[PATCH 8/8] video: imx: Add LCDIF driver

Miquel Raynal miquel.raynal at bootlin.com
Tue Sep 10 12:13:44 CEST 2024


Add support for the LCD interfaces (LCDIF1/2). When probed, these
interfaces request numerous clocks and power doomains, attach the bridge
and look for a panel in order to retrieve its capabilities and
properties.

There is a similar driver existing in the upper folder for other i.MX
targets, I discovered this driver a bit late. It is not tergetting the
i.MX8 and I have no idea how different can the LCDIF be on this SoC, but
I did not manage to get it work, especially because it is not fully
compliant with the device-model, especially on the clocks/power
management side which is all ad-hoc. This is normal though, it was
contributed more than ten years ago.

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
 drivers/video/imx/Kconfig  |   3 +
 drivers/video/imx/Makefile |   1 +
 drivers/video/imx/lcdif.c  | 315 +++++++++++++++++++++++++++++++++++++
 3 files changed, 319 insertions(+)
 create mode 100644 drivers/video/imx/lcdif.c

diff --git a/drivers/video/imx/Kconfig b/drivers/video/imx/Kconfig
index f8e0e3b23b3..1a36d907e0c 100644
--- a/drivers/video/imx/Kconfig
+++ b/drivers/video/imx/Kconfig
@@ -17,3 +17,6 @@ config IMX_HDMI
 config IMX_LDB
 	bool "i.MX LVDS display bridge (LDB)"
 	depends on VIDEO_BRIDGE
+
+config IMX_LCDIF
+	bool "i.MX LCD interface"
diff --git a/drivers/video/imx/Makefile b/drivers/video/imx/Makefile
index 8d106589b75..1edf5a6bdf0 100644
--- a/drivers/video/imx/Makefile
+++ b/drivers/video/imx/Makefile
@@ -5,3 +5,4 @@
 
