free electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Jayeeta Banerjee <jayeeta.banerjee@stericsson.com>
 * Author: Sundar Iyer <sundar.iyer@stericsson.com>
 *
 * License Terms: GNU General Public License, version 2
 *
 * TC35893 MFD Keypad Controller driver
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/input/matrix_keypad.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/mfd/tc3589x.h>
#include <linux/device.h>

/* Maximum supported keypad matrix row/columns size */
#define TC3589x_MAX_KPROW               8
#define TC3589x_MAX_KPCOL               12

/* keypad related Constants */
#define TC3589x_MAX_DEBOUNCE_SETTLE     0xFF
#define DEDICATED_KEY_VAL		0xFF

/* Pull up/down masks */
#define TC3589x_NO_PULL_MASK		0x0
#define TC3589x_PULL_DOWN_MASK		0x1
#define TC3589x_PULL_UP_MASK		0x2
#define TC3589x_PULLUP_ALL_MASK		0xAA
#define TC3589x_IO_PULL_VAL(index, mask)	((mask)<<((index)%4)*2)

/* Bit masks for IOCFG register */
#define IOCFG_BALLCFG		0x01
#define IOCFG_IG		0x08

#define KP_EVCODE_COL_MASK	0x0F
#define KP_EVCODE_ROW_MASK	0x70
#define KP_RELEASE_EVT_MASK	0x80

#define KP_ROW_SHIFT		4

#define KP_NO_VALID_KEY_MASK	0x7F

/* bit masks for RESTCTRL register */
#define TC3589x_KBDRST		0x2
#define TC3589x_IRQRST		0x10
#define TC3589x_RESET_ALL	0x1B

/* KBDMFS register bit mask */
#define TC3589x_KBDMFS_EN	0x1

/* CLKEN register bitmask */
#define KPD_CLK_EN		0x1

/* RSTINTCLR register bit mask */
#define IRQ_CLEAR		0x1

/* bit masks for keyboard interrupts*/
#define TC3589x_EVT_LOSS_INT	0x8
#define TC3589x_EVT_INT		0x4
#define TC3589x_KBD_LOSS_INT	0x2
#define TC3589x_KBD_INT		0x1

/* bit masks for keyboard interrupt clear*/
#define TC3589x_EVT_INT_CLR	0x2
#define TC3589x_KBD_INT_CLR	0x1

/**
 * struct tc35893_keypad_platform_data - platform specific keypad data
 * @keymap_data:        matrix scan code table for keycodes
 * @krow:               mask for available rows, value is 0xFF
 * @kcol:               mask for available columns, value is 0xFF
 * @debounce_period:    platform specific debounce time
 * @settle_time:        platform specific settle down time
 * @irqtype:            type of interrupt, falling or rising edge
 * @enable_wakeup:      specifies if keypad event can wake up system from sleep
 * @no_autorepeat:      flag for auto repetition
 */
struct tc3589x_keypad_platform_data {
	const struct matrix_keymap_data *keymap_data;
	u8                      krow;
	u8                      kcol;
	u8                      debounce_period;
	u8                      settle_time;
	unsigned long           irqtype;
	bool                    enable_wakeup;
	bool                    no_autorepeat;
};

/**
 * struct tc_keypad - data structure used by keypad driver
 * @tc3589x:    pointer to tc35893
 * @input:      pointer to input device object
 * @board:      keypad platform device
 * @krow:	number of rows
 * @kcol:	number of columns
 * @keymap:     matrix scan code table for keycodes
 * @keypad_stopped: holds keypad status
 */
struct tc_keypad {
	struct tc3589x *tc3589x;
	struct input_dev *input;
	const struct tc3589x_keypad_platform_data *board;
	unsigned int krow;
	unsigned int kcol;
	unsigned short *keymap;
	bool keypad_stopped;
};

static int tc3589x_keypad_init_key_hardware(struct tc_keypad *keypad)
{
	int ret;
	struct tc3589x *tc3589x = keypad->tc3589x;
	const struct tc3589x_keypad_platform_data *board = keypad->board;

	/* validate platform configuration */
	if (board->kcol > TC3589x_MAX_KPCOL || board->krow > TC3589x_MAX_KPROW)
		return -EINVAL;

	/* configure KBDSIZE 4 LSbits for cols and 4 MSbits for rows */
	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSIZE,
			(board->krow << KP_ROW_SHIFT) | board->kcol);
	if (ret < 0)
		return ret;

	/* configure dedicated key config, no dedicated key selected */
	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_LSB, DEDICATED_KEY_VAL);
	if (ret < 0)
		return ret;

	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_MSB, DEDICATED_KEY_VAL);
	if (ret < 0)
		return ret;

	/* Configure settle time */
	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSETTLE_REG,
				board->settle_time);
	if (ret < 0)
		return ret;

	/* Configure debounce time */
	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDBOUNCE,
				board->debounce_period);
	if (ret < 0)
		return ret;

	/* Start of initialise keypad GPIOs */
	ret = tc3589x_set_bits(tc3589x, TC3589x_IOCFG, 0x0, IOCFG_IG);
	if (ret < 0)
		return ret;

