add: 11_编程_LCD驱动程序框架_使用设备树

IMX6ULL/doc_pic/03_LCD/11_编程_LCD驱动程序框架_使用设备树.md

@@ -0,0 +1,61 @@
+## 编程\_LCD驱动程序框架\_使用设备树
+
+参考资料，GIT仓库里：
+
+* 基于这个程序修改：
+  * `IMX6ULL\source\03_LCD\03_lcd_drv_qemu_ok`
+  * `STM32MP157\source\A7\03_LCD\03_lcd_drv_qemu_ok`
+  
+* 参考：内核自带的示例驱动程序
+  
+  * Linux驱动源码：`drivers/video/fbdev/simplefb.c`
+  * 设备树：
+    * `arch/arm/boot/dts/sun4i-a10.dtsi`
+  
+
+* 本节视频编写好的代码
+  * `IMX6ULL\source\03_LCD\06_lcd_drv_framework_use_devicetree`
+  * `STM32MP157\source\A7\03_LCD\06_lcd_drv_framework_use_devicetree`
+
+### 1. 说明
+
+Linux驱动程序 = 驱动程序框架 + 硬件编程。
+在前面已经基于QEMU编写了LCD驱动程序，对LCD驱动程序的框架已经分析清楚。
+核心就是：
+
+* 分配fb_info
+* 设置fb_info
+* 注册fb_info
+* 硬件相关的设置
+
+本节课程我们基于设备树来编写驱动程序。
+
+
+
+### 2. 入口函数注册platform_driver
+
+### 3. 设备树有对应节点
+
+```shell
+
+                framebuffer-mylcd {
+                        compatible = "100ask,lcd_drv";
+                };
+
+```
+
+
+
+### 4. 编写probe函数
+
+* 分配fb_info
+* 设置fb_info
+* 注册fb_info
+* 硬件相关的设置
+  * 引脚设置
+  * 时钟设置
+  * LCD控制器设置
+
+
+
+

