video_osd: Add ihs_video_out driver

Add a driver for IHS OSDs on IHS FPGAs.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/video/ihs_video_out.c b/drivers/video/ihs_video_out.c
new file mode 100644
index 0000000..5cdf17a
--- /dev/null
+++ b/drivers/video/ihs_video_out.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ *
+ * based on the gdsys osd driver, which is
+ *
+ * (C) Copyright 2010
+ * Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.de
+ */
+
+#include <common.h>
+#include <display.h>
+#include <dm.h>
+#include <regmap.h>
+#include <video_osd.h>
+#include <asm/gpio.h>
+
+static const uint MAX_X_CHARS = 53;
+static const uint MAX_Y_CHARS = 26;
+static const uint MAX_VIDEOMEM_WIDTH = 64;
+static const uint MAX_VIDEOMEM_HEIGHT = 32;
+static const uint CHAR_WIDTH = 12;
+static const uint CHAR_HEIGHT = 18;
+
+static const u16 BASE_WIDTH_MASK = 0x3f00;
+static const uint BASE_WIDTH_SHIFT = 8;
+static const u16 BASE_HEIGTH_MASK = 0x001f;
+static const uint BASE_HEIGTH_SHIFT;
+
+struct ihs_video_out_regs {
+	/* Device version register */
+	u16 versions;
+	/* Device feature register */
+	u16 features;
+	/* Device control register */
+	u16 control;
+	/* Register controlling screen size */
+	u16 xy_size;
+	/* Register controlling screen scaling */
+	u16 xy_scale;
+	/* Register controlling screen x position */
+	u16 x_pos;
+	/* Register controlling screen y position */
+	u16 y_pos;
+};
+
+#define ihs_video_out_set(map, member, val) \
+	regmap_range_set(map, 1, struct ihs_video_out_regs, member, val)
+
+#define ihs_video_out_get(map, member, valp) \
+	regmap_range_get(map, 1, struct ihs_video_out_regs, member, valp)
+
+enum {
+	CONTROL_FILTER_BLACK = (0 << 0),
+	CONTROL_FILTER_ORIGINAL = (1 << 0),
+	CONTROL_FILTER_DARKER = (2 << 0),
+	CONTROL_FILTER_GRAY = (3 << 0),
+
+	CONTROL_MODE_PASSTHROUGH = (0 << 3),
+	CONTROL_MODE_OSD = (1 << 3),
+	CONTROL_MODE_AUTO = (2 << 3),
+	CONTROL_MODE_OFF = (3 << 3),
+
+	CONTROL_ENABLE_OFF = (0 << 6),
+	CONTROL_ENABLE_ON = (1 << 6),
+};
+
+struct ihs_video_out_priv {
+	/* Register map for OSD device */
+	struct regmap *map;
+	/* Pointer to video memory */
+	u16 *vidmem;
+	/* Display width in text columns */
+	uint base_width;
+	/* Display height in text rows */
+	uint base_height;
+	/* x-resolution of the display in pixels */
+	uint res_x;
+	/* y-resolution of the display in pixels */
+	uint res_y;
+	/* OSD's sync mode (resolution + frequency) */
+	int sync_src;
+	/* The display port output for this OSD */
+	struct udevice *video_tx;
+	/* The pixel clock generator for the display */
+	struct udevice *clk_gen;
+};
+
+static const struct udevice_id ihs_video_out_ids[] = {
+	{ .compatible = "gdsys,ihs_video_out" },
+	{ }
+};
+
+/**
+ * set_control() - Set the control register to a given value
+ *
+ * The current value of sync_src is preserved by the function automatically.
