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Linux/drivers/input/keyboard/tca8418_keypad.c

  1 /*
  2  * Driver for TCA8418 I2C keyboard
  3  *
  4  * Copyright (C) 2011 Fuel7, Inc.  All rights reserved.
  5  *
  6  * Author: Kyle Manna <kyle.manna@fuel7.com>
  7  *
  8  * This program is free software; you can redistribute it and/or
  9  * modify it under the terms of the GNU General Public
 10  * License v2 as published by the Free Software Foundation.
 11  *
 12  * This program is distributed in the hope that it will be useful,
 13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 15  * General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU General Public
 18  * License along with this program; if not, write to the
 19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 20  * Boston, MA 021110-1307, USA.
 21  *
 22  * If you can't comply with GPLv2, alternative licensing terms may be
 23  * arranged. Please contact Fuel7, Inc. (http://fuel7.com/) for proprietary
 24  * alternative licensing inquiries.
 25  */
 26 
 27 #include <linux/types.h>
 28 #include <linux/module.h>
 29 #include <linux/init.h>
 30 #include <linux/delay.h>
 31 #include <linux/slab.h>
 32 #include <linux/interrupt.h>
 33 #include <linux/workqueue.h>
 34 #include <linux/gpio.h>
 35 #include <linux/i2c.h>
 36 #include <linux/input.h>
 37 #include <linux/input/tca8418_keypad.h>
 38 #include <linux/of.h>
 39 
 40 /* TCA8418 hardware limits */
 41 #define TCA8418_MAX_ROWS        8
 42 #define TCA8418_MAX_COLS        10
 43 
 44 /* TCA8418 register offsets */
 45 #define REG_CFG                 0x01
 46 #define REG_INT_STAT            0x02
 47 #define REG_KEY_LCK_EC          0x03
 48 #define REG_KEY_EVENT_A         0x04
 49 #define REG_KEY_EVENT_B         0x05
 50 #define REG_KEY_EVENT_C         0x06
 51 #define REG_KEY_EVENT_D         0x07
 52 #define REG_KEY_EVENT_E         0x08
 53 #define REG_KEY_EVENT_F         0x09
 54 #define REG_KEY_EVENT_G         0x0A
 55 #define REG_KEY_EVENT_H         0x0B
 56 #define REG_KEY_EVENT_I         0x0C
 57 #define REG_KEY_EVENT_J         0x0D
 58 #define REG_KP_LCK_TIMER        0x0E
 59 #define REG_UNLOCK1             0x0F
 60 #define REG_UNLOCK2             0x10
 61 #define REG_GPIO_INT_STAT1      0x11
 62 #define REG_GPIO_INT_STAT2      0x12
 63 #define REG_GPIO_INT_STAT3      0x13
 64 #define REG_GPIO_DAT_STAT1      0x14
 65 #define REG_GPIO_DAT_STAT2      0x15
 66 #define REG_GPIO_DAT_STAT3      0x16
 67 #define REG_GPIO_DAT_OUT1       0x17
 68 #define REG_GPIO_DAT_OUT2       0x18
 69 #define REG_GPIO_DAT_OUT3       0x19
 70 #define REG_GPIO_INT_EN1        0x1A
 71 #define REG_GPIO_INT_EN2        0x1B
 72 #define REG_GPIO_INT_EN3        0x1C
 73 #define REG_KP_GPIO1            0x1D
 74 #define REG_KP_GPIO2            0x1E
 75 #define REG_KP_GPIO3            0x1F
 76 #define REG_GPI_EM1             0x20
 77 #define REG_GPI_EM2             0x21
 78 #define REG_GPI_EM3             0x22
 79 #define REG_GPIO_DIR1           0x23
 80 #define REG_GPIO_DIR2           0x24
 81 #define REG_GPIO_DIR3           0x25
 82 #define REG_GPIO_INT_LVL1       0x26
 83 #define REG_GPIO_INT_LVL2       0x27
 84 #define REG_GPIO_INT_LVL3       0x28
 85 #define REG_DEBOUNCE_DIS1       0x29
 86 #define REG_DEBOUNCE_DIS2       0x2A
 87 #define REG_DEBOUNCE_DIS3       0x2B
 88 #define REG_GPIO_PULL1          0x2C
 89 #define REG_GPIO_PULL2          0x2D
 90 #define REG_GPIO_PULL3          0x2E
 91 
 92 /* TCA8418 bit definitions */
 93 #define CFG_AI                  BIT(7)
 94 #define CFG_GPI_E_CFG           BIT(6)
 95 #define CFG_OVR_FLOW_M          BIT(5)
 96 #define CFG_INT_CFG             BIT(4)
 97 #define CFG_OVR_FLOW_IEN        BIT(3)
 98 #define CFG_K_LCK_IEN           BIT(2)
 99 #define CFG_GPI_IEN             BIT(1)
100 #define CFG_KE_IEN              BIT(0)
101 
102 #define INT_STAT_CAD_INT        BIT(4)
103 #define INT_STAT_OVR_FLOW_INT   BIT(3)
104 #define INT_STAT_K_LCK_INT      BIT(2)
105 #define INT_STAT_GPI_INT        BIT(1)
106 #define INT_STAT_K_INT          BIT(0)
107 
108 /* TCA8418 register masks */
109 #define KEY_LCK_EC_KEC          0x7
110 #define KEY_EVENT_CODE          0x7f
111 #define KEY_EVENT_VALUE         0x80
112 
113 struct tca8418_keypad {
114         struct i2c_client *client;
115         struct input_dev *input;
116 
117         unsigned int row_shift;
118 };
119 
120 /*
121  * Write a byte to the TCA8418
122  */
123 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
124                               int reg, u8 val)
125 {
126         int error;
127 
128         error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
129         if (error < 0) {
130                 dev_err(&keypad_data->client->dev,
131                         "%s failed, reg: %d, val: %d, error: %d\n",
132                         __func__, reg, val, error);
133                 return error;
134         }
135 
136         return 0;
137 }
138 
139 /*
140  * Read a byte from the TCA8418
141  */
142 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
143                              int reg, u8 *val)
