1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  *
4  * Author: Jayeeta Banerjee <jayeeta.banerjee@stericsson.com>
5  * Author: Sundar Iyer <sundar.iyer@stericsson.com>
6  *
7  * License Terms: GNU General Public License, version 2
8  *
9  * TC35893 MFD Keypad Controller driver
10  */
11 
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/input.h>
15 #include <linux/platform_device.h>
16 #include <linux/input/matrix_keypad.h>
17 #include <linux/i2c.h>
18 #include <linux/slab.h>
19 #include <linux/mfd/tc3589x.h>
20 
21 /* Maximum supported keypad matrix row/columns size */
22 #define TC3589x_MAX_KPROW               8
23 #define TC3589x_MAX_KPCOL               12
24 
25 /* keypad related Constants */
26 #define TC3589x_MAX_DEBOUNCE_SETTLE     0xFF
27 #define DEDICATED_KEY_VAL		0xFF
28 
29 /* Pull up/down masks */
30 #define TC3589x_NO_PULL_MASK		0x0
31 #define TC3589x_PULL_DOWN_MASK		0x1
32 #define TC3589x_PULL_UP_MASK		0x2
33 #define TC3589x_PULLUP_ALL_MASK		0xAA
34 #define TC3589x_IO_PULL_VAL(index, mask)	((mask)<<((index)%4)*2))
35 
36 /* Bit masks for IOCFG register */
37 #define IOCFG_BALLCFG		0x01
38 #define IOCFG_IG		0x08
39 
40 #define KP_EVCODE_COL_MASK	0x0F
41 #define KP_EVCODE_ROW_MASK	0x70
42 #define KP_RELEASE_EVT_MASK	0x80
43 
44 #define KP_ROW_SHIFT		4
45 
46 #define KP_NO_VALID_KEY_MASK	0x7F
47 
48 /* bit masks for RESTCTRL register */
49 #define TC3589x_KBDRST		0x2
50 #define TC3589x_IRQRST		0x10
51 #define TC3589x_RESET_ALL	0x1B
52 
53 /* KBDMFS register bit mask */
54 #define TC3589x_KBDMFS_EN	0x1
55 
56 /* CLKEN register bitmask */
57 #define KPD_CLK_EN		0x1
58 
59 /* RSTINTCLR register bit mask */
60 #define IRQ_CLEAR		0x1
61 
62 /* bit masks for keyboard interrupts*/
63 #define TC3589x_EVT_LOSS_INT	0x8
64 #define TC3589x_EVT_INT		0x4
65 #define TC3589x_KBD_LOSS_INT	0x2
66 #define TC3589x_KBD_INT		0x1
67 
68 /* bit masks for keyboard interrupt clear*/
69 #define TC3589x_EVT_INT_CLR	0x2
70 #define TC3589x_KBD_INT_CLR	0x1
71 
72 /**
73  * struct tc_keypad - data structure used by keypad driver
74  * @tc3589x:    pointer to tc35893
75  * @input:      pointer to input device object
76  * @board:      keypad platform device
77  * @krow:	number of rows
78  * @kcol:	number of columns
79  * @keymap:     matrix scan code table for keycodes
80  * @keypad_stopped: holds keypad status
81  */
82 struct tc_keypad {
83 	struct tc3589x *tc3589x;
84 	struct input_dev *input;
85 	const struct tc3589x_keypad_platform_data *board;
86 	unsigned int krow;
87 	unsigned int kcol;
88 	unsigned short *keymap;
89 	bool keypad_stopped;
90 };
91 
92 static int tc3589x_keypad_init_key_hardware(struct tc_keypad *keypad)
93 {
94 	int ret;
95 	struct tc3589x *tc3589x = keypad->tc3589x;
96 	const struct tc3589x_keypad_platform_data *board = keypad->board;
97 
98 	/* validate platform configuration */
99 	if (board->kcol > TC3589x_MAX_KPCOL || board->krow > TC3589x_MAX_KPROW)
100 		return -EINVAL;
101 
102 	/* configure KBDSIZE 4 LSbits for cols and 4 MSbits for rows */
103 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSIZE,
104 			(board->krow << KP_ROW_SHIFT) | board->kcol);
105 	if (ret < 0)
106 		return ret;
107 
108 	/* configure dedicated key config, no dedicated key selected */
109 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_LSB, DEDICATED_KEY_VAL);
110 	if (ret < 0)
111 		return ret;
112 
113 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_MSB, DEDICATED_KEY_VAL);
114 	if (ret < 0)
115 		return ret;
116 
117 	/* Configure settle time */
118 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSETTLE_REG,
119 				board->settle_time);
120 	if (ret < 0)
121 		return ret;
122 
123 	/* Configure debounce time */
124 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDBOUNCE,
125 				board->debounce_period);