	/* Configure pull-up resistors for all row GPIOs */
	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_LSB,
					TC3589x_PULLUP_ALL_MASK);
	if (ret < 0)
		return ret;

	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_MSB,
					TC3589x_PULLUP_ALL_MASK);
	if (ret < 0)
		return ret;

	/* Configure pull-up resistors for all column GPIOs */
	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_LSB,
			TC3589x_PULLUP_ALL_MASK);
	if (ret < 0)
		return ret;

	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_MSB,
			TC3589x_PULLUP_ALL_MASK);
	if (ret < 0)
		return ret;

	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG2_LSB,
			TC3589x_PULLUP_ALL_MASK);

	return ret;
}

#define TC35893_DATA_REGS		4
#define TC35893_KEYCODE_FIFO_EMPTY	0x7f
#define TC35893_KEYCODE_FIFO_CLEAR	0xff
#define TC35893_KEYPAD_ROW_SHIFT	0x3

static irqreturn_t tc3589x_keypad_irq(int irq, void *dev)
{
	struct tc_keypad *keypad = dev;
	struct tc3589x *tc3589x = keypad->tc3589x;
	u8 i, row_index, col_index, kbd_code, up;
	u8 code;

	for (i = 0; i < TC35893_DATA_REGS * 2; i++) {
		kbd_code = tc3589x_reg_read(tc3589x, TC3589x_EVTCODE_FIFO);

		/* loop till fifo is empty and no more keys are pressed */
		if (kbd_code == TC35893_KEYCODE_FIFO_EMPTY ||
				kbd_code == TC35893_KEYCODE_FIFO_CLEAR)
			continue;

		/* valid key is found */
		col_index = kbd_code & KP_EVCODE_COL_MASK;
		row_index = (kbd_code & KP_EVCODE_ROW_MASK) >> KP_ROW_SHIFT;
		code = MATRIX_SCAN_CODE(row_index, col_index,
						TC35893_KEYPAD_ROW_SHIFT);
		up = kbd_code & KP_RELEASE_EVT_MASK;

		input_event(keypad->input, EV_MSC, MSC_SCAN, code);
		input_report_key(keypad->input, keypad->keymap[code], !up);
		input_sync(keypad->input);
	}

	/* clear IRQ */
	tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
	/* enable IRQ */
	tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
			0x0, TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);

	return IRQ_HANDLED;
}

static int tc3589x_keypad_enable(struct tc_keypad *keypad)
{
	struct tc3589x *tc3589x = keypad->tc3589x;
	int ret;

	/* pull the keypad module out of reset */
	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x0);
	if (ret < 0)
		return ret;

	/* configure KBDMFS */
	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMFS, 0x0, TC3589x_KBDMFS_EN);
	if (ret < 0)
		return ret;

	/* enable the keypad clock */
	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x0, KPD_CLK_EN);
	if (ret < 0)
		return ret;

	/* clear pending IRQs */
	ret =  tc3589x_set_bits(tc3589x, TC3589x_RSTINTCLR, 0x0, 0x1);
	if (ret < 0)
		return ret;

	/* enable the IRQs */
	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK, 0x0,
					TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
	if (ret < 0)
		return ret;

	keypad->keypad_stopped = false;

	return ret;
}

static int tc3589x_keypad_disable(struct tc_keypad *keypad)
{
	struct tc3589x *tc3589x = keypad->tc3589x;
	int ret;

	/* clear IRQ */
	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
	if (ret < 0)
		return ret;

	/* disable all interrupts */
	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
			~(TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT), 0x0);
	if (ret < 0)
		return ret;

	/* disable the keypad module */
	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x1, 0x0);
	if (ret < 0)
		return ret;

	/* put the keypad module into reset */
	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x1);

	keypad->keypad_stopped = true;

	return ret;
}

static int tc3589x_keypad_open(struct input_dev *input)
{
	int error;
	struct tc_keypad *keypad = input_get_drvdata(input);

	/* enable the keypad module */
	error = tc3589x_keypad_enable(keypad);
	if (error < 0) {
		dev_err(&input->dev, "failed to enable keypad module\n");
		return error;
	}

	error = tc3589x_keypad_init_key_hardware(keypad);
	if (error < 0) {
		dev_err(&input->dev, "failed to configure keypad module\n");
		return error;
	}

	return 0;
}

static void tc3589x_keypad_close(struct input_dev *input)
{
	struct tc_keypad *keypad = input_get_drvdata(input);

	/* disable the keypad module */
	tc3589x_keypad_disable(keypad);
}

static const struct tc3589x_keypad_platform_data *
tc3589x_keypad_of_probe(struct device *dev)
{
	struct device_node *np = dev->of_node;
	struct tc3589x_keypad_platform_data *plat;
	u32 cols, rows;
	u32 debounce_ms;
	int proplen;

	if (!np)
		return ERR_PTR(-ENODEV);

