diff --git a/IMX6ULL/doc_pic/07_GPIO/02_使用GPIO子系统要掌握的重要概念.docx b/IMX6ULL/doc_pic/07_GPIO/02_使用GPIO子系统要掌握的重要概念.docx
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diff --git a/IMX6ULL/doc_pic/07_GPIO/04_在100ASK_IMX6ULL上机实验.docx b/IMX6ULL/doc_pic/07_GPIO/04_在100ASK_IMX6ULL上机实验.docx
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diff --git a/IMX6ULL/source/07_GPIO/01_led/Makefile b/IMX6ULL/source/07_GPIO/01_led/Makefile
new file mode 100644
index 0000000..090f6cd
--- /dev/null
+++ b/IMX6ULL/source/07_GPIO/01_led/Makefile
@@ -0,0 +1,29 @@
+
+# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
+# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
+# 2.1 ARCH,          比如: export ARCH=arm64
+# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
+# 2.3 PATH,          比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin 
+# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
+#       请参考各开发板的高级用户使用手册
+
+KERN_DIR = # 板子所用内核源码的目录
+
+all:
+	make -C $(KERN_DIR) M=`pwd` modules 
+	$(CROSS_COMPILE)gcc -o ledtest ledtest.c 
+
+clean:
+	make -C $(KERN_DIR) M=`pwd` modules clean
+	rm -rf modules.order
+	rm -f ledtest
+
+# 参考内核源码drivers/char/ipmi/Makefile
+# 要想把a.c, b.c编译成ab.ko, 可以这样指定:
+# ab-y := a.o b.o
+# obj-m += ab.o
+
+
+
+obj-m += leddrv.o
+
diff --git a/IMX6ULL/source/07_GPIO/01_led/leddrv.c b/IMX6ULL/source/07_GPIO/01_led/leddrv.c
new file mode 100644
index 0000000..0bd3e5e
--- /dev/null
+++ b/IMX6ULL/source/07_GPIO/01_led/leddrv.c
@@ -0,0 +1,166 @@
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/kmod.h>
+#include <linux/gfp.h>
+#include <linux/gpio/consumer.h>
+#include <linux/platform_device.h>
+
+
+/* 1. 确定主设备号                                                                 */
+static int major = 0;
+static struct class *led_class;
+static struct gpio_desc *led_gpio;
+
+
+/* 3. 实现对应的open/read/write等函数，填入file_operations结构体                   */
+static ssize_t led_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* write(fd, &val, 1); */
+static ssize_t led_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
+{
+	int err;
+	char status;
+	//struct inode *inode = file_inode(file);
+	//int minor = iminor(inode);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	err = copy_from_user(&status, buf, 1);
+
+	/* 根据次设备号和status控制LED */
+	gpiod_set_value(led_gpio, status);
+	
+	return 1;
+}
+
+static int led_drv_open (struct inode *node, struct file *file)
+{
+	//int minor = iminor(node);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 根据次设备号初始化LED */
+	gpiod_direction_output(led_gpio, 0);
+	
+	return 0;
+}
+
+static int led_drv_close (struct inode *node, struct file *file)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* 定义自己的file_operations结构体                                              */
+static struct file_operations led_drv = {
+	.owner	 = THIS_MODULE,
+	.open    = led_drv_open,
+	.read    = led_drv_read,
+	.write   = led_drv_write,
+	.release = led_drv_close,
+};
+
+/* 4. 从platform_device获得GPIO
+ *    把file_operations结构体告诉内核：注册驱动程序
+ */
+static int chip_demo_gpio_probe(struct platform_device *pdev)
+{
+	//int err;
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* 4.1 设备树中定义有: led-gpios=<...>;	*/
+    led_gpio = gpiod_get(&pdev->dev, "led", 0);
+	if (IS_ERR(led_gpio)) {
