[PATCH 1/2] Add support for Samsung S3C24x0 framebuffer.

Alex Galakhov agalakhov at gmail.com
Tue May 17 12:44:00 EDT 2011


Heavily based on original Juergen Beisert's code.

Signed-off-by: Alex Galakhov <agalakhov at gmail.com>
---
 arch/arm/mach-s3c24xx/include/mach/fb.h |   59 ++++
 drivers/video/Kconfig                   |   13 +
 drivers/video/Makefile                  |    1 +
 drivers/video/s3c.c                     |  451 +++++++++++++++++++++++++++++++
 4 files changed, 524 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-s3c24xx/include/mach/fb.h
 create mode 100644 drivers/video/s3c.c

diff --git a/arch/arm/mach-s3c24xx/include/mach/fb.h b/arch/arm/mach-s3c24xx/include/mach/fb.h
new file mode 100644
index 0000000..05e013a
--- /dev/null
+++ b/arch/arm/mach-s3c24xx/include/mach/fb.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2010 Juergen Beisert
+ * Copyright (C) 2011 Alexey Galakhov
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#ifndef __MACH_FB_H_
+# define __MACH_FB_H_
+
+#include <fb.h>
+
+/** Proprietary flags corresponding to  S3C24x0 LCDCON5 register */
+
+/** ! INVVDEN - DE active high */
+#define FB_SYNC_DE_HIGH_ACT	(1 << 23)
+/** INVVCLK - invert CLK signal */
+#define FB_SYNC_CLK_INVERT	(1 << 24)
+/** INVVD - invert data */
+#define FB_SYNC_DATA_INVERT	(1 << 25)
+/** INVPWREN - use PWREN signal */
+#define FB_SYNC_INVERT_PWREN	(1 << 26)
+/** INVLEND - use LEND signal */
+#define FB_SYNC_INVERT_LEND	(1 << 27)
+/** PWREN - use PWREN signal */
+#define FB_SYNC_USE_PWREN	(1 << 28)
+/** ENLEND - use LEND signal */
+#define FB_SYNC_USE_LEND	(1 << 29)
+/** BSWP - swap bytes */
+#define FB_SYNC_SWAP_BYTES	(1 << 30)
+/** HWSWP - swap half words */
+#define FB_SYNC_SWAP_HW		(1 << 31)
+
+struct s3c_fb_platform_data {
+	struct fb_videomode *mode_list;
+	unsigned mode_cnt;
+
+	unsigned bits_per_pixel;
+	int passive_display;	/**< enable support for STN or CSTN displays */
+
+	/** hook to enable backlight and stuff */
+	void (*enable)(int enable);
+};
+
+#endif /* __MACH_FB_H_ */
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index c652622..28bcfed 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -27,4 +27,17 @@ config DRIVER_VIDEO_STM
 	  Say 'Y' here to enable framebuffer and splash screen support for
 	  i.MX23 and i.MX28 based systems.
 
+config DRIVER_VIDEO_S3C
+	bool "S3C244x framebuffer driver"
+	depends on ARCH_S3C24xx
+	help
+	  Add support for the S3C244x LCD controller.
+
+if DRIVER_VIDEO_S3C
+
+config DRIVER_VIDEO_S3C_VERBOSE
+	bool "S3C244x verbose framebuffer info"
+
+endif
+
 endif
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index a217a0b..66b08d8 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_VIDEO) += fb.o
 obj-$(CONFIG_DRIVER_VIDEO_STM) += stm.o
 obj-$(CONFIG_DRIVER_VIDEO_IMX) += imx.o
 obj-$(CONFIG_DRIVER_VIDEO_IMX_IPU) += imx-ipu-fb.o
+obj-$(CONFIG_DRIVER_VIDEO_S3C) += s3c.o
diff --git a/drivers/video/s3c.c b/drivers/video/s3c.c
new file mode 100644
index 0000000..ba3c3fa
--- /dev/null
+++ b/drivers/video/s3c.c
@@ -0,0 +1,451 @@
+/*
+ * Copyright (C) 2010 Juergen Beisert
+ * Copyright (C) 2011 Alexey Galakhov
+ *
+ * This driver is based on a patch found in the web:
+ * (C) Copyright 2006 by OpenMoko, Inc.