126 	if (ret < 0)
127 		return ret;
128 
129 	/* Start of initialise keypad GPIOs */
130 	ret = tc3589x_set_bits(tc3589x, TC3589x_IOCFG, 0x0, IOCFG_IG);
131 	if (ret < 0)
132 		return ret;
133 
134 	/* Configure pull-up resistors for all row GPIOs */
135 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_LSB,
136 					TC3589x_PULLUP_ALL_MASK);
137 	if (ret < 0)
138 		return ret;
139 
140 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_MSB,
141 					TC3589x_PULLUP_ALL_MASK);
142 	if (ret < 0)
143 		return ret;
144 
145 	/* Configure pull-up resistors for all column GPIOs */
146 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_LSB,
147 			TC3589x_PULLUP_ALL_MASK);
148 	if (ret < 0)
149 		return ret;
150 
151 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_MSB,
152 			TC3589x_PULLUP_ALL_MASK);
153 	if (ret < 0)
154 		return ret;
155 
156 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG2_LSB,
157 			TC3589x_PULLUP_ALL_MASK);
158 
159 	return ret;
160 }
161 
162 #define TC35893_DATA_REGS		4
163 #define TC35893_KEYCODE_FIFO_EMPTY	0x7f
164 #define TC35893_KEYCODE_FIFO_CLEAR	0xff
165 #define TC35893_KEYPAD_ROW_SHIFT	0x3
166 
167 static irqreturn_t tc3589x_keypad_irq(int irq, void *dev)
168 {
169 	struct tc_keypad *keypad = dev;
170 	struct tc3589x *tc3589x = keypad->tc3589x;
171 	u8 i, row_index, col_index, kbd_code, up;
172 	u8 code;
173 
174 	for (i = 0; i < TC35893_DATA_REGS * 2; i++) {
175 		kbd_code = tc3589x_reg_read(tc3589x, TC3589x_EVTCODE_FIFO);
176 
177 		/* loop till fifo is empty and no more keys are pressed */
178 		if (kbd_code == TC35893_KEYCODE_FIFO_EMPTY ||
179 				kbd_code == TC35893_KEYCODE_FIFO_CLEAR)
180 			continue;
181 
182 		/* valid key is found */
183 		col_index = kbd_code & KP_EVCODE_COL_MASK;
184 		row_index = (kbd_code & KP_EVCODE_ROW_MASK) >> KP_ROW_SHIFT;
185 		code = MATRIX_SCAN_CODE(row_index, col_index,
186 						TC35893_KEYPAD_ROW_SHIFT);
187 		up = kbd_code & KP_RELEASE_EVT_MASK;
188 
189 		input_event(keypad->input, EV_MSC, MSC_SCAN, code);
190 		input_report_key(keypad->input, keypad->keymap[code], !up);
191 		input_sync(keypad->input);
192 	}
193 
194 	/* clear IRQ */
195 	tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
196 			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
197 	/* enable IRQ */
198 	tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
199 			0x0, TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
200 
201 	return IRQ_HANDLED;
202 }
203 
204 static int tc3589x_keypad_enable(struct tc_keypad *keypad)
205 {
206 	struct tc3589x *tc3589x = keypad->tc3589x;
207 	int ret;
208 
209 	/* pull the keypad module out of reset */
210 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x0);
211 	if (ret < 0)
212 		return ret;
213 
214 	/* configure KBDMFS */
215 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMFS, 0x0, TC3589x_KBDMFS_EN);
216 	if (ret < 0)
217 		return ret;
218 
219 	/* enable the keypad clock */
220 	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x0, KPD_CLK_EN);
221 	if (ret < 0)
222 		return ret;
223 
224 	/* clear pending IRQs */
225 	ret =  tc3589x_set_bits(tc3589x, TC3589x_RSTINTCLR, 0x0, 0x1);
226 	if (ret < 0)
227 		return ret;
228 
229 	/* enable the IRQs */
230 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK, 0x0,
231 					TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
232 	if (ret < 0)
233 		return ret;
234 
235 	keypad->keypad_stopped = false;
236 
237 	return ret;
238 }
239 
240 static int tc3589x_keypad_disable(struct tc_keypad *keypad)
241 {
242 	struct tc3589x *tc3589x = keypad->tc3589x;
243 	int ret;
244 
245 	/* clear IRQ */
246 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
247 			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
248 	if (ret < 0)
249 		return ret;
250 