	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
	if (!plat)
		return ERR_PTR(-ENOMEM);

	of_property_read_u32(np, "keypad,num-columns", &cols);
	of_property_read_u32(np, "keypad,num-rows", &rows);
	plat->kcol = (u8) cols;
	plat->krow = (u8) rows;
	if (!plat->krow || !plat->kcol ||
	     plat->krow > TC_KPD_ROWS || plat->kcol > TC_KPD_COLUMNS) {
		dev_err(dev,
			"keypad columns/rows not properly specified (%ux%u)\n",
			plat->kcol, plat->krow);
		return ERR_PTR(-EINVAL);
	}

	if (!of_get_property(np, "linux,keymap", &proplen)) {
		dev_err(dev, "property linux,keymap not found\n");
		return ERR_PTR(-ENOENT);
	}

	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");

	plat->enable_wakeup = of_property_read_bool(np, "wakeup-source") ||
			      /* legacy name */
			      of_property_read_bool(np, "linux,wakeup");

	/* The custom delay format is ms/16 */
	of_property_read_u32(np, "debounce-delay-ms", &debounce_ms);
	if (debounce_ms)
		plat->debounce_period = debounce_ms * 16;
	else
		plat->debounce_period = TC_KPD_DEBOUNCE_PERIOD;

	plat->settle_time = TC_KPD_SETTLE_TIME;
	/* FIXME: should be property of the IRQ resource? */
	plat->irqtype = IRQF_TRIGGER_FALLING;

	return plat;
}

static int tc3589x_keypad_probe(struct platform_device *pdev)
{
	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
	struct tc_keypad *keypad;
	struct input_dev *input;
	const struct tc3589x_keypad_platform_data *plat;
	int error, irq;

	plat = tc3589x_keypad_of_probe(&pdev->dev);
	if (IS_ERR(plat)) {
		dev_err(&pdev->dev, "invalid keypad platform data\n");
		return PTR_ERR(plat);
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	keypad = devm_kzalloc(&pdev->dev, sizeof(struct tc_keypad),
			      GFP_KERNEL);
	if (!keypad)
		return -ENOMEM;

	input = devm_input_allocate_device(&pdev->dev);
	if (!input) {
		dev_err(&pdev->dev, "failed to allocate input device\n");
		return -ENOMEM;
	}

	keypad->board = plat;
	keypad->input = input;
	keypad->tc3589x = tc3589x;

	input->id.bustype = BUS_I2C;
	input->name = pdev->name;
	input->dev.parent = &pdev->dev;

	input->open = tc3589x_keypad_open;
	input->close = tc3589x_keypad_close;

	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
					   TC3589x_MAX_KPROW, TC3589x_MAX_KPCOL,
					   NULL, input);
	if (error) {
		dev_err(&pdev->dev, "Failed to build keymap\n");
		return error;
	}

	keypad->keymap = input->keycode;

	input_set_capability(input, EV_MSC, MSC_SCAN);
	if (!plat->no_autorepeat)
		__set_bit(EV_REP, input->evbit);

	input_set_drvdata(input, keypad);

	tc3589x_keypad_disable(keypad);

	error = devm_request_threaded_irq(&pdev->dev, irq,
					  NULL, tc3589x_keypad_irq,
					  plat->irqtype | IRQF_ONESHOT,
					  "tc3589x-keypad", keypad);
	if (error) {
		dev_err(&pdev->dev,
				"Could not allocate irq %d,error %d\n",
				irq, error);
		return error;
	}

	error = input_register_device(input);
	if (error) {
		dev_err(&pdev->dev, "Could not register input device\n");
		return error;
	}

	/* let platform decide if keypad is a wakeup source or not */
	device_init_wakeup(&pdev->dev, plat->enable_wakeup);
	device_set_wakeup_capable(&pdev->dev, plat->enable_wakeup);

	platform_set_drvdata(pdev, keypad);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tc3589x_keypad_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct tc_keypad *keypad = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	/* keypad is already off; we do nothing */
	if (keypad->keypad_stopped)
		return 0;

	/* if device is not a wakeup source, disable it for powersave */
	if (!device_may_wakeup(&pdev->dev))
		tc3589x_keypad_disable(keypad);
	else
		enable_irq_wake(irq);

	return 0;
}

static int tc3589x_keypad_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct tc_keypad *keypad = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	if (!keypad->keypad_stopped)
		return 0;

	/* enable the device to resume normal operations */
	if (!device_may_wakeup(&pdev->dev))
		tc3589x_keypad_enable(keypad);
	else
		disable_irq_wake(irq);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(tc3589x_keypad_dev_pm_ops,
			 tc3589x_keypad_suspend, tc3589x_keypad_resume);

static struct platform_driver tc3589x_keypad_driver = {
	.driver	= {
		.name	= "tc3589x-keypad",
		.pm	= &tc3589x_keypad_dev_pm_ops,
	},
	.probe	= tc3589x_keypad_probe,
};
module_platform_driver(tc3589x_keypad_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jayeeta Banerjee/Sundar Iyer");
MODULE_DESCRIPTION("TC35893 Keypad Driver");
MODULE_ALIAS("platform:tc3589x-keypad");