IMX6ULL/source/03_LCD/06_lcd_drv_framework_use_devicetree/lcd_drv.c

@@ -0,0 +1,201 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/io.h>
+
+#include <asm/div64.h>
+
+#include <asm/mach/map.h>
+
+struct lcd_regs {
+	volatile unsigned int fb_base_phys;
+	volatile unsigned int fb_xres;
+	volatile unsigned int fb_yres;
+	volatile unsigned int fb_bpp;	
+};
+
+static struct lcd_regs *mylcd_regs;
+
+static struct fb_info *myfb_info;
+
+static unsigned int pseudo_palette[16];
+
+/* 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 mylcd_setcolreg(unsigned regno,
+			       unsigned red, unsigned green, unsigned blue,
+			       unsigned transp, struct fb_info *info)
+{
+	unsigned int val;
+
+	/* dprintk("setcol: regno=%d, rgb=%d,%d,%d\n",
+		   regno, red, green, blue); */
+
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		/* true-colour, use pseudo-palette */
+
+		if (regno < 16) {
+			u32 *pal = info->pseudo_palette;
+
+			val  = chan_to_field(red,   &info->var.red);
+			val |= chan_to_field(green, &info->var.green);
+			val |= chan_to_field(blue,  &info->var.blue);
+
+			pal[regno] = val;
+		}
+		break;
+
+	default:
+		return 1;	/* unknown type */
+	}
+
+	return 0;
+}
+
+
+static struct fb_ops myfb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_setcolreg	= mylcd_setcolreg,
+	.fb_fillrect	= cfb_fillrect,
+	.fb_copyarea	= cfb_copyarea,
+	.fb_imageblit	= cfb_imageblit,
+};
+
+static int mylcd_probe(struct platform_device *pdev)
+{
+	dma_addr_t phy_addr;
+	
+	/* 1.1 分配fb_info */
+	myfb_info = framebuffer_alloc(0, NULL);
+
+	/* 1.2 设置fb_info */
+	/* a. var : LCD分辨率、颜色格式 */
+	myfb_info->var.xres_virtual = myfb_info->var.xres = 500;
+	myfb_info->var.yres_virtual = myfb_info->var.yres = 300;
+	
+	myfb_info->var.bits_per_pixel = 16;  /* rgb565 */
+	myfb_info->var.red.offset = 11;
+	myfb_info->var.red.length = 5;
+
+	myfb_info->var.green.offset = 5;
+	myfb_info->var.green.length = 6;
+
+	myfb_info->var.blue.offset = 0;
+	myfb_info->var.blue.length = 5;
+	
+
+	/* b. fix */
+	strcpy(myfb_info->fix.id, "100ask_lcd");
+	myfb_info->fix.smem_len = myfb_info->var.xres * myfb_info->var.yres * myfb_info->var.bits_per_pixel / 8;
+	if (myfb_info->var.bits_per_pixel == 24)
+		myfb_info->fix.smem_len = myfb_info->var.xres * myfb_info->var.yres * 4;
+
+
+	/* fb的虚拟地址 */
+	myfb_info->screen_base = dma_alloc_wc(NULL, myfb_info->fix.smem_len, &phy_addr,
+					 GFP_KERNEL);
+	myfb_info->fix.smem_start = phy_addr;  /* fb的物理地址 */
+	
+	myfb_info->fix.type = FB_TYPE_PACKED_PIXELS;
+	myfb_info->fix.visual = FB_VISUAL_TRUECOLOR;
+
+	myfb_info->fix.line_length = myfb_info->var.xres * myfb_info->var.bits_per_pixel / 8;
+	if (myfb_info->var.bits_per_pixel == 24)
+		myfb_info->fix.line_length = myfb_info->var.xres * 4;
+	
+
+	/* c. fbops */
+	myfb_info->fbops = &myfb_ops;
+	myfb_info->pseudo_palette = pseudo_palette;
+
+
+	/* 1.3 注册fb_info */
+	register_framebuffer(myfb_info);
+
+	/* 1.4 硬件操作 */
+	mylcd_regs = ioremap(0x021C8000, sizeof(struct lcd_regs));
+	mylcd_regs->fb_base_phys = phy_addr;
+	mylcd_regs->fb_xres = 500;
+	mylcd_regs->fb_yres = 300;
+	mylcd_regs->fb_bpp  = 16;
+
+	return 0;
+}
+
+
+static int mylcd_remove(struct platform_device *pdev)
+{
+	/* 反过来操作 */
+	/* 2.1 反注册fb_info */
+	unregister_framebuffer(myfb_info);
+
+	/* 2.2 释放fb_info */
+	framebuffer_release(myfb_info);
+	
+	iounmap(mylcd_regs);
+
+	return 0;
+}
+
+
+static const struct of_device_id mylcd_of_match[] = {
+	{ .compatible = "100ask,lcd_drv", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, simplefb_of_match);
+
+static struct platform_driver mylcd_driver = {
+	.driver = {
+		.name = "mylcd",
+		.of_match_table = mylcd_of_match,
+	},
+	.probe = mylcd_probe,
+	.remove = mylcd_remove,
+};
+
+static int __init lcd_drv_init(void)
+{
+	int ret;
+	struct device_node *np;
+
+	ret = platform_driver_register(&mylcd_driver);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/* 2. 出口 */
+static void __exit lcd_drv_exit(void)
+{
+	platform_driver_unregister(&mylcd_driver);
+}
+
+
+module_init(lcd_drv_init);
+module_exit(lcd_drv_exit);
+
+MODULE_AUTHOR("www.100ask.net");
+MODULE_DESCRIPTION("Framebuffer driver for the linux");
+MODULE_LICENSE("GPL");
+