+ * Author: Harald Welte <laforge at openmoko.org>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/* #define DEBUG */
+
+#include <common.h>
+#include <init.h>
+#include <fb.h>
+#include <driver.h>
+#include <malloc.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <mach/gpio.h>
+#include <mach/s3c24xx-generic.h>
+#include <mach/fb.h>
+
+#define LCDCON1 0x00
+# define PNRMODE(x) (((x) & 3) << 5)
+# define BPPMODE(x) (((x) & 0xf) << 1)
+# define SET_CLKVAL(x) (((x) & 0x3ff) << 8)
+# define GET_CLKVAL(x) (((x) >> 8) & 0x3ff)
+# define ENVID (1 << 0)
+
+#define LCDCON2 0x04
+# define SET_VBPD(x) (((x) & 0xff) << 24)
+# define SET_LINEVAL(x) (((x) & 0x3ff) << 14)
+# define SET_VFPD(x) (((x) & 0xff) << 6)
+# define SET_VSPW(x) ((x) & 0x3f)
+
+#define LCDCON3 0x08
+# define SET_HBPD(x) (((x) & 0x7f) << 19)
+# define SET_HOZVAL(x) (((x) & 0x7ff) << 8)
+# define SET_HFPD(x) ((x) & 0xff)
+
+#define LCDCON4 0x0c
+# define SET_HSPW(x) ((x) & 0xff)
+
+#define LCDCON5 0x10
+# define BPP24BL (1 << 12)
+# define FRM565 (1 << 11)
+# define INV_CLK (1 << 10)
+# define INV_HS (1 << 9)
+# define INV_VS (1 << 8)
+# define INV_DTA (1 << 7)
+# define INV_DE (1 << 6)
+# define INV_PWREN (1 << 5)
+# define INV_LEND (1 << 4)
+# define ENA_PWREN (1 << 3)
+# define ENA_LEND (1 << 2)
+# define BSWP (1 << 1)
+# define HWSWP (1 << 0)
+
+#define LCDSADDR1 0x14
+# define SET_LCDBANK(x) (((x) & 0x1ff) << 21)
+# define GET_LCDBANK(x) (((x) >> 21) & 0x1ff)
+# define SET_LCDBASEU(x) ((x) & 0x1fffff)
+# define GET_LCDBASEU(x) ((x) & 0x1fffff)
+
+#define LCDSADDR2 0x18
+# define SET_LCDBASEL(x) ((x) & 0x1fffff)
+# define GET_LCDBASEL(x) ((x) & 0x1fffff)
+
+#define LCDSADDR3 0x1c
+# define SET_OFFSIZE(x) (((x) & 0x7ff) << 11)
+# define GET_OFFSIZE(x) (((x) >> 11) & 0x7ff)
+# define SET_PAGE_WIDTH(x) ((x) & 0x3ff)
+# define GET_PAGE_WIDTH(x) ((x) & 0x3ff)
+
+#define RED_LUT 0x20
+#define GREEN_LUT 0x24
+#define BLUE_LUT 0x28
+
+#define DITHMODE 0x4c
+
+#define TPAL 0x50
+
+#define LCDINTPND 0x54
+#define LCDSRCPND 0x58
+#define LCDINTMSK 0x5c
+# define FIWSEL (1 << 2)
+# define INT_FrSyn (1 << 1)
+# define INT_FiCnt (1 << 0)
+
+#define TCONSEL 0x60
+
+#define RED 0
+#define GREEN 1
+#define BLUE 2
+#define TRANSP 3
+
+struct s3cfb_info {
+	void __iomem *base;
+	unsigned memory_size;
+	struct fb_info info;
+	struct device_d *hw_dev;
+	int passive_display;
+	void (*enable)(int enable);
+};
+
+/* the RGB565 true colour mode */
+static const struct fb_bitfield def_rgb565[] = {
+	[RED] = {
+		.offset = 11,
+		.length = 5,
+	},
+	[GREEN] = {
+		.offset = 5,
+		.length = 6,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 5,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+/* the RGB888 true colour mode */
+static const struct fb_bitfield def_rgb888[] = {
+	[RED] = {
