drm/imx: Add initial support for DCSS on iMX8MQ

This adds initial support for iMX8MQ's Display Controller Subsystem (DCSS).
Some of its capabilities include:
 * 4K@60fps;
 * HDR10;
 * one graphics and 2 video pipelines;
 * on-the-fly decompression of compressed video and graphics;

The reference manual can be found here:
https://www.nxp.com/webapp/Download?colCode=IMX8MDQLQRM

The current patch adds only basic functionality: one primary plane for
graphics, linear, tiled and super-tiled buffers support (no graphics
decompression yet), no HDR10 and no video planes.

Video planes support and HDR10 will be added in subsequent patches once
per-plane de-gamma/CSC/gamma support is in.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200731081836.3048-3-laurentiu.palcu@oss.nxp.com

1 files changed, 180 insertions, 0 deletions

diff --git a/drivers/gpu/drm/imx/dcss/dcss-ss.c b/drivers/gpu/drm/imx/dcss/dcss-ss.c
new file mode 100644
index 000000000000..8ddf08da911b
--- /dev/null
+++ b/drivers/gpu/drm/imx/dcss/dcss-ss.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "dcss-dev.h"
+
+#define DCSS_SS_SYS_CTRL			0x00
+#define   RUN_EN				BIT(0)
+#define DCSS_SS_DISPLAY				0x10
+#define   LRC_X_POS				0
+#define   LRC_X_MASK				GENMASK(12, 0)
+#define   LRC_Y_POS				16
+#define   LRC_Y_MASK				GENMASK(28, 16)
+#define DCSS_SS_HSYNC				0x20
+#define DCSS_SS_VSYNC				0x30
+#define   SYNC_START_POS			0
+#define   SYNC_START_MASK			GENMASK(12, 0)
+#define   SYNC_END_POS				16
+#define   SYNC_END_MASK				GENMASK(28, 16)
+#define   SYNC_POL				BIT(31)
+#define DCSS_SS_DE_ULC				0x40
+#define   ULC_X_POS				0
+#define   ULC_X_MASK				GENMASK(12, 0)
+#define   ULC_Y_POS				16
+#define   ULC_Y_MASK				GENMASK(28, 16)
+#define   ULC_POL				BIT(31)
+#define DCSS_SS_DE_LRC				0x50
+#define DCSS_SS_MODE				0x60
+#define   PIPE_MODE_POS				0
+#define   PIPE_MODE_MASK			GENMASK(1, 0)
+#define DCSS_SS_COEFF				0x70
+#define   HORIZ_A_POS				0
+#define   HORIZ_A_MASK				GENMASK(3, 0)
+#define   HORIZ_B_POS				4
+#define   HORIZ_B_MASK				GENMASK(7, 4)
+#define   HORIZ_C_POS				8
+#define   HORIZ_C_MASK				GENMASK(11, 8)
+#define   HORIZ_H_NORM_POS			12
+#define   HORIZ_H_NORM_MASK			GENMASK(14, 12)
+#define   VERT_A_POS				16
+#define   VERT_A_MASK				GENMASK(19, 16)
+#define   VERT_B_POS				20
+#define   VERT_B_MASK				GENMASK(23, 20)
+#define   VERT_C_POS				24
+#define   VERT_C_MASK				GENMASK(27, 24)
+#define   VERT_H_NORM_POS			28
+#define   VERT_H_NORM_MASK			GENMASK(30, 28)
+#define DCSS_SS_CLIP_CB				0x80
+#define DCSS_SS_CLIP_CR				0x90
+#define   CLIP_MIN_POS				0
+#define   CLIP_MIN_MASK				GENMASK(9, 0)
+#define   CLIP_MAX_POS				0
+#define   CLIP_MAX_MASK				GENMASK(23, 16)
+#define DCSS_SS_INTER_MODE			0xA0
+#define   INT_EN				BIT(0)
+#define   VSYNC_SHIFT				BIT(1)
+
+struct dcss_ss {
+	struct device *dev;
