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  * 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 /*
54  * Note that we add space for an extra column so that we can handle
55  * row lines connected to the gnd (see twl4030_col_xlate()).
56  */
57 #define TWL4030_ROW_SHIFT	4
58 #define TWL4030_KEYMAP_SIZE	(TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
59 
60 struct twl4030_keypad {
61 	unsigned short	keymap[TWL4030_KEYMAP_SIZE];
62 	u16		kp_state[TWL4030_MAX_ROWS];
63 	unsigned	n_rows;
64 	unsigned	n_cols;
65 	unsigned	irq;
66 
67 	struct device *dbg_dev;
68 	struct input_dev *input;
69 };
70 
71 /*----------------------------------------------------------------------*/
72 
73 /* arbitrary prescaler value 0..7 */
74 #define PTV_PRESCALER			4
75 
76 /* Register Offsets */
77 #define KEYP_CTRL			0x00
78 #define KEYP_DEB			0x01
79 #define KEYP_LONG_KEY			0x02
80 #define KEYP_LK_PTV			0x03
81 #define KEYP_TIMEOUT_L			0x04
82 #define KEYP_TIMEOUT_H			0x05
83 #define KEYP_KBC			0x06
84 #define KEYP_KBR			0x07
85 #define KEYP_SMS			0x08
86 #define KEYP_FULL_CODE_7_0		0x09	/* row 0 column status */
87 #define KEYP_FULL_CODE_15_8		0x0a	/* ... row 1 ... */
88 #define KEYP_FULL_CODE_23_16		0x0b
89 #define KEYP_FULL_CODE_31_24		0x0c
90 #define KEYP_FULL_CODE_39_32		0x0d
91 #define KEYP_FULL_CODE_47_40		0x0e
92 #define KEYP_FULL_CODE_55_48		0x0f
93 #define KEYP_FULL_CODE_63_56		0x10
94 #define KEYP_ISR1			0x11
95 #define KEYP_IMR1			0x12
96 #define KEYP_ISR2			0x13
97 #define KEYP_IMR2			0x14
98 #define KEYP_SIR			0x15
99 #define KEYP_EDR			0x16	/* edge triggers */
100 #define KEYP_SIH_CTRL			0x17
101 
102 /* KEYP_CTRL_REG Fields */
103 #define KEYP_CTRL_SOFT_NRST		BIT(0)
104 #define KEYP_CTRL_SOFTMODEN		BIT(1)
105 #define KEYP_CTRL_LK_EN			BIT(2)
106 #define KEYP_CTRL_TOE_EN		BIT(3)
107 #define KEYP_CTRL_TOLE_EN		BIT(4)
108 #define KEYP_CTRL_RP_EN			BIT(5)
109 #define KEYP_CTRL_KBD_ON		BIT(6)
110 
111 /* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
112 #define KEYP_PERIOD_US(t, prescale)	((t) / (31 << (prescale + 1)) - 1)
113 
114 /* KEYP_LK_PTV_REG Fields */
115 #define KEYP_LK_PTV_PTV_SHIFT		5
116 
117 /* KEYP_{IMR,ISR,SIR} Fields */
118 #define KEYP_IMR1_MIS			BIT(3)
119 #define KEYP_IMR1_TO			BIT(2)
120 #define KEYP_IMR1_LK			BIT(1)
121 #define KEYP_IMR1_KP			BIT(0)
122 
123 /* KEYP_EDR Fields */
124 #define KEYP_EDR_KP_FALLING		0x01
125 #define KEYP_EDR_KP_RISING		0x02
126 #define KEYP_EDR_KP_BOTH		0x03
127 #define KEYP_EDR_LK_FALLING		0x04
128 #define KEYP_EDR_LK_RISING		0x08
129 #define KEYP_EDR_TO_FALLING		0x10
130 #define KEYP_EDR_TO_RISING		0x20
131 #define KEYP_EDR_MIS_FALLING		0x40
132 #define KEYP_EDR_MIS_RISING		0x80
133 
134 
135 /*----------------------------------------------------------------------*/
136 
137 static int twl4030_kpread(struct twl4030_keypad *kp,
138 		u8 *data, u32 reg, u8 num_bytes)
139 {
140 	int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
141 
142 	if (ret < 0)
143 		dev_warn(kp->dbg_dev,
144 			"Couldn't read TWL4030: %X - ret %d[%x]\n",
145 			 reg, ret, ret);
146 
147 	return ret;
148 }
149 
150 static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
151 {
152 	int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
153 
154 	if (ret < 0)
155 		dev_warn(kp->dbg_dev,
156 			"Could not write TWL4030: %X - ret %d[%x]\n",
157 			 reg, ret, ret);
158 
159 	return ret;
160 }
161 
162 static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
163 {
164 	/* If all bits in a row are active for all coloumns then
165 	 * we have that row line connected to gnd. Mark this
166 	 * key on as if it was on matrix position n_cols (ie
167 	 * one higher than the size of the matrix).