+		.offset = 16,
+		.length = 8,
+	},
+	[GREEN] = {
+		.offset = 8,
+		.length = 8,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 8,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+/**
+ * @param fb_info Framebuffer information
+ */
+static void s3cfb_enable_controller(struct fb_info *fb_info)
+{
+	struct s3cfb_info *fbi = fb_info->priv;
+	uint32_t con1;
+
+	con1 = readl(fbi->base + LCDCON1);
+
+	con1 |= ENVID;
+
+	writel(con1, fbi->base + LCDCON1);
+
+	if (fbi->enable)
+		(fbi->enable)(1);
+}
+
+/**
+ * @param fb_info Framebuffer information
+ */
+static void s3cfb_disable_controller(struct fb_info *fb_info)
+{
+	struct s3cfb_info *fbi = fb_info->priv;
+	uint32_t con1;
+
+	if (fbi->enable)
+		(fbi->enable)(0);
+
+	con1 = readl(fbi->base + LCDCON1);
+
+	con1 &= ~ENVID;
+
+	writel(con1, fbi->base + LCDCON1);
+}
+
+/**
+ * Prepare the video hardware for a specified video mode
+ * @param fb_info Framebuffer information
+ * @param mode The video mode description to initialize
+ * @return 0 on success
+ */
+static int s3cfb_activate_var(struct fb_info *fb_info)
+{
+	struct s3cfb_info *fbi = fb_info->priv;
+	struct fb_videomode *mode = fb_info->mode;
+	unsigned size, hclk, div;
+	uint32_t con1, con2, con3, con4, con5 = 0;
+
+	if (fbi->passive_display != 0) {
+		pr_err("Passive displays are currently not supported\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * we need at least this amount of memory for the framebuffer
+	 */
+	size = mode->xres * mode->yres * (fb_info->bits_per_pixel >> 3);
+	if (fbi->memory_size != size || fb_info->screen_base == NULL) {
+		if (fb_info->screen_base)
+			free(fb_info->screen_base);
+		fbi->memory_size = 0;
+		fb_info->screen_base = malloc(size);
+		if (! fb_info->screen_base)
+			return -ENOMEM;
+		memset(fb_info->screen_base, 0, size);
+		fbi->memory_size = size;
+	}
+
+	/* ensure video output is _off_ */
+	writel(0x00000000, fbi->base + LCDCON1);
+
+	hclk = s3c24xx_get_hclk() / 1000U;	/* hclk in kHz */
+	div = hclk / PICOS2KHZ(mode->pixclock);
+	if (div < 3)
+		div  = 3;
+	/* pixel clock is: (hclk) / ((div + 1) * 2) */
+	div += 1;
+	div >>= 1;
+	div -= 1;
+
+	con1 = PNRMODE(3) | SET_CLKVAL(div);	/* PNRMODE=3 is TFT */
+
+	switch (fb_info->bits_per_pixel) {
+#if 0
+	/* TODO add CLUT based modes */
+	case 1:
+		con1 |= BPPMODE(8);
+		break;
+	case 2:
+		con1 |= BPPMODE(9);
+		break;
+	case 4:
+		con1 |= BPPMODE(10);
+		break;
+	case 8:
+		con1 |= BPPMODE(11);
+		break;
+#endif
+	case 16:
+		con1 |= BPPMODE(12);
+		con5 |= FRM565;
+		con5 |= HWSWP;
+		fb_info->red = def_rgb565[RED];
+		fb_info->green = def_rgb565[GREEN];
+		fb_info->blue = def_rgb565[BLUE];
+		fb_info->transp =  def_rgb565[TRANSP];
+		break;
+	case 24:
+		con1 |= BPPMODE(13);
+		/* con5 |= BPP24BL;	*/ /* FIXME maybe needed, check alignment */