+	void __iomem *base_reg;
+	u32 base_ofs;
+
+	struct dcss_ctxld *ctxld;
+	u32 ctx_id;
+
+	bool in_use;
+};
+
+static void dcss_ss_write(struct dcss_ss *ss, u32 val, u32 ofs)
+{
+	if (!ss->in_use)
+		dcss_writel(val, ss->base_reg + ofs);
+
+	dcss_ctxld_write(ss->ctxld, ss->ctx_id, val,
+			 ss->base_ofs + ofs);
+}
+
+int dcss_ss_init(struct dcss_dev *dcss, unsigned long ss_base)
+{
+	struct dcss_ss *ss;
+
+	ss = kzalloc(sizeof(*ss), GFP_KERNEL);
+	if (!ss)
+		return -ENOMEM;
+
+	dcss->ss = ss;
+	ss->dev = dcss->dev;
+	ss->ctxld = dcss->ctxld;
+
+	ss->base_reg = ioremap(ss_base, SZ_4K);
+	if (!ss->base_reg) {
+		dev_err(dcss->dev, "ss: unable to remap ss base\n");
+		kfree(ss);
+		return -ENOMEM;
+	}
+
+	ss->base_ofs = ss_base;
+	ss->ctx_id = CTX_SB_HP;
+
+	return 0;
+}
+
+void dcss_ss_exit(struct dcss_ss *ss)
+{
+	/* stop SS */
+	dcss_writel(0, ss->base_reg + DCSS_SS_SYS_CTRL);
+
+	if (ss->base_reg)
+		iounmap(ss->base_reg);
+
+	kfree(ss);
+}
+
+void dcss_ss_subsam_set(struct dcss_ss *ss)
+{
+	dcss_ss_write(ss, 0x41614161, DCSS_SS_COEFF);
+	dcss_ss_write(ss, 0, DCSS_SS_MODE);
+	dcss_ss_write(ss, 0x03ff0000, DCSS_SS_CLIP_CB);
+	dcss_ss_write(ss, 0x03ff0000, DCSS_SS_CLIP_CR);
+}
+
+void dcss_ss_sync_set(struct dcss_ss *ss, struct videomode *vm,
+		      bool phsync, bool pvsync)
+{
+	u16 lrc_x, lrc_y;
+	u16 hsync_start, hsync_end;
+	u16 vsync_start, vsync_end;
+	u16 de_ulc_x, de_ulc_y;
+	u16 de_lrc_x, de_lrc_y;
+
+	lrc_x = vm->hfront_porch + vm->hback_porch + vm->hsync_len +
+		vm->hactive - 1;
+	lrc_y = vm->vfront_porch + vm->vback_porch + vm->vsync_len +
+		vm->vactive - 1;
+
+	dcss_ss_write(ss, (lrc_y << LRC_Y_POS) | lrc_x, DCSS_SS_DISPLAY);
+
+	hsync_start = vm->hfront_porch + vm->hback_porch + vm->hsync_len +
+		      vm->hactive - 1;
+	hsync_end = vm->hsync_len - 1;
+
+	dcss_ss_write(ss, (phsync ? SYNC_POL : 0) |
+		      ((u32)hsync_end << SYNC_END_POS) | hsync_start,
+		      DCSS_SS_HSYNC);
+
+	vsync_start = vm->vfront_porch - 1;
+	vsync_end = vm->vfront_porch + vm->vsync_len - 1;
+
+	dcss_ss_write(ss, (pvsync ? SYNC_POL : 0) |
+		      ((u32)vsync_end << SYNC_END_POS) | vsync_start,
+		      DCSS_SS_VSYNC);
+
+	de_ulc_x = vm->hsync_len + vm->hback_porch - 1;
+	de_ulc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch;
+
+	dcss_ss_write(ss, SYNC_POL | ((u32)de_ulc_y << ULC_Y_POS) | de_ulc_x,
+		      DCSS_SS_DE_ULC);
+
+	de_lrc_x = vm->hsync_len + vm->hback_porch + vm->hactive - 1;
+	de_lrc_y = vm->vsync_len + vm->vfront_porch + vm->vback_porch +
+		   vm->vactive - 1;
+
+	dcss_ss_write(ss, (de_lrc_y << LRC_Y_POS) | de_lrc_x, DCSS_SS_DE_LRC);
+}
+
+void dcss_ss_enable(struct dcss_ss *ss)
+{
+	dcss_ss_write(ss, RUN_EN, DCSS_SS_SYS_CTRL);
+	ss->in_use = true;
+}
+
+void dcss_ss_shutoff(struct dcss_ss *ss)
+{
+	dcss_writel(0, ss->base_reg + DCSS_SS_SYS_CTRL);
+	ss->in_use = false;
+}