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
twl4030_kpread(struct twl4030_keypad * kp,u8 * data,u32 reg,u8 num_bytes)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
twl4030_kpwrite_u8(struct twl4030_keypad * kp,u8 data,u32 reg)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
twl4030_col_xlate(struct twl4030_keypad * kp,u8 col)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
twl4030_read_kp_matrix_state(struct twl4030_keypad * kp,u16 * state)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
twl4030_is_in_ghost_state(struct twl4030_keypad * kp,u16 * key_state)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
twl4030_kp_scan(struct twl4030_keypad * kp,bool release_all)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 */
do_kp_irq(int irq,void * _kp)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, ®, 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
twl4030_kp_program(struct twl4030_keypad * kp)274 static int __devinit 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 */
twl4030_kp_probe(struct platform_device * pdev)331 static int __devinit 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 __set_bit(EV_KEY, input->evbit);
365
366 /* Enable auto repeat feature of Linux input subsystem */
367 if (pdata->rep)
368 __set_bit(EV_REP, input->evbit);
369
370 input_set_capability(input, EV_MSC, MSC_SCAN);
371
372 input->name = "TWL4030 Keypad";
373 input->phys = "twl4030_keypad/input0";
374 input->dev.parent = &pdev->dev;
375
376 input->id.bustype = BUS_HOST;
377 input->id.vendor = 0x0001;
378 input->id.product = 0x0001;
379 input->id.version = 0x0003;
380
381 input->keycode = kp->keymap;
382 input->keycodesize = sizeof(kp->keymap[0]);
383 input->keycodemax = ARRAY_SIZE(kp->keymap);
384
385 matrix_keypad_build_keymap(keymap_data, TWL4030_ROW_SHIFT,
386 input->keycode, input->keybit);
387
388 error = input_register_device(input);
389 if (error) {
390 dev_err(kp->dbg_dev,
391 "Unable to register twl4030 keypad device\n");
392 goto err1;
393 }
394
395 error = twl4030_kp_program(kp);
396 if (error)
397 goto err2;
398
399 /*
400 * This ISR will always execute in kernel thread context because of
401 * the need to access the TWL4030 over the I2C bus.
402 *
403 * NOTE: we assume this host is wired to TWL4040 INT1, not INT2 ...
404 */
405 error = request_threaded_irq(kp->irq, NULL, do_kp_irq,
406 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 err2;
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 err3;
418 }
419
420 platform_set_drvdata(pdev, kp);
421 return 0;
422
423 err3:
424 /* mask all events - we don't care about the result */
425 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
426 free_irq(kp->irq, NULL);
427 err2:
428 input_unregister_device(input);
429 input = NULL;
430 err1:
431 input_free_device(input);
432 kfree(kp);
433 return error;
434 }
435
twl4030_kp_remove(struct platform_device * pdev)436 static 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
454 static 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 module_platform_driver(twl4030_kp_driver);
463
464 MODULE_AUTHOR("Texas Instruments");
465 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
466 MODULE_LICENSE("GPL");
467 MODULE_ALIAS("platform:twl4030_keypad");
468