+		dev_err(&pdev->dev, "Failed to get GPIO for led\n");
+		return PTR_ERR(led_gpio);
+	}
+    
+	/* 4.2 注册file_operations 	*/
+	major = register_chrdev(0, "100ask_led", &led_drv);  /* /dev/led */
+
+	led_class = class_create(THIS_MODULE, "100ask_led_class");
+	if (IS_ERR(led_class)) {
+		printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+		unregister_chrdev(major, "led");
+		gpiod_put(led_gpio);
+		return PTR_ERR(led_class);
+	}
+
+	device_create(led_class, NULL, MKDEV(major, 0), NULL, "100ask_led%d", 0); /* /dev/100ask_led0 */
+        
+    return 0;
+    
+}
+
+static int chip_demo_gpio_remove(struct platform_device *pdev)
+{
+	device_destroy(led_class, MKDEV(major, 0));
+	class_destroy(led_class);
+	unregister_chrdev(major, "100ask_led");
+	gpiod_put(led_gpio);
+    
+    return 0;
+}
+
+
+static const struct of_device_id ask100_leds[] = {
+    { .compatible = "100ask,leddrv" },
+    { },
+};
+
+/* 1. 定义platform_driver */
+static struct platform_driver chip_demo_gpio_driver = {
+    .probe      = chip_demo_gpio_probe,
+    .remove     = chip_demo_gpio_remove,
+    .driver     = {
+        .name   = "100ask_led",
+        .of_match_table = ask100_leds,
+    },
+};
+
+/* 2. 在入口函数注册platform_driver */
+static int __init led_init(void)
+{
+    int err;
+    
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	
+    err = platform_driver_register(&chip_demo_gpio_driver); 
+	
+	return err;
+}
+
+/* 3. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数
+ *     卸载platform_driver
+ */
+static void __exit led_exit(void)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+    platform_driver_unregister(&chip_demo_gpio_driver);
+}
+
+
+/* 7. 其他完善：提供设备信息，自动创建设备节点                                     */
+
+module_init(led_init);
+module_exit(led_exit);
+
+MODULE_LICENSE("GPL");
+
+
diff --git a/IMX6ULL/source/07_GPIO/01_led/leddrv_未测试的原始版本.c b/IMX6ULL/source/07_GPIO/01_led/leddrv_未测试的原始版本.c
new file mode 100644
index 0000000..6ef1a7c
--- /dev/null
+++ b/IMX6ULL/source/07_GPIO/01_led/leddrv_未测试的原始版本.c
@@ -0,0 +1,165 @@
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/kmod.h>
+#include <linux/gfp.h>
+#include <linux/gpio/consumer.h>
+
+
+/* 1. 确定主设备号                                                                 */
+static int major = 0;
+static struct class *led_class;
+static struct gpio_desc *led_gpio;
+
+
+/* 3. 实现对应的open/read/write等函数，填入file_operations结构体                   */
+static ssize_t led_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* write(fd, &val, 1); */
+static ssize_t led_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
+{
+	int err;
+	char status;
+	struct inode *inode = file_inode(file);
+	int minor = iminor(inode);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	err = copy_from_user(&status, buf, 1);
+
+	/* 根据次设备号和status控制LED */
+	gpiod_set_value(led_gpio, status);
+	
+	return 1;
+}
+
+static int led_drv_open (struct inode *node, struct file *file)
+{
+	int minor = iminor(node);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 根据次设备号初始化LED */
+	gpiod_direction_output(led_gpio, 0);
+	
+	return 0;
+}
+
+static int led_drv_close (struct inode *node, struct file *file)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* 定义自己的file_operations结构体                                              */
