1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * Author: Jayeeta Banerjee <jayeeta.banerjee@stericsson.com>
6  * Author: Sundar Iyer <sundar.iyer@stericsson.com>
7  *
8  * TC35893 MFD Keypad Controller driver
9  */
10 
11 #include <linux/module.h>
12 #include <linux/interrupt.h>
13 #include <linux/input.h>
14 #include <linux/platform_device.h>
15 #include <linux/input/matrix_keypad.h>
16 #include <linux/i2c.h>
17 #include <linux/slab.h>
18 #include <linux/mfd/tc3589x.h>
19 #include <linux/device.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 tc3589x_keypad_platform_data - platform specific keypad data
74  * @keymap_data:        matrix scan code table for keycodes
75  * @krow:               mask for available rows, value is 0xFF
76  * @kcol:               mask for available columns, value is 0xFF
77  * @debounce_period:    platform specific debounce time
78  * @settle_time:        platform specific settle down time
79  * @irqtype:            type of interrupt, falling or rising edge
80  * @enable_wakeup:      specifies if keypad event can wake up system from sleep
81  * @no_autorepeat:      flag for auto repetition
82  */
83 struct tc3589x_keypad_platform_data {
84 	const struct matrix_keymap_data *keymap_data;
85 	u8                      krow;
86 	u8                      kcol;
87 	u8                      debounce_period;
88 	u8                      settle_time;
89 	unsigned long           irqtype;
90 	bool                    enable_wakeup;
91 	bool                    no_autorepeat;
92 };
93 
94 /**
95  * struct tc_keypad - data structure used by keypad driver
96  * @tc3589x:    pointer to tc35893
97  * @input:      pointer to input device object
98  * @board:      keypad platform device
99  * @krow:	number of rows
100  * @kcol:	number of columns
101  * @keymap:     matrix scan code table for keycodes
102  * @keypad_stopped: holds keypad status
103  */
104 struct tc_keypad {
105 	struct tc3589x *tc3589x;
106 	struct input_dev *input;
107 	const struct tc3589x_keypad_platform_data *board;
108 	unsigned int krow;
109 	unsigned int kcol;
110 	unsigned short *keymap;
111 	bool keypad_stopped;
112 };
113 
tc3589x_keypad_init_key_hardware(struct tc_keypad * keypad)114 static int tc3589x_keypad_init_key_hardware(struct tc_keypad *keypad)
115 {
116 	int ret;
117 	struct tc3589x *tc3589x = keypad->tc3589x;
118 	const struct tc3589x_keypad_platform_data *board = keypad->board;
119 
120 	/* validate platform configuration */
121 	if (board->kcol > TC3589x_MAX_KPCOL || board->krow > TC3589x_MAX_KPROW)
122 		return -EINVAL;
123 
124 	/* configure KBDSIZE 4 LSbits for cols and 4 MSbits for rows */
125 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSIZE,
126 			(board->krow << KP_ROW_SHIFT) | board->kcol);
127 	if (ret < 0)
128 		return ret;
129 
130 	/* configure dedicated key config, no dedicated key selected */
131 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_LSB, DEDICATED_KEY_VAL);
132 	if (ret < 0)
133 		return ret;
134 
135 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_MSB, DEDICATED_KEY_VAL);
136 	if (ret < 0)
137 		return ret;
138 
139 	/* Configure settle time */
140 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSETTLE_REG,
141 				board->settle_time);
142 	if (ret < 0)
143 		return ret;
144 
145 	/* Configure debounce time */
146 	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDBOUNCE,
147 				board->debounce_period);
148 	if (ret < 0)
149 		return ret;
150 
151 	/* Start of initialise keypad GPIOs */
152 	ret = tc3589x_set_bits(tc3589x, TC3589x_IOCFG, 0x0, IOCFG_IG);
153 	if (ret < 0)
154 		return ret;
155 
