Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 1 | /* drivers/input/misc/gpio_matrix.c |
| 2 | * |
| 3 | * Copyright (C) 2007 Google, Inc. |
| 4 | * |
| 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. |
| 8 | * |
| 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. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame^] | 17 | #include <linux/slab.h> |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 18 | #include <linux/gpio.h> |
| 19 | #include <linux/gpio_event.h> |
| 20 | #include <linux/hrtimer.h> |
| 21 | #include <linux/interrupt.h> |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 22 | |
| 23 | struct gpio_kp { |
| 24 | struct input_dev *input_dev; |
| 25 | struct gpio_event_matrix_info *keypad_info; |
| 26 | struct hrtimer timer; |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 27 | int current_output; |
| 28 | unsigned int use_irq:1; |
| 29 | unsigned int key_state_changed:1; |
| 30 | unsigned int last_key_state_changed:1; |
| 31 | unsigned int some_keys_pressed:2; |
| 32 | unsigned long keys_pressed[0]; |
| 33 | }; |
| 34 | |
| 35 | static void clear_phantom_key(struct gpio_kp *kp, int out, int in) |
| 36 | { |
| 37 | struct gpio_event_matrix_info *mi = kp->keypad_info; |
| 38 | int key_index = out * mi->ninputs + in; |
| 39 | unsigned short keycode = mi->keymap[key_index];; |
| 40 | |
| 41 | if (!test_bit(keycode, kp->input_dev->key)) { |
| 42 | if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS) |
| 43 | pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) " |
| 44 | "cleared\n", keycode, out, in, |
| 45 | mi->output_gpios[out], mi->input_gpios[in]); |
| 46 | __clear_bit(key_index, kp->keys_pressed); |
| 47 | } else { |
| 48 | if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS) |
| 49 | pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) " |
| 50 | "not cleared\n", keycode, out, in, |
| 51 | mi->output_gpios[out], mi->input_gpios[in]); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | static int restore_keys_for_input(struct gpio_kp *kp, int out, int in) |
| 56 | { |
| 57 | int rv = 0; |
| 58 | int key_index; |
| 59 | |
| 60 | key_index = out * kp->keypad_info->ninputs + in; |
| 61 | while (out < kp->keypad_info->noutputs) { |
| 62 | if (test_bit(key_index, kp->keys_pressed)) { |
| 63 | rv = 1; |
| 64 | clear_phantom_key(kp, out, in); |
| 65 | } |
| 66 | key_index += kp->keypad_info->ninputs; |
| 67 | out++; |
| 68 | } |
| 69 | return rv; |
| 70 | } |
| 71 | |
| 72 | static void remove_phantom_keys(struct gpio_kp *kp) |
| 73 | { |
| 74 | int out, in, inp; |
| 75 | int key_index; |
| 76 | |
| 77 | if (kp->some_keys_pressed < 3) |
| 78 | return; |
| 79 | |
| 80 | for (out = 0; out < kp->keypad_info->noutputs; out++) { |
| 81 | inp = -1; |
| 82 | key_index = out * kp->keypad_info->ninputs; |
| 83 | for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) { |
| 84 | if (test_bit(key_index, kp->keys_pressed)) { |
| 85 | if (inp == -1) { |
| 86 | inp = in; |
| 87 | continue; |
| 88 | } |
| 89 | if (inp >= 0) { |
| 90 | if (!restore_keys_for_input(kp, out + 1, |
| 91 | inp)) |
| 92 | break; |
| 93 | clear_phantom_key(kp, out, inp); |
| 94 | inp = -2; |
| 95 | } |
| 96 | restore_keys_for_input(kp, out, in); |
| 97 | } |
| 98 | } |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | static void report_key(struct gpio_kp *kp, int key_index, int out, int in) |
| 103 | { |
| 104 | struct gpio_event_matrix_info *mi = kp->keypad_info; |
| 105 | int pressed = test_bit(key_index, kp->keys_pressed); |
| 106 | unsigned short keycode = mi->keymap[key_index]; |
| 107 | if (pressed != test_bit(keycode, kp->input_dev->key)) { |
