twl4030_keypad.c revision 3fea60261e73dbf4a51130d40cafcc8465b0f2c3 
1/*
2 * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
3 *
4 * Copyright (C) 2007 Texas Instruments, Inc.
5 * Copyright (C) 2008 Nokia Corporation
6 *
7 * Code re-written for 2430SDP by:
8 * Syed Mohammed Khasim <x0khasim@ti.com>
9 *
10 * Initial Code:
11 * Manjunatha G K <manjugk@ti.com>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 */
27
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/init.h>
31#include <linux/interrupt.h>
32#include <linux/input.h>
33#include <linux/platform_device.h>
34#include <linux/i2c/twl.h>
35#include <linux/slab.h>
36
37
38/*
39 * The TWL4030 family chips include a keypad controller that supports
40 * up to an 8x8 switch matrix.  The controller can issue system wakeup
41 * events, since it uses only the always-on 32KiHz oscillator, and has
42 * an internal state machine that decodes pressed keys, including
43 * multi-key combinations.
44 *
45 * This driver lets boards define what keycodes they wish to report for
46 * which scancodes, as part of the "struct twl4030_keypad_data" used in
47 * the probe() routine.
48 *
49 * See the TPS65950 documentation; that's the general availability
50 * version of the TWL5030 second generation part.
51 */
52#define TWL4030_MAX_ROWS	8	/* TWL4030 hard limit */
53#define TWL4030_MAX_COLS	8
54/*
55 * Note that we add space for an extra column so that we can handle
56 * row lines connected to the gnd (see twl4030_col_xlate()).
57 */
58#define TWL4030_ROW_SHIFT	4
59#define TWL4030_KEYMAP_SIZE	(TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
60
61struct twl4030_keypad {
62	unsigned short	keymap[TWL4030_KEYMAP_SIZE];
63	u16		kp_state[TWL4030_MAX_ROWS];
64	unsigned	n_rows;
65	unsigned	n_cols;
66	unsigned	irq;
67
68	struct device *dbg_dev;
69	struct input_dev *input;
70};
71
72/*----------------------------------------------------------------------*/
73
74/* arbitrary prescaler value 0..7 */
75#define PTV_PRESCALER			4
76
77/* Register Offsets */
78#define KEYP_CTRL			0x00
79#define KEYP_DEB			0x01
80#define KEYP_LONG_KEY			0x02
81#define KEYP_LK_PTV			0x03
82#define KEYP_TIMEOUT_L			0x04
83#define KEYP_TIMEOUT_H			0x05
84#define KEYP_KBC			0x06
85#define KEYP_KBR			0x07
86#define KEYP_SMS			0x08
87#define KEYP_FULL_CODE_7_0		0x09	/* row 0 column status */
88#define KEYP_FULL_CODE_15_8		0x0a	/* ... row 1 ... */
89#define KEYP_FULL_CODE_23_16		0x0b
90#define KEYP_FULL_CODE_31_24		0x0c
91#define KEYP_FULL_CODE_39_32		0x0d
92#define KEYP_FULL_CODE_47_40		0x0e
93#define KEYP_FULL_CODE_55_48		0x0f
94#define KEYP_FULL_CODE_63_56		0x10
95#define KEYP_ISR1			0x11
96#define KEYP_IMR1			0x12
97#define KEYP_ISR2			0x13
98#define KEYP_IMR2			0x14
99#define KEYP_SIR			0x15
100#define KEYP_EDR			0x16	/* edge triggers */
101#define KEYP_SIH_CTRL			0x17
102
103/* KEYP_CTRL_REG Fields */
104#define KEYP_CTRL_SOFT_NRST		BIT(0)
105#define KEYP_CTRL_SOFTMODEN		BIT(1)
106#define KEYP_CTRL_LK_EN			BIT(2)
107#define KEYP_CTRL_TOE_EN		BIT(3)
108#define KEYP_CTRL_TOLE_EN		BIT(4)
109#define KEYP_CTRL_RP_EN			BIT(5)
110#define KEYP_CTRL_KBD_ON		BIT(6)
111
112/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
113#define KEYP_PERIOD_US(t, prescale)	((t) / (31 << (prescale + 1)) - 1)
114
115/* KEYP_LK_PTV_REG Fields */
116#define KEYP_LK_PTV_PTV_SHIFT		5
117
118/* KEYP_{IMR,ISR,SIR} Fields */
119#define KEYP_IMR1_MIS			BIT(3)
120#define KEYP_IMR1_TO			BIT(2)
121#define KEYP_IMR1_LK			BIT(1)
122#define KEYP_IMR1_KP			BIT(0)
123
124/* KEYP_EDR Fields */
125#define KEYP_EDR_KP_FALLING		0x01
126#define KEYP_EDR_KP_RISING		0x02
127#define KEYP_EDR_KP_BOTH		0x03
128#define KEYP_EDR_LK_FALLING		0x04
129#define KEYP_EDR_LK_RISING		0x08
130#define KEYP_EDR_TO_FALLING		0x10
131#define KEYP_EDR_TO_RISING		0x20
132#define KEYP_EDR_MIS_FALLING		0x40
133#define KEYP_EDR_MIS_RISING		0x80
134
135
136/*----------------------------------------------------------------------*/
137
138static int twl4030_kpread(struct twl4030_keypad *kp,
139		u8 *data, u32 reg, u8 num_bytes)
140{
141	int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
142
143	if (ret < 0)
144		dev_warn(kp->dbg_dev,
145			"Couldn't read TWL4030: %X - ret %d[%x]\n",
146			 reg, ret, ret);
147
148	return ret;
149}
150
151static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
152{
153	int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
154
155	if (ret < 0)
156		dev_warn(kp->dbg_dev,
157			"Could not write TWL4030: %X - ret %d[%x]\n",
158			 reg, ret, ret);
159
160	return ret;
161}
162
163static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
164{
165	/* If all bits in a row are active for all coloumns then
166	 * we have that row line connected to gnd. Mark this
167	 * key on as if it was on matrix position n_cols (ie
168	 * one higher than the size of the matrix).