156 	/* Configure pull-up resistors for all row GPIOs */
157 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_LSB,
158 					TC3589x_PULLUP_ALL_MASK);
159 	if (ret < 0)
160 		return ret;
161 
162 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_MSB,
163 					TC3589x_PULLUP_ALL_MASK);
164 	if (ret < 0)
165 		return ret;
166 
167 	/* Configure pull-up resistors for all column GPIOs */
168 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_LSB,
169 			TC3589x_PULLUP_ALL_MASK);
170 	if (ret < 0)
171 		return ret;
172 
173 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_MSB,
174 			TC3589x_PULLUP_ALL_MASK);
175 	if (ret < 0)
176 		return ret;
177 
178 	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG2_LSB,
179 			TC3589x_PULLUP_ALL_MASK);
180 
181 	return ret;
182 }
183 
184 #define TC35893_DATA_REGS		4
185 #define TC35893_KEYCODE_FIFO_EMPTY	0x7f
186 #define TC35893_KEYCODE_FIFO_CLEAR	0xff
187 #define TC35893_KEYPAD_ROW_SHIFT	0x3
188 
tc3589x_keypad_irq(int irq,void * dev)189 static irqreturn_t tc3589x_keypad_irq(int irq, void *dev)
190 {
191 	struct tc_keypad *keypad = dev;
192 	struct tc3589x *tc3589x = keypad->tc3589x;
193 	u8 i, row_index, col_index, kbd_code, up;
194 	u8 code;
195 
196 	for (i = 0; i < TC35893_DATA_REGS * 2; i++) {
197 		kbd_code = tc3589x_reg_read(tc3589x, TC3589x_EVTCODE_FIFO);
198 
199 		/* loop till fifo is empty and no more keys are pressed */
200 		if (kbd_code == TC35893_KEYCODE_FIFO_EMPTY ||
201 				kbd_code == TC35893_KEYCODE_FIFO_CLEAR)
202 			continue;
203 
204 		/* valid key is found */
205 		col_index = kbd_code & KP_EVCODE_COL_MASK;
206 		row_index = (kbd_code & KP_EVCODE_ROW_MASK) >> KP_ROW_SHIFT;
207 		code = MATRIX_SCAN_CODE(row_index, col_index,
208 						TC35893_KEYPAD_ROW_SHIFT);
209 		up = kbd_code & KP_RELEASE_EVT_MASK;
210 
211 		input_event(keypad->input, EV_MSC, MSC_SCAN, code);
212 		input_report_key(keypad->input, keypad->keymap[code], !up);
213 		input_sync(keypad->input);
214 	}
215 
216 	/* clear IRQ */
217 	tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
218 			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
219 	/* enable IRQ */
220 	tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
221 			0x0, TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
222 
223 	return IRQ_HANDLED;
224 }
225 
tc3589x_keypad_enable(struct tc_keypad * keypad)226 static int tc3589x_keypad_enable(struct tc_keypad *keypad)
227 {
228 	struct tc3589x *tc3589x = keypad->tc3589x;
229 	int ret;
230 
231 	/* pull the keypad module out of reset */
232 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x0);
233 	if (ret < 0)
234 		return ret;
235 
236 	/* configure KBDMFS */
237 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMFS, 0x0, TC3589x_KBDMFS_EN);
238 	if (ret < 0)
239 		return ret;
240 
241 	/* enable the keypad clock */
242 	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x0, KPD_CLK_EN);
243 	if (ret < 0)
244 		return ret;
245 
246 	/* clear pending IRQs */
247 	ret =  tc3589x_set_bits(tc3589x, TC3589x_RSTINTCLR, 0x0, 0x1);
248 	if (ret < 0)
249 		return ret;
250 
251 	/* enable the IRQs */
252 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK, 0x0,
253 					TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
254 	if (ret < 0)
255 		return ret;
256 
257 	keypad->keypad_stopped = false;
258 
259 	return ret;
260 }
261 
tc3589x_keypad_disable(struct tc_keypad * keypad)262 static int tc3589x_keypad_disable(struct tc_keypad *keypad)
263 {
264 	struct tc3589x *tc3589x = keypad->tc3589x;
265 	int ret;
266 
267 	/* clear IRQ */
268 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
269 			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
