x4412 linux4.9.123的lcd驱动移植
本文分享一下如何移植x4412的lcd驱动程序。x4412默认使用的液晶屏型号VS070CXN,分辨率: 1024X600。根据4412手册， LCD 接口支持三种接口, RGB-interface indirect-i80 interface and YUV interface for write-back。使用 RGB888 接口,包含 24 位并行数据总线。
首先需要修改设备树，添加如下节点：
lcd_vs070@11C00000 {
compatible = "x4412, lcd_vs070";
reg = <0x11C00000 0x20c0 0x10010210 0x08 0x10023c80 0x04 0x1003c000 0x1000>;
pinctrl-names = "default";
pinctrl-0 = <&lcd_vs070>;
clocks = <&clock CLK_FIMD0 &clock CLK_ACLK160>;
clock-names = "fimd0","aclk160";
};
然后添加lcd的pin管脚配置，如下：
&pinctrl_0 {
lcd_vs070:lcd {
samsung,pins = "gpf0-0", "gpf0-1", "gpf0-2", "gpf0-3", "gpf0-4",
"gpf0-5", "gpf0-6","gpf0-7", "gpf1-0", "gpf1-1",
"gpf1-2", "gpf1-3", "gpf1-4", "gpf1-5", "gpf1-6",
"gpf1-7", "gpf2-0", "gpf2-1", "gpf2-2", "gpf2-3",
"gpf2-4", "gpf2-5", "gpf2-6","gpf2-7", "gpf3-0",
"gpf3-1", "gpf3-2", "gpf3-3";
samsung,pin-function = <2>;
samsung,pin-pud = <0>;
samsung,pin-drv = <0>;
};
};
接着要执行menuconfig指令，添加相关驱动支持。如下：
Device Drivers --->
Graphics support --->
Console display driver support --->
<*> Framebuffer Console support
完成后重新编译生成uImage内核文件，替换老的版本。
接下来最重要的是添加lcd驱动源码，具体配置可以参考x4412提供的源码，在kernel/driver/video/samsung下的fb文件里。
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define VIDCON0 0x00
#define VIDCON1 0x04
#define VIDTCON0 0x10
#define VIDTCON1 0x14
#define VIDTCON2 0x18
#define WINCON0 0x20
#define VIDOSD0C 0x48
#define SHADOWCON 0x34
#define WINCHMAP2 0x3c
#define VIDOSD0A 0x40
#define VIDOSD0B 0x44
#define VIDW00ADD0B0 0xA0
#define VIDW00ADD1B0 0xD0
#define CLK_SRC_LCD0 0x234
#define CLK_SRC_MASK_LCD 0x334
#define CLK_DIV_LCD 0x534
#define CLK_GATE_IP_LCD 0x934
#define LCDBLK_CFG 0x00
#define LCDBLK_CFG2 0x04
#define LCD_LENTH 1024
#define LCD_WIDTH 600
#define BITS_PER_PIXEL 32
static int s3c_lcdfb_setcolreg(unsigned int regno, unsigned int red,
unsigned int green, unsigned int blue,
unsigned int transp, struct fb_info *info);
static struct fb_ops s3c_lcdfb_ops =
{ .owner = THIS_MODULE,
.fb_setcolreg = s3c_lcdfb_setcolreg,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
};
static struct fb_info *s3c_lcd;
static volatile void __iomem *lcd_regs_base;
static volatile void __iomem *clk_regs_base;
static volatile void __iomem *lcdblk_regs_base;
static volatile void __iomem *lcd0_configuration;
static u32 pseudo_palette[16];
static struct resource *res1, *res2, *res3, *res4;
/* from pxafb.c */