 obj-$(CONFIG_VIDEO_IPUV3) += mxc_ipuv3_fb.o ipu_common.o ipu_disp.o
 obj-$(CONFIG_IMX_LDB) += ldb.o
+obj-$(CONFIG_IMX_LCDIF) += lcdif.o
diff --git a/drivers/video/imx/lcdif.c b/drivers/video/imx/lcdif.c
new file mode 100644
index 00000000000..7871bba8d90
--- /dev/null
+++ b/drivers/video/imx/lcdif.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * i.MX8 LCD interface driver inspired from the Linux driver
+ * Copyright 2019 NXP
+ * Copyright 2024 Bootlin
+ * Adapted by Miquel Raynal <miquel.raynal at bootlin.com>
+ */
+
+#include <asm/io.h>
+#include <asm/mach-imx/dma.h>
+#include <clk.h>
+#include <dm.h>
+#include <panel.h>
+#include <power-domain.h>
+#include <video.h>
+#include <video_bridge.h>
+#include <linux/delay.h>
+
+#include "../videomodes.h"
+
+#define LCDIFV3_CTRL 0x0
+#define LCDIFV3_CTRL_SET 0x4
+#define LCDIFV3_CTRL_CLR 0x8
+#define   CTRL_INV_HS BIT(0)
+#define   CTRL_INV_VS BIT(1)
+#define   CTRL_INV_DE BIT(2)
+#define   CTRL_INV_PXCK BIT(3)
+#define   CTRL_CLK_GATE BIT(30)
+#define   CTRL_SW_RESET BIT(31)
+
+#define LCDIFV3_DISP_PARA 0x10
+#define   DISP_PARA_DISP_MODE_NORMAL 0
+#define   DISP_PARA_LINE_PATTERN_RGB_YUV 0
+#define   DISP_PARA_DISP_ON BIT(31)
+
+#define LCDIFV3_DISP_SIZE 0x14
+#define   DISP_SIZE_DELTA_X(x) ((x) & 0xffff)
+#define   DISP_SIZE_DELTA_Y(x) ((x) << 16)
+
+#define LCDIFV3_HSYN_PARA 0x18
+#define   HSYN_PARA_FP_H(x) ((x) & 0xffff)
+#define   HSYN_PARA_BP_H(x) ((x) << 16)
+
+#define LCDIFV3_VSYN_PARA 0x1C
+#define   VSYN_PARA_FP_V(x) ((x) & 0xffff)
+#define   VSYN_PARA_BP_V(x) ((x) << 16)
+
+#define LCDIFV3_VSYN_HSYN_WIDTH 0x20
+#define   VSYN_HSYN_PW_H(x) ((x) & 0xffff)
+#define   VSYN_HSYN_PW_V(x) ((x) << 16)
+
+#define LCDIFV3_CTRLDESCL0_1 0x200
+#define   CTRLDESCL0_1_WIDTH(x) ((x) & 0xffff)
+#define   CTRLDESCL0_1_HEIGHT(x) ((x) << 16)
+
+#define LCDIFV3_CTRLDESCL0_3 0x208
+#define   CTRLDESCL0_3_PITCH(x) ((x) & 0xFFFF)
+
+#define LCDIFV3_CTRLDESCL_LOW0_4 0x20C
+#define LCDIFV3_CTRLDESCL_HIGH0_4 0x210
+
+#define LCDIFV3_CTRLDESCL0_5 0x214
+#define   CTRLDESCL0_5_YUV_FORMAT(x) (((x) & 0x3) << 14)
+#define   CTRLDESCL0_5_BPP(x) (((x) & 0xf) << 24)
+#define     BPP32_ARGB8888 0x9
+#define   CTRLDESCL0_5_SHADOW_LOAD_EN BIT(30)
+#define   CTRLDESCL0_5_EN BIT(31)
+
+struct lcdifv3_priv {
+	void __iomem *base;
+	struct clk pix_clk;
+	struct power_domain pd;
+	struct udevice *panel;
+	struct udevice *bridge;
+};
+
+static void lcdifv3_set_mode(struct lcdifv3_priv *priv,
+			     struct display_timing *timings)
+{
+	u32 reg;
+
+	writel(DISP_SIZE_DELTA_X(timings->hactive.typ) |
+	       DISP_SIZE_DELTA_Y(timings->vactive.typ),
+	       priv->base + LCDIFV3_DISP_SIZE);
+
+	writel(HSYN_PARA_FP_H(timings->hfront_porch.typ) |
+	       HSYN_PARA_BP_H(timings->hback_porch.typ),
+	       priv->base + LCDIFV3_HSYN_PARA);
+
+	writel(VSYN_PARA_BP_V(timings->vback_porch.typ) |
+	       VSYN_PARA_FP_V(timings->vfront_porch.typ),
+	       priv->base + LCDIFV3_VSYN_PARA);