README.md

@@ -61,6 +61,7 @@ git clone https://e.coding.net/weidongshan/doc_and_source_for_drivers.git
 * 2021.01.14 发布"LCD驱动"：09\_硬件\_IMX6ULL的LCD控制器、09\_硬件\_STM32MP157的LCD控制器 
 * 2021.01.15 发布"LCD驱动"：10\_分析内核自带的LCD驱动程序\_基于IMX6ULL
 * 2021.01.20 发布"LCD驱动"：10\_分析内核自带的LCD驱动程序\_基于STM32MP157
+* 2021.01.21 发布"LCD驱动"：11\_编程\_LCD驱动程序框架\_使用设备树
 
 
 

STM32MP157/doc_pic/03_LCD/11_编程_LCD驱动程序框架_使用设备树.md

@@ -0,0 +1,61 @@
+## 编程\_LCD驱动程序框架\_使用设备树
+
+参考资料，GIT仓库里：
+
+* 基于这个程序修改：
+  * `IMX6ULL\source\03_LCD\03_lcd_drv_qemu_ok`
+  * `STM32MP157\source\A7\03_LCD\03_lcd_drv_qemu_ok`
+  
+* 参考：内核自带的示例驱动程序
+  
+  * Linux驱动源码：`drivers/video/fbdev/simplefb.c`
+  * 设备树：
+    * `arch/arm/boot/dts/sun4i-a10.dtsi`
+  
+
+* 本节视频编写好的代码
+  * `IMX6ULL\source\03_LCD\06_lcd_drv_framework_use_devicetree`
+  * `STM32MP157\source\A7\03_LCD\06_lcd_drv_framework_use_devicetree`
+
+### 1. 说明
+
+Linux驱动程序 = 驱动程序框架 + 硬件编程。
+在前面已经基于QEMU编写了LCD驱动程序，对LCD驱动程序的框架已经分析清楚。
+核心就是：
+
+* 分配fb_info
+* 设置fb_info
+* 注册fb_info
+* 硬件相关的设置
+
+本节课程我们基于设备树来编写驱动程序。
+
+
+
+### 2. 入口函数注册platform_driver
+
+### 3. 设备树有对应节点
+
+```shell
+
+                framebuffer-mylcd {
+                        compatible = "100ask,lcd_drv";
+                };
+
+```
+
+
+
+### 4. 编写probe函数
+
+* 分配fb_info
+* 设置fb_info
+* 注册fb_info
+* 硬件相关的设置
+  * 引脚设置
+  * 时钟设置
+  * LCD控制器设置
+
+
+
+