+		fb_info->red = def_rgb888[RED];
+		fb_info->green = def_rgb888[GREEN];
+		fb_info->blue = def_rgb888[BLUE];
+		fb_info->transp =  def_rgb888[TRANSP];
+		break;
+	default:
+		pr_err("Invalid bits per pixel value: %u\n", fb_info->bits_per_pixel);
+		return -EINVAL;
+	}
+
+	/* 'normal' in register description means positive logic */
+	if (!(mode->sync & FB_SYNC_HOR_HIGH_ACT))
+		con5 |= INV_HS;
+	if (!(mode->sync & FB_SYNC_VERT_HIGH_ACT))
+		con5 |= INV_VS;
+	if (!(mode->sync & FB_SYNC_DE_HIGH_ACT))
+		con5 |= INV_DE;
+	if (mode->sync & FB_SYNC_CLK_INVERT)
+		con5 |= INV_CLK;	/* display should latch at the rising edge */
+	if (mode->sync & FB_SYNC_DATA_INVERT)
+		con5 |= INV_DTA;
+	if (mode->sync & FB_SYNC_INVERT_PWREN)
+		con5 |= INV_PWREN;
+	if (mode->sync & FB_SYNC_INVERT_LEND)
+		con5 |= INV_LEND;
+	if (mode->sync & FB_SYNC_USE_PWREN)
+		con5 |= ENA_PWREN;	/* FIXME should this be done conditionally/later? */
+	if (mode->sync & FB_SYNC_USE_LEND)
+		con5 |= ENA_LEND;
+	if (mode->sync & FB_SYNC_SWAP_BYTES)
+		con5 ^= BSWP;
+	if (mode->sync & FB_SYNC_SWAP_HW)
+		con5 ^= HWSWP;
+
+	/* vertical timing */
+	con2 = SET_VBPD(mode->upper_margin - 1) |
+		SET_LINEVAL(mode->yres - 1) |
+		SET_VFPD(mode->lower_margin - 1) |
+		SET_VSPW(mode->vsync_len - 1);
+
+	/* horizontal timing */
+	con3 = SET_HBPD(mode->left_margin - 1) |
+		SET_HOZVAL(mode->xres - 1) |
+		SET_HFPD(mode->right_margin - 1);
+	con4 = SET_HSPW(mode->hsync_len - 1);
+
+	/* basic timing setup */
+	writel(con1, fbi->base + LCDCON1);
+	pr_debug(" Writing %08X into %08X (con1)\n", con1, fbi->base + LCDCON1);
+	writel(con2, fbi->base + LCDCON2);
+	pr_debug(" Writing %08X into %08X (con2)\n", con2, fbi->base + LCDCON2);
+	writel(con3, fbi->base + LCDCON3);
+	pr_debug(" Writing %08X into %08X (con3)\n", con3, fbi->base + LCDCON3);
+	writel(con4, fbi->base + LCDCON4);
+	pr_debug(" Writing %08X into %08X (con4)\n", con4, fbi->base + LCDCON4);
+	writel(con5, fbi->base + LCDCON5);
+	pr_debug(" Writing %08X into %08X (con5)\n", con5, fbi->base + LCDCON5);
+
+	pr_debug("Setting up the fb baseadress to %08X\n", fb_info->screen_base);
+
+	/* framebuffer memory setup */
+	writel((unsigned)fb_info->screen_base >> 1, fbi->base + LCDSADDR1);
+	size = mode->xres * (fb_info->bits_per_pixel >> 3) * (mode->yres);
+	writel(SET_LCDBASEL(((unsigned)fb_info->screen_base + size) >> 1), fbi->base + LCDSADDR2);
+	writel(SET_OFFSIZE(0) |
+		SET_PAGE_WIDTH((mode->xres * fb_info->bits_per_pixel) >> 4),
+		fbi->base + LCDSADDR3);
+	writel(FIWSEL | INT_FrSyn | INT_FiCnt, fbi->base + LCDINTMSK);
+
+	return 0;
+}
+
+/**
+ * Print some information about the current hardware state
+ * @param hw_dev S3C video device
+ */
+#ifdef CONFIG_DRIVER_VIDEO_S3C_VERBOSE
+static void s3cfb_info(struct device_d *hw_dev)
+{
