2 * linux/arch/arm/plat-omap/gpio-switch.c
4 * Copyright (C) 2004-2006 Nokia Corporation
5 * Written by Juha Yrjölä <juha.yrjola@nokia.com>
6 * and Paul Mundt <paul.mundt@nokia.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/sched.h>
14 #include <linux/init.h>
15 #include <linux/list.h>
16 #include <linux/irq.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/timer.h>
21 #include <linux/err.h>
22 #include <asm/arch/hardware.h>
23 #include <asm/arch/gpio.h>
24 #include <asm/arch/irqs.h>
25 #include <asm/arch/mux.h>
26 #include <asm/arch/board.h>
27 #include <asm/arch/gpio-switch.h>
35 unsigned both_edges:1;
40 void (* notify)(void *data, int state);
43 struct work_struct work;
44 struct timer_list timer;
45 struct platform_device pdev;
47 struct list_head node;
50 static LIST_HEAD(gpio_switches);
51 static struct platform_device *gpio_sw_platform_dev;
52 static struct platform_driver gpio_sw_driver;
54 static const struct omap_gpio_switch *board_gpio_sw_table;
55 static int board_gpio_sw_count;
57 static const char *cover_str[2] = { "open", "closed" };
58 static const char *connection_str[2] = { "disconnected", "connected" };
59 static const char *activity_str[2] = { "inactive", "active" };
62 * GPIO switch state default debounce delay in ms
64 #define OMAP_GPIO_SW_DEFAULT_DEBOUNCE 10
66 static const char **get_sw_str(struct gpio_switch *sw)
69 case OMAP_GPIO_SWITCH_TYPE_COVER:
71 case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
72 return connection_str;
73 case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
81 static const char *get_sw_type(struct gpio_switch *sw)
84 case OMAP_GPIO_SWITCH_TYPE_COVER:
86 case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
88 case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
96 static void print_sw_state(struct gpio_switch *sw, int state)
100 str = get_sw_str(sw);
102 printk(KERN_INFO "%s (GPIO %d) is now %s\n", sw->name, sw->gpio, str[state]);
105 static int gpio_sw_get_state(struct gpio_switch *sw)
109 state = omap_get_gpio_datain(sw->gpio);
110 if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
116 static ssize_t gpio_sw_state_store(struct device *dev,
117 struct device_attribute *attr,
121 struct gpio_switch *sw = dev_get_drvdata(dev);
126 if (!(sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT))
129 if (sscanf(buf, "%15s", state) != 1)
132 str = get_sw_str(sw);
133 if (strcmp(state, str[0]) == 0)
135 else if (strcmp(state, str[1]) == 0)
139 if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
141 omap_set_gpio_dataout(sw->gpio, enable);
146 static ssize_t gpio_sw_state_show(struct device *dev,
147 struct device_attribute *attr,
150 struct gpio_switch *sw = dev_get_drvdata(dev);
153 str = get_sw_str(sw);
154 return sprintf(buf, "%s\n", str[sw->state]);
157 static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, gpio_sw_state_show,
158 gpio_sw_state_store);
160 static ssize_t gpio_sw_type_show(struct device *dev,
161 struct device_attribute *attr,
164 struct gpio_switch *sw = dev_get_drvdata(dev);
166 return sprintf(buf, "%s\n", get_sw_type(sw));
169 static DEVICE_ATTR(type, S_IRUGO, gpio_sw_type_show, NULL);
171 static ssize_t gpio_sw_direction_show(struct device *dev,
172 struct device_attribute *attr,
175 struct gpio_switch *sw = dev_get_drvdata(dev);
178 is_output = sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT;
179 return sprintf(buf, "%s\n", is_output ? "output" : "input");
182 static DEVICE_ATTR(direction, S_IRUGO, gpio_sw_direction_show, NULL);
185 static irqreturn_t gpio_sw_irq_handler(int irq, void *arg)
187 struct gpio_switch *sw = arg;