168 	 */
169 	if (col == 0xFF)
170 		return 1 << kp->n_cols;
171 	else
172 		return col & ((1 << kp->n_cols) - 1);
173 }
174 
175 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
176 {
177 	u8 new_state[TWL4030_MAX_ROWS];
178 	int row;
179 	int ret = twl4030_kpread(kp, new_state,
180 				 KEYP_FULL_CODE_7_0, kp->n_rows);
181 	if (ret >= 0)
182 		for (row = 0; row < kp->n_rows; row++)
183 			state[row] = twl4030_col_xlate(kp, new_state[row]);
184 
185 	return ret;
186 }
187 
188 static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
189 {
190 	int i;
191 	u16 check = 0;
192 
193 	for (i = 0; i < kp->n_rows; i++) {
194 		u16 col = key_state[i];
195 
196 		if ((col & check) && hweight16(col) > 1)
197 			return true;
198 
199 		check |= col;
200 	}
201 
202 	return false;
203 }
204 
205 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
206 {
207 	struct input_dev *input = kp->input;
208 	u16 new_state[TWL4030_MAX_ROWS];
209 	int col, row;
210 
211 	if (release_all)
212 		memset(new_state, 0, sizeof(new_state));
213 	else {
214 		/* check for any changes */
215 		int ret = twl4030_read_kp_matrix_state(kp, new_state);
216 
217 		if (ret < 0)	/* panic ... */
218 			return;
219 
220 		if (twl4030_is_in_ghost_state(kp, new_state))
221 			return;
222 	}
223 
224 	/* check for changes and print those */
225 	for (row = 0; row < kp->n_rows; row++) {
226 		int changed = new_state[row] ^ kp->kp_state[row];
227 
228 		if (!changed)
229 			continue;
230 
231 		/* Extra column handles "all gnd" rows */
232 		for (col = 0; col < kp->n_cols + 1; col++) {
233 			int code;
234 
235 			if (!(changed & (1 << col)))
236 				continue;
237 
238 			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
239 				(new_state[row] & (1 << col)) ?
240 				"press" : "release");
241 
242 			code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
243 			input_event(input, EV_MSC, MSC_SCAN, code);
244 			input_report_key(input, kp->keymap[code],
245 					 new_state[row] & (1 << col));
246 		}
247 		kp->kp_state[row] = new_state[row];
248 	}
249 	input_sync(input);
250 }
251 
252 /*
253  * Keypad interrupt handler
254  */
255 static irqreturn_t do_kp_irq(int irq, void *_kp)
256 {
257 	struct twl4030_keypad *kp = _kp;
258 	u8 reg;
259 	int ret;
260 
261 	/* Read & Clear TWL4030 pending interrupt */
262 	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
263 
264 	/* Release all keys if I2C has gone bad or
265 	 * the KEYP has gone to idle state */
266 	if (ret >= 0 && (reg & KEYP_IMR1_KP))
267 		twl4030_kp_scan(kp, false);
268 	else
269 		twl4030_kp_scan(kp, true);
270 
271 	return IRQ_HANDLED;
272 }
273 
274 static int twl4030_kp_program(struct twl4030_keypad *kp)
275 {
276 	u8 reg;
277 	int i;
278 
279 	/* Enable controller, with hardware decoding but not autorepeat */
280 	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
281 		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
282 	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
283 		return -EIO;
284 
285 	/* NOTE:  we could use sih_setup() here to package keypad
286 	 * event sources as four different IRQs ... but we don't.