+	uint32_t con1, addr1, addr2, addr3;
+
+	con1 = readl(hw_dev->map_base + LCDCON1);
+	addr1 = readl(hw_dev->map_base + LCDSADDR1);
+	addr2 = readl(hw_dev->map_base + LCDSADDR2);
+	addr3 = readl(hw_dev->map_base + LCDSADDR3);
+
+	printf(" Video hardware info:\n");
+	printf("  Video clock is running at %u Hz\n", s3c24xx_get_hclk() / ((GET_CLKVAL(con1) + 1) * 2));
+	printf("  Video memory bank starts at 0x%08X\n", GET_LCDBANK(addr1) << 22);
+	printf("  Video memory bank offset: 0x%08X\n", GET_LCDBASEU(addr1));
+	printf("  Video memory end: 0x%08X\n", GET_LCDBASEU(addr2));
+	printf("  Virtual screen offset size: %u half words\n", GET_OFFSIZE(addr3));
+	printf("  Virtual screen page width: %u half words\n", GET_PAGE_WIDTH(addr3));
+}
+#endif
+
+/*
+ * There is only one video hardware instance available.
+ * It makes no sense to dynamically allocate this data
+ */
+static struct fb_ops s3cfb_ops = {
+	.fb_activate_var = s3cfb_activate_var,
+	.fb_enable = s3cfb_enable_controller,
+	.fb_disable = s3cfb_disable_controller,
+};
+
+static struct s3cfb_info fbi = {
+	.info = {
+		.fbops = &s3cfb_ops,
+	},
+};
+
+static int s3cfb_probe(struct device_d *hw_dev)
+{
+	struct s3c_fb_platform_data *pdata = hw_dev->platform_data;
+	int ret;
+
+	if (! pdata)
+		return -ENODEV;
+
+	writel(0, hw_dev->map_base + LCDCON1);
+	writel(0, hw_dev->map_base + LCDCON5); /* FIXME not 0 for some displays */
+
+	/* just init */
+	fbi.info.priv = &fbi;
+
+	/* add runtime hardware info */
+	fbi.hw_dev = hw_dev;
+	fbi.base = (void*)hw_dev->map_base;
+
+	/* add runtime video info */
+	fbi.info.mode_list = pdata->mode_list;
+	fbi.info.num_modes = pdata->mode_cnt;
+	fbi.info.mode = &fbi.info.mode_list[1];
+	fbi.info.xres = fbi.info.mode->xres;
+	fbi.info.yres = fbi.info.mode->yres;
+	if (pdata->bits_per_pixel)
+		fbi.info.bits_per_pixel = pdata->bits_per_pixel;
+	else
+		fbi.info.bits_per_pixel = 16;
+	fbi.passive_display = pdata->passive_display;
+	fbi.enable = pdata->enable;
+
+	ret = register_framebuffer(&fbi.info);
+	if (ret != 0) {
+		dev_err(hw_dev, "Failed to register framebuffer\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct driver_d s3cfb_driver = {
+	.name	= "s3c_fb",
+	.probe	= s3cfb_probe,
+#ifdef CONFIG_DRIVER_VIDEO_S3C_VERBOSE
+	.info	= s3cfb_info,
+#endif
+};
+
+static int s3cfb_init(void)
+{
+	return register_driver(&s3cfb_driver);
+}
+
+device_initcall(s3cfb_init);
+
+/**
+ * The S3C244x LCD controller supports passive (CSTN/STN) and active (TFT) LC displays
+ *
+ * The driver itself currently supports only active TFT LC displays in the follwing manner:
+ *
+ *  * Palletized colours
+ *    - 1 bpp
+ *    - 2 bpp
+ *    - 4 bpp
+ *    - 8 bpp
+ *  * True colours
+ *    - 16 bpp
+ *    - 24 bpp
+ */
-- 
1.7.4.1




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