嵌入式Linux字符设备驱动-分层后的LED字符设备驱动-系统级驱动+芯片级驱动

#include <linux/module.h> #include <linux/kernel.h> #include <linux/slab.h> #include "led_drv.h" #include "led_imx6ull.h" /*该数组中gpio_regs结构体的个数决定了LED灯的数量，一个gpio_regs结构体代表一个LED灯 */ static const struct gpio_regs led_regs[] = { { { 0x020C406C, 0x0C000000, 0x3 }, //GPIO时钟模块配置 { 0x020E0068, 0x0000000F, 0x5 }, //GPIO引脚复用配置 { 0x020E02F4, 0x0001FFFF, 0x10B0 }, //GPIO引脚电气属性配置 { 0x0209C004, 0x00000008, 0x1 }, //GPIO引脚配置为输出 { 0x0209C000, 0x00000008, 0x1 }, //GPIO默认输出高电平 }, //可在此添加gpio_regs结构体，增加LED灯 }; /*准备LED设备的驱动资源 */ static void * prepare_drv_resource(int count) { int i; struct led_resource *led_res; //分配LED内存映射结构体 led_res = (struct led_resource *)kzalloc(sizeof(struct led_resource) * count, GFP_KERNEL); //将LED用到的寄存器进行内存映射 for(i = 0; i < count; i++) { led_res[i].ccm_map = ioremap(led_regs[i].ccm_reg[0], 4); led_res[i].mux_map = ioremap(led_regs[i].mux_reg[0], 4); led_res[i].pad_map = ioremap(led_regs[i].pad_reg[0], 4); led_res[i].gdir_map = ioremap(led_regs[i].gdir_reg[0], 4); led_res[i].dr_map = ioremap(led_regs[i].dr_reg[0], 4); led_res[i].bitmask = led_regs[i].dr_reg[1]; } return (void *)led_res; } static void release_drv_resource(void *res, int count) { int i; struct led_resource *led_res = (struct led_resource *)res; if(led_res) { for(i = 0; i < count; i++) { iounmap(led_res[i].ccm_map); iounmap(led_res[i].mux_map); iounmap(led_res[i].pad_map); iounmap(led_res[i].gdir_map); iounmap(led_res[i].dr_map); } kfree(led_res); } } static int init_led_gpio(int which, void *res, void **ppriv) { unsigned int value, offset; struct led_resource *led_res; if(which < 0) return -1; if(!res || !ppriv) return -1; led_res = (struct led_resource *)res; //开启GPIO模块时钟 GET_MASK_OFFSET(led_regs[which].ccm_reg[1], offset); value = readl(led_res[which].ccm_map); value &= (~led_regs[which].ccm_reg[1]); value |= (led_regs[which].ccm_reg[2] << offset); writel(value, led_res[which].ccm_map); //复用引脚为GPIO GET_MASK_OFFSET(led_regs[which].mux_reg[1], offset); value = readl(led_res[which].mux_map); value &= (~led_regs[which].mux_reg[1]); value |= (led_regs[which].mux_reg[2] << offset); writel(value, led_res[which].mux_map); //设置引脚电气属性 GET_MASK_OFFSET(led_regs[which].pad_reg[1], offset); value = readl(led_res[which].pad_map); value &= (~led_regs[which].pad_reg[1]); value |= (led_regs[which].pad_reg[2] << offset); writel(value, led_res[which].pad_map); //配置GPIO引脚为输出 GET_MASK_OFFSET(led_regs[which].gdir_reg[1], offset); value = readl(led_res[which].gdir_map); value &= (~led_regs[which].gdir_reg[1]); value |= (led_regs[which].gdir_reg[2] << offset); writel(value, led_res[which].gdir_map); //默认输出高电平 GET_MASK_OFFSET(led_regs[which].dr_reg[1], offset); value = readl(led_res[which].dr_map); value &= (~led_regs[which].dr_reg[1]); value |= (led_regs[which].dr_reg[2] << offset); writel(value, led_res[which].dr_map); //返回该LED设备的私有数据 *ppriv = (void*)&led_res[which]; return 0; } static int set_led_gpio(void *res, char val) { unsigned int value, offset; struct led_resource *led_res; //获取LED设备对应的资源结构体 led_res = (struct led_resource *)res; if(!led_res) return -1; //设置GPIO引脚电平 GET_MASK_OFFSET(led_res->bitmask, offset); value = readl(led_res->dr_map); value &= (~led_res->bitmask); if(val == LED_ON) value &= (0x0 << offset); else value |= (0x1 << offset); writel(value, led_res->dr_map); return 0; } static int close_led_gpio(void *res) { unsigned int value, offset; struct led_resource *led_res; //获取LED设备对应的资源结构体 led_res = (struct led_resource *)res; if(!led_res) return -1; //关闭LED GET_MASK_OFFSET(led_res->bitmask, offset); value = readl(led_res->dr_map); value &= (~led_res->bitmask); value |= (0x1 << offset); writel(value, led_res->dr_map); return 0; } static struct led_drv_func func_list; static int __init imx6ull_led_init(void) { int ret; func_list.func_prepare_drv_resource = prepare_drv_resource; func_list.func_release_drv_resource = release_drv_resource; func_list.func_init_led_gpio = init_led_gpio; func_list.func_set_led_gpio = set_led_gpio; func_list.func_close_led_gpio = close_led_gpio; leddrv_register_func(&func_list); ret = leddrv_register_leds(sizeof(led_regs) / sizeof(struct gpio_regs)); if(ret != 0) return -1; return 0; } static void __exit imx6ull_led_exit(void) { leddrv_unresister_func(); leddrv_unregister_leds(); } module_init(imx6ull_led_init); module_exit(imx6ull_led_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David.Tang");