188 unsigned long timeout;
191 if (!sw->both_edges) {
192 if (omap_get_gpio_datain(sw->gpio))
193 set_irq_type(OMAP_GPIO_IRQ(sw->gpio), IRQT_FALLING);
195 set_irq_type(OMAP_GPIO_IRQ(sw->gpio), IRQT_RISING);
198 state = gpio_sw_get_state(sw);
199 if (sw->state == state)
203 timeout = sw->debounce_rising;
205 timeout = sw->debounce_falling;
207 schedule_work(&sw->work);
209 mod_timer(&sw->timer, jiffies + msecs_to_jiffies(timeout));
214 static void gpio_sw_timer(unsigned long arg)
216 struct gpio_switch *sw = (struct gpio_switch *) arg;
218 schedule_work(&sw->work);
221 static void gpio_sw_handler(struct work_struct *work)
223 struct gpio_switch *sw = container_of(work, struct gpio_switch, work);
226 state = gpio_sw_get_state(sw);
227 if (sw->state == state)
231 if (sw->notify != NULL)
232 sw->notify(sw->notify_data, state);
233 sysfs_notify(&sw->pdev.dev.kobj, NULL, "state");
234 print_sw_state(sw, state);
237 static int __init can_do_both_edges(struct gpio_switch *sw)
239 if (!cpu_class_is_omap1())
241 if (OMAP_GPIO_IS_MPUIO(sw->gpio))
247 static void gpio_sw_release(struct device *dev)
251 static int __init new_switch(struct gpio_switch *sw)
253 int r, direction, trigger;
256 case OMAP_GPIO_SWITCH_TYPE_COVER:
257 case OMAP_GPIO_SWITCH_TYPE_CONNECTION:
258 case OMAP_GPIO_SWITCH_TYPE_ACTIVITY:
261 printk(KERN_ERR "invalid GPIO switch type: %d\n", sw->type);
265 sw->pdev.name = sw->name;
268 sw->pdev.dev.parent = &gpio_sw_platform_dev->dev;
269 sw->pdev.dev.driver = &gpio_sw_driver.driver;
270 sw->pdev.dev.release = gpio_sw_release;
272 r = platform_device_register(&sw->pdev);
274 printk(KERN_ERR "gpio-switch: platform device registration "
275 "failed for %s", sw->name);
278 dev_set_drvdata(&sw->pdev.dev, sw);
280 r = omap_request_gpio(sw->gpio);
282 platform_device_unregister(&sw->pdev);
286 /* input: 1, output: 0 */
287 direction = !(sw->flags & OMAP_GPIO_SWITCH_FLAG_OUTPUT);
288 omap_set_gpio_direction(sw->gpio, direction);
290 sw->state = gpio_sw_get_state(sw);
293 r |= device_create_file(&sw->pdev.dev, &dev_attr_state);
294 r |= device_create_file(&sw->pdev.dev, &dev_attr_type);
295 r |= device_create_file(&sw->pdev.dev, &dev_attr_direction);
297 printk(KERN_ERR "gpio-switch: attribute file creation "
298 "failed for %s\n", sw->name);
303 if (can_do_both_edges(sw)) {
304 trigger = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
307 if (omap_get_gpio_datain(sw->gpio))
308 trigger = IRQF_TRIGGER_FALLING;
310 trigger = IRQF_TRIGGER_RISING;
312 r = request_irq(OMAP_GPIO_IRQ(sw->gpio), gpio_sw_irq_handler,
313 IRQF_SHARED | trigger, sw->name, sw);
315 printk(KERN_ERR "gpio-switch: request_irq() failed "
316 "for GPIO %d\n", sw->gpio);
317 platform_device_unregister(&sw->pdev);
318 omap_free_gpio(sw->gpio);
322 INIT_WORK(&sw->work, gpio_sw_handler);
323 init_timer(&sw->timer);
325 sw->timer.function = gpio_sw_timer;
326 sw->timer.data = (unsigned long)sw;
328 list_add(&sw->node, &gpio_switches);
333 static int __init add_atag_switches(void)
335 const struct omap_gpio_switch_config *cfg;
336 struct gpio_switch *sw;
340 cfg = omap_get_nr_config(OMAP_TAG_GPIO_SWITCH,
341 struct omap_gpio_switch_config, i);
344 sw = kzalloc(sizeof(*sw), GFP_KERNEL);
346 printk(KERN_ERR "gpio-switch: kmalloc failed\n");
349 strncpy(sw->name, cfg->name, sizeof(cfg->name));
350 sw->gpio = cfg->gpio;
351 sw->flags = cfg->flags;
352 sw->type = cfg->type;
353 sw->debounce_rising = OMAP_GPIO_SW_DEFAULT_DEBOUNCE;
354 sw->debounce_falling = OMAP_GPIO_SW_DEFAULT_DEBOUNCE;
355 if ((r = new_switch(sw)) < 0) {
363 static struct gpio_switch * __init find_switch(int gpio, const char *name)