251 	/* disable all interrupts */
252 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
253 			~(TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT), 0x0);
254 	if (ret < 0)
255 		return ret;
256 
257 	/* disable the keypad module */
258 	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x1, 0x0);
259 	if (ret < 0)
260 		return ret;
261 
262 	/* put the keypad module into reset */
263 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x1);
264 
265 	keypad->keypad_stopped = true;
266 
267 	return ret;
268 }
269 
270 static int tc3589x_keypad_open(struct input_dev *input)
271 {
272 	int error;
273 	struct tc_keypad *keypad = input_get_drvdata(input);
274 
275 	/* enable the keypad module */
276 	error = tc3589x_keypad_enable(keypad);
277 	if (error < 0) {
278 		dev_err(&input->dev, "failed to enable keypad module\n");
279 		return error;
280 	}
281 
282 	error = tc3589x_keypad_init_key_hardware(keypad);
283 	if (error < 0) {
284 		dev_err(&input->dev, "failed to configure keypad module\n");
285 		return error;
286 	}
287 
288 	return 0;
289 }
290 
291 static void tc3589x_keypad_close(struct input_dev *input)
292 {
293 	struct tc_keypad *keypad = input_get_drvdata(input);
294 
295 	/* disable the keypad module */
296 	tc3589x_keypad_disable(keypad);
297 }
298 
299 #ifdef CONFIG_OF
300 static const struct tc3589x_keypad_platform_data *
301 tc3589x_keypad_of_probe(struct device *dev)
302 {
303 	struct device_node *np = dev->of_node;
304 	struct tc3589x_keypad_platform_data *plat;
305 	u32 cols, rows;
306 	u32 debounce_ms;
307 	int proplen;
308 
309 	if (!np)
310 		return ERR_PTR(-ENODEV);
311 
312 	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
313 	if (!plat)
314 		return ERR_PTR(-ENOMEM);
315 
316 	of_property_read_u32(np, "keypad,num-columns", &cols);
317 	of_property_read_u32(np, "keypad,num-rows", &rows);
318 	plat->kcol = (u8) cols;
319 	plat->krow = (u8) rows;
320 	if (!plat->krow || !plat->kcol ||
321 	     plat->krow > TC_KPD_ROWS || plat->kcol > TC_KPD_COLUMNS) {
322 		dev_err(dev,
323 			"keypad columns/rows not properly specified (%ux%u)\n",
324 			plat->kcol, plat->krow);
325 		return ERR_PTR(-EINVAL);
326 	}
327 
328 	if (!of_get_property(np, "linux,keymap", &proplen)) {
329 		dev_err(dev, "property linux,keymap not found\n");
330 		return ERR_PTR(-ENOENT);
331 	}
332 
333 	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
334 	plat->enable_wakeup = of_property_read_bool(np, "linux,wakeup");
335 
336 	/* The custom delay format is ms/16 */
337 	of_property_read_u32(np, "debounce-delay-ms", &debounce_ms);
338 	if (debounce_ms)
339 		plat->debounce_period = debounce_ms * 16;
340 	else
341 		plat->debounce_period = TC_KPD_DEBOUNCE_PERIOD;
342 
343 	plat->settle_time = TC_KPD_SETTLE_TIME;
344 	/* FIXME: should be property of the IRQ resource? */
345 	plat->irqtype = IRQF_TRIGGER_FALLING;
346 
347 	return plat;
348 }
349 #else
350 static inline const struct tc3589x_keypad_platform_data *
351 tc3589x_keypad_of_probe(struct device *dev)
352 {
353 	return ERR_PTR(-ENODEV);
354 }
355 #endif
356 
357 
358 static int tc3589x_keypad_probe(struct platform_device *pdev)
359 {
360 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
361 	struct tc_keypad *keypad;
362 	struct input_dev *input;
363 	const struct tc3589x_keypad_platform_data *plat;
364 	int error, irq;
365 
366 	plat = tc3589x->pdata->keypad;
367 	if (!plat) {
368 		plat = tc3589x_keypad_of_probe(&pdev->dev);
369 		if (IS_ERR(plat)) {
370 			dev_err(&pdev->dev, "invalid keypad platform data\n");
371 			return PTR_ERR(plat);
372 		}
373 	}
374 
375 	irq = platform_get_irq(pdev, 0);
376 	if (irq < 0)
377 		return irq;
378 
379 	keypad = kzalloc(sizeof(struct tc_keypad), GFP_KERNEL);
380 	input = input_allocate_device();
381 	if (!keypad || !input) {