static inline unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
{
chan &= 0xffff;
chan >>= 16 - bf->length;
return chan << bf->offset;
}
static int s3c_lcdfb_setcolreg(unsigned int regno, unsigned int red,
unsigned int green, unsigned int blue,
unsigned int transp, struct fb_info *info)
{
unsigned int color = 0;
uint32_t *p;
color = chan_to_field(red, &info->var.red);
color |= chan_to_field(green, &info->var.green);
color |= chan_to_field(blue, &info->var.blue);
p = info->pseudo_palette;
p[regno] = color;
return 0;
}
static int lcd_probe(struct platform_device *pdev)
{
int ret;
unsigned int temp;
/* 1. 分配一个fb_info */
s3c_lcd = framebuffer_alloc(0, NULL);
/* 2. 设置 */
/* 2.1 设置 fix 固定的参数 */
strcpy(s3c_lcd->fix.id, "s702");
s3c_lcd->fix.smem_len = LCD_LENTH * LCD_WIDTH * BITS_PER_PIXEL / 8; //显存的长度
s3c_lcd->fix.type = FB_TYPE_PACKED_PIXELS; //类型
s3c_lcd->fix.visual = FB_VISUAL_TRUECOLOR; //TFT 真彩色
s3c_lcd->fix.line_length = LCD_LENTH * BITS_PER_PIXEL / 8; //一行的长度
/* 2.2 设置 var 可变的参数 */
s3c_lcd->var.xres = LCD_LENTH; //x方向分辨率
s3c_lcd->var.yres = LCD_WIDTH; //y方向分辨率
s3c_lcd->var.xres_virtual = LCD_LENTH; //x方向虚拟分辨率
s3c_lcd->var.yres_virtual = LCD_WIDTH; //y方向虚拟分辨率
s3c_lcd->var.bits_per_pixel = BITS_PER_PIXEL; //每个像素占的bit
/* RGB:888 */
s3c_lcd->var.red.length = 8;
s3c_lcd->var.red.offset = 16; //红
s3c_lcd->var.green.length = 8;
s3c_lcd->var.green.offset = 8; //绿
s3c_lcd->var.blue.length = 8;
s3c_lcd->var.blue.offset = 0; //蓝
s3c_lcd->var.activate = FB_ACTIVATE_NOW;
/* 2.3 设置操作函数 */
s3c_lcd->fbops = &s3c_lcdfb_ops;
/* 2.4 其他的设置 */
s3c_lcd->pseudo_palette = pseudo_palette; //调色板
s3c_lcd->screen_size = LCD_LENTH * LCD_WIDTH * BITS_PER_PIXEL / 8; //显存大小
/* 3. 硬件相关的操作 */
/* 3.1 配置GPIO用于LCD */
//设备树中使用"default"
/* 3.2 根据LCD手册设置LCD控制器, 比如VCLK的频率等 */
//寄存器映射
res1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res1 == NULL)
{
printk("platform_get_resource error\n");
return -EINVAL;
}
lcd_regs_base = devm_ioremap_resource(&pdev->dev, res1);
if (lcd_regs_base == NULL)
{
printk("devm_ioremap_resource error\n");
return -EINVAL;
}
res2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res2 == NULL)
{
printk("platform_get_resource error\n");
return -EINVAL;
}
lcdblk_regs_base = devm_ioremap_resource(&pdev->dev, res2);
if (lcdblk_regs_base == NULL)
{
printk("devm_ioremap_resource error\n");
return -EINVAL;
}
res3 = platform_get_resource(pdev, IORESOURCE_MEM, 2);
if (res3 == NULL)
{