270 	if (ret < 0)
271 		return ret;
272 
273 	/* disable all interrupts */
274 	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
275 			~(TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT), 0x0);
276 	if (ret < 0)
277 		return ret;
278 
279 	/* disable the keypad module */
280 	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x1, 0x0);
281 	if (ret < 0)
282 		return ret;
283 
284 	/* put the keypad module into reset */
285 	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x1);
286 
287 	keypad->keypad_stopped = true;
288 
289 	return ret;
290 }
291 
tc3589x_keypad_open(struct input_dev * input)292 static int tc3589x_keypad_open(struct input_dev *input)
293 {
294 	int error;
295 	struct tc_keypad *keypad = input_get_drvdata(input);
296 
297 	/* enable the keypad module */
298 	error = tc3589x_keypad_enable(keypad);
299 	if (error < 0) {
300 		dev_err(&input->dev, "failed to enable keypad module\n");
301 		return error;
302 	}
303 
304 	error = tc3589x_keypad_init_key_hardware(keypad);
305 	if (error < 0) {
306 		dev_err(&input->dev, "failed to configure keypad module\n");
307 		return error;
308 	}
309 
310 	return 0;
311 }
312 
tc3589x_keypad_close(struct input_dev * input)313 static void tc3589x_keypad_close(struct input_dev *input)
314 {
315 	struct tc_keypad *keypad = input_get_drvdata(input);
316 
317 	/* disable the keypad module */
318 	tc3589x_keypad_disable(keypad);
319 }
320 
321 static const struct tc3589x_keypad_platform_data *
tc3589x_keypad_of_probe(struct device * dev)322 tc3589x_keypad_of_probe(struct device *dev)
323 {
324 	struct device_node *np = dev->of_node;
325 	struct tc3589x_keypad_platform_data *plat;
326 	u32 cols, rows;
327 	u32 debounce_ms;
328 	int proplen;
329 
330 	if (!np)
331 		return ERR_PTR(-ENODEV);
332 
333 	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
334 	if (!plat)
335 		return ERR_PTR(-ENOMEM);
336 
337 	of_property_read_u32(np, "keypad,num-columns", &cols);
338 	of_property_read_u32(np, "keypad,num-rows", &rows);
339 	plat->kcol = (u8) cols;
340 	plat->krow = (u8) rows;
341 	if (!plat->krow || !plat->kcol ||
342 	     plat->krow > TC_KPD_ROWS || plat->kcol > TC_KPD_COLUMNS) {
343 		dev_err(dev,
344 			"keypad columns/rows not properly specified (%ux%u)\n",
345 			plat->kcol, plat->krow);
346 		return ERR_PTR(-EINVAL);
347 	}
348 
349 	if (!of_get_property(np, "linux,keymap", &proplen)) {
350 		dev_err(dev, "property linux,keymap not found\n");
351 		return ERR_PTR(-ENOENT);
352 	}
353 
354 	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
355 
356 	plat->enable_wakeup = of_property_read_bool(np, "wakeup-source") ||
357 			      /* legacy name */
358 			      of_property_read_bool(np, "linux,wakeup");
359 
360 	/* The custom delay format is ms/16 */
361 	of_property_read_u32(np, "debounce-delay-ms", &debounce_ms);
362 	if (debounce_ms)
363 		plat->debounce_period = debounce_ms * 16;
364 	else
365 		plat->debounce_period = TC_KPD_DEBOUNCE_PERIOD;
366 
367 	plat->settle_time = TC_KPD_SETTLE_TIME;
368 	/* FIXME: should be property of the IRQ resource? */
369 	plat->irqtype = IRQF_TRIGGER_FALLING;
370 
371 	return plat;
372 }
373 
tc3589x_keypad_probe(struct platform_device * pdev)374 static int tc3589x_keypad_probe(struct platform_device *pdev)
375 {
376 	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
377 	struct tc_keypad *keypad;
378 	struct input_dev *input;
379 	const struct tc3589x_keypad_platform_data *plat;
380 	int error, irq;
381 
382 	plat = tc3589x_keypad_of_probe(&pdev->dev);
383 	if (IS_ERR(plat)) {
384 		dev_err(&pdev->dev, "invalid keypad platform data\n");
