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
39 /* TCA8418 hardware limits */
40 #define TCA8418_MAX_ROWS 8
41 #define TCA8418_MAX_COLS 10
42
43 /* TCA8418 register offsets */
44 #define REG_CFG 0x01
45 #define REG_INT_STAT 0x02
46 #define REG_KEY_LCK_EC 0x03
47 #define REG_KEY_EVENT_A 0x04
48 #define REG_KEY_EVENT_B 0x05
49 #define REG_KEY_EVENT_C 0x06
50 #define REG_KEY_EVENT_D 0x07
51 #define REG_KEY_EVENT_E 0x08
52 #define REG_KEY_EVENT_F 0x09
53 #define REG_KEY_EVENT_G 0x0A
54 #define REG_KEY_EVENT_H 0x0B
55 #define REG_KEY_EVENT_I 0x0C
56 #define REG_KEY_EVENT_J 0x0D
57 #define REG_KP_LCK_TIMER 0x0E
58 #define REG_UNLOCK1 0x0F
59 #define REG_UNLOCK2 0x10
60 #define REG_GPIO_INT_STAT1 0x11
61 #define REG_GPIO_INT_STAT2 0x12
62 #define REG_GPIO_INT_STAT3 0x13
63 #define REG_GPIO_DAT_STAT1 0x14
64 #define REG_GPIO_DAT_STAT2 0x15
65 #define REG_GPIO_DAT_STAT3 0x16
66 #define REG_GPIO_DAT_OUT1 0x17
67 #define REG_GPIO_DAT_OUT2 0x18
68 #define REG_GPIO_DAT_OUT3 0x19
69 #define REG_GPIO_INT_EN1 0x1A
70 #define REG_GPIO_INT_EN2 0x1B
71 #define REG_GPIO_INT_EN3 0x1C
72 #define REG_KP_GPIO1 0x1D
73 #define REG_KP_GPIO2 0x1E
74 #define REG_KP_GPIO3 0x1F
75 #define REG_GPI_EM1 0x20
76 #define REG_GPI_EM2 0x21
77 #define REG_GPI_EM3 0x22
78 #define REG_GPIO_DIR1 0x23
79 #define REG_GPIO_DIR2 0x24
80 #define REG_GPIO_DIR3 0x25
81 #define REG_GPIO_INT_LVL1 0x26
82 #define REG_GPIO_INT_LVL2 0x27
83 #define REG_GPIO_INT_LVL3 0x28
84 #define REG_DEBOUNCE_DIS1 0x29
85 #define REG_DEBOUNCE_DIS2 0x2A
86 #define REG_DEBOUNCE_DIS3 0x2B
87 #define REG_GPIO_PULL1 0x2C
88 #define REG_GPIO_PULL2 0x2D
89 #define REG_GPIO_PULL3 0x2E
90
91 /* TCA8418 bit definitions */
92 #define CFG_AI BIT(7)
93 #define CFG_GPI_E_CFG BIT(6)
94 #define CFG_OVR_FLOW_M BIT(5)
95 #define CFG_INT_CFG BIT(4)
96 #define CFG_OVR_FLOW_IEN BIT(3)
97 #define CFG_K_LCK_IEN BIT(2)
98 #define CFG_GPI_IEN BIT(1)
99 #define CFG_KE_IEN BIT(0)
100
101 #define INT_STAT_CAD_INT BIT(4)
102 #define INT_STAT_OVR_FLOW_INT BIT(3)
103 #define INT_STAT_K_LCK_INT BIT(2)
104 #define INT_STAT_GPI_INT BIT(1)
105 #define INT_STAT_K_INT BIT(0)
106
107 /* TCA8418 register masks */
108 #define KEY_LCK_EC_KEC 0x7
109 #define KEY_EVENT_CODE 0x7f
110 #define KEY_EVENT_VALUE 0x80
111
112
113 static const struct i2c_device_id tca8418_id[] = {
114 { TCA8418_NAME, 8418, },
115 { }
116 };
117 MODULE_DEVICE_TABLE(i2c, tca8418_id);
118
119 struct tca8418_keypad {
120 unsigned int rows;
121 unsigned int cols;
122 unsigned int keypad_mask; /* Mask for keypad col/rol regs */
123 unsigned int irq;
124 unsigned int row_shift;
125
126 struct i2c_client *client;
127 struct input_dev *input;
128
129 /* Flexible array member, must be at end of struct */
130 unsigned short keymap[];
131 };
132
133 /*
134 * Write a byte to the TCA8418
135 */
tca8418_write_byte(struct tca8418_keypad * keypad_data,int reg,u8 val)136 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
137 int reg, u8 val)
138 {
139 int error;
140
141 error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
142 if (error < 0) {
143 dev_err(&keypad_data->client->dev,
144 "%s failed, reg: %d, val: %d, error: %d\n",
145 __func__, reg, val, error);
146 return error;
147 }
148
149 return 0;
150 }
151
152 /*
153 * Read a byte from the TCA8418
154 */
tca8418_read_byte(struct tca8418_keypad * keypad_data,int reg,u8 * val)155 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
156 int reg, u8 *val)
157 {
158 int error;
159
160 error = i2c_smbus_read_byte_data(keypad_data->client, reg);
161 if (error < 0) {
162 dev_err(&keypad_data->client->dev,
163 "%s failed, reg: %d, error: %d\n",
164 __func__, reg, error);
165 return error;
166 }
167
168 *val = (u8)error;
169
170 return 0;
171 }