| 108 | if (keycode == KEY_RESERVED) { |
| 109 | if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS) |
| 110 | pr_info("gpiomatrix: unmapped key, %d-%d " |
| 111 | "(%d-%d) changed to %d\n", |
| 112 | out, in, mi->output_gpios[out], |
| 113 | mi->input_gpios[in], pressed); |
| 114 | } else { |
| 115 | if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS) |
| 116 | pr_info("gpiomatrix: key %x, %d-%d (%d-%d) " |
| 117 | "changed to %d\n", keycode, |
| 118 | out, in, mi->output_gpios[out], |
| 119 | mi->input_gpios[in], pressed); |
| 120 | input_report_key(kp->input_dev, keycode, pressed); |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer) |
| 126 | { |
| 127 | int out, in; |
| 128 | int key_index; |
| 129 | int gpio; |
| 130 | struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer); |
| 131 | struct gpio_event_matrix_info *mi = kp->keypad_info; |
| 132 | unsigned gpio_keypad_flags = mi->flags; |
| 133 | unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH); |
| 134 | |
| 135 | out = kp->current_output; |
| 136 | if (out == mi->noutputs) { |
| 137 | out = 0; |
| 138 | kp->last_key_state_changed = kp->key_state_changed; |
| 139 | kp->key_state_changed = 0; |
| 140 | kp->some_keys_pressed = 0; |
| 141 | } else { |
| 142 | key_index = out * mi->ninputs; |
| 143 | for (in = 0; in < mi->ninputs; in++, key_index++) { |
| 144 | gpio = mi->input_gpios[in]; |
| 145 | if (gpio_get_value(gpio) ^ !polarity) { |
| 146 | if (kp->some_keys_pressed < 3) |
| 147 | kp->some_keys_pressed++; |
| 148 | kp->key_state_changed |= !__test_and_set_bit( |
| 149 | key_index, kp->keys_pressed); |
| 150 | } else |
| 151 | kp->key_state_changed |= __test_and_clear_bit( |
| 152 | key_index, kp->keys_pressed); |
| 153 | } |
| 154 | gpio = mi->output_gpios[out]; |
| 155 | if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE) |
| 156 | gpio_set_value(gpio, !polarity); |
| 157 | else |
| 158 | gpio_direction_input(gpio); |
| 159 | out++; |
| 160 | } |
| 161 | kp->current_output = out; |
| 162 | if (out < mi->noutputs) { |
| 163 | gpio = mi->output_gpios[out]; |
| 164 | if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE) |
| 165 | gpio_set_value(gpio, polarity); |
| 166 | else |
| 167 | gpio_direction_output(gpio, polarity); |
| 168 | hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL); |
| 169 | return HRTIMER_NORESTART; |
| 170 | } |
| 171 | if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) { |
| 172 | if (kp->key_state_changed) { |
| 173 | hrtimer_start(&kp->timer, mi->debounce_delay, |
| 174 | HRTIMER_MODE_REL); |
| 175 | return HRTIMER_NORESTART; |
| 176 | } |
| 177 | kp->key_state_changed = kp->last_key_state_changed; |
| 178 | } |
| 179 | if (kp->key_state_changed) { |
| 180 | if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS) |
| 181 | remove_phantom_keys(kp); |
| 182 | key_index = 0; |
| 183 | for (out = 0; out < mi->noutputs; out++) |
| 184 | for (in = 0; in < mi->ninputs; in++, key_index++) |
| 185 | report_key(kp, key_index, out, in); |
| 186 | } |
| 187 | if (!kp->use_irq || kp->some_keys_pressed) { |
| 188 | hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL); |
| 189 | return HRTIMER_NORESTART; |
| 190 | } |
| 191 | |
| 192 | /* No keys are pressed, reenable interrupt */ |
| 193 | for (out = 0; out < mi->noutputs; out++) { |
| 194 | if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE) |
| 195 | gpio_set_value(mi->output_gpios[out], polarity); |
| 196 | else |
| 197 | gpio_direction_output(mi->output_gpios[out], polarity); |
| 198 | } |
| 199 | for (in = 0; in < mi->ninputs; in++) |