144 {
145         int error;
146 
147         error = i2c_smbus_read_byte_data(keypad_data->client, reg);
148         if (error < 0) {
149                 dev_err(&keypad_data->client->dev,
150                                 "%s failed, reg: %d, error: %d\n",
151                                 __func__, reg, error);
152                 return error;
153         }
154 
155         *val = (u8)error;
156 
157         return 0;
158 }
159 
160 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
161 {
162         struct input_dev *input = keypad_data->input;
163         unsigned short *keymap = input->keycode;
164         int error, col, row;
165         u8 reg, state, code;
166 
167         /* Initial read of the key event FIFO */
168         error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
169 
170         /* Assume that key code 0 signifies empty FIFO */
171         while (error >= 0 && reg > 0) {
172                 state = reg & KEY_EVENT_VALUE;
173                 code  = reg & KEY_EVENT_CODE;
174 
175                 row = code / TCA8418_MAX_COLS;
176                 col = code % TCA8418_MAX_COLS;
177 
178                 row = (col) ? row : row - 1;
179                 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
180 
181                 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
182                 input_event(input, EV_MSC, MSC_SCAN, code);
183                 input_report_key(input, keymap[code], state);
184 
185                 /* Read for next loop */
186                 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
187         }
188 
189         if (error < 0)
190                 dev_err(&keypad_data->client->dev,
191                         "unable to read REG_KEY_EVENT_A\n");
192 
193         input_sync(input);
194 }
195 
196 /*
197  * Threaded IRQ handler and this can (and will) sleep.
198  */
199 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
200 {
201         struct tca8418_keypad *keypad_data = dev_id;
202         u8 reg;
203         int error;
204 
205         error = tca8418_read_byte(keypad_data, REG_INT_STAT, &reg);
206         if (error) {
207                 dev_err(&keypad_data->client->dev,
208                         "unable to read REG_INT_STAT\n");
209                 return IRQ_NONE;
210         }
211 
212         if (!reg)
213                 return IRQ_NONE;
214 
215         if (reg & INT_STAT_OVR_FLOW_INT)
216                 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
217 
218         if (reg & INT_STAT_K_INT)
219                 tca8418_read_keypad(keypad_data);
220 
221         /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
222         reg = 0xff;
223         error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
224         if (error)
225                 dev_err(&keypad_data->client->dev,
226                         "unable to clear REG_INT_STAT\n");
227 
228         return IRQ_HANDLED;
229 }
230 
231 /*
232  * Configure the TCA8418 for keypad operation
233  */
234 static int tca8418_configure(struct tca8418_keypad *keypad_data,
235                              u32 rows, u32 cols)
236 {
237         int reg, error;
238 
239         /* Write config register, if this fails assume device not present */
240         error = tca8418_write_byte(keypad_data, REG_CFG,
241                                 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
242         if (error < 0)
243                 return -ENODEV;
244 
245 
246         /* Assemble a mask for row and column registers */
247         reg  =  ~(~0 << rows);
248         reg += (~(~0 << cols)) << 8;
249 
250         /* Set registers to keypad mode */
251         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
252         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
253         error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
254 
255         /* Enable column debouncing */
256         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
257         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
258         error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
259 
260         return error;
261 }
262 
263 static int tca8418_keypad_probe(struct i2c_client *client,
264                                           const struct i2c_device_id *id)
265 {
266         struct device *dev = &client->dev;
267         const struct tca8418_keypad_platform_data *pdata =
268                                                 dev_get_platdata(dev);
269         struct tca8418_keypad *keypad_data;
270         struct input_dev *input;
271         const struct matrix_keymap_data *keymap_data = NULL;
272         u32 rows = 0, cols = 0;
273         bool rep = false;
274         bool irq_is_gpio = false;
275         int irq;
276         int error, row_shift, max_keys;
277 
278         /* Copy the platform data */
279         if (pdata) {
280                 if (!pdata->keymap_data) {
281                         dev_err(dev, "no keymap data defined\n");
282                         return -EINVAL;
283                 }
