1 /* drivers/input/misc/gpio_matrix.c
3 * Copyright (C) 2007 Google, Inc.
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <linux/kernel.h>
17 #include <linux/gpio.h>
18 #include <linux/gpio_event.h>
19 #include <linux/hrtimer.h>
20 #include <linux/interrupt.h>
23 struct input_dev *input_dev;
24 struct gpio_event_matrix_info *keypad_info;
27 unsigned int use_irq:1;
28 unsigned int key_state_changed:1;
29 unsigned int last_key_state_changed:1;
30 unsigned int some_keys_pressed:2;
31 unsigned long keys_pressed[0];
34 static void clear_phantom_key(struct gpio_kp *kp, int out, int in)
36 struct gpio_event_matrix_info *mi = kp->keypad_info;
37 int key_index = out * mi->ninputs + in;
38 unsigned short keycode = mi->keymap[key_index];;
40 if (!test_bit(keycode, kp->input_dev->key)) {
41 if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
42 pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
43 "cleared\n", keycode, out, in,
44 mi->output_gpios[out], mi->input_gpios[in]);
45 __clear_bit(key_index, kp->keys_pressed);
47 if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
48 pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
49 "not cleared\n", keycode, out, in,
50 mi->output_gpios[out], mi->input_gpios[in]);
54 static int restore_keys_for_input(struct gpio_kp *kp, int out, int in)
59 key_index = out * kp->keypad_info->ninputs + in;
60 while (out < kp->keypad_info->noutputs) {
61 if (test_bit(key_index, kp->keys_pressed)) {
63 clear_phantom_key(kp, out, in);
65 key_index += kp->keypad_info->ninputs;
71 static void remove_phantom_keys(struct gpio_kp *kp)
76 if (kp->some_keys_pressed < 3)
79 for (out = 0; out < kp->keypad_info->noutputs; out++) {
81 key_index = out * kp->keypad_info->ninputs;
82 for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) {
83 if (test_bit(key_index, kp->keys_pressed)) {
89 if (!restore_keys_for_input(kp, out + 1,
92 clear_phantom_key(kp, out, inp);
95 restore_keys_for_input(kp, out, in);
101 static void report_key(struct gpio_kp *kp, int key_index, int out, int in)
103 struct gpio_event_matrix_info *mi = kp->keypad_info;
104 int pressed = test_bit(key_index, kp->keys_pressed);
105 unsigned short keycode = mi->keymap[key_index];
106 if (pressed != test_bit(keycode, kp->input_dev->key)) {
107 if (keycode == KEY_RESERVED) {
108 if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS)
109 pr_info("gpiomatrix: unmapped key, %d-%d "
110 "(%d-%d) changed to %d\n",
111 out, in, mi->output_gpios[out],
112 mi->input_gpios[in], pressed);
114 if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS)
115 pr_info("gpiomatrix: key %x, %d-%d (%d-%d) "
116 "changed to %d\n", keycode,
117 out, in, mi->output_gpios[out],
118 mi->input_gpios[in], pressed);
119 input_report_key(kp->input_dev, keycode, pressed);
124 static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
129 struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
130 struct gpio_event_matrix_info *mi = kp->keypad_info;
131 unsigned gpio_keypad_flags = mi->flags;
132 unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);
134 out = kp->current_output;
135 if (out == mi->noutputs) {
137 kp->last_key_state_changed = kp->key_state_changed;
138 kp->key_state_changed = 0;
139 kp->some_keys_pressed = 0;
141 key_index = out * mi->ninputs;
142 for (in = 0; in < mi->ninputs; in++, key_index++) {
143 gpio = mi->input_gpios[in];
144 if (gpio_get_value(gpio) ^ !polarity) {
145 if (kp->some_keys_pressed < 3)
146 kp->some_keys_pressed++;
147 kp->key_state_changed |= !__test_and_set_bit(
148 key_index, kp->keys_pressed);
150 kp->key_state_changed |= __test_and_clear_bit(
151 key_index, kp->keys_pressed);
153 gpio = mi->output_gpios[out];
154 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
155 gpio_set_value(gpio, !polarity);
157 gpio_direction_input(gpio);
160 kp->current_output = out;
161 if (out < mi->noutputs) {
162 gpio = mi->output_gpios[out];
163 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
164 gpio_set_value(gpio, polarity);
166 gpio_direction_output(gpio, polarity);
167 hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
168 return HRTIMER_NORESTART;
170 if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
171 if (kp->key_state_changed) {
172 hrtimer_start(&kp->timer, mi->debounce_delay,
174 return HRTIMER_NORESTART;
176 kp->key_state_changed = kp->last_key_state_changed;
178 if (kp->key_state_changed) {
179 if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
180 remove_phantom_keys(kp);
182 for (out = 0; out < mi->noutputs; out++)
183 for (in = 0; in < mi->ninputs; in++, key_index++)
184 report_key(kp, key_index, out, in);
186 if (!kp->use_irq || kp->some_keys_pressed) {
187 hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
188 return HRTIMER_NORESTART;
191 /* No keys are pressed, reenable interrupt */
192 for (out = 0; out < mi->noutputs; out++) {
193 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
194 gpio_set_value(mi->output_gpios[out], polarity);