287 	 */
288 
289 	/* Enable TO rising and KP rising and falling edge detection */
290 	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
291 	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
292 		return -EIO;
293 
294 	/* Set PTV prescaler Field */
295 	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
296 	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
297 		return -EIO;
298 
299 	/* Set key debounce time to 20 ms */
300 	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
301 	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
302 		return -EIO;
303 
304 	/* Set timeout period to 200 ms */
305 	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
306 	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
307 		return -EIO;
308 
309 	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
310 		return -EIO;
311 
312 	/*
313 	 * Enable Clear-on-Read; disable remembering events that fire
314 	 * after the IRQ but before our handler acks (reads) them,
315 	 */
316 	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
317 	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
318 		return -EIO;
319 
320 	/* initialize key state; irqs update it from here on */
321 	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
322 		return -EIO;
323 
324 	return 0;
325 }
326 
327 /*
328  * Registers keypad device with input subsystem
329  * and configures TWL4030 keypad registers
330  */
331 static int twl4030_kp_probe(struct platform_device *pdev)
332 {
333 	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
334 	const struct matrix_keymap_data *keymap_data;
335 	struct twl4030_keypad *kp;
336 	struct input_dev *input;
337 	u8 reg;
338 	int error;
339 
340 	if (!pdata || !pdata->rows || !pdata->cols || !pdata->keymap_data ||
341 	    pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) {
342 		dev_err(&pdev->dev, "Invalid platform_data\n");
343 		return -EINVAL;
344 	}
345 
346 	keymap_data = pdata->keymap_data;
347 
348 	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
349 	input = input_allocate_device();
350 	if (!kp || !input) {
351 		error = -ENOMEM;
352 		goto err1;
353 	}
354 
355 	/* Get the debug Device */
356 	kp->dbg_dev = &pdev->dev;
357 	kp->input = input;
358 
359 	kp->n_rows = pdata->rows;
360 	kp->n_cols = pdata->cols;
361 	kp->irq = platform_get_irq(pdev, 0);
362 
363 	/* setup input device */
364 	input->name		= "TWL4030 Keypad";
365 	input->phys		= "twl4030_keypad/input0";
366 	input->dev.parent	= &pdev->dev;
367 
368 	input->id.bustype	= BUS_HOST;
369 	input->id.vendor	= 0x0001;
370 	input->id.product	= 0x0001;
371 	input->id.version	= 0x0003;
372 
373 	error = matrix_keypad_build_keymap(keymap_data, NULL,
374 					   TWL4030_MAX_ROWS,
375 					   1 << TWL4030_ROW_SHIFT,
376 					   kp->keymap, input);
377 	if (error) {
378 		dev_err(kp->dbg_dev, "Failed to build keymap\n");
379 		goto err1;
380 	}
381 
382 	input_set_capability(input, EV_MSC, MSC_SCAN);
383 	/* Enable auto repeat feature of Linux input subsystem */
384 	if (pdata->rep)
385 		__set_bit(EV_REP, input->evbit);
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 err2;
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 err3;
417 	}
418 
419 	platform_set_drvdata(pdev, kp);
420 	return 0;
421 
422 err3:
423 	/* mask all events - we don't care about the result */
424 	(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
425 	free_irq(kp->irq, kp);
426 err2:
427 	input_unregister_device(input);
428 	input = NULL;
429 err1:
430 	input_free_device(input);
431 	kfree(kp);
432 	return error;
433 }
434 
435 static int twl4030_kp_remove(struct platform_device *pdev)
436 {
437 	struct twl4030_keypad *kp = platform_get_drvdata(pdev);
438 
439 	free_irq(kp->irq, kp);
440 	input_unregister_device(kp->input);
441 	kfree(kp);
442 
443 	return 0;
444 }
445 
446 /*
447  * NOTE: twl4030 are multi-function devices connected via I2C.
448  * So this device is a child of an I2C parent, thus it needs to
449  * support unplug/replug (which most platform devices don't).
450  */
451 
452 static struct platform_driver twl4030_kp_driver = {
453 	.probe		= twl4030_kp_probe,
454 	.remove		= twl4030_kp_remove,
455 	.driver		= {
456 		.name	= "twl4030_keypad",
457 		.owner	= THIS_MODULE,
458 	},
459 };
460 module_platform_driver(twl4030_kp_driver);
461 
462 MODULE_AUTHOR("Texas Instruments");
463 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
464 MODULE_LICENSE("GPL");
465 MODULE_ALIAS("platform:twl4030_keypad");
466