169	 */
170	if (col == 0xFF)
171		return 1 << kp->n_cols;
172	else
173		return col & ((1 << kp->n_cols) - 1);
174}
175
176static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
177{
178	u8 new_state[TWL4030_MAX_ROWS];
179	int row;
180	int ret = twl4030_kpread(kp, new_state,
181				 KEYP_FULL_CODE_7_0, kp->n_rows);
182	if (ret >= 0)
183		for (row = 0; row < kp->n_rows; row++)
184			state[row] = twl4030_col_xlate(kp, new_state[row]);
185
186	return ret;
187}
188
189static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
190{
191	int i;
192	u16 check = 0;
193
194	for (i = 0; i < kp->n_rows; i++) {
195		u16 col = key_state[i];
196
197		if ((col & check) && hweight16(col) > 1)
198			return true;
199
200		check |= col;
201	}
202
203	return false;
204}
205
206static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
207{
208	struct input_dev *input = kp->input;
209	u16 new_state[TWL4030_MAX_ROWS];
210	int col, row;
211
212	if (release_all)
213		memset(new_state, 0, sizeof(new_state));
214	else {
215		/* check for any changes */
216		int ret = twl4030_read_kp_matrix_state(kp, new_state);
217
218		if (ret < 0)	/* panic ... */
219			return;
220
221		if (twl4030_is_in_ghost_state(kp, new_state))
222			return;
223	}
224
225	/* check for changes and print those */
226	for (row = 0; row < kp->n_rows; row++) {
227		int changed = new_state[row] ^ kp->kp_state[row];
228
229		if (!changed)
230			continue;
231
232		/* Extra column handles "all gnd" rows */
233		for (col = 0; col < kp->n_cols + 1; col++) {
234			int code;
235
236			if (!(changed & (1 << col)))
237				continue;
238
239			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
240				(new_state[row] & (1 << col)) ?
241				"press" : "release");
242
243			code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
244			input_event(input, EV_MSC, MSC_SCAN, code);
245			input_report_key(input, kp->keymap[code],
246					 new_state[row] & (1 << col));
247		}
248		kp->kp_state[row] = new_state[row];
249	}
250	input_sync(input);
251}
252
253/*
254 * Keypad interrupt handler
255 */
256static irqreturn_t do_kp_irq(int irq, void *_kp)
257{
258	struct twl4030_keypad *kp = _kp;
259	u8 reg;
260	int ret;
261
262	/* Read & Clear TWL4030 pending interrupt */
263	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
264
265	/* Release all keys if I2C has gone bad or
266	 * the KEYP has gone to idle state */
267	if (ret >= 0 && (reg & KEYP_IMR1_KP))
268		twl4030_kp_scan(kp, false);
269	else
270		twl4030_kp_scan(kp, true);
271
272	return IRQ_HANDLED;
273}
274
275static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
276{
277	u8 reg;
278	int i;
279
280	/* Enable controller, with hardware decoding but not autorepeat */
281	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
282		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
283	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
284		return -EIO;
285
286	/* NOTE:  we could use sih_setup() here to package keypad
287	 * event sources as four different IRQs ... but we don't.
288	 */
289
290	/* Enable TO rising and KP rising and falling edge detection */
291	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
292	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
293		return -EIO;
294
295	/* Set PTV prescaler Field */
296	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
297	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
298		return -EIO;
299
300	/* Set key debounce time to 20 ms */
301	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
302	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
303		return -EIO;
304
305	/* Set timeout period to 100 ms */
306	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
307	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
308		return -EIO;
309
310	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
311		return -EIO;
312
313	/*
314	 * Enable Clear-on-Read; disable remembering events that fire
315	 * after the IRQ but before our handler acks (reads) them,
316	 */
317	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
318	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
319		return -EIO;
320
321	/* initialize key state; irqs update it from here on */
322	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
323		return -EIO;
324
325	return 0;
326}
327
328/*
329 * Registers keypad device with input subsystem
330 * and configures TWL4030 keypad registers
331 */
332static int __devinit twl4030_kp_probe(struct platform_device *pdev)
333{
334	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
335	const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
336	struct twl4030_keypad *kp;
337	struct input_dev *input;
338	u8 reg;
339	int error;
340
341	if (!pdata || !pdata->rows || !pdata->cols ||
342	    pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
343		dev_err(&pdev->dev, "Invalid platform_data\n");
344		return -EINVAL;
345	}
346
347	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
348	input = input_allocate_device();
349	if (!kp || !input) {
350		error = -ENOMEM;
351		goto err1;
352	}
353
354	/* Get the debug Device */
355	kp->dbg_dev = &pdev->dev;
356	kp->input = input;
357
358	kp->n_rows = pdata->rows;
359	kp->n_cols = pdata->cols;
360	kp->irq = platform_get_irq(pdev, 0);
361
362	/* setup input device */
363	__set_bit(EV_KEY, input->evbit);
364
365	/* Enable auto repeat feature of Linux input subsystem */
366	if (pdata->rep)
367		__set_bit(EV_REP, input->evbit);
368
369	input_set_capability(input, EV_MSC, MSC_SCAN);
370
371	input->name		= "TWL4030 Keypad";
372	input->phys		= "twl4030_keypad/input0";
373	input->dev.parent	= &pdev->dev;
374
375	input->id.bustype	= BUS_HOST;
376	input->id.vendor	= 0x0001;
377	input->id.product	= 0x0001;
378	input->id.version	= 0x0003;
379
380	input->keycode		= kp->keymap;
381	input->keycodesize	= sizeof(kp->keymap[0]);
382	input->keycodemax	= ARRAY_SIZE(kp->keymap);
383
384	matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
385				   input->keycode, input->keybit);
386
387	error = input_register_device(input);
388	if (error) {
389		dev_err(kp->dbg_dev,
390			"Unable to register twl4030 keypad device\n");
391		goto err1;
392	}
393
394	error = twl4030_kp_program(kp);
395	if (error)
396		goto err2;
397
398	/*
399	 * This ISR will always execute in kernel thread context because of
400	 * the need to access the TWL4030 over the I2C bus.
401	 *
402	 * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
403	 */
404	error = request_threaded_irq(kp->irq, NULL, do_kp_irq,
405			0, pdev->name, kp);
406	if (error) {
407		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
408			kp->irq);
409		goto err3;
410	}
411
412	/* Enable KP and TO interrupts now. */
413	reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
414	if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
415		error = -EIO;
416		goto err4;
417	}
418
419	platform_set_drvdata(pdev, kp);
420	return 0;
421
422err4:
423	/* mask all events - we don't care about the result */
424	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
425err3:
426	free_irq(kp->irq, NULL);
427err2:
428	input_unregister_device(input);
429	input = NULL;
430err1:
431	input_free_device(input);
432	kfree(kp);
433	return error;
434}
435
436static int __devexit twl4030_kp_remove(struct platform_device *pdev)
437{
438	struct twl4030_keypad *kp = platform_get_drvdata(pdev);
439
440	free_irq(kp->irq, kp);
441	input_unregister_device(kp->input);
442	platform_set_drvdata(pdev, NULL);
443	kfree(kp);
444
445	return 0;
446}
447
448/*
449 * NOTE: twl4030 are multi-function devices connected via I2C.
450 * So this device is a child of an I2C parent, thus it needs to
451 * support unplug/replug (which most platform devices don't).
452 */
453
454static struct platform_driver twl4030_kp_driver = {
455	.probe		= twl4030_kp_probe,
456	.remove		= __devexit_p(twl4030_kp_remove),
457	.driver		= {
458		.name	= "twl4030_keypad",
459		.owner	= THIS_MODULE,
460	},
461};
462
463static int __init twl4030_kp_init(void)
464{
465	return platform_driver_register(&twl4030_kp_driver);
466}
467module_init(twl4030_kp_init);
468
469static void __exit twl4030_kp_exit(void)
470{
471	platform_driver_unregister(&twl4030_kp_driver);
472}
473module_exit(twl4030_kp_exit);
474
475MODULE_AUTHOR("Texas Instruments");
476MODULE_DESCRIPTION("TWL4030 Keypad Driver");
477MODULE_LICENSE("GPL");
478MODULE_ALIAS("platform:twl4030_keypad");
479
480