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7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/sched.h>
10#include <linux/interrupt.h>
11#include <linux/time.h>
12#include <linux/timer.h>
13#include <linux/fs.h>
14#include <linux/miscdevice.h>
15#include <linux/string.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18
19#include <asm/uaccess.h>
20#include <asm/irq.h>
21#include <asm/mach-types.h>
22
23#define __NWBUTTON_C
24#include "nwbutton.h"
25
26static void button_sequence_finished (unsigned long parameters);
27
28static int button_press_count;
29
30static DEFINE_TIMER(button_timer, button_sequence_finished, 0, 0);
31static DECLARE_WAIT_QUEUE_HEAD(button_wait_queue);
32static char button_output_buffer[32];
33static int bcount;
34static int bdelay = BUTTON_DELAY;
35static struct button_callback button_callback_list[32];
36static int callback_count;
37static int reboot_count = NUM_PRESSES_REBOOT;
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56int button_add_callback (void (*callback) (void), int count)
57{
58 int lp = 0;
59 if (callback_count == 32) {
60 return -ENOMEM;
61 }
62 if (!callback) {
63 return -EINVAL;
64 }
65 callback_count++;
66 for (; (button_callback_list [lp].callback); lp++);
67 button_callback_list [lp].callback = callback;
68 button_callback_list [lp].count = count;
69 return 0;
70}
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83
84int button_del_callback (void (*callback) (void))
85{
86 int lp = 31;
87 if (!callback) {
88 return -EINVAL;
89 }
90 while (lp >= 0) {
91 if ((button_callback_list [lp].callback) == callback) {
92 button_callback_list [lp].callback = NULL;
93 button_callback_list [lp].count = 0;
94 callback_count--;
95 return 0;
96 }
97 lp--;
98 }
99 return -EINVAL;
100}
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109
110static void button_consume_callbacks (int bpcount)
111{
112 int lp = 0;
113 for (; lp <= 31; lp++) {
114 if ((button_callback_list [lp].count) == bpcount) {
115 if (button_callback_list [lp].callback) {
116 button_callback_list[lp].callback();
117 }
118 }
119 }
120}
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130static void button_sequence_finished (unsigned long parameters)
131{
132#ifdef CONFIG_NWBUTTON_REBOOT
133 if (button_press_count == reboot_count)
134 kill_cad_pid(SIGINT, 1);
135#endif
136 button_consume_callbacks (button_press_count);
137 bcount = sprintf (button_output_buffer, "%d\n", button_press_count);
138 button_press_count = 0;
139 wake_up_interruptible (&button_wait_queue);
140}
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150static irqreturn_t button_handler (int irq, void *dev_id)
151{
152 button_press_count++;
153 mod_timer(&button_timer, jiffies + bdelay);
154
155 return IRQ_HANDLED;
156}
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168static int button_read (struct file *filp, char __user *buffer,
169 size_t count, loff_t *ppos)
170{
171 DEFINE_WAIT(wait);
172 prepare_to_wait(&button_wait_queue, &wait, TASK_INTERRUPTIBLE);
173 schedule();
174 finish_wait(&button_wait_queue, &wait);
175 return (copy_to_user (buffer, &button_output_buffer, bcount))
176 ? -EFAULT : bcount;
177}
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185static const struct file_operations button_fops = {
186 .owner = THIS_MODULE,
187 .read = button_read,
188 .llseek = noop_llseek,
189};
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197static struct miscdevice button_misc_device = {
198 BUTTON_MINOR,
199 "nwbutton",
200 &button_fops,
201};
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211
212static int __init nwbutton_init(void)
213{
214 if (!machine_is_netwinder())
215 return -ENODEV;
216
217 printk (KERN_INFO "NetWinder Button Driver Version %s (C) Alex Holden "
218 "<alex@linuxhacker.org> 1998.\n", VERSION);
219
220 if (misc_register (&button_misc_device)) {
221 printk (KERN_WARNING "nwbutton: Couldn't register device 10, "
222 "%d.\n", BUTTON_MINOR);
223 return -EBUSY;
224 }
225
226 if (request_irq (IRQ_NETWINDER_BUTTON, button_handler, 0,
227 "nwbutton", NULL)) {
228 printk (KERN_WARNING "nwbutton: IRQ %d is not free.\n",
229 IRQ_NETWINDER_BUTTON);
230 misc_deregister (&button_misc_device);
231 return -EIO;
232 }
233 return 0;
234}
235
236static void __exit nwbutton_exit (void)
237{
238 free_irq (IRQ_NETWINDER_BUTTON, NULL);
239 misc_deregister (&button_misc_device);
240}
241
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243MODULE_AUTHOR("Alex Holden");
244MODULE_LICENSE("GPL");
245
246module_init(nwbutton_init);
247module_exit(nwbutton_exit);
248