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怎样去编写rk3288的led驱动源码呢

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问答对人有帮助，内容完整，我也想知道答案 0 怎样去编写rk3288的led驱动源码呢？ 0
2022-3-4 07:39:49　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × liutiefu 该类别下有 26 个回答。邀请回答 ze55me 该类别下有 20 个回答。邀请回答 tigerwang711 该类别下有 20 个回答。邀请回答杀狼000 该类别下有 19 个回答。邀请回答 zhuzb0754 该类别下有 19 个回答。邀请回答冰箱洗衣机该类别下有 18 个回答。邀请回答 YYXIAO 该类别下有 18 个回答。邀请回答安德森大该类别下有 17 个回答。邀请回答 CDCNKA 该类别下有 17 个回答。邀请回答 jjll652 该类别下有 17 个回答。邀请回答河神大人该类别下有 17 个回答。邀请回答 mede1001 该类别下有 17 个回答。邀请回答 YOYOOO 该类别下有 16 个回答。邀请回答麻酱该类别下有 16 个回答。邀请回答世态薄凉该类别下有 16 个回答。邀请回答熊本熊该类别下有 16 个回答。邀请回答 Green_LJ 该类别下有 15 个回答。邀请回答江左盟该类别下有 15 个回答。邀请回答 wang21cj 该类别下有 15 个回答。邀请回答 dfgsdf 该类别下有 15 个回答。邀请回答举报龙献益相关推荐 • 在RK3288主板上怎样去编译Android 5.1源码呢 1468 • 怎样去编写一个基于RK3288平台的hello word程序呢 829 • 请问一下RK3288系统是怎样通用GPIO驱动去控制LED的 1106 • 有关RK3288开发板驱动的知识点分享 2215 • 请教大神怎样去修改RK3288的休眠锁屏时间呢 1397 • 怎样去编译RK3288平台上的Android系统源码呢 1956 • 在RK3288下怎样去添加PCF8563 RTC驱动支持呢 1212 • 怎样去区分RK3288和RK3288W两者之间的型号呢 1946 • 怎样去解决RK3288系统出现偶尔关机的问题呢 2875 • 在RK3288上怎样去编译Android源码呢 982 1个回答

答案对人有帮助，有参考价值 0 开始编写LED驱动程序我之前学习了rk3288 的led驱动编写的准备然后也编写了led驱动的框架。现在只要把框架适当的填充具体的硬件操作，就可以实现led的电灯了。 1.需要用到的函数ioremap 因为linux内核并不像单片机一样是直接用寄存器地址控制的，操作系统有内存寻址的架构。所以我们需要把物理地址转换成Linux可以操作的地址。这个转换的过程就需要调用ioremap函数，下面的它的函数原型： #include //需要使用时包含头文件 void __iomen ioremap(resource_size_t res_cookie, size_t size); void iounmap(volatile void __iomen cookie); /* virtual_addr = ioremap(physical_addr, size); * 把physical_addr开始的size映射为虚拟地址，返回值时该段虚拟地址的首地址。 * physical_addr和size都会按页取整 / 2.firefly3288 led原理图 WORK_LED使用GPIO8_A1，POWER_LED使用GPIO8_A2。这两个LED引脚在高电平时熄灭，低电平时点亮。 3.Led初始化步骤使能GPIO对应的CRU控制器 CRU_CLKGATE14_CON的b[8]位为0时使能，这里要注意31：16为时掩码位，必须把b[24]位设置为1。才能避免被屏蔽。 / rk3288 GPIO8_A1 / / a. 使能 GPIO8 * set CRU to enable GPIO8 * CRU_CLKGATE14_CON 0xFF760000 + 0x198 * (1<<(8+16)) \| (0<<8) / 设置GPIO可写，并且引脚用作GPIO功能设置GRF_GPIO8A_IOMUX的b[3:2]和b[4]为0，把GPIO_A1和GPIO_A2作为GPIO。同时b[19:18]和b[21:20]设置为0b11。 / b. 设置 GPIO8_A1 用于 GPIO * set PMU/GRF to configure GPIO8_A1 as GPIO * GRF_GPIO8A_IOMUX 0xFF770000 + 0x0080 * bit[3:2] = 0b00 * (3<<(2+16)) \| (0<<2) / 把对应的GPIO设置为输出设置 GPIO_SWPORTA_DDR 寄存器 b[1]为 1 b[2]为1，把 GPIO8_A1 和GPIO8_A2设置为输出引脚。 / c. 设置 GPIO8_A1 作为 output 引脚 * set GPIO_SWPORTA_DDR to configure GPIO8_A1 as output * GPIO_SWPORTA_DDR 0xFF7F0000 + 0x0004 * bit[1] = 0b1 / 设置GPIO默认的电平为高电平设置 GPIO_SWPORTA_DR 寄存器 b[1]为 1，让 GPIO8_A1 输出高电平。 / d. 设置 GPIO8_A1 输出高电平 * set GPIO_SWPORTA_DR to configure GPIO8_A1 output 1 * GPIO_SWPORTA_DR 0xFF7F0000 + 0x0000 * bit[1] = 0b1 / / e. 