1 #include <linux/init.h>
2 #include <linux/module.h>
3 #include <linux/of.h>
4 #include <linux/of_irq.h>
5 #include <linux/interrupt.h>
6
7
8 #define U32_DATA_LEN 4
9
10 static int is_good;
11 static int irqno;
12
13 irqreturn_t key_irq_handler(int irqno, void *devid)
14 {
15 printk("------------------------key pressed \n");
16 return IRQ_HANDLED;
17 }
18
19 static int __init dt_drv_init(void)
20 {
21 /*
22 test_nod@12345678{
23 compatible = "farsight,test";
24 reg = <0x12345678 0x24
25 0x87654321 0x24>;
26 testprop,mytest;
27 test_list_string = "red fish","fly fish", "blue fish";
28 interrupt-parent = <&gpx1>;
29 interrupts = <1 4>;
30
31 };
32 */
33
34 // 在代码中获取节点的所有信息
35 //先把节点获取到
36 struct device_node *np = NULL;
37
38
39 np = of_find_node_by_path("/test_nod@12345678");
40 if(np){
41 printk("find test node ok\n");
42 printk("node name = %s\n", np->name);
43 printk("node full name = %s\n", np->full_name);
44
45 }else{
46 printk("find test node failed\n");
47
48 }
49
50 //获取到节点中的属性
51 struct property *prop = NULL;
52 prop = of_find_property(np, "compatible",NULL);
53 if(prop)
54 {
55 printk("find compatible ok\n");
56 printk("compatible value = %s\n", prop->value);
57 printk("compatible name = %s\n", prop->name);
58 }else{
59 printk("find compatible failed\n");
60
61 }
62
63 if(of_device_is_compatible(np, "farsight,test"))
64 {
65 printk("we have a compatible named farsight,test\n");
66 }
67
68 //读取到属性中的整数的数组
69
70 u32 regdata[U32_DATA_LEN];
71 int ret;
72
73 ret = of_property_read_u32_array(np, "reg", regdata, U32_DATA_LEN);
74 if(!ret)
75 {
76 int i;
77 for(i=0; i<U32_DATA_LEN; i++)
78 printk("----regdata[%d] = 0x%x\n", i,regdata[i]);
79
80 }else{
81 printk("get reg data failed\n");
82 }
83
84 //读取到属性中的字符串的数组
85 const char *pstr[3];
86
87 int i;
88 for(i=0; i<3; i++)
89 {
90 ret = of_property_read_string_index(np, "test_list_string", i, &pstr[i]);
91 if(!ret)
92 {
93 printk("----pstr[%d] = %s\n", i,pstr[i]);
94 }else{
95 printk("get pstr data failed\n");
96 }
97 }
98
99 // 属性的值为空，实际可以用于设置标志
100 if(of_find_property(np, "testprop,mytest", NULL))
101 {
102 is_good = 1;
103 printk("is_good = %d\n", is_good);
104 }
105
106 // 获取到中断的号码
107 irqno = irq_of_parse_and_map(np, 0);
108 printk("-----irqno = %d\n", irqno);
109
110 //验证中断号码是否有效
111 ret = request_irq(irqno, key_irq_handler, IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,
112 "key_irq", NULL);
113 if(ret)
114 {
115 printk("request_irq error\n");
116 return -EBUSY;
117 }
118
119
120 return 0;
121
122 }
123
124 static void __exit dt_drv_exit(void)
125 {
126 free_irq(irqno, NULL);
127
128 }
129
130
131
132
133 module_init(dt_drv_init);
134 module_exit(dt_drv_exit);
135 MODULE_LICENSE("GPL");