STM32MP157/source/A7/03_LCD/06_lcd_drv_framework_use_devicetree/lcd_drv.c

@@ -0,0 +1,201 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/io.h>
+
+#include <asm/div64.h>
+
+#include <asm/mach/map.h>
+
+struct lcd_regs {
+	volatile unsigned int fb_base_phys;
+	volatile unsigned int fb_xres;
+	volatile unsigned int fb_yres;
+	volatile unsigned int fb_bpp;	
+};
+
+static struct lcd_regs *mylcd_regs;
+
+static struct fb_info *myfb_info;
+
+static unsigned int pseudo_palette[16];
+
+/* 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 mylcd_setcolreg(unsigned regno,
+			       unsigned red, unsigned green, unsigned blue,
+			       unsigned transp, struct fb_info *info)
+{
+	unsigned int val;
+
+	/* dprintk("setcol: regno=%d, rgb=%d,%d,%d\n",
+		   regno, red, green, blue); */
+
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		/* true-colour, use pseudo-palette */
+
+		if (regno < 16) {
+			u32 *pal = info->pseudo_palette;
+
+			val  = chan_to_field(red,   &info->var.red);
+			val |= chan_to_field(green, &info->var.green);
+			val |= chan_to_field(blue,  &info->var.blue);
+
+			pal[regno] = val;
+		}
+		break;
+
+	default:
+		return 1;	/* unknown type */
+	}
+
+	return 0;
+}
+
+
+static struct fb_ops myfb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_setcolreg	= mylcd_setcolreg,
+	.fb_fillrect	= cfb_fillrect,
+	.fb_copyarea	= cfb_copyarea,
+	.fb_imageblit	= cfb_imageblit,
+};
+
+static int mylcd_probe(struct platform_device *pdev)
+{
+	dma_addr_t phy_addr;
+	
+	/* 1.1 分配fb_info */
+	myfb_info = framebuffer_alloc(0, NULL);
+
+	/* 1.2 设置fb_info */
+	/* a. var : LCD分辨率、颜色格式 */
+	myfb_info->var.xres_virtual = myfb_info->var.xres = 500;
+	myfb_info->var.yres_virtual = myfb_info->var.yres = 300;
+	
+	myfb_info->var.bits_per_pixel = 16;  /* rgb565 */
+	myfb_info->var.red.offset = 11;
+	myfb_info->var.red.length = 5;
+
+	myfb_info->var.green.offset = 5;
+	myfb_info->var.green.length = 6;
+
+	myfb_info->var.blue.offset = 0;
+	myfb_info->var.blue.length = 5;
+	
+
+	/* b. fix */
+	strcpy(myfb_info->fix.id, "100ask_lcd");
+	myfb_info->fix.smem_len = myfb_info->var.xres * myfb_info->var.yres * myfb_info->var.bits_per_pixel / 8;
+	if (myfb_info->var.bits_per_pixel == 24)
+		myfb_info->fix.smem_len = myfb_info->var.xres * myfb_info->var.yres * 4;
+
+
+	/* fb的虚拟地址 */
+	myfb_info->screen_base = dma_alloc_wc(NULL, myfb_info->fix.smem_len, &phy_addr,
+					 GFP_KERNEL);
+	myfb_info->fix.smem_start = phy_addr;  /* fb的物理地址 */
+	
+	myfb_info->fix.type = FB_TYPE_PACKED_PIXELS;
+	myfb_info->fix.visual = FB_VISUAL_TRUECOLOR;
+
+	myfb_info->fix.line_length = myfb_info->var.xres * myfb_info->var.bits_per_pixel / 8;
+	if (myfb_info->var.bits_per_pixel == 24)
+		myfb_info->fix.line_length = myfb_info->var.xres * 4;
+	
+
+	/* c. fbops */
+	myfb_info->fbops = &myfb_ops;
+	myfb_info->pseudo_palette = pseudo_palette;
+
+
+	/* 1.3 注册fb_info */
+	register_framebuffer(myfb_info);
+
+	/* 1.4 硬件操作 */
+	mylcd_regs = ioremap(0x021C8000, sizeof(struct lcd_regs));
+	mylcd_regs->fb_base_phys = phy_addr;
+	mylcd_regs->fb_xres = 500;
+	mylcd_regs->fb_yres = 300;
+	mylcd_regs->fb_bpp  = 16;
+
+	return 0;
+}
+
+
+static int mylcd_remove(struct platform_device *pdev)
+{
+	/* 反过来操作 */
+	/* 2.1 反注册fb_info */
+	unregister_framebuffer(myfb_info);
+
+	/* 2.2 释放fb_info */
+	framebuffer_release(myfb_info);
+	
+	iounmap(mylcd_regs);
+
+	return 0;
+}
+
+
+static const struct of_device_id mylcd_of_match[] = {
+	{ .compatible = "100ask,lcd_drv", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, simplefb_of_match);
+
+static struct platform_driver mylcd_driver = {
+	.driver = {
+		.name = "mylcd",
+		.of_match_table = mylcd_of_match,
+	},
+	.probe = mylcd_probe,
+	.remove = mylcd_remove,
+};
+
+static int __init lcd_drv_init(void)
+{
+	int ret;
+	struct device_node *np;
+
+	ret = platform_driver_register(&mylcd_driver);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/* 2. 出口 */
+static void __exit lcd_drv_exit(void)
+{
+	platform_driver_unregister(&mylcd_driver);
+}
+
+
+module_init(lcd_drv_init);
+module_exit(lcd_drv_exit);
+
+MODULE_AUTHOR("www.100ask.net");
+MODULE_DESCRIPTION("Framebuffer driver for the linux");
+MODULE_LICENSE("GPL");
+