twl4030_keypad.c revision 3f58061d0160424d244e3a72258a1366ab4a8547 
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
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 = twl_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 = twl_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	/* Read & Clear TWL4030 pending interrupt */
257	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
258
259	/* Release all keys if I2C has gone bad or
260	 * the KEYP has gone to idle state */
261	if (ret >= 0 && (reg & KEYP_IMR1_KP))
262		twl4030_kp_scan(kp, false);
263	else
264		twl4030_kp_scan(kp, true);
265
266	return IRQ_HANDLED;
267}
268
269static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
270{
271	u8 reg;
272	int i;
273
274	/* Enable controller, with hardware decoding but not autorepeat */
275	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
276		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
277	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
278		return -EIO;
279
280	/* NOTE:  we could use sih_setup() here to package keypad
281	 * event sources as four different IRQs ... but we don't.
282	 */
283
284	/* Enable TO rising and KP rising and falling edge detection */
285	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
286	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
287		return -EIO;
288
289	/* Set PTV prescaler Field */
290	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
291	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
292		return -EIO;
293
294	/* Set key debounce time to 20 ms */
295	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
296	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
297		return -EIO;
298
299	/* Set timeout period to 100 ms */
300	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
301	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
302		return -EIO;
303
304	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
305		return -EIO;
306
307	/*
308	 * Enable Clear-on-Read; disable remembering events that fire
309	 * after the IRQ but before our handler acks (reads) them,
310	 */
311	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
312	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
313		return -EIO;
314
315	/* initialize key state; irqs update it from here on */
316	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
317		return -EIO;
318
319	return 0;
320}
321
322/*
323 * Registers keypad device with input subsystem
324 * and configures TWL4030 keypad registers
325 */
326static int __devinit twl4030_kp_probe(struct platform_device *pdev)
327{
328	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
329	const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
330	struct twl4030_keypad *kp;
331	struct input_dev *input;
332	u8 reg;
333	int error;
334
335	if (!pdata || !pdata->rows || !pdata->cols ||
336	    pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
337		dev_err(&pdev->dev, "Invalid platform_data\n");
338		return -EINVAL;
339	}
340
341	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
342	input = input_allocate_device();
343	if (!kp || !input) {
344		error = -ENOMEM;
345		goto err1;
346	}
347
348	/* Get the debug Device */
349	kp->dbg_dev = &pdev->dev;
350	kp->input = input;
351
352	kp->n_rows = pdata->rows;
353	kp->n_cols = pdata->cols;
354	kp->irq = platform_get_irq(pdev, 0);
355
356	/* setup input device */
357	__set_bit(EV_KEY, input->evbit);
358
359	/* Enable auto repeat feature of Linux input subsystem */
360	if (pdata->rep)
361		__set_bit(EV_REP, input->evbit);
362
363	input_set_capability(input, EV_MSC, MSC_SCAN);
364
365	input->name		= "TWL4030 Keypad";
366	input->phys		= "twl4030_keypad/input0";
367	input->dev.parent	= &pdev->dev;
368
369	input->id.bustype	= BUS_HOST;
370	input->id.vendor	= 0x0001;
371	input->id.product	= 0x0001;
372	input->id.version	= 0x0003;
373
374	input->keycode		= kp->keymap;
375	input->keycodesize	= sizeof(kp->keymap[0]);
376	input->keycodemax	= ARRAY_SIZE(kp->keymap);
377
378	matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
379				   input->keycode, input->keybit);
380
381	error = input_register_device(input);
382	if (error) {
383		dev_err(kp->dbg_dev,
384			"Unable to register twl4030 keypad device\n");
385		goto err1;
386	}
387
388	error = twl4030_kp_program(kp);
389	if (error)
390		goto err2;
391
392	/*
393	 * This ISR will always execute in kernel thread context because of
394	 * the need to access the TWL4030 over the I2C bus.
395	 *
396	 * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
397	 */
398	error = request_threaded_irq(kp->irq, NULL, do_kp_irq,
399			0, pdev->name, kp);
400	if (error) {
401		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n",
402			kp->irq);
403		goto err3;
404	}
405
406	/* Enable KP and TO interrupts now. */
407	reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
408	if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
409		error = -EIO;
410		goto err4;
411	}
412
413	platform_set_drvdata(pdev, kp);
414	return 0;
415
416err4:
417	/* mask all events - we don't care about the result */
418	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
419err3:
420	free_irq(kp->irq, NULL);
421err2:
422	input_unregister_device(input);
423	input = NULL;
424err1:
425	input_free_device(input);
426	kfree(kp);
427	return error;
428}
429
430static int __devexit twl4030_kp_remove(struct platform_device *pdev)
431{
432	struct twl4030_keypad *kp = platform_get_drvdata(pdev);
433
434	free_irq(kp->irq, kp);
435	input_unregister_device(kp->input);
436	platform_set_drvdata(pdev, NULL);
437	kfree(kp);
438
439	return 0;
440}
441
442/*
443 * NOTE: twl4030 are multi-function devices connected via I2C.
444 * So this device is a child of an I2C parent, thus it needs to
445 * support unplug/replug (which most platform devices don't).
446 */
447
448static struct platform_driver twl4030_kp_driver = {
449	.probe		= twl4030_kp_probe,
450	.remove		= __devexit_p(twl4030_kp_remove),
451	.driver		= {
452		.name	= "twl4030_keypad",
453		.owner	= THIS_MODULE,
454	},
455};
456
457static int __init twl4030_kp_init(void)
458{
459	return platform_driver_register(&twl4030_kp_driver);
460}
461module_init(twl4030_kp_init);
462
463static void __exit twl4030_kp_exit(void)
464{
465	platform_driver_unregister(&twl4030_kp_driver);
466}
467module_exit(twl4030_kp_exit);
468
469MODULE_AUTHOR("Texas Instruments");
470MODULE_DESCRIPTION("TWL4030 Keypad Driver");
471MODULE_LICENSE("GPL");
472MODULE_ALIAS("platform:twl4030_keypad");
473
474