196 gpio_direction_output(mi->output_gpios[out], polarity);
198 for (in = 0; in < mi->ninputs; in++)
199 enable_irq(gpio_to_irq(mi->input_gpios[in]));
200 return HRTIMER_NORESTART;
203 static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
206 struct gpio_kp *kp = dev_id;
207 struct gpio_event_matrix_info *mi = kp->keypad_info;
208 unsigned gpio_keypad_flags = mi->flags;
210 if (!kp->use_irq) /* ignore interrupt while registering the handler */
213 for (i = 0; i < mi->ninputs; i++)
214 disable_irq(gpio_to_irq(mi->input_gpios[i]));
215 for (i = 0; i < mi->noutputs; i++) {
216 if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
217 gpio_set_value(mi->output_gpios[i],
218 !(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
220 gpio_direction_input(mi->output_gpios[i]);
222 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
226 static int gpio_keypad_request_irqs(struct gpio_kp *kp)
231 unsigned long request_flags;
232 struct gpio_event_matrix_info *mi = kp->keypad_info;
234 switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
236 request_flags = IRQF_TRIGGER_FALLING;
238 case GPIOKPF_ACTIVE_HIGH:
239 request_flags = IRQF_TRIGGER_RISING;
241 case GPIOKPF_LEVEL_TRIGGERED_IRQ:
242 request_flags = IRQF_TRIGGER_LOW;
244 case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
245 request_flags = IRQF_TRIGGER_HIGH;
249 for (i = 0; i < mi->ninputs; i++) {
250 err = irq = gpio_to_irq(mi->input_gpios[i]);
252 goto err_gpio_get_irq_num_failed;
253 err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
256 pr_err("gpiomatrix: request_irq failed for input %d, "
257 "irq %d\n", mi->input_gpios[i], irq);
258 goto err_request_irq_failed;
260 err = set_irq_wake(irq, 1);
262 pr_err("gpiomatrix: set_irq_wake failed for input %d, "
263 "irq %d\n", mi->input_gpios[i], irq);
269 for (i = mi->noutputs - 1; i >= 0; i--) {
270 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
271 err_request_irq_failed:
272 err_gpio_get_irq_num_failed:
278 int gpio_event_matrix_func(struct input_dev *input_dev,
279 struct gpio_event_info *info, void **data, int func)
285 struct gpio_event_matrix_info *mi;
287 mi = container_of(info, struct gpio_event_matrix_info, info);
288 if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
289 /* TODO: disable scanning */
293 if (func == GPIO_EVENT_FUNC_INIT) {
294 if (mi->keymap == NULL ||
295 mi->input_gpios == NULL ||
296 mi->output_gpios == NULL) {
298 pr_err("gpiomatrix: Incomplete pdata\n");
299 goto err_invalid_platform_data;
301 key_count = mi->ninputs * mi->noutputs;
303 *data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
304 BITS_TO_LONGS(key_count), GFP_KERNEL);
307 pr_err("gpiomatrix: Failed to allocate private data\n");
308 goto err_kp_alloc_failed;
310 kp->input_dev = input_dev;
311 kp->keypad_info = mi;
312 set_bit(EV_KEY, input_dev->evbit);
313 for (i = 0; i < key_count; i++) {
315 set_bit(mi->keymap[i] & KEY_MAX,
319 for (i = 0; i < mi->noutputs; i++) {
320 if (gpio_cansleep(mi->output_gpios[i])) {
321 pr_err("gpiomatrix: unsupported output gpio %d,"
322 " can sleep\n", mi->output_gpios[i]);
324 goto err_request_output_gpio_failed;
326 err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
328 pr_err("gpiomatrix: gpio_request failed for "
329 "output %d\n", mi->output_gpios[i]);
330 goto err_request_output_gpio_failed;
332 if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
333 err = gpio_direction_output(mi->output_gpios[i],
334 !(mi->flags & GPIOKPF_ACTIVE_HIGH));
336 err = gpio_direction_input(mi->output_gpios[i]);
338 pr_err("gpiomatrix: gpio_configure failed for "
339 "output %d\n", mi->output_gpios[i]);
340 goto err_output_gpio_configure_failed;
343 for (i = 0; i < mi->ninputs; i++) {
344 err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
346 pr_err("gpiomatrix: gpio_request failed for "
347 "input %d\n", mi->input_gpios[i]);
348 goto err_request_input_gpio_failed;
350 err = gpio_direction_input(mi->input_gpios[i]);
352 pr_err("gpiomatrix: gpio_direction_input failed"
353 " for input %d\n", mi->input_gpios[i]);
354 goto err_gpio_direction_input_failed;
357 kp->current_output = mi->noutputs;
358 kp->key_state_changed = 1;
360 hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
361 kp->timer.function = gpio_keypad_timer_func;
362 err = gpio_keypad_request_irqs(kp);
363 kp->use_irq = err == 0;
365 pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for %s "
366 "in %s mode\n", input_dev->name,
367 kp->use_irq ? "interrupt" : "polling");
369 hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
378 for (i = mi->noutputs - 1; i >= 0; i--)
379 free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
381 hrtimer_cancel(&kp->timer);
382 for (i = mi->noutputs - 1; i >= 0; i--) {
383 err_gpio_direction_input_failed:
384 gpio_free(mi->input_gpios[i]);
385 err_request_input_gpio_failed:
388 for (i = mi->noutputs - 1; i >= 0; i--) {
389 err_output_gpio_configure_failed:
390 gpio_free(mi->output_gpios[i]);
391 err_request_output_gpio_failed:
396 err_invalid_platform_data: