twl4030_keypad.c revision 9d8340687c524ce61e3c9c76758c4c81303acfc0 
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/twl4030.h>
35
36
37/*
38 * The TWL4030 family chips include a keypad controller that supports
39 * up to an 8x8 switch matrix.  The controller can issue system wakeup
40 * events, since it uses only the always-on 32KiHz oscillator, and has
41 * an internal state machine that decodes pressed keys, including
42 * multi-key combinations.
43 *
44 * This driver lets boards define what keycodes they wish to report for
45 * which scancodes, as part of the "struct twl4030_keypad_data" used in
46 * the probe() routine.
47 *
48 * See the TPS65950 documentation; that's the general availability
49 * version of the TWL5030 second generation part.
50 */
51#define TWL4030_MAX_ROWS	8	/* TWL4030 hard limit */
52#define TWL4030_MAX_COLS	8
53#define TWL4030_ROW_SHIFT	3
54#define TWL4030_KEYMAP_SIZE	(TWL4030_MAX_ROWS * TWL4030_MAX_COLS)
55
56struct twl4030_keypad {
57	unsigned short	keymap[TWL4030_KEYMAP_SIZE];
58	u16		kp_state[TWL4030_MAX_ROWS];
59	unsigned	n_rows;
60	unsigned	n_cols;
61	unsigned	irq;
62
63	struct device *dbg_dev;
64	struct input_dev *input;
65};
66
67/*----------------------------------------------------------------------*/
68
69/* arbitrary prescaler value 0..7 */
70#define PTV_PRESCALER			4
71
72/* Register Offsets */
73#define KEYP_CTRL			0x00
74#define KEYP_DEB			0x01
75#define KEYP_LONG_KEY			0x02
76#define KEYP_LK_PTV			0x03
77#define KEYP_TIMEOUT_L			0x04
78#define KEYP_TIMEOUT_H			0x05
79#define KEYP_KBC			0x06
80#define KEYP_KBR			0x07
81#define KEYP_SMS			0x08
82#define KEYP_FULL_CODE_7_0		0x09	/* row 0 column status */
83#define KEYP_FULL_CODE_15_8		0x0a	/* ... row 1 ... */
84#define KEYP_FULL_CODE_23_16		0x0b
85#define KEYP_FULL_CODE_31_24		0x0c
86#define KEYP_FULL_CODE_39_32		0x0d
87#define KEYP_FULL_CODE_47_40		0x0e
88#define KEYP_FULL_CODE_55_48		0x0f
89#define KEYP_FULL_CODE_63_56		0x10
90#define KEYP_ISR1			0x11
91#define KEYP_IMR1			0x12
92#define KEYP_ISR2			0x13
93#define KEYP_IMR2			0x14
94#define KEYP_SIR			0x15
95#define KEYP_EDR			0x16	/* edge triggers */
96#define KEYP_SIH_CTRL			0x17
97
98/* KEYP_CTRL_REG Fields */
99#define KEYP_CTRL_SOFT_NRST		BIT(0)
100#define KEYP_CTRL_SOFTMODEN		BIT(1)
101#define KEYP_CTRL_LK_EN			BIT(2)
102#define KEYP_CTRL_TOE_EN		BIT(3)
103#define KEYP_CTRL_TOLE_EN		BIT(4)
104#define KEYP_CTRL_RP_EN			BIT(5)
105#define KEYP_CTRL_KBD_ON		BIT(6)
106
107/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
108#define KEYP_PERIOD_US(t, prescale)	((t) / (31 << (prescale + 1)) - 1)
109
110/* KEYP_LK_PTV_REG Fields */
111#define KEYP_LK_PTV_PTV_SHIFT		5
112
113/* KEYP_{IMR,ISR,SIR} Fields */
114#define KEYP_IMR1_MIS			BIT(3)
115#define KEYP_IMR1_TO			BIT(2)
116#define KEYP_IMR1_LK			BIT(1)
117#define KEYP_IMR1_KP			BIT(0)
118
119/* KEYP_EDR Fields */
120#define KEYP_EDR_KP_FALLING		0x01
121#define KEYP_EDR_KP_RISING		0x02
122#define KEYP_EDR_KP_BOTH		0x03
123#define KEYP_EDR_LK_FALLING		0x04
124#define KEYP_EDR_LK_RISING		0x08
125#define KEYP_EDR_TO_FALLING		0x10
126#define KEYP_EDR_TO_RISING		0x20
127#define KEYP_EDR_MIS_FALLING		0x40
128#define KEYP_EDR_MIS_RISING		0x80
129
130
131/*----------------------------------------------------------------------*/
132
133static int twl4030_kpread(struct twl4030_keypad *kp,
134		u8 *data, u32 reg, u8 num_bytes)
135{
136	int ret = twl4030_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
137
138	if (ret < 0)
139		dev_warn(kp->dbg_dev,
140			"Couldn't read TWL4030: %X - ret %d[%x]\n",
141			 reg, ret, ret);
142
143	return ret;
144}
145
146static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
147{
148	int ret = twl4030_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
149
150	if (ret < 0)
151		dev_warn(kp->dbg_dev,
152			"Could not write TWL4030: %X - ret %d[%x]\n",
153			 reg, ret, ret);
154
155	return ret;
156}
157
158static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
159{
160	/* If all bits in a row are active for all coloumns then
161	 * we have that row line connected to gnd. Mark this
162	 * key on as if it was on matrix position n_cols (ie
163	 * one higher than the size of the matrix).
164	 */
165	if (col == 0xFF)
166		return 1 << kp->n_cols;
167	else
168		return col & ((1 << kp->n_cols) - 1);
169}
170
171static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
172{
173	u8 new_state[TWL4030_MAX_ROWS];
174	int row;
175	int ret = twl4030_kpread(kp, new_state,
176				 KEYP_FULL_CODE_7_0, kp->n_rows);
177	if (ret >= 0)
178		for (row = 0; row < kp->n_rows; row++)
179			state[row] = twl4030_col_xlate(kp, new_state[row]);
180
181	return ret;
182}
183
184static int twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
185{
186	int i;
187	u16 check = 0;
188
189	for (i = 0; i < kp->n_rows; i++) {
190		u16 col = key_state[i];
191
192		if ((col & check) && hweight16(col) > 1)
193			return 1;
194
195		check |= col;
196	}
197
198	return 0;
199}
200
201static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
202{
203	struct input_dev *input = kp->input;
204	u16 new_state[TWL4030_MAX_ROWS];
205	int col, row;
206
207	if (release_all)
208		memset(new_state, 0, sizeof(new_state));
209	else {
210		/* check for any changes */
211		int ret = twl4030_read_kp_matrix_state(kp, new_state);
212
213		if (ret < 0)	/* panic ... */
214			return;
215
216		if (twl4030_is_in_ghost_state(kp, new_state))
217			return;
218	}
219
220	/* check for changes and print those */
221	for (row = 0; row < kp->n_rows; row++) {
222		int changed = new_state[row] ^ kp->kp_state[row];
223
224		if (!changed)
225			continue;
226
227		for (col = 0; col < kp->n_cols; col++) {
228			int code;
229
230			if (!(changed & (1 << col)))
231				continue;
232
233			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
234				(new_state[row] & (1 << col)) ?
235				"press" : "release");
236
237			code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
238			input_event(input, EV_MSC, MSC_SCAN, code);
239			input_report_key(input, kp->keymap[code],
240					 new_state[row] & (1 << col));
241		}
242		kp->kp_state[row] = new_state[row];
243	}
244	input_sync(input);
245}
246
247/*
248 * Keypad interrupt handler
249 */
250static irqreturn_t do_kp_irq(int irq, void *_kp)
251{
252	struct twl4030_keypad *kp = _kp;
253	u8 reg;
254	int ret;
255
256#ifdef CONFIG_LOCKDEP
257	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
258	 * we don't want and can't tolerate.  Although it might be
259	 * friendlier not to borrow this thread context...
260	 */
261	local_irq_enable();
262#endif
263
264	/* Read & Clear TWL4030 pending interrupt */
265	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
266
267	/* Release all keys if I2C has gone bad or
268	 * the KEYP has gone to idle state */
269	if (ret >= 0 && (reg & KEYP_IMR1_KP))
270		twl4030_kp_scan(kp, false);
271	else
272		twl4030_kp_scan(kp, true);
273
274	return IRQ_HANDLED;
275}
276
277static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
278{
279	u8 reg;
280	int i;
281
282	/* Enable controller, with hardware decoding but not autorepeat */
283	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
284		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
285	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
286		return -EIO;
287
288	/* NOTE:  we could use sih_setup() here to package keypad
289	 * event sources as four different IRQs ... but we don't.