printk("platform_get_resource error\n");
return -EINVAL;
}
lcd0_configuration = ioremap(res3->start, 0x04);
if (lcd0_configuration == NULL)
{
printk("devm_ioremap_resource error\n");
return -EINVAL;
}
*(unsigned long *)lcd0_configuration = 7;
res4 = platform_get_resource(pdev, IORESOURCE_MEM, 3);
if (res3 == NULL)
{
printk("platform_get_resource error\n");
return -EINVAL;
}
clk_regs_base = ioremap(res4->start, 0x1000);
if (clk_regs_base == NULL)
{
printk("devm_ioremap_resource error\n");
return -EINVAL;
}
//使能时钟
//时钟源选择 0110 SCLKMPLL_USER_T 800M
temp = readl(clk_regs_base + CLK_SRC_LCD0);
temp &= ~0x0f;
temp |= 0x06;
writel(temp, clk_regs_base + CLK_SRC_LCD0);
//FIMD0_MASK
temp = readl(clk_regs_base + CLK_SRC_MASK_LCD);
temp |= 0x01;
writel(temp, clk_regs_base + CLK_SRC_MASK_LCD);
//SCLK_FIMD0 = MOUTFIMD0/(FIMD0_RATIO + 1),分频 1/1
temp = readl(clk_regs_base + CLK_DIV_LCD);
temp &= ~0x0f;
writel(temp, clk_regs_base + CLK_DIV_LCD);
//CLK_FIMD0 Pass
temp = readl(clk_regs_base + CLK_GATE_IP_LCD);
temp |= 0x01;
writel(temp, clk_regs_base + CLK_GATE_IP_LCD);
//FIMDBYPASS_LBLK0 FIMD Bypass
temp = readl(lcdblk_regs_base + LCDBLK_CFG);
temp |= 1 << 1;
writel(temp, lcdblk_regs_base + LCDBLK_CFG);
temp = readl(lcdblk_regs_base + LCDBLK_CFG2);
temp |= 1 << 0;
writel(temp, lcdblk_regs_base + LCDBLK_CFG2);
mdelay(1000);
//分频 800/(23 +1 ) == 33.3M
temp = readl(lcd_regs_base + VIDCON0);
temp |= (11 << 6);
writel(temp, lcd_regs_base + VIDCON0);
/*
* VIDTCON1:
* [5]:IVSYNC ===> 1 : Inverted(反转)
* [6]:IHSYNC ===> 1 : Inverted(反转)
* [7]:IVCLK ===> 1 : Fetches video data at VCLK rising edge (下降沿触发)
* [10:9]:FIXVCLK ====> 01 : VCLK running
*/
temp = readl(lcd_regs_base + VIDCON1);
temp |= (1 << 5) | (1 << 6);
writel(temp, lcd_regs_base + VIDCON1);
/*
* VIDTCON0:
* [23:16]: VBPD + 1 <------> tvpw (1 - 20) 13
* [15:8] : VFPD + 1 <------> tvfp 22
* [7:0] : VSPW + 1 <------> tvb - tvpw = 23 - 13 = 10
*/
temp = 0;//readl(lcd_regs_base + VIDTCON0);
temp |= (17 << 16) | (21 << 8) | (6);
writel(temp, lcd_regs_base + VIDTCON0);
/*
* VIDTCON1:
* [23:16]: HBPD + 1 <------> thpw (1 - 40) 36
* [15:8] : HFPD + 1 <------> thfp 210
* [7:0] : HSPW + 1 <------> thb - thpw = 46 - 36 = 10
*/
temp = readl(lcd_regs_base + VIDTCON1);
temp |= (37 << 16) | (209 << 8) | (9);
writel(temp, lcd_regs_base + VIDTCON1);
/*
* HOZVAL = (Horizontal display size) - 1 and LINEVAL = (Vertical display size) - 1.