385 		return PTR_ERR(plat);
386 	}
387 
388 	irq = platform_get_irq(pdev, 0);
389 	if (irq < 0)
390 		return irq;
391 
392 	keypad = devm_kzalloc(&pdev->dev, sizeof(struct tc_keypad),
393 			      GFP_KERNEL);
394 	if (!keypad)
395 		return -ENOMEM;
396 
397 	input = devm_input_allocate_device(&pdev->dev);
398 	if (!input) {
399 		dev_err(&pdev->dev, "failed to allocate input device\n");
400 		return -ENOMEM;
401 	}
402 
403 	keypad->board = plat;
404 	keypad->input = input;
405 	keypad->tc3589x = tc3589x;
406 
407 	input->id.bustype = BUS_I2C;
408 	input->name = pdev->name;
409 	input->dev.parent = &pdev->dev;
410 
411 	input->open = tc3589x_keypad_open;
412 	input->close = tc3589x_keypad_close;
413 
414 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
415 					   TC3589x_MAX_KPROW, TC3589x_MAX_KPCOL,
416 					   NULL, input);
417 	if (error) {
418 		dev_err(&pdev->dev, "Failed to build keymap\n");
419 		return error;
420 	}
421 
422 	keypad->keymap = input->keycode;
423 
424 	input_set_capability(input, EV_MSC, MSC_SCAN);
425 	if (!plat->no_autorepeat)
426 		__set_bit(EV_REP, input->evbit);
427 
428 	input_set_drvdata(input, keypad);
429 
430 	tc3589x_keypad_disable(keypad);
431 
432 	error = devm_request_threaded_irq(&pdev->dev, irq,
433 					  NULL, tc3589x_keypad_irq,
434 					  plat->irqtype | IRQF_ONESHOT,
435 					  "tc3589x-keypad", keypad);
436 	if (error) {
437 		dev_err(&pdev->dev,
438 				"Could not allocate irq %d,error %d\n",
439 				irq, error);
440 		return error;
441 	}
442 
443 	error = input_register_device(input);
444 	if (error) {
445 		dev_err(&pdev->dev, "Could not register input device\n");
446 		return error;
447 	}
448 
449 	/* let platform decide if keypad is a wakeup source or not */
450 	device_init_wakeup(&pdev->dev, plat->enable_wakeup);
451 	device_set_wakeup_capable(&pdev->dev, plat->enable_wakeup);
452 
453 	platform_set_drvdata(pdev, keypad);
454 
455 	return 0;
456 }
457 
tc3589x_keypad_suspend(struct device * dev)458 static int tc3589x_keypad_suspend(struct device *dev)
459 {
460 	struct platform_device *pdev = to_platform_device(dev);
461 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
462 	int irq = platform_get_irq(pdev, 0);
463 
464 	/* keypad is already off; we do nothing */
465 	if (keypad->keypad_stopped)
466 		return 0;
467 
468 	/* if device is not a wakeup source, disable it for powersave */
469 	if (!device_may_wakeup(&pdev->dev))
470 		tc3589x_keypad_disable(keypad);
471 	else
472 		enable_irq_wake(irq);
473 
474 	return 0;
475 }
476 
tc3589x_keypad_resume(struct device * dev)477 static int tc3589x_keypad_resume(struct device *dev)
478 {
479 	struct platform_device *pdev = to_platform_device(dev);
480 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
481 	int irq = platform_get_irq(pdev, 0);
482 
483 	if (!keypad->keypad_stopped)
484 		return 0;
485 
486 	/* enable the device to resume normal operations */
487 	if (!device_may_wakeup(&pdev->dev))
488 		tc3589x_keypad_enable(keypad);
489 	else
490 		disable_irq_wake(irq);
491 
492 	return 0;
493 }
494 
495 static DEFINE_SIMPLE_DEV_PM_OPS(tc3589x_keypad_dev_pm_ops,
496 				tc3589x_keypad_suspend, tc3589x_keypad_resume);
497 
498 static struct platform_driver tc3589x_keypad_driver = {
499 	.driver	= {
500 		.name	= "tc3589x-keypad",
501 		.pm	= pm_sleep_ptr(&tc3589x_keypad_dev_pm_ops),
502 	},
503 	.probe	= tc3589x_keypad_probe,
504 };
505 module_platform_driver(tc3589x_keypad_driver);
506 
507 MODULE_LICENSE("GPL v2");
508 MODULE_AUTHOR("Jayeeta Banerjee/Sundar Iyer");
509 MODULE_DESCRIPTION("TC35893 Keypad Driver");
510 MODULE_ALIAS("platform:tc3589x-keypad");
511