20150223 IMX257 BEEP驱动程序实现
2015-02-23 李海沿
和我们今天上午编写的LED驱动程序一样，此处我们实现一个beep蜂鸣器的鸣叫驱动程序
我们知道我们蜂鸣器的引脚由 GPIO1_26控制的，所以我们此处只需要将前面led驱动程序的相关引脚修改为GPIO1_26 就可以了
（和前面几乎一样，LED驱动程序参考：http://www.cnblogs.com/lihaiyan/p/4297923.html）
1.确定相关寄存器基址
确定IOMUX地址 0x43fa_c000 0x43fa_ffff
GPIO1的地址 0x53fc_c000 0x53fc_ffff
MUX_CTL寄存器偏移地址 0x011c
PAD-CTL 寄存器偏移 0x0314
GPIO寄存器偏移地址
2.编译测试
本驱动程序亲测成功：
附上驱动程序代码：
1 #include<linux/cdev.h> 2 #include<linux/module.h> 3 #include<linux/types.h> 4 #include<linux/fs.h> 5 #include<linux/errno.h> 6 #include<linux/mm.h> 7 #include<linux/sched.h> 8 #include<linux/init.h> 9 #include<asm/io.h> 10 #include<asm/system.h> 11 #include<asm/uaccess.h> 12 #include<linux/device.h> 13 #include <linux/delay.h> 14 15 #define Driver_NAME "beep_dev" 16 #define DEVICE_NAME "beep_dev" 17 18 static int major = 0; 19 20 //auto to create device node 21 static struct class *drv_class = NULL; 22 static struct class_device *drv_class_dev = NULL; 23 24 //beep 25 //寄存器基址; 26 static unsigned long mem_iomux; 27 static unsigned long mem_gpio1; 28 static unsigned long base_iomux; //iomux基址 0X 43FA C000 - 0X 43FA FFFF 29 static unsigned long base_gpio1; //gpio3 0X 53FC C000 - 0X 53FC FFFF 30 // MUX_CTL模式选择 配置寄存器 31 #define MUX_CTL (*(volatile unsigned long *)(base_iomux + 0x011c)) 32 // PAD_CTL GPIO常用功能设置 33 #define PAD_CTL (*(volatile unsigned long *)(base_iomux + 0x0314)) 34 // GPIO DR 数据寄存器 DR 35 #define DR_GPIO1 (*(volatile unsigned long *)(base_gpio1 + 0x0000)) 36 // GPIO GDIR 方向控制寄存器 GDIR 37 #define GDIR_GPIO1 (*(volatile unsigned long *)(base_gpio1 + 0x0004)) 38 39 40 static int key_open(struct inode *inode, struct file *file) 41 { 42 printk("<0>function open! "); 43 return 0; 44 } 45 46 static int key_read(struct file *filp, char __user *buff, size_t count, loff_t *offp) 47 { 48 return 0; 49 } 50 51 static ssize_t key_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) 52 { 53 printk("<0>function write! "); 54 return 1; 55 } 56 57 static int key_release(struct inode *inode, struct file *filp) 58 { 59 printk("<0>function write! "); 60 return 0; 61 } 62 63 static int key_ioctl(struct inode *inode,struct file *flip,unsigned int command,unsigned long arg) 64 { 65 printk("<0>function ioctl! "); 66 return 0; 67 } 68 static struct file_operations key_fops = { 69 .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */ 70 .open = key_open, 71 .read = key_read, 72 .write = key_write, 73 .release= key_release, 74 .ioctl = key_ioctl, 75 }; 76 77 void gpio_addr(void){ 78 printk("<0>addr base_iomux : %x ",base_iomux); 79 printk("<0>addr base_gpio1 : %x ",base_gpio1); 80 printk("<0>addr MUX_CTL : %x ",&MUX_CTL); 81 printk("<0>addr PAD_CTL : %x ",&PAD_CTL); 82 printk("<0>addr GDIR_GPIO1 : %x ",&GDIR_GPIO1); 83 printk("<0>addr DR_GPIO1 : %x ",&DR_GPIO1); 84 } 85 86 void beep_on_off(void){ 87 ssleep(1); 88 DR_GPIO1 |= (0x01 << 26); //将GPIO1_26置1 89 ssleep(1); 90 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 91 ssleep(1); 92 DR_GPIO1 |= (0x01 << 26); //将GPIO1_26置1 93 ssleep(1); 94 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 95 ssleep(1); 96 DR_GPIO1 |= (0x01 << 26); //将GPIO1_26置1 97 ssleep(1); 98 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 99 ssleep(1); 100 DR_GPIO1 |= (0x01 << 26); //将GPIO1_26置1 101 ssleep(1); 102 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 103 ssleep(1); 104 DR_GPIO1 |= (0x01 << 26); //将GPIO1_26置1 105 ssleep(1); 106 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 107 } 108 109 static int __init key_irq_init(void) 110 { 111 printk("<0> Hello,this is %s module! ",Driver_NAME); 112 //register and mknod 113 major = register_chrdev(0,Driver_NAME,&key_fops); 114 drv_class = class_create(THIS_MODULE,Driver_NAME); 115 drv_class_dev = device_create(drv_class,NULL,MKDEV(major,0),NULL,DEVICE_NAME); /*/dev/key_query*/ 116 117 //IO端口申请 ioremap 可以直接通过指针来访问这些地址 118 base_iomux = ioremap(0x43FAC000,0xFFF); 119 base_gpio1 = ioremap(0x53FCC000,0xFFF); 120 121 //MUX_CTL 122 MUX_CTL &= ~(0x07 << 0); 123 MUX_CTL |= (0X05 << 0); //设置为ALT5 GPIO1_26 BEEP 124 //PAD_CTL 125 PAD_CTL &= ~(0x01<<13 | 0x01<<3 | 0x03<<1 | 0x01<<0); //1.8v 不需要上拉下拉 CMOS输出 slew rate 126 //GDIR_GPIO1 配置为输出模式 127 GDIR_GPIO1 &= ~(0x01 << 26); 128 GDIR_GPIO1 |= (0x01 << 26); //配置为输出模式 129 130 //DR_GPIO1 配置为输出0 点亮ERR_LED 131 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 132 DR_GPIO1 &= ~(0x01 << 26); //将GPIO1_26清零 133 gpio_addr(); 134 beep_on_off(); 135 return 0; 136 } 137 138 static void __exit key_irq_exit(void) 139 { 140 gpio_addr(); 141 printk("<0> Goodbye,%s! ",Driver_NAME); 142 beep_on_off(); 143 144 unregister_chrdev(major,Driver_NAME); 145 device_unregister(drv_class_dev); 146 class_destroy(drv_class); 147 148 //释放IO端口 149 iounmap(base_iomux); 150 iounmap(base_gpio1); 151 } 152 153 154 /* 这两行指定驱动程序的初始化函数和卸载函数 */ 155 module_init(key_irq_init); 156 module_exit(key_irq_exit); 157 158 /* 描述驱动程序的一些信息，不是必须的 */ 159 MODULE_AUTHOR("Lover雪儿"); 160 MODULE_VERSION("0.1.0"); 161 MODULE_DESCRIPTION("IMX257 key Driver"); 162 MODULE_LICENSE("GPL");