*
+	 * This looks suspicious, but it works...
+	 *
+	 * The datasheet says that this should be set higher than 20 *
+	 * pixel cycle, but it's not clear what a pixel cycle is.
+	 */
+	regmap_read(tcon->regs, SUN4I_TCON0_DCLK_REG, &tcon_div);
+	tcon_div &= GENMASK(6, 0);
+	block_space = mode->htotal * bpp / (tcon_div * lanes);
+	block_space -= mode->hdisplay + 40;
+
+	regmap_write(tcon->regs, SUN4I_TCON0_CPU_TRI0_REG,
+		     SUN4I_TCON0_CPU_TRI0_BLOCK_SPACE(block_space) |
+		     SUN4I_TCON0_CPU_TRI0_BLOCK_SIZE(mode->hdisplay));
+
+	regmap_write(tcon->regs, SUN4I_TCON0_CPU_TRI1_REG,
+		     SUN4I_TCON0_CPU_TRI1_BLOCK_NUM(mode->vdisplay));
+
+	start_delay = (mode->crtc_vtotal - mode->crtc_vdisplay - 10 - 1);
+	start_delay = start_delay * mode->crtc_htotal * 149;
+	start_delay = start_delay / (mode->crtc_clock / 1000) / 8;
+	regmap_write(tcon->regs, SUN4I_TCON0_CPU_TRI2_REG,
+		     SUN4I_TCON0_CPU_TRI2_TRANS_START_SET(10) |
+		     SUN4I_TCON0_CPU_TRI2_START_DELAY(start_delay));
+
+	/*
+	 * The Allwinner BSP has a comment that the period should be
+	 * the display clock * 15, but uses an hardcoded 3000...
+	 */
+	regmap_write(tcon->regs, SUN4I_TCON_SAFE_PERIOD_REG,
+		     SUN4I_TCON_SAFE_PERIOD_NUM(3000) |
+		     SUN4I_TCON_SAFE_PERIOD_MODE(3));
+
+	/* Enable the output on the pins */
+	regmap_write(tcon->regs, SUN4I_TCON0_IO_TRI_REG,
+		     0xe0000000);
+}
+
 static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon,
 				      const struct drm_encoder *encoder,
 				      const struct drm_display_mode *mode)
@@ -539,7 +606,17 @@ void sun4i_tcon_mode_set(struct sun4i_tcon *tcon,
 			 const struct drm_encoder *encoder,
 			 const struct drm_display_mode *mode)
 {
+	struct sun6i_dsi *dsi;
+
 	switch (encoder->encoder_type) {
+	case DRM_MODE_ENCODER_DSI:
+		/*
+		 * This is not really elegant, but it's the "cleaner"
+		 * way I could think of...
+		 */
+		dsi = encoder_to_sun6i_dsi(encoder);
+		sun4i_tcon0_mode_set_cpu(tcon, dsi->device, mode);
+		break;
 	case DRM_MODE_ENCODER_LVDS:
 		sun4i_tcon0_mode_set_lvds(tcon, encoder, mode);
 		break;

drivers/gpu/drm/sun4i/sun4i_tcon.h

@@ -35,10 +35,25 @@
 #define SUN4I_TCON_GINT0_TCON0_TRI_COUNTER_INT		BIT(10)
 
 #define SUN4I_TCON_GINT1_REG			0x8
+
 #define SUN4I_TCON_FRM_CTL_REG			0x10
+#define SUN4I_TCON_FRM_CTL_EN				BIT(31)
+
+#define SUN4I_TCON_FRM_SEED_PR_REG		0x14
+#define SUN4I_TCON_FRM_SEED_PG_REG		0x18
+#define SUN4I_TCON_FRM_SEED_PB_REG		0x1c
+#define SUN4I_TCON_FRM_SEED_LR_REG		0x20
+#define SUN4I_TCON_FRM_SEED_LG_REG		0x24
+#define SUN4I_TCON_FRM_SEED_LB_REG		0x28
+#define SUN4I_TCON_FRM_TBL0_REG			0x2c
+#define SUN4I_TCON_FRM_TBL1_REG			0x30
+#define SUN4I_TCON_FRM_TBL2_REG			0x34
+#define SUN4I_TCON_FRM_TBL3_REG			0x38
 