284                 keymap_data = pdata->keymap_data;
285                 rows = pdata->rows;
286                 cols = pdata->cols;
287                 rep  = pdata->rep;
288                 irq_is_gpio = pdata->irq_is_gpio;
289         } else {
290                 struct device_node *np = dev->of_node;
291                 int err;
292 
293                 err = matrix_keypad_parse_of_params(dev, &rows, &cols);
294                 if (err)
295                         return err;
296                 rep = of_property_read_bool(np, "keypad,autorepeat");
297         }
298 
299         if (!rows || rows > TCA8418_MAX_ROWS) {
300                 dev_err(dev, "invalid rows\n");
301                 return -EINVAL;
302         }
303 
304         if (!cols || cols > TCA8418_MAX_COLS) {
305                 dev_err(dev, "invalid columns\n");
306                 return -EINVAL;
307         }
308 
309         /* Check i2c driver capabilities */
310         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
311                 dev_err(dev, "%s adapter not supported\n",
312                         dev_driver_string(&client->adapter->dev));
313                 return -ENODEV;
314         }
315 
316         row_shift = get_count_order(cols);
317         max_keys = rows << row_shift;
318 
319         /* Allocate memory for keypad_data and input device */
320         keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
321         if (!keypad_data)
322                 return -ENOMEM;
323 
324         keypad_data->client = client;
325         keypad_data->row_shift = row_shift;
326 
327         /* Initialize the chip or fail if chip isn't present */
328         error = tca8418_configure(keypad_data, rows, cols);
329         if (error < 0)
330                 return error;
331 
332         /* Configure input device */
333         input = devm_input_allocate_device(dev);
334         if (!input)
335                 return -ENOMEM;
336 
337         keypad_data->input = input;
338 
339         input->name = client->name;
340         input->id.bustype = BUS_I2C;
341         input->id.vendor  = 0x0001;
342         input->id.product = 0x001;
343         input->id.version = 0x0001;
344 
345         error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
346                                            NULL, input);
347         if (error) {
348                 dev_err(dev, "Failed to build keymap\n");
349                 return error;
350         }
351 
352         if (rep)
353                 __set_bit(EV_REP, input->evbit);
354         input_set_capability(input, EV_MSC, MSC_SCAN);
355 
356         input_set_drvdata(input, keypad_data);
357 
358         irq = client->irq;
359         if (irq_is_gpio)
360                 irq = gpio_to_irq(irq);
361 
362         error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler,
363                                           IRQF_TRIGGER_FALLING |
364                                                 IRQF_SHARED |
365                                                 IRQF_ONESHOT,
366                                           client->name, keypad_data);
367         if (error) {
368                 dev_err(dev, "Unable to claim irq %d; error %d\n",
369                         client->irq, error);
370                 return error;
371         }
372 
373         error = input_register_device(input);
374         if (error) {
375                 dev_err(dev, "Unable to register input device, error: %d\n",
376                         error);
377                 return error;
378         }
379 
380         return 0;
381 }
382 
383 static const struct i2c_device_id tca8418_id[] = {
384         { TCA8418_NAME, 8418, },
385         { }
386 };
387 MODULE_DEVICE_TABLE(i2c, tca8418_id);
388 
389 #ifdef CONFIG_OF
390 static const struct of_device_id tca8418_dt_ids[] = {
391         { .compatible = "ti,tca8418", },
392         { }
393 };
394 MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
395 
396 /*
397  * The device tree based i2c loader looks for
398  * "i2c:" + second_component_of(property("compatible"))
399  * and therefore we need an alias to be found.
400  */
401 MODULE_ALIAS("i2c:tca8418");
402 #endif
403 
404 static struct i2c_driver tca8418_keypad_driver = {
405         .driver = {
406                 .name   = TCA8418_NAME,
407                 .owner  = THIS_MODULE,
408                 .of_match_table = of_match_ptr(tca8418_dt_ids),
409         },
410         .probe          = tca8418_keypad_probe,
411         .id_table       = tca8418_id,
412 };
413 
414 static int __init tca8418_keypad_init(void)
415 {
416         return i2c_add_driver(&tca8418_keypad_driver);
417 }
418 subsys_initcall(tca8418_keypad_init);
419 
420 static void __exit tca8418_keypad_exit(void)
421 {
422         i2c_del_driver(&tca8418_keypad_driver);
423 }
424 module_exit(tca8418_keypad_exit);
425 
426 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
427 MODULE_DESCRIPTION("Keypad driver for TCA8418");
428 MODULE_LICENSE("GPL");
429 

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