* Horizontal(水平) display size : 1024
* Vertical(垂直) display size : 600
*/
temp = ((LCD_WIDTH-1) << 11) | (LCD_LENTH-1);
writel(temp, lcd_regs_base + VIDTCON2);
/*
* WINCON0:
* [16]:Specifies Half-Word swap control bit. 1 = Enables swap P1779 低位像素存放在低字节
* [5:2]: Selects Bits Per Pixel (BPP) mode for Window image : 0101 ===> 16BPP RGB565
* [1]:Enables/disables video output 1 = Enables
*/
temp = readl(lcd_regs_base + WINCON0);
temp &= ~(0xf << 2);
temp |= (1 << 15) | (0xd << 2) | 1;
writel(temp, lcd_regs_base + WINCON0);
//Window Size For example, Height ? Width (number of word)
temp = (LCD_LENTH * LCD_WIDTH) >> 1;
writel(temp, lcd_regs_base + VIDOSD0C);
temp = readl(lcd_regs_base + SHADOWCON);
writel(temp | 0x01, lcd_regs_base + SHADOWCON);
//p1769
temp = readl(lcd_regs_base + WINCHMAP2);
temp &= ~(7 << 16);
temp |= 1 << 16;
temp &= ~7;
temp |= 1;
writel(temp, lcd_regs_base + WINCHMAP2);
/*
* bit0-10 : 指定OSD图像左上像素的垂直屏幕坐标
* bit11-21: 指定OSD图像左上像素的水平屏幕坐标
*/
writel(0, lcd_regs_base + VIDOSD0A);
/*
* bit0-10 : 指定OSD图像右下像素的垂直屏幕坐标
* bit11-21: 指定OSD图像右下像素的水平屏幕坐标
*/
writel(((LCD_LENTH-1) << 11) | (LCD_WIDTH-1), lcd_regs_base + VIDOSD0B);
//Enables video output and logic immediately
temp = readl(lcd_regs_base + VIDCON0);
writel(temp | 0x03, lcd_regs_base + VIDCON0);
/* 3.3 分配显存(framebuffer), 并把地址告诉LCD控制器 */
// s3c_lcd->screen_base 显存虚拟地址
// s3c_lcd->fix.smem_len 显存大小,前面计算的
// s3c_lcd->fix.smem_start 显存物理地址
s3c_lcd->screen_base = dma_alloc_writecombine(NULL, s3c_lcd->fix.smem_len, (dma_addr_t *)&s3c_lcd->fix.smem_start, GFP_KERNEL);
//显存起始地址
writel(s3c_lcd->fix.smem_start, lcd_regs_base + VIDW00ADD0B0);
//显存结束地址
writel(s3c_lcd->fix.smem_start + s3c_lcd->fix.smem_len, lcd_regs_base + VIDW00ADD1B0);
/* 4. 注册 */
ret = register_framebuffer(s3c_lcd);
return ret;
}
static int lcd_remove(struct platform_device *pdev)
{
unregister_framebuffer(s3c_lcd);
dma_free_writecombine(NULL, s3c_lcd->fix.smem_len, s3c_lcd->screen_base, s3c_lcd->fix.smem_start);
framebuffer_release(s3c_lcd);
return 0;
}
static const struct of_device_id lcd_dt_ids[] =
{
{ .compatible = "x4412,lcd_s702", },
{},
};
MODULE_DEVICE_TABLE(of, lcd_dt_ids);
static struct platform_driver lcd_driver =
{
.driver = {
.name = "lcd_vs070",
.of_match_table = of_match_ptr(lcd_dt_ids),
},
.probe = lcd_probe,
.remove = lcd_remove,
};
static int lcd_init(void)
{
int ret;
ret = platform_driver_register(&lcd_driver);
if (ret)
{
printk(KERN_ERR "lcd: probe fail: %d\n", ret);
}
return ret;
}
static void lcd_exit(void)
{
printk("enter %s\n", __func__);
platform_driver_unregister(&lcd_driver);
}
module_init(lcd_init);
module_exit(lcd_exit);
MODULE_LICENSE("GPL"); 编译生成lcd_vs070.ko驱动文件，将其放在最小文件系统的指定目录下，例如放在/driver/lcd/下。然后修改rcS文件，添加如下内容: insmod /lcd/app/lcd_vs070.ko 。这样开机启动后就会自动加载驱动文件，就可以使用lcd作为显示用。
然后进入 etc/inittab ，输入如下内容，确保可以用lcd输出控制信息:
::sysinit:/etc/init.d/rcS
::respawn:-/bin/sh
console::askfirst:-/bin/sh
tty0::askfirst:-/bin/sh
::ctrlaltdel:/bin/umount -a -r
注意：tty0 设备表示 lcd 输出, askfirst 会询问用户激活命令行, /bin/sh 表示命令行脚本。 这样,重新上电后 lcd 默认加载命令行,命令行同时可以在lcd和uart里输出