 #define SUN4I_TCON0_CTL_REG			0x40
 #define SUN4I_TCON0_CTL_TCON_ENABLE			BIT(31)
+#define SUN4I_TCON0_CTL_IF_MASK				GENMASK(25, 24)
+#define SUN4I_TCON0_CTL_IF_8080				(1 << 24)
 #define SUN4I_TCON0_CTL_CLK_DELAY_MASK			GENMASK(8, 4)
 #define SUN4I_TCON0_CTL_CLK_DELAY(delay)		((delay << 4) & SUN4I_TCON0_CTL_CLK_DELAY_MASK)
 #define SUN4I_TCON0_CTL_SRC_SEL_MASK			GENMASK(2, 0)
@@ -65,7 +80,14 @@
 #define SUN4I_TCON0_BASIC3_V_SYNC(height)		(((height) - 1) & 0x7ff)
 
 #define SUN4I_TCON0_HV_IF_REG			0x58
+
 #define SUN4I_TCON0_CPU_IF_REG			0x60
+#define SUN4I_TCON0_CPU_IF_MODE_MASK			GENMASK(31, 28)
+#define SUN4I_TCON0_CPU_IF_MODE_DSI			(1 << 28)
+#define SUN4I_TCON0_CPU_IF_TRI_FIFO_FLUSH		BIT(16)
+#define SUN4I_TCON0_CPU_IF_TRI_FIFO_EN			BIT(2)
+#define SUN4I_TCON0_CPU_IF_TRI_EN			BIT(0)
+
 #define SUN4I_TCON0_CPU_WR_REG			0x64
 #define SUN4I_TCON0_CPU_RD0_REG			0x68
 #define SUN4I_TCON0_CPU_RDA_REG			0x6c
@@ -132,6 +154,10 @@
 
 #define SUN4I_TCON1_IO_POL_REG			0xf0
 #define SUN4I_TCON1_IO_TRI_REG			0xf4
+
+#define SUN4I_TCON_ECC_FIFO_REG			0xf8
+#define SUN4I_TCON_ECC_FIFO_EN				BIT(3)
+
 #define SUN4I_TCON_CEU_CTL_REG			0x100
 #define SUN4I_TCON_CEU_MUL_RR_REG		0x110
 #define SUN4I_TCON_CEU_MUL_RG_REG		0x114
@@ -148,6 +174,22 @@
 #define SUN4I_TCON_CEU_RANGE_R_REG		0x140
 #define SUN4I_TCON_CEU_RANGE_G_REG		0x144
 #define SUN4I_TCON_CEU_RANGE_B_REG		0x148
+
+#define SUN4I_TCON0_CPU_TRI0_REG		0x160
+#define SUN4I_TCON0_CPU_TRI0_BLOCK_SPACE(space)		((((space) - 1) & 0xfff) << 16)
+#define SUN4I_TCON0_CPU_TRI0_BLOCK_SIZE(size)		(((size) - 1) & 0xfff)
+
+#define SUN4I_TCON0_CPU_TRI1_REG		0x164
+#define SUN4I_TCON0_CPU_TRI1_BLOCK_NUM(num)		(((num) - 1) & 0xffff)
+
+#define SUN4I_TCON0_CPU_TRI2_REG		0x168
+#define SUN4I_TCON0_CPU_TRI2_START_DELAY(delay)		(((delay) & 0xffff) << 16)
+#define SUN4I_TCON0_CPU_TRI2_TRANS_START_SET(set)	((set) & 0xfff)
+
+#define SUN4I_TCON_SAFE_PERIOD_REG		0x1f0
+#define SUN4I_TCON_SAFE_PERIOD_NUM(num)			(((num) & 0xfff) << 16)
+#define SUN4I_TCON_SAFE_PERIOD_MODE(mode)		((mode) & 0x3)
+
 #define SUN4I_TCON_MUX_CTRL_REG			0x200
 
 #define SUN4I_TCON0_LVDS_ANA0_REG		0x220