+ *
+ * @dev: the OSD device whose control register to set
+ * @value: the 16-bit value to write to the control register
+ * Return: 0
+ */
+static int set_control(struct udevice *dev, u16 value)
+{
+	struct ihs_video_out_priv *priv = dev_get_priv(dev);
+
+	if (priv->sync_src)
+		value |= ((priv->sync_src & 0x7) << 8);
+
+	ihs_video_out_set(priv->map, control, value);
+
+	return 0;
+}
+
+int ihs_video_out_get_info(struct udevice *dev, struct video_osd_info *info)
+{
+	struct ihs_video_out_priv *priv = dev_get_priv(dev);
+	u16 versions;
+
+	ihs_video_out_get(priv->map, versions, &versions);
+
+	info->width = priv->base_width;
+	info->height = priv->base_height;
+	info->major_version = versions / 100;
+	info->minor_version = versions % 100;
+
+	return 0;
+}
+
+int ihs_video_out_set_mem(struct udevice *dev, uint col, uint row, u8 *buf,
+			  size_t buflen, uint count)
+{
+	struct ihs_video_out_priv *priv = dev_get_priv(dev);
+	int res;
+	uint offset;
+	uint k, rep;
+	u16 data;
+
+	/* Repetitions (controlled via count parmeter) */
+	for (rep = 0; rep < count; ++rep) {
+		offset = row * priv->base_width + col + rep * (buflen / 2);
+
+		/* Write a single buffer copy */
+		for (k = 0; k < buflen / 2; ++k) {
+			uint max_size = priv->base_width * priv->base_height;
+
+			if (offset + k >= max_size) {
+				debug("%s: Write would be out of OSD bounds\n",
+				      dev->name);
+				return -E2BIG;
+			}
+
+			data = buf[2 * k + 1] + 256 * buf[2 * k];
+			out_le16(priv->vidmem + offset + k, data);
+		}
+	}
+
+	res = set_control(dev, CONTROL_FILTER_ORIGINAL |
+			       CONTROL_MODE_OSD |
+			       CONTROL_ENABLE_ON);
+	if (res) {
+		debug("%s: Could not set control register\n", dev->name);
+		return res;
+	}
+
+	return 0;
+}
+
+/**
+ * div2_u16() - Approximately divide a 16-bit number by 2
+ *
+ * @val: The 16-bit value to divide by two
+ * Return: The approximate division of val by two
+ */
+static inline u16 div2_u16(u16 val)
+{
+	return (32767 * val) / 65535;
+}
+
+int ihs_video_out_set_size(struct udevice *dev, uint col, uint row)
+{
+	struct ihs_video_out_priv *priv = dev_get_priv(dev);
+
+	if (!col || col > MAX_VIDEOMEM_WIDTH || col > MAX_X_CHARS ||
+	    !row || row > MAX_VIDEOMEM_HEIGHT || row > MAX_Y_CHARS) {
+		debug("%s: Desired OSD size invalid\n", dev->name);
+		return -EINVAL;
+	}
+
+	ihs_video_out_set(priv->map, xy_size, ((col - 1) << 8) | (row - 1));
+	/* Center OSD on screen */
+	ihs_video_out_set(priv->map, x_pos,
+			  div2_u16(priv->res_x - CHAR_WIDTH * col));
+	ihs_video_out_set(priv->map, y_pos,
+			  div2_u16(priv->res_y - CHAR_HEIGHT * row));
+
+	return 0;
+}
+
+int ihs_video_out_print(struct udevice *dev, uint col, uint row, ulong color,
+			char *text)
+{
+	int res;
+	u8 buffer[2 * MAX_VIDEOMEM_WIDTH];
+	uint k;
+	uint charcount = strlen(text);
+	uint len = min(charcount, 2 * MAX_VIDEOMEM_WIDTH);
+
+	for (k = 0; k < len; ++k) {
+		buffer[2 * k] = text[k];
+		buffer[2 * k + 1] = color;
+	}
+
+	res = ihs_video_out_set_mem(dev, col, row, buffer, 2 * len, 1);
+	if (res < 0) {
+		debug("%s: Could not write to video memory\n", dev->name);