172
tca8418_read_keypad(struct tca8418_keypad * keypad_data)173 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
174 {
175 int error, col, row;
176 u8 reg, state, code;
177
178 /* Initial read of the key event FIFO */
179 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
180
181 /* Assume that key code 0 signifies empty FIFO */
182 while (error >= 0 && reg > 0) {
183 state = reg & KEY_EVENT_VALUE;
184 code = reg & KEY_EVENT_CODE;
185
186 row = code / TCA8418_MAX_COLS;
187 col = code % TCA8418_MAX_COLS;
188
189 row = (col) ? row : row - 1;
190 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
191
192 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
193 input_event(keypad_data->input, EV_MSC, MSC_SCAN, code);
194 input_report_key(keypad_data->input,
195 keypad_data->keymap[code], state);
196
197 /* Read for next loop */
198 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
199 }
200
201 if (error < 0)
202 dev_err(&keypad_data->client->dev,
203 "unable to read REG_KEY_EVENT_A\n");
204
205 input_sync(keypad_data->input);
206 }
207
208 /*
209 * Threaded IRQ handler and this can (and will) sleep.
210 */
tca8418_irq_handler(int irq,void * dev_id)211 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
212 {
213 struct tca8418_keypad *keypad_data = dev_id;
214 u8 reg;
215 int error;
216
217 error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®);
218 if (error) {
219 dev_err(&keypad_data->client->dev,
220 "unable to read REG_INT_STAT\n");
221 goto exit;
222 }
223
224 if (reg & INT_STAT_OVR_FLOW_INT)
225 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
226
227 if (reg & INT_STAT_K_INT)
228 tca8418_read_keypad(keypad_data);
229
230 exit:
231 /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
232 reg = 0xff;
233 error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
234 if (error)
235 dev_err(&keypad_data->client->dev,
236 "unable to clear REG_INT_STAT\n");
237
238 return IRQ_HANDLED;
239 }
240
241 /*
242 * Configure the TCA8418 for keypad operation
243 */
tca8418_configure(struct tca8418_keypad * keypad_data)244 static int __devinit tca8418_configure(struct tca8418_keypad *keypad_data)
245 {
246 int reg, error;
247
248 /* Write config register, if this fails assume device not present */
249 error = tca8418_write_byte(keypad_data, REG_CFG,
250 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
251 if (error < 0)
252 return -ENODEV;
253
254
255 /* Assemble a mask for row and column registers */
256 reg = ~(~0 << keypad_data->rows);
257 reg += (~(~0 << keypad_data->cols)) << 8;
258 keypad_data->keypad_mask = reg;
259
260 /* Set registers to keypad mode */
261 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
262 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
263 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
264
265 /* Enable column debouncing */
266 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
267 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
268 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
269
270 return error;
271 }
272
tca8418_keypad_probe(struct i2c_client * client,const struct i2c_device_id * id)273 static int __devinit tca8418_keypad_probe(struct i2c_client *client,
274 const struct i2c_device_id *id)
275 {
276 const struct tca8418_keypad_platform_data *pdata =
277 client->dev.platform_data;
278 struct tca8418_keypad *keypad_data;
279 struct input_dev *input;
280 int error, row_shift, max_keys;
281
282 /* Copy the platform data */
283 if (!pdata) {
284 dev_dbg(&client->dev, "no platform data\n");
285 return -EINVAL;
286 }
287
288 if (!pdata->keymap_data) {
289 dev_err(&client->dev, "no keymap data defined\n");
290 return -EINVAL;
291 }
292
293 if (!pdata->rows || pdata->rows > TCA8418_MAX_ROWS) {