+static struct file_operations led_drv = {
+	.owner	 = THIS_MODULE,
+	.open    = led_drv_open,
+	.read    = led_drv_read,
+	.write   = led_drv_write,
+	.release = led_drv_close,
+};
+
+/* 4. 从platform_device获得GPIO
+ *    把file_operations结构体告诉内核：注册驱动程序
+ */
+static int chip_demo_gpio_probe(struct platform_device *pdev)
+{
+	int err;
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* 4.1 设备树中定义有: led-gpios=<...>;	*/
+    led_gpio = gpiod_get(&pdev->dev, "led", 0);
+	if (IS_ERR(led_gpio)) {
+		dev_err(&pdev->dev, "Failed to get GPIO for led\n");
+		return PTR_ERR(led_gpio);
+	}
+    
+	/* 4.2 注册file_operations 	*/
+	major = register_chrdev(0, "100ask_led", &led_drv);  /* /dev/led */
+
+	led_class = class_create(THIS_MODULE, "100ask_led_class");
+	if (IS_ERR(led_class)) {
+		printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+		unregister_chrdev(major, "led");
+		gpiod_free(led_gpio);
+		return PTR_ERR(led_class);
+	}
+
+	device_create(led_class, NULL, MKDEV(major, 0), NULL, "100ask_led%d", 0); /* /dev/100ask_led0 */
+        
+    return 0;
+    
+}
+
+static int chip_demo_gpio_remove(struct platform_device *pdev)
+{
+	device_destroy(led_class, MKDEV(major, 0));
+	class_destroy(led_class);
+	unregister_chrdev(major, "100ask_led");
+	gpiod_free(led_gpio);
+    
+    return 0;
+}
+
+
+static const struct of_device_id ask100_leds[] = {
+    { .compatible = "100ask,leddrv" },
+    { },
+};
+
+/* 1. 定义platform_driver */
+static struct platform_driver chip_demo_gpio_driver = {
+    .probe      = chip_demo_gpio_probe,
+    .remove     = chip_demo_gpio_remove,
+    .driver     = {
+        .name   = "100ask_led",
+        .of_match_table = ask100_leds,
+    },
+};
+
+/* 2. 在入口函数注册platform_driver */
+static int __init led_init(void)
+{
+    int err;
+    
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	
+    err = platform_driver_register(&chip_demo_gpio_driver); 
+	
+	return err;
+}
+
+/* 3. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数
+ *     卸载platform_driver
+ */
+static void __exit led_exit(void)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+    platform_driver_unregister(&chip_demo_gpio_driver);
+}
+
+
+/* 7. 其他完善：提供设备信息，自动创建设备节点                                     */
+
+module_init(led_init);
+module_exit(led_exit);
+
+MODULE_LICENSE("GPL");
+
+
diff --git a/IMX6ULL/source/07_GPIO/01_led/ledtest.c b/IMX6ULL/source/07_GPIO/01_led/ledtest.c
new file mode 100644
index 0000000..099eb11
--- /dev/null
+++ b/IMX6ULL/source/07_GPIO/01_led/ledtest.c
@@ -0,0 +1,50 @@
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+
+/*
+ * ./ledtest /dev/100ask_led0 on
+ * ./ledtest /dev/100ask_led0 off
+ */
+int main(int argc, char **argv)
+{
+	int fd;
+	char status;
+	
+	/* 1. 判断参数 */
+	if (argc != 3) 
+	{
+		printf("Usage: %s <dev> <on | off>\n", argv[0]);
+		return -1;
+	}
+
+	/* 2. 打开文件 */
+	fd = open(argv[1], O_RDWR);
+	if (fd == -1)
+	{
+		printf("can not open file %s\n", argv[1]);
+		return -1;
+	}
+
+	/* 3. 写文件 */
+	if (0 == strcmp(argv[2], "on"))
+	{
+		status = 1;
+		write(fd, &status, 1);
+	}
+	else
+	{
+		status = 0;
+		write(fd, &status, 1);
+	}
+	
+	close(fd);
+	
+	return 0;
+}
+
+
diff --git a/README.md b/README.md
index 32ea5d8..0db05bb 100644
--- a/README.md
