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Linux/drivers/input/keyboard/twl4030_keypad.c

  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/interrupt.h>
 31 #include <linux/input.h>
 32 #include <linux/platform_device.h>
 33 #include <linux/i2c/twl.h>
 34 #include <linux/slab.h>
 35 #include <linux/of.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         bool            autorepeat;
 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 
138 static 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 
151 static 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 
163 static 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 
176 static 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 
189 static 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 
206 static 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  */
256 static 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 
275 static int 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 200 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  */
332 static int twl4030_kp_probe(struct platform_device *pdev)
333 {
334         struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
335         const struct matrix_keymap_data *keymap_data = NULL;
336         struct twl4030_keypad *kp;
337         struct input_dev *input;
338         u8 reg;
339         int error;
340 
341         kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
342         if (!kp)
343                 return -ENOMEM;
344 
345         input = devm_input_allocate_device(&pdev->dev);
346         if (!input)
347                 return -ENOMEM;
348 
349         /* get the debug device */
350         kp->dbg_dev             = &pdev->dev;
351         kp->input               = input;
352 
353         /* setup input device */
354         input->name             = "TWL4030 Keypad";
355         input->phys             = "twl4030_keypad/input0";
356 
357         input->id.bustype       = BUS_HOST;
358         input->id.vendor        = 0x0001;
359         input->id.product       = 0x0001;
360         input->id.version       = 0x0003;
361 
362         if (pdata) {
363                 if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
364                         dev_err(&pdev->dev, "Missing platform_data\n");
365                         return -EINVAL;
366                 }
367 
368                 kp->n_rows = pdata->rows;
369                 kp->n_cols = pdata->cols;
370                 kp->autorepeat = pdata->rep;
371                 keymap_data = pdata->keymap_data;
372         } else {
373                 error = matrix_keypad_parse_of_params(&pdev->dev, &kp->n_rows,
374                                                       &kp->n_cols);
375                 if (error)
376                         return error;
377 
378                 kp->autorepeat = true;
379         }
380 
381         if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
382                 dev_err(&pdev->dev,
383                         "Invalid rows/cols amount specified in platform/devicetree data\n");
384                 return -EINVAL;
385         }
386 
387         kp->irq = platform_get_irq(pdev, 0);
388         if (!kp->irq) {
389                 dev_err(&pdev->dev, "no keyboard irq assigned\n");
390                 return -EINVAL;
391         }
392 
393         error = matrix_keypad_build_keymap(keymap_data, NULL,
394                                            TWL4030_MAX_ROWS,
395                                            1 << TWL4030_ROW_SHIFT,
396                                            kp->keymap, input);
397         if (error) {
398                 dev_err(kp->dbg_dev, "Failed to build keymap\n");
399                 return error;
400         }
401 
402         input_set_capability(input, EV_MSC, MSC_SCAN);
403         /* Enable auto repeat feature of Linux input subsystem */
404         if (kp->autorepeat)
405                 __set_bit(EV_REP, input->evbit);
406 
407         error = input_register_device(input);
408         if (error) {
409                 dev_err(kp->dbg_dev,
410                         "Unable to register twl4030 keypad device\n");
411                 return error;
412         }
413 
414         error = twl4030_kp_program(kp);
415         if (error)
416                 return error;
417 
418         /*
419          * This ISR will always execute in kernel thread context because of
420          * the need to access the TWL4030 over the I2C bus.
421          *
422          * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
423          */
424         error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
425                                           0, pdev->name, kp);
426         if (error) {
427                 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
428                         kp->irq, error);
429                 return error;
430         }
431 
432         /* Enable KP and TO interrupts now. */
433         reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
434         if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
435                 /* mask all events - we don't care about the result */
436                 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
437                 return -EIO;
438         }
439 
440         platform_set_drvdata(pdev, kp);
441         return 0;
442 }
443 
444 #ifdef CONFIG_OF
445 static const struct of_device_id twl4030_keypad_dt_match_table[] = {
446         { .compatible = "ti,twl4030-keypad" },
447         {},
448 };
449 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
450 #endif
451 
452 /*
453  * NOTE: twl4030 are multi-function devices connected via I2C.
454  * So this device is a child of an I2C parent, thus it needs to
455  * support unplug/replug (which most platform devices don't).
456  */
457 
458 static struct platform_driver twl4030_kp_driver = {
459         .probe          = twl4030_kp_probe,
460         .driver         = {
461                 .name   = "twl4030_keypad",
462                 .owner  = THIS_MODULE,
463                 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
464         },
465 };
466 module_platform_driver(twl4030_kp_driver);
467 
468 MODULE_AUTHOR("Texas Instruments");
469 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
470 MODULE_LICENSE("GPL");
471 MODULE_ALIAS("platform:twl4030_keypad");
472 

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