设置 GPIO8_A1 输出低电平 * set GPIO_SWPORTA_DR to configure GPIO8_A1 output 0 * GPIO_SWPORTA_DR 0xFF7F0000 + 0x0000 * bit[1] = 0b0 / Led操作步骤和上面第四步时一样的。源码 Makefile KERN_DIR = /home/book/Documents/100ask_firefly-rk3288/linux-4.4 all: make -C $(KERN_DIR) M=`pwd` modules $(CROSS_COMPILE)gcc -o led_app led_app.c -Wno-error=unused-but-set-variable clean: make -C $(KERN_DIR) M=`pwd` modules clean rm -rf modules.order rm -f hello_drv_test myled_drv-y:=led_drv.o board_demoo.o obj-m += myled_drv.o led_drv.c #include #include #include #include #include #include #include #include #include #include "led_ops.h" static int major = 0; static struct class led_class; struct led_operations p_led_ops; static int led_drv_open(struct inode node, struct file file) { int minor = iminor(node); printk("%s %s line %dn", __FILE__, __FUNCTION__, __LINE__); p_led_ops->init(minor); return 0; } static ssize_t led_drv_read(struct file file, char __user buf, size_t size, loff_t offset) { printk("%s %s line %dn", __FILE__, __FUNCTION__, __LINE__); return 0; } 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 %dn", __FILE__, __FUNCTION__, __LINE__); err = copy_from_user(&status, buf, 1); printk("write status:%x n", status); p_led_ops->ctl(minor, status); return 1; } static int led_drv_close(struct inode node, struct file file) { printk("%s %s line %dn", __FILE__, __FUNCTION__, __LINE__); return 0; } 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, }; static int __init led_drv_init(void) { int err; int i = 0; major = register_chrdev(0, "myled", &led_drv); led_class = class_create(THIS_MODULE, "led_class"); err = PTR_ERR(led_class); if(IS_ERR(led_class)) { unregister_chrdev(major, "myled"); printk(KERN_WARNING "class creatge failed %dn", err); return -1; } p_led_ops = get_board_led_ops(); for(i=0;inum;i++) device_create(led_class, NULL, MKDEV(major, i), NULL, "myled%d", i); printk("%s %sled_drv_initn", __FILE__, __FUNCTION__); return 0; } static void __exit led_drv_exit(void) { int i; printk("%s %sled_drv_exitn", __FILE__, __FUNCTION__); for(i=0;inum;i++) device_destroy(led_class, MKDEV(major, i)); class_destroy(led_class); unregister_chrdev(major, "myled"); } module_init(led_drv_init); module_exit(led_drv_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("chen"); board_demoo.c #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "led_ops.h" #define CRU_BASE_PHY_ADDRESS ((unsigned long)(0xff760000)) #define GRF_BASE_PHY_ADDRESS ((unsigned long)(0xff770000)) #define GPIO8_BASE_PHY_ADDRESS ((unsigned long)(0xff7f0000)) #define CRU_CLKGATE14_PHY_CON (0x0198) #define GRF_GPIO8A_PHY_IOMUX (0x0080) #define GPIO_SWPORTA_PHY_DR (0x0000) #define GPIO_SWPORTA_PHY_DDR (0x0004) static volatile unsigned int CRU_CLKGATE14_CON; static volatile unsigned int GRF_GPIO8A_IOMUX; static volatile unsigned int GPIO8_SWPORTA_DDR; static volatile unsigned int GPIO8_SWPORTA_DR; static int board_demoo_led_init(int which) { printk("%s %s line %d, led %dn", __FILE__, __FUNCTION__, __LINE__, which); if(!CRU_CLKGATE14_CON) { CRU_CLKGATE14_CON = ioremap(CRU_BASE_PHY_ADDRESS + CRU_CLKGATE14_PHY_CON, 4); GRF_GPIO8A_IOMUX = ioremap(GRF_BASE_PHY_ADDRESS + GRF_GPIO8A_PHY_IOMUX, 4); GPIO8_SWPORTA_DDR = ioremap(GPIO8_BASE_PHY_ADDRESS + GPIO_SWPORTA_PHY_DDR, 4); GPIO8_SWPORTA_DR = ioremap(GPIO8_BASE_PHY_ADDRESS + GPIO_SWPORTA_PHY_DR, 4); } if(which == 0) { CRU_CLKGATE14_CON = (1<<(8+16)) \| (0<<8); GRF_GPIO8A_IOMUX \|= (3<<(2+16)) \| (0<<2); GPIO8_SWPORTA_DDR \|= (1<<1); } else if(which == 1) { CRU_CLKGATE14_CON = (1<<(8+16)) \| (0<<8); GRF_GPIO8A_IOMUX \|= (3<<(4+16)) \| (0<<4); GPIO8_SWPORTA_DDR \|= (1<<2); } return 0; } static int board_demoo_led_ctl(int which, char status) { printk("%s %s line %d, led %d, %sn", __FILE__, __FUNCTION__, __LINE__, which, status?"on":"off"); if(which == 0) { if(status) { /* on: output 0 / GPIO8_SWPORTA_DR &= ~(1<<1); } else { /* off: output 1 / GPIO8_SWPORTA_DR \|= (1<<1); } } else if(which == 1) { if(status) { GPIO8_SWPORTA_DR &= ~(1<<2); } else { GPIO8_SWPORTA_DR \|= (1<<2); } } return 0; } static struct led_operations board_demoo_led_ops = { .num = 2, .init = board_demoo_led_init, .ctl = board_demoo_led_ctl, }; struct led_operations get_board_led_ops(void) { return &board_demoo_led_ops; } led_ops.h #ifndef __LED_OPS_H_ #define __LED_OPS_H_ struct led_operations { int num; int (init)(int which); /* init led, which:led num / int (ctl)(int which, char status); /* control led, whic:led num,status:0-On 1-Off / }; struct led_operations get_board_led_ops(void); #endif led_app.c #include #include #include #include #include #include void showUsage(void) { printf("app [dev_path] [on,off]n"); } int main(int argc, char *argv[]) { char status; if(argc < 3) { showUsage(); return -1; } int fd = open(argv[1], O_RDWR); if(fd < 0) { printf("app open device failed path:%s", argv[1]); return -1; } if(0 == strcmp(argv[2], "on")) { status = 1; int ret = write(fd, &status, 1); if(ret <= 0) { printf("app write device fialed %s",argv[2]); return -1; } else { printf("app write device %x", status); } } else if(0 == strcmp(argv[2], "off")) { status = 0; int ret = write(fd, &status, 1); if(ret <= 0) { printf("app write device fialed %s",argv[2]); return -1; } else { printf("app write device %x", status); } } return 0; }

2022-3-4 14:49:09 评论举报吴樵