382 		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
383 		error = -ENOMEM;
384 		goto err_free_mem;
385 	}
386 
387 	keypad->board = plat;
388 	keypad->input = input;
389 	keypad->tc3589x = tc3589x;
390 
391 	input->id.bustype = BUS_I2C;
392 	input->name = pdev->name;
393 	input->dev.parent = &pdev->dev;
394 
395 	input->open = tc3589x_keypad_open;
396 	input->close = tc3589x_keypad_close;
397 
398 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
399 					   TC3589x_MAX_KPROW, TC3589x_MAX_KPCOL,
400 					   NULL, input);
401 	if (error) {
402 		dev_err(&pdev->dev, "Failed to build keymap\n");
403 		goto err_free_mem;
404 	}
405 
406 	keypad->keymap = input->keycode;
407 
408 	input_set_capability(input, EV_MSC, MSC_SCAN);
409 	if (!plat->no_autorepeat)
410 		__set_bit(EV_REP, input->evbit);
411 
412 	input_set_drvdata(input, keypad);
413 
414 	error = request_threaded_irq(irq, NULL,
415 			tc3589x_keypad_irq, plat->irqtype,
416 			"tc3589x-keypad", keypad);
417 	if (error < 0) {
418 		dev_err(&pdev->dev,
419 				"Could not allocate irq %d,error %d\n",
420 				irq, error);
421 		goto err_free_mem;
422 	}
423 
424 	error = input_register_device(input);
425 	if (error) {
426 		dev_err(&pdev->dev, "Could not register input device\n");
427 		goto err_free_irq;
428 	}
429 
430 	/* let platform decide if keypad is a wakeup source or not */
431 	device_init_wakeup(&pdev->dev, plat->enable_wakeup);
432 	device_set_wakeup_capable(&pdev->dev, plat->enable_wakeup);
433 
434 	platform_set_drvdata(pdev, keypad);
435 
436 	return 0;
437 
438 err_free_irq:
439 	free_irq(irq, keypad);
440 err_free_mem:
441 	input_free_device(input);
442 	kfree(keypad);
443 	return error;
444 }
445 
446 static int tc3589x_keypad_remove(struct platform_device *pdev)
447 {
448 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
449 	int irq = platform_get_irq(pdev, 0);
450 
451 	if (!keypad->keypad_stopped)
452 		tc3589x_keypad_disable(keypad);
453 
454 	free_irq(irq, keypad);
455 
456 	input_unregister_device(keypad->input);
457 
458 	kfree(keypad);
459 
460 	return 0;
461 }
462 
463 #ifdef CONFIG_PM_SLEEP
464 static int tc3589x_keypad_suspend(struct device *dev)
465 {
466 	struct platform_device *pdev = to_platform_device(dev);
467 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
468 	int irq = platform_get_irq(pdev, 0);
469 
470 	/* keypad is already off; we do nothing */
471 	if (keypad->keypad_stopped)
472 		return 0;
473 
474 	/* if device is not a wakeup source, disable it for powersave */
475 	if (!device_may_wakeup(&pdev->dev))
476 		tc3589x_keypad_disable(keypad);
477 	else
478 		enable_irq_wake(irq);
479 
480 	return 0;
481 }
482 
483 static int tc3589x_keypad_resume(struct device *dev)
484 {
485 	struct platform_device *pdev = to_platform_device(dev);
486 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
487 	int irq = platform_get_irq(pdev, 0);
488 
489 	if (!keypad->keypad_stopped)
490 		return 0;
491 
492 	/* enable the device to resume normal operations */
493 	if (!device_may_wakeup(&pdev->dev))
494 		tc3589x_keypad_enable(keypad);
495 	else
496 		disable_irq_wake(irq);
497 
498 	return 0;
499 }
500 #endif
501 
502 static SIMPLE_DEV_PM_OPS(tc3589x_keypad_dev_pm_ops,
503 			 tc3589x_keypad_suspend, tc3589x_keypad_resume);
504 
505 static struct platform_driver tc3589x_keypad_driver = {
506 	.driver	= {
507 		.name	= "tc3589x-keypad",
508 		.owner	= THIS_MODULE,
509 		.pm	= &tc3589x_keypad_dev_pm_ops,
510 	},
511 	.probe	= tc3589x_keypad_probe,
512 	.remove	= tc3589x_keypad_remove,
513 };
514 module_platform_driver(tc3589x_keypad_driver);
515 
516 MODULE_LICENSE("GPL v2");
517 MODULE_AUTHOR("Jayeeta Banerjee/Sundar Iyer");
518 MODULE_DESCRIPTION("TC35893 Keypad Driver");
519 MODULE_ALIAS("platform:tc3589x-keypad");
520