+++ b/README.md
@@ -223,6 +223,10 @@ git clone https://e.coding.net/weidongshan/linux/doc_and_source_for_drivers.git
   
   ```shell
   01_GPIO子系统视频介绍
+  02_使用GPIO子系统要掌握的重要概念
+  03_基于GPIO子系统的LED驱动程序
+  04_在100ASK_IMX6ULL上机实验
+  04_在100ASK_STM32MP157上机实验
   ```
   
   
diff --git a/STM32MP157/doc_pic/07_GPIO/02_使用GPIO子系统要掌握的重要概念.docx b/STM32MP157/doc_pic/07_GPIO/02_使用GPIO子系统要掌握的重要概念.docx
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diff --git a/STM32MP157/source/A7/07_GPIO/01_led/Makefile b/STM32MP157/source/A7/07_GPIO/01_led/Makefile
new file mode 100644
index 0000000..090f6cd
--- /dev/null
+++ b/STM32MP157/source/A7/07_GPIO/01_led/Makefile
@@ -0,0 +1,29 @@
+
+# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
+# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
+# 2.1 ARCH,          比如: export ARCH=arm64
+# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
+# 2.3 PATH,          比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin 
+# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
+#       请参考各开发板的高级用户使用手册
+
+KERN_DIR = # 板子所用内核源码的目录
+
+all:
+	make -C $(KERN_DIR) M=`pwd` modules 
+	$(CROSS_COMPILE)gcc -o ledtest ledtest.c 
+
+clean:
+	make -C $(KERN_DIR) M=`pwd` modules clean
+	rm -rf modules.order
+	rm -f ledtest
+
+# 参考内核源码drivers/char/ipmi/Makefile
+# 要想把a.c, b.c编译成ab.ko, 可以这样指定:
+# ab-y := a.o b.o
+# obj-m += ab.o
+
+
+
+obj-m += leddrv.o
+
diff --git a/STM32MP157/source/A7/07_GPIO/01_led/leddrv.c b/STM32MP157/source/A7/07_GPIO/01_led/leddrv.c
new file mode 100644
index 0000000..521c65d
--- /dev/null
+++ b/STM32MP157/source/A7/07_GPIO/01_led/leddrv.c
@@ -0,0 +1,161 @@
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/kmod.h>
+#include <linux/gfp.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+
+
+/* 1. 确定主设备号                                                                 */
+static int major = 0;
+static struct class *led_class;
+static struct gpio_desc *led_gpio;
+
+
+/* 3. 实现对应的open/read/write等函数，填入file_operations结构体                   */
+static ssize_t led_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* write(fd, &val, 1); */
+static ssize_t led_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
+{
+	int err;
+	char status;
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	err = copy_from_user(&status, buf, 1);
+
+	/* 根据次设备号和status控制LED */
+	gpiod_set_value(led_gpio, status);
+	
+	return 1;
+}
+
+static int led_drv_open (struct inode *node, struct file *file)
+{	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 根据次设备号初始化LED */
+	gpiod_direction_output(led_gpio, 0);
+	
+	return 0;
+}
+
+static int led_drv_close (struct inode *node, struct file *file)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* 定义自己的file_operations结构体                                              */
+static struct file_operations led_drv = {
+	.owner	 = THIS_MODULE,
+	.open    = led_drv_open,
+	.read    = led_drv_read,
+	.write   = led_drv_write,
+	.release = led_drv_close,
+};
+
+/* 4. 从platform_device获得GPIO
+ *    把file_operations结构体告诉内核：注册驱动程序
+ */
+static int chip_demo_gpio_probe(struct platform_device *pdev)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* 4.1 设备树中定义有: led-gpios=<...>;	*/
+    led_gpio = gpiod_get(&pdev->dev, "led", 0);
+	if (IS_ERR(led_gpio)) {