| 200 | enable_irq(gpio_to_irq(mi->input_gpios[in])); |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 201 | return HRTIMER_NORESTART; |
| 202 | } |
| 203 | |
| 204 | static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id) |
| 205 | { |
| 206 | int i; |
| 207 | struct gpio_kp *kp = dev_id; |
| 208 | struct gpio_event_matrix_info *mi = kp->keypad_info; |
| 209 | unsigned gpio_keypad_flags = mi->flags; |
| 210 | |
| 211 | if (!kp->use_irq) /* ignore interrupt while registering the handler */ |
| 212 | return IRQ_HANDLED; |
| 213 | |
| 214 | for (i = 0; i < mi->ninputs; i++) |
| 215 | disable_irq(gpio_to_irq(mi->input_gpios[i])); |
| 216 | for (i = 0; i < mi->noutputs; i++) { |
| 217 | if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE) |
| 218 | gpio_set_value(mi->output_gpios[i], |
| 219 | !(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH)); |
| 220 | else |
| 221 | gpio_direction_input(mi->output_gpios[i]); |
| 222 | } |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 223 | hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL); |
| 224 | return IRQ_HANDLED; |
| 225 | } |
| 226 | |
| 227 | static int gpio_keypad_request_irqs(struct gpio_kp *kp) |
| 228 | { |
| 229 | int i; |
| 230 | int err; |
| 231 | unsigned int irq; |
| 232 | unsigned long request_flags; |
| 233 | struct gpio_event_matrix_info *mi = kp->keypad_info; |
| 234 | |
| 235 | switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) { |
| 236 | default: |
| 237 | request_flags = IRQF_TRIGGER_FALLING; |
| 238 | break; |
| 239 | case GPIOKPF_ACTIVE_HIGH: |
| 240 | request_flags = IRQF_TRIGGER_RISING; |
| 241 | break; |
| 242 | case GPIOKPF_LEVEL_TRIGGERED_IRQ: |
| 243 | request_flags = IRQF_TRIGGER_LOW; |
| 244 | break; |
| 245 | case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH: |
| 246 | request_flags = IRQF_TRIGGER_HIGH; |
| 247 | break; |
| 248 | } |
| 249 | |
| 250 | for (i = 0; i < mi->ninputs; i++) { |
| 251 | err = irq = gpio_to_irq(mi->input_gpios[i]); |
| 252 | if (err < 0) |
| 253 | goto err_gpio_get_irq_num_failed; |
| 254 | err = request_irq(irq, gpio_keypad_irq_handler, request_flags, |
| 255 | "gpio_kp", kp); |
| 256 | if (err) { |
| 257 | pr_err("gpiomatrix: request_irq failed for input %d, " |
| 258 | "irq %d\n", mi->input_gpios[i], irq); |
| 259 | goto err_request_irq_failed; |
| 260 | } |
| 261 | err = set_irq_wake(irq, 1); |
| 262 | if (err) { |
| 263 | pr_err("gpiomatrix: set_irq_wake failed for input %d, " |
| 264 | "irq %d\n", mi->input_gpios[i], irq); |
| 265 | } |
| 266 | disable_irq(irq); |
| 267 | } |
| 268 | return 0; |
| 269 | |
| 270 | for (i = mi->noutputs - 1; i >= 0; i--) { |
| 271 | free_irq(gpio_to_irq(mi->input_gpios[i]), kp); |
| 272 | err_request_irq_failed: |
| 273 | err_gpio_get_irq_num_failed: |
| 274 | ; |
| 275 | } |
| 276 | return err; |
| 277 | } |
| 278 | |
| 279 | int gpio_event_matrix_func(struct input_dev *input_dev, |
| 280 | struct gpio_event_info *info, void **data, int func) |
| 281 | { |
| 282 | int i; |
| 283 | int err; |
| 284 | int key_count; |
| 285 | struct gpio_kp *kp; |
| 286 | struct gpio_event_matrix_info *mi; |
| 287 | |
| 288 | mi = container_of(info, struct gpio_event_matrix_info, info); |
| 289 | if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) { |
| 290 | /* TODO: disable scanning */ |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | if (func == GPIO_EVENT_FUNC_INIT) { |
| 295 | if (mi->keymap == NULL || |
| 296 | mi->input_gpios == NULL || |
| 297 | mi->output_gpios == NULL) { |
| 298 | err = -ENODEV; |
| 299 | pr_err("gpiomatrix: Incomplete pdata\n"); |
| 300 | goto err_invalid_platform_data; |
| 301 | } |
| 302 | key_count = mi->ninputs * mi->noutputs; |