290	 */
291
292	/* Enable TO rising and KP rising and falling edge detection */
293	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
294	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
295		return -EIO;
296
297	/* Set PTV prescaler Field */
298	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
299	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
300		return -EIO;
301
302	/* Set key debounce time to 20 ms */
303	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
304	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
305		return -EIO;
306
307	/* Set timeout period to 100 ms */
308	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
309	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
310		return -EIO;
311
312	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
313		return -EIO;
314
315	/*
316	 * Enable Clear-on-Read; disable remembering events that fire
317	 * after the IRQ but before our handler acks (reads) them,
318	 */
319	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
320	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
321		return -EIO;
322
323	/* initialize key state; irqs update it from here on */
324	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
325		return -EIO;
326
327	return 0;
328}
329
330/*
331 * Registers keypad device with input subsystem
332 * and configures TWL4030 keypad registers
333 */
334static int __devinit twl4030_kp_probe(struct platform_device *pdev)
335{
336	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
337	const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
338	struct twl4030_keypad *kp;
339	struct input_dev *input;
340	u8 reg;
341	int error;
342
343	if (!pdata || !pdata->rows || !pdata->cols ||
344	    pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
345		dev_err(&pdev->dev, "Invalid platform_data\n");
346		return -EINVAL;
347	}
348
349	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
350	input = input_allocate_device();
351	if (!kp || !input) {
352		error = -ENOMEM;
353		goto err1;
354	}
355
356	/* Get the debug Device */
357	kp->dbg_dev = &pdev->dev;
358	kp->input = input;
359
360	kp->n_rows = pdata->rows;
361	kp->n_cols = pdata->cols;
362	kp->irq = platform_get_irq(pdev, 0);
363
364	/* setup input device */
365	__set_bit(EV_KEY, input->evbit);
366
367	/* Enable auto repeat feature of Linux input subsystem */
368	if (pdata->rep)
369		__set_bit(EV_REP, input->evbit);
370
371	input_set_capability(input, EV_MSC, MSC_SCAN);
372
373	input->name		= "TWL4030 Keypad";
374	input->phys		= "twl4030_keypad/input0";
375	input->dev.parent	= &pdev->dev;
376
377	input->id.bustype	= BUS_HOST;
378	input->id.vendor	= 0x0001;
379	input->id.product	= 0x0001;
380	input->id.version	= 0x0003;
381
382	input->keycode		= kp->keymap;
383	input->keycodesize	= sizeof(kp->keymap[0]);
384	input->keycodemax	= ARRAY_SIZE(kp->keymap);
385
386	matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
387				   input->keycode, input->keybit);
388
389	error = input_register_device(input);
390	if (error) {
391		dev_err(kp->dbg_dev,
392			"Unable to register twl4030 keypad device\n");
393		goto err1;
394	}
395
396	error = twl4030_kp_program(kp);
397	if (error)
398		goto err2;
399
400	/*
401	 * This ISR will always execute in kernel thread context because of
402	 * the need to access the TWL4030 over the I2C bus.
403	 *
404	 * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
405	 */
406	error = request_irq(kp->irq, do_kp_irq, 0, pdev->name, kp);
407	if (error) {
408		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
409			kp->irq);
410		goto err3;
411	}
412
413	/* Enable KP and TO interrupts now. */
414	reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
415	if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
416		error = -EIO;
417		goto err4;
418	}
419
420	platform_set_drvdata(pdev, kp);
421	return 0;
422
423err4:
424	/* mask all events - we don't care about the result */
425	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
426err3:
427	free_irq(kp->irq, NULL);
428err2:
429	input_unregister_device(input);
430	input = NULL;
431err1:
432	input_free_device(input);
433	kfree(kp);
434	return error;
435}
436
437static int __devexit twl4030_kp_remove(struct platform_device *pdev)
438{
439	struct twl4030_keypad *kp = platform_get_drvdata(pdev);
440
441	free_irq(kp->irq, kp);
442	input_unregister_device(kp->input);
443	platform_set_drvdata(pdev, NULL);
444	kfree(kp);
445
446	return 0;
447}
448
449/*
450 * NOTE: twl4030 are multi-function devices connected via I2C.
451 * So this device is a child of an I2C parent, thus it needs to
452 * support unplug/replug (which most platform devices don't).
453 */
454
455static struct platform_driver twl4030_kp_driver = {
456	.probe		= twl4030_kp_probe,
457	.remove		= __devexit_p(twl4030_kp_remove),
458	.driver		= {
459		.name	= "twl4030_keypad",
460		.owner	= THIS_MODULE,
461	},
462};
463
464static int __init twl4030_kp_init(void)
465{
466	return platform_driver_register(&twl4030_kp_driver);
467}
468module_init(twl4030_kp_init);
469
470static void __exit twl4030_kp_exit(void)
471{
472	platform_driver_unregister(&twl4030_kp_driver);
473}
474module_exit(twl4030_kp_exit);
475
476MODULE_AUTHOR("Texas Instruments");
477MODULE_DESCRIPTION("TWL4030 Keypad Driver");
478MODULE_LICENSE("GPL");
479MODULE_ALIAS("platform:twl4030_keypad");
480
481