+		dev_err(&pdev->dev, "Failed to get GPIO for led\n");
+		return PTR_ERR(led_gpio);
+	}
+    
+	/* 4.2 注册file_operations 	*/
+	major = register_chrdev(0, "100ask_led", &led_drv);  /* /dev/led */
+
+	led_class = class_create(THIS_MODULE, "100ask_led_class");
+	if (IS_ERR(led_class)) {
+		printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+		unregister_chrdev(major, "led");
+		gpiod_put(led_gpio);
+		return PTR_ERR(led_class);
+	}
+
+	device_create(led_class, NULL, MKDEV(major, 0), NULL, "100ask_led%d", 0); /* /dev/100ask_led0 */
+        
+    return 0;
+    
+}
+
+static int chip_demo_gpio_remove(struct platform_device *pdev)
+{
+	device_destroy(led_class, MKDEV(major, 0));
+	class_destroy(led_class);
+	unregister_chrdev(major, "100ask_led");
+	gpiod_put(led_gpio);
+    
+    return 0;
+}
+
+
+static const struct of_device_id ask100_leds[] = {
+    { .compatible = "100ask,leddrv" },
+    { },
+};
+
+/* 1. 定义platform_driver */
+static struct platform_driver chip_demo_gpio_driver = {
+    .probe      = chip_demo_gpio_probe,
+    .remove     = chip_demo_gpio_remove,
+    .driver     = {
+        .name   = "100ask_led",
+        .of_match_table = ask100_leds,
+    },
+};
+
+/* 2. 在入口函数注册platform_driver */
+static int __init led_init(void)
+{
+    int err;
+    
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	
+    err = platform_driver_register(&chip_demo_gpio_driver); 
+	
+	return err;
+}
+
+/* 3. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数
+ *     卸载platform_driver
+ */
+static void __exit led_exit(void)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+    platform_driver_unregister(&chip_demo_gpio_driver);
+}
+
+
+/* 7. 其他完善：提供设备信息，自动创建设备节点                                     */
+
+module_init(led_init);
+module_exit(led_exit);
+
+MODULE_LICENSE("GPL");
+
+
diff --git a/STM32MP157/source/A7/07_GPIO/01_led/leddrv_未测试的原始版本.c b/STM32MP157/source/A7/07_GPIO/01_led/leddrv_未测试的原始版本.c
new file mode 100644
index 0000000..6ef1a7c
--- /dev/null
+++ b/STM32MP157/source/A7/07_GPIO/01_led/leddrv_未测试的原始版本.c
@@ -0,0 +1,165 @@
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/kmod.h>
+#include <linux/gfp.h>
+#include <linux/gpio/consumer.h>
+
+
+/* 1. 确定主设备号                                                                 */
+static int major = 0;
+static struct class *led_class;
+static struct gpio_desc *led_gpio;
+
+
+/* 3. 实现对应的open/read/write等函数，填入file_operations结构体                   */
+static ssize_t led_drv_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* write(fd, &val, 1); */
+static ssize_t led_drv_write (struct file *file, const char __user *buf, size_t size, loff_t *offset)
+{
+	int err;
+	char status;
+	struct inode *inode = file_inode(file);
+	int minor = iminor(inode);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	err = copy_from_user(&status, buf, 1);
+
+	/* 根据次设备号和status控制LED */
+	gpiod_set_value(led_gpio, status);
+	
+	return 1;
+}
+
+static int led_drv_open (struct inode *node, struct file *file)
+{
+	int minor = iminor(node);
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 根据次设备号初始化LED */
+	gpiod_direction_output(led_gpio, 0);
+	
+	return 0;
+}
+
+static int led_drv_close (struct inode *node, struct file *file)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+/* 定义自己的file_operations结构体                                              */
+static struct file_operations led_drv = {
+	.owner	 = THIS_MODULE,
+	.open    = led_drv_open,
+	.read    = led_drv_read,
+	.write   = led_drv_write,
+	.release = led_drv_close,
+};
+
+/* 4. 从platform_device获得GPIO
+ *    把file_operations结构体告诉内核：注册驱动程序
+ */
+static int chip_demo_gpio_probe(struct platform_device *pdev)
+{
+	int err;
+	
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* 4.1 设备树中定义有: led-gpios=<...>;	*/
+    led_gpio = gpiod_get(&pdev->dev, "led", 0);
+	if (IS_ERR(led_gpio)) {
+		dev_err(&pdev->dev, "Failed to get GPIO for led\n");
+		return PTR_ERR(led_gpio);
+	}
+    
+	/* 4.2 注册file_operations 	*/
+	major = register_chrdev(0, "100ask_led", &led_drv);  /* /dev/led */
+
+	led_class = class_create(THIS_MODULE, "100ask_led_class");
+	if (IS_ERR(led_class)) {
+		printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+		unregister_chrdev(major, "led");
+		gpiod_free(led_gpio);
+		return PTR_ERR(led_class);
+	}
+
+	device_create(led_class, NULL, MKDEV(major, 0), NULL, "100ask_led%d", 0); /* /dev/100ask_led0 */
+        
+    return 0;
+    
+}
+
+static int chip_demo_gpio_remove(struct platform_device *pdev)
+{
+	device_destroy(led_class, MKDEV(major, 0));
+	class_destroy(led_class);
+	unregister_chrdev(major, "100ask_led");
+	gpiod_free(led_gpio);
+    
+    return 0;
+}
+
+
+static const struct of_device_id ask100_leds[] = {
+    { .compatible = "100ask,leddrv" },
+    { },
+};
+
+/* 1. 定义platform_driver */
+static struct platform_driver chip_demo_gpio_driver = {
+    .probe      = chip_demo_gpio_probe,
+    .remove     = chip_demo_gpio_remove,
+    .driver     = {
+        .name   = "100ask_led",
+        .of_match_table = ask100_leds,
+    },
+};
+
+/* 2. 在入口函数注册platform_driver */
+static int __init led_init(void)
+{
+    int err;
+    
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+	
+    err = platform_driver_register(&chip_demo_gpio_driver); 
+	
+	return err;
+}
+
+/* 3. 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数
+ *     卸载platform_driver
+ */
+static void __exit led_exit(void)
+{
+	printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+    platform_driver_unregister(&chip_demo_gpio_driver);
+}
+
+
+/* 7. 其他完善：提供设备信息，自动创建设备节点                                     */
+
+module_init(led_init);
+module_exit(led_exit);
+
+MODULE_LICENSE("GPL");
+
+
diff --git a/STM32MP157/source/A7/07_GPIO/01_led/ledtest.c b/STM32MP157/source/A7/07_GPIO/01_led/ledtest.c
new file mode 100644
index 0000000..099eb11
--- /dev/null
+++ b/STM32MP157/source/A7/07_GPIO/01_led/ledtest.c
@@ -0,0 +1,50 @@
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+
+/*
+ * ./ledtest /dev/100ask_led0 on
+ * ./ledtest /dev/100ask_led0 off
+ */
+int main(int argc, char **argv)
+{
+	int fd;
+	char status;
+	
+	/* 1. 判断参数 */
+	if (argc != 3) 
+	{
+		printf("Usage: %s <dev> <on | off>\n", argv[0]);
+		return -1;
+	}
+
+	/* 2. 打开文件 */
+	fd = open(argv[1], O_RDWR);
+	if (fd == -1)
+	{
+		printf("can not open file %s\n", argv[1]);
+		return -1;
+	}
+
+	/* 3. 写文件 */
+	if (0 == strcmp(argv[2], "on"))
+	{
+		status = 1;
+		write(fd, &status, 1);
+	}
+	else
+	{
+		status = 0;
+		write(fd, &status, 1);
+	}
+	
+	close(fd);
+	
+	return 0;
+}
+
+