| 303 | |
| 304 | *data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) * |
| 305 | BITS_TO_LONGS(key_count), GFP_KERNEL); |
| 306 | if (kp == NULL) { |
| 307 | err = -ENOMEM; |
| 308 | pr_err("gpiomatrix: Failed to allocate private data\n"); |
| 309 | goto err_kp_alloc_failed; |
| 310 | } |
| 311 | kp->input_dev = input_dev; |
| 312 | kp->keypad_info = mi; |
| 313 | set_bit(EV_KEY, input_dev->evbit); |
| 314 | for (i = 0; i < key_count; i++) { |
| 315 | if (mi->keymap[i]) |
| 316 | set_bit(mi->keymap[i] & KEY_MAX, |
| 317 | input_dev->keybit); |
| 318 | } |
| 319 | |
| 320 | for (i = 0; i < mi->noutputs; i++) { |
| 321 | if (gpio_cansleep(mi->output_gpios[i])) { |
| 322 | pr_err("gpiomatrix: unsupported output gpio %d," |
| 323 | " can sleep\n", mi->output_gpios[i]); |
| 324 | err = -EINVAL; |
| 325 | goto err_request_output_gpio_failed; |
| 326 | } |
| 327 | err = gpio_request(mi->output_gpios[i], "gpio_kp_out"); |
| 328 | if (err) { |
| 329 | pr_err("gpiomatrix: gpio_request failed for " |
| 330 | "output %d\n", mi->output_gpios[i]); |
| 331 | goto err_request_output_gpio_failed; |
| 332 | } |
| 333 | if (mi->flags & GPIOKPF_DRIVE_INACTIVE) |
| 334 | err = gpio_direction_output(mi->output_gpios[i], |
| 335 | !(mi->flags & GPIOKPF_ACTIVE_HIGH)); |
| 336 | else |
| 337 | err = gpio_direction_input(mi->output_gpios[i]); |
| 338 | if (err) { |
| 339 | pr_err("gpiomatrix: gpio_configure failed for " |
| 340 | "output %d\n", mi->output_gpios[i]); |
| 341 | goto err_output_gpio_configure_failed; |
| 342 | } |
| 343 | } |
| 344 | for (i = 0; i < mi->ninputs; i++) { |
| 345 | err = gpio_request(mi->input_gpios[i], "gpio_kp_in"); |
| 346 | if (err) { |
| 347 | pr_err("gpiomatrix: gpio_request failed for " |
| 348 | "input %d\n", mi->input_gpios[i]); |
| 349 | goto err_request_input_gpio_failed; |
| 350 | } |
| 351 | err = gpio_direction_input(mi->input_gpios[i]); |
| 352 | if (err) { |
| 353 | pr_err("gpiomatrix: gpio_direction_input failed" |
| 354 | " for input %d\n", mi->input_gpios[i]); |
| 355 | goto err_gpio_direction_input_failed; |
| 356 | } |
| 357 | } |
| 358 | kp->current_output = mi->noutputs; |
| 359 | kp->key_state_changed = 1; |
| 360 | |
| 361 | hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| 362 | kp->timer.function = gpio_keypad_timer_func; |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 363 | err = gpio_keypad_request_irqs(kp); |
| 364 | kp->use_irq = err == 0; |
| 365 | |
| 366 | pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for %s " |
| 367 | "in %s mode\n", input_dev->name, |
| 368 | kp->use_irq ? "interrupt" : "polling"); |
| 369 | |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 370 | hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL); |
| 371 | |
| 372 | return 0; |
| 373 | } |
| 374 | |
| 375 | err = 0; |
| 376 | kp = *data; |
| 377 | |
| 378 | if (kp->use_irq) |
| 379 | for (i = mi->noutputs - 1; i >= 0; i--) |
| 380 | free_irq(gpio_to_irq(mi->input_gpios[i]), kp); |
| 381 | |
| 382 | hrtimer_cancel(&kp->timer); |
Arve Hjønnevåg | 420818f | 2009-08-08 15:03:15 +0200 | [diff] [blame] | 383 | for (i = mi->noutputs - 1; i >= 0; i--) { |
| 384 | err_gpio_direction_input_failed: |
| 385 | gpio_free(mi->input_gpios[i]); |
| 386 | err_request_input_gpio_failed: |
| 387 | ; |
| 388 | } |
| 389 | for (i = mi->noutputs - 1; i >= 0; i--) { |
| 390 | err_output_gpio_configure_failed: |
| 391 | gpio_free(mi->output_gpios[i]); |
| 392 | err_request_output_gpio_failed: |
| 393 | ; |
| 394 | } |
| 395 | kfree(kp); |
| 396 | err_kp_alloc_failed: |
| 397 | err_invalid_platform_data: |
| 398 | return err; |
| 399 | } |