294 dev_err(&client->dev, "invalid rows\n");
295 return -EINVAL;
296 }
297
298 if (!pdata->cols || pdata->cols > TCA8418_MAX_COLS) {
299 dev_err(&client->dev, "invalid columns\n");
300 return -EINVAL;
301 }
302
303 /* Check i2c driver capabilities */
304 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
305 dev_err(&client->dev, "%s adapter not supported\n",
306 dev_driver_string(&client->adapter->dev));
307 return -ENODEV;
308 }
309
310 row_shift = get_count_order(pdata->cols);
311 max_keys = pdata->rows << row_shift;
312
313 /* Allocate memory for keypad_data, keymap and input device */
314 keypad_data = kzalloc(sizeof(*keypad_data) +
315 max_keys * sizeof(keypad_data->keymap[0]), GFP_KERNEL);
316 if (!keypad_data)
317 return -ENOMEM;
318
319 keypad_data->rows = pdata->rows;
320 keypad_data->cols = pdata->cols;
321 keypad_data->client = client;
322 keypad_data->row_shift = row_shift;
323
324 /* Initialize the chip or fail if chip isn't present */
325 error = tca8418_configure(keypad_data);
326 if (error < 0)
327 goto fail1;
328
329 /* Configure input device */
330 input = input_allocate_device();
331 if (!input) {
332 error = -ENOMEM;
333 goto fail1;
334 }
335 keypad_data->input = input;
336
337 input->name = client->name;
338 input->dev.parent = &client->dev;
339
340 input->id.bustype = BUS_I2C;
341 input->id.vendor = 0x0001;
342 input->id.product = 0x001;
343 input->id.version = 0x0001;
344
345 input->keycode = keypad_data->keymap;
346 input->keycodesize = sizeof(keypad_data->keymap[0]);
347 input->keycodemax = max_keys;
348
349 __set_bit(EV_KEY, input->evbit);
350 if (pdata->rep)
351 __set_bit(EV_REP, input->evbit);
352
353 input_set_capability(input, EV_MSC, MSC_SCAN);
354
355 input_set_drvdata(input, keypad_data);
356
357 matrix_keypad_build_keymap(pdata->keymap_data, row_shift,
358 input->keycode, input->keybit);
359
360 if (pdata->irq_is_gpio)
361 client->irq = gpio_to_irq(client->irq);
362
363 error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler,
364 IRQF_TRIGGER_FALLING,
365 client->name, keypad_data);
366 if (error) {
367 dev_dbg(&client->dev,
368 "Unable to claim irq %d; error %d\n",
369 client->irq, error);
370 goto fail2;
371 }
372
373 error = input_register_device(input);
374 if (error) {
375 dev_dbg(&client->dev,
376 "Unable to register input device, error: %d\n", error);
377 goto fail3;
378 }
379
380 i2c_set_clientdata(client, keypad_data);
381 return 0;
382
383 fail3:
384 free_irq(client->irq, keypad_data);
385 fail2:
386 input_free_device(input);
387 fail1:
388 kfree(keypad_data);
389 return error;
390 }
391
tca8418_keypad_remove(struct i2c_client * client)392 static int __devexit tca8418_keypad_remove(struct i2c_client *client)
393 {
394 struct tca8418_keypad *keypad_data = i2c_get_clientdata(client);
395
396 free_irq(keypad_data->client->irq, keypad_data);
397
398 input_unregister_device(keypad_data->input);
399
400 kfree(keypad_data);
401
402 return 0;
403 }
404
405
406 static struct i2c_driver tca8418_keypad_driver = {
407 .driver = {
408 .name = TCA8418_NAME,
409 .owner = THIS_MODULE,
410 },
411 .probe = tca8418_keypad_probe,
412 .remove = __devexit_p(tca8418_keypad_remove),
413 .id_table = tca8418_id,
414 };
415
tca8418_keypad_init(void)416 static int __init tca8418_keypad_init(void)
417 {
418 return i2c_add_driver(&tca8418_keypad_driver);
419 }
420 subsys_initcall(tca8418_keypad_init);
421
tca8418_keypad_exit(void)422 static void __exit tca8418_keypad_exit(void)
423 {
424 i2c_del_driver(&tca8418_keypad_driver);
425 }
426 module_exit(tca8418_keypad_exit);
427
428 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
429 MODULE_DESCRIPTION("Keypad driver for TCA8418");
430 MODULE_LICENSE("GPL");
431