+
+	writel(VSYN_HSYN_PW_H(timings->hsync_len.typ) |
+	       VSYN_HSYN_PW_V(timings->vsync_len.typ),
+	       priv->base + LCDIFV3_VSYN_HSYN_WIDTH);
+
+	writel(CTRLDESCL0_1_WIDTH(timings->hactive.typ) |
+	       CTRLDESCL0_1_HEIGHT(timings->vactive.typ),
+	       priv->base + LCDIFV3_CTRLDESCL0_1);
+
+	if (timings->flags & DISPLAY_FLAGS_HSYNC_LOW)
+		writel(CTRL_INV_HS, priv->base + LCDIFV3_CTRL_SET);
+	else
+		writel(CTRL_INV_HS, priv->base + LCDIFV3_CTRL_CLR);
+
+	if (timings->flags & DISPLAY_FLAGS_VSYNC_LOW)
+		writel(CTRL_INV_VS, priv->base + LCDIFV3_CTRL_SET);
+	else
+		writel(CTRL_INV_VS, priv->base + LCDIFV3_CTRL_CLR);
+
+	if (timings->flags & DISPLAY_FLAGS_DE_LOW)
+		writel(CTRL_INV_DE, priv->base + LCDIFV3_CTRL_SET);
+	else
+		writel(CTRL_INV_DE, priv->base + LCDIFV3_CTRL_CLR);
+
+	if (timings->flags & DISPLAY_FLAGS_PIXDATA_POSEDGE)
+		writel(CTRL_INV_PXCK, priv->base + LCDIFV3_CTRL_SET);
+	else
+		writel(CTRL_INV_PXCK, priv->base + LCDIFV3_CTRL_CLR);
+
+	writel(0, priv->base + LCDIFV3_DISP_PARA);
+
+	reg = readl(priv->base + LCDIFV3_CTRLDESCL0_5);
+	reg &= ~(CTRLDESCL0_5_BPP(0xf) | CTRLDESCL0_5_YUV_FORMAT(0x3));
+	reg |= CTRLDESCL0_5_BPP(BPP32_ARGB8888);
+	writel(reg, priv->base + LCDIFV3_CTRLDESCL0_5);
+}
+
+static void lcdifv3_enable_controller(struct lcdifv3_priv *priv)
+{
+	u32 reg;
+
+	reg = readl(priv->base + LCDIFV3_DISP_PARA);
+	reg |= DISP_PARA_DISP_ON;
+	writel(reg, priv->base + LCDIFV3_DISP_PARA);
+
+	reg = readl(priv->base + LCDIFV3_CTRLDESCL0_5);
+	reg |= CTRLDESCL0_5_EN;
+	writel(reg, priv->base + LCDIFV3_CTRLDESCL0_5);
+}
+
+static int lcdifv3_video_sync(struct udevice *dev)
+{
+	struct lcdifv3_priv *priv = dev_get_priv(dev);
+	u32 reg;
+
+	reg = readl(priv->base + LCDIFV3_CTRLDESCL0_5);
+	reg |= CTRLDESCL0_5_SHADOW_LOAD_EN;
+	writel(reg, priv->base + LCDIFV3_CTRLDESCL0_5);
+
+	return 0;
+}
+
+static void lcdifv3_init(struct udevice *dev, struct display_timing *timings)
+{
+	struct video_uc_plat *plat = dev_get_uclass_plat(dev);
+	struct lcdifv3_priv *priv = dev_get_priv(dev);
+
+	clk_set_rate(&priv->pix_clk, timings->pixelclock.typ);
+
+	writel(CTRL_SW_RESET | CTRL_CLK_GATE, priv->base + LCDIFV3_CTRL_CLR);
+	udelay(10);
+
+	lcdifv3_set_mode(priv, timings);
+
+	writel(plat->base & 0xFFFFFFFF, priv->base + LCDIFV3_CTRLDESCL_LOW0_4);
+	writel(plat->base >> 32, priv->base + LCDIFV3_CTRLDESCL_HIGH0_4);
+
+	writel(CTRLDESCL0_3_PITCH(timings->hactive.typ * 4), /* 32bpp */
+	       priv->base + LCDIFV3_CTRLDESCL0_3);
+
+	lcdifv3_enable_controller(priv);
+}
+
+static int lcdifv3_video_probe(struct udevice *dev)
+{
+	struct video_uc_plat *plat = dev_get_uclass_plat(dev);
+	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct lcdifv3_priv *priv = dev_get_priv(dev);
+	struct clk axi_clk, disp_axi_clk;
+	struct display_timing timings;
+	u32 fb_start, fb_end;
+	int ret;
+