+		return res;
+	}
+
+	return 0;
+}
+
+static const struct video_osd_ops ihs_video_out_ops = {
+	.get_info = ihs_video_out_get_info,
+	.set_mem = ihs_video_out_set_mem,
+	.set_size = ihs_video_out_set_size,
+	.print = ihs_video_out_print,
+};
+
+int ihs_video_out_probe(struct udevice *dev)
+{
+	struct ihs_video_out_priv *priv = dev_get_priv(dev);
+	struct ofnode_phandle_args phandle_args;
+	const char *mode;
+	u16 features;
+	struct display_timing timing;
+	int res;
+
+	res = regmap_init_mem(dev_ofnode(dev), &priv->map);
+	if (!res) {
+		debug("%s: Could initialize regmap (err = %d)\n", dev->name,
+		      res);
+		return res;
+	}
+
+	/* Range with index 2 is video memory */
+	priv->vidmem = regmap_get_range(priv->map, 2);
+
+	mode = dev_read_string(dev, "mode");
+	if (!mode) {
+		debug("%s: Could not read mode property\n", dev->name);
+		return -EINVAL;
+	}
+
+	if (!strcmp(mode, "1024_768_60")) {
+		priv->sync_src = 2;
+		priv->res_x = 1024;
+		priv->res_y = 768;
+		timing.hactive.typ = 1024;
+		timing.vactive.typ = 768;
+	} else if (!strcmp(mode, "720_400_70")) {
+		priv->sync_src = 1;
+		priv->res_x = 720;
+		priv->res_y = 400;
+		timing.hactive.typ = 720;
+		timing.vactive.typ = 400;
+	} else {
+		priv->sync_src = 0;
+		priv->res_x = 640;
+		priv->res_y = 480;
+		timing.hactive.typ = 640;
+		timing.vactive.typ = 480;
+	}
+
+	ihs_video_out_get(priv->map, features, &features);
+
+	res = set_control(dev, CONTROL_FILTER_ORIGINAL |
+			       CONTROL_MODE_OSD |
+			       CONTROL_ENABLE_OFF);
+	if (res) {
+		debug("%s: Could not set control register (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	priv->base_width = ((features & BASE_WIDTH_MASK)
+			    >> BASE_WIDTH_SHIFT) + 1;
+	priv->base_height = ((features & BASE_HEIGTH_MASK)
+			     >> BASE_HEIGTH_SHIFT) + 1;
+
+	res = dev_read_phandle_with_args(dev, "clk_gen", NULL, 0, 0,
+					 &phandle_args);
+	if (res) {
+		debug("%s: Could not get clk_gen node (err = %d)\n",
+		      dev->name, res);
+		return -EINVAL;
+	}
+
+	res = uclass_get_device_by_ofnode(UCLASS_CLK, phandle_args.node,
+					  &priv->clk_gen);
+	if (res) {
+		debug("%s: Could not get clk_gen dev (err = %d)\n",
+		      dev->name, res);
+		return -EINVAL;
+	}
+
+	res = dev_read_phandle_with_args(dev, "video_tx", NULL, 0, 0,
+					 &phandle_args);
+	if (res) {
+		debug("%s: Could not get video_tx (err = %d)\n",
+		      dev->name, res);
+		return -EINVAL;
+	}
+
+	res = uclass_get_device_by_ofnode(UCLASS_DISPLAY, phandle_args.node,
+					  &priv->video_tx);
+	if (res) {
+		debug("%s: Could not get video_tx dev (err = %d)\n",
+		      dev->name, res);
+		return -EINVAL;
+	}
+
+	res = display_enable(priv->video_tx, 8, &timing);
+	if (res) {
+		debug("%s: Could not enable the display (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	return 0;
+}
+
+U_BOOT_DRIVER(ihs_video_out_drv) = {
+	.name           = "ihs_video_out_drv",
+	.id             = UCLASS_VIDEO_OSD,
+	.ops		= &ihs_video_out_ops,
+	.of_match       = ihs_video_out_ids,
+	.probe          = ihs_video_out_probe,
+	.priv_auto_alloc_size = sizeof(struct ihs_video_out_priv),
+};