365 struct gpio_switch *sw;
367 list_for_each_entry(sw, &gpio_switches, node) {
368 if ((gpio < 0 || sw->gpio != gpio) &&
369 (name == NULL || strcmp(sw->name, name) != 0))
372 if (gpio < 0 || name == NULL)
375 if (strcmp(sw->name, name) != 0)
376 printk("gpio-switch: name mismatch for %d (%s, %s)\n",
377 gpio, name, sw->name);
378 else if (sw->gpio != gpio)
379 printk("gpio-switch: GPIO mismatch for %s (%d, %d)\n",
380 name, gpio, sw->gpio);
387 static int __init add_board_switches(void)
391 for (i = 0; i < board_gpio_sw_count; i++) {
392 const struct omap_gpio_switch *cfg;
393 struct gpio_switch *sw;
396 cfg = board_gpio_sw_table + i;
397 if (strlen(cfg->name) > sizeof(sw->name) - 1)
399 /* Check whether we only update an existing switch
400 * or add a new switch. */
401 sw = find_switch(cfg->gpio, cfg->name);
403 sw->debounce_rising = cfg->debounce_rising;
404 sw->debounce_falling = cfg->debounce_falling;
405 sw->notify = cfg->notify;
406 sw->notify_data = cfg->notify_data;
409 if (cfg->gpio < 0 || cfg->name == NULL) {
410 printk("gpio-switch: required switch not "
411 "found (%d, %s)\n", cfg->gpio,
416 sw = kzalloc(sizeof(*sw), GFP_KERNEL);
418 printk(KERN_ERR "gpio-switch: kmalloc failed\n");
421 strlcpy(sw->name, cfg->name, sizeof(sw->name));
422 sw->gpio = cfg->gpio;
423 sw->flags = cfg->flags;
424 sw->type = cfg->type;
425 sw->debounce_rising = cfg->debounce_rising;
426 sw->debounce_falling = cfg->debounce_falling;
427 sw->notify = cfg->notify;
428 sw->notify_data = cfg->notify_data;
429 if ((r = new_switch(sw)) < 0) {
437 static void gpio_sw_cleanup(void)
439 struct gpio_switch *sw = NULL, *old = NULL;
441 list_for_each_entry(sw, &gpio_switches, node) {
444 flush_scheduled_work();
445 del_timer_sync(&sw->timer);
447 free_irq(OMAP_GPIO_IRQ(sw->gpio), sw);
449 device_remove_file(&sw->pdev.dev, &dev_attr_state);
450 device_remove_file(&sw->pdev.dev, &dev_attr_type);
451 device_remove_file(&sw->pdev.dev, &dev_attr_direction);
453 platform_device_unregister(&sw->pdev);
454 omap_free_gpio(sw->gpio);
460 static void __init report_initial_state(void)
462 struct gpio_switch *sw;
464 list_for_each_entry(sw, &gpio_switches, node) {
467 state = omap_get_gpio_datain(sw->gpio);
468 if (sw->flags & OMAP_GPIO_SWITCH_FLAG_INVERTED)
470 if (sw->notify != NULL)
471 sw->notify(sw->notify_data, state);
472 print_sw_state(sw, state);
476 static int gpio_sw_remove(struct platform_device *dev)
481 static struct platform_driver gpio_sw_driver = {
482 .remove = gpio_sw_remove,
484 .name = "gpio-switch",
488 void __init omap_register_gpio_switches(const struct omap_gpio_switch *tbl,
491 BUG_ON(board_gpio_sw_table != NULL);
493 board_gpio_sw_table = tbl;
494 board_gpio_sw_count = count;
497 static int __init gpio_sw_init(void)
501 printk(KERN_INFO "OMAP GPIO switch handler initializing\n");
503 r = platform_driver_register(&gpio_sw_driver);
507 gpio_sw_platform_dev = platform_device_register_simple("gpio-switch",
509 if (IS_ERR(gpio_sw_platform_dev)) {
510 r = PTR_ERR(gpio_sw_platform_dev);
514 r = add_atag_switches();
518 r = add_board_switches();
522 report_initial_state();
527 platform_device_unregister(gpio_sw_platform_dev);
529 platform_driver_unregister(&gpio_sw_driver);
533 static void __exit gpio_sw_exit(void)
536 platform_device_unregister(gpio_sw_platform_dev);
537 platform_driver_unregister(&gpio_sw_driver);
541 late_initcall(gpio_sw_init);
543 module_init(gpio_sw_init);
545 module_exit(gpio_sw_exit);
547 MODULE_AUTHOR("Juha Yrjölä <juha.yrjola@nokia.com>, Paul Mundt <paul.mundt@nokia.com");
548 MODULE_DESCRIPTION("GPIO switch driver");
549 MODULE_LICENSE("GPL");