+	ret = power_domain_get(dev, &priv->pd);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_get_by_name(dev, "pix", &priv->pix_clk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_get_by_name(dev, "axi", &axi_clk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_get_by_name(dev, "disp_axi", &disp_axi_clk);
+	if (ret < 0)
+		return ret;
+
+	ret = power_domain_on(&priv->pd);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(&priv->pix_clk);
+	if (ret)
+		goto dis_pd;
+
+	ret = clk_enable(&axi_clk);
+	if (ret)
+		goto dis_pix_clk;
+
+	ret = clk_enable(&disp_axi_clk);
+	if (ret)
+		goto dis_axi_clk;
+
+	priv->base = dev_remap_addr(dev);
+	if (!priv->base) {
+		ret = -EINVAL;
+		goto dis_clks;
+	}
+
+	/* Attach bridge */
+	ret = uclass_get_device_by_endpoint(UCLASS_VIDEO_BRIDGE, dev,
+					    0, &priv->bridge);
+	if (ret)
+		goto dis_clks;
+
+	ret = video_bridge_attach(priv->bridge);
+	if (ret)
+		goto dis_clks;
+
+	ret = video_bridge_set_backlight(priv->bridge, 80);
+	if (ret)
+		goto dis_clks;
+
+	/* Attach panels */
+	ret = uclass_get_device_by_endpoint(UCLASS_PANEL, priv->bridge,
+					    1, &priv->panel);
+	if (ret) {
+		ret = uclass_get_device_by_endpoint(UCLASS_PANEL, priv->bridge,
+						    2, &priv->panel);
+		if (ret)
+			goto dis_clks;
+	}
+
+	ret = panel_get_display_timing(priv->panel, &timings);
+	if (ret) {
+		ret = ofnode_decode_display_timing(dev_ofnode(priv->panel),
+						   0, &timings);
+		if (ret) {
+			printf("Cannot decode panel timings (%d)\n", ret);
+			goto dis_clks;
+		}
+	}
+
+	lcdifv3_init(dev, &timings);
+
+	/* Only support 32bpp for now */
+	uc_priv->bpix = VIDEO_BPP32;
+	uc_priv->xsize = timings.hactive.typ;
+	uc_priv->ysize = timings.vactive.typ;
+
+	/* Enable dcache for the frame buffer */
+	fb_start = plat->base & ~(MMU_SECTION_SIZE - 1);
+	fb_end = ALIGN(plat->base + plat->size, 1 << MMU_SECTION_SHIFT);
+	mmu_set_region_dcache_behaviour(fb_start, fb_end - fb_start,
+					DCACHE_WRITEBACK);
+	video_set_flush_dcache(dev, true);
+	gd->fb_base = plat->base;
+
+	return 0;
+
+dis_clks:
+	clk_disable(&disp_axi_clk);
+dis_axi_clk:
+	clk_disable(&axi_clk);
+dis_pix_clk:
+	clk_disable(&priv->pix_clk);
+dis_pd:
+	power_domain_off(&priv->pd);
+
+	return ret;
+}
+
+static int lcdifv3_video_bind(struct udevice *dev)
+{
+	struct video_uc_plat *plat = dev_get_uclass_plat(dev);
+
+	/* Max size supported by LCDIF */
+	plat->size = 1920 * 1080 * VNBYTES(VIDEO_BPP32);
+
+	return 0;
+}
+
+static const struct udevice_id lcdifv3_video_ids[] = {
+	{ .compatible = "fsl,imx8mp-lcdif" },
+	{ }
+};
+
+static struct video_ops lcdifv3_video_ops = {
+	.video_sync = lcdifv3_video_sync,
+};
+
+U_BOOT_DRIVER(lcdifv3_video) = {
+	.name = "lcdif",
+	.id = UCLASS_VIDEO,
+	.of_match = lcdifv3_video_ids,
+	.bind = lcdifv3_video_bind,
+	.ops = &lcdifv3_video_ops,
+	.probe = lcdifv3_video_probe,
+	.priv_auto = sizeof(struct lcdifv3_priv),
+	.flags = DM_FLAG_PRE_RELOC | DM_FLAG_OS_PREPARE,
+};
-- 
2.43.0



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