2 * Driver for TCA8418 I2C keyboard
4 * Copyright (C) 2011 Fuel7, Inc. All rights reserved.
6 * Author: Kyle Manna <kyle.manna@fuel7.com>
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.
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.
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.
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.
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>
40 /* TCA8418 hardware limits */
41 #define TCA8418_MAX_ROWS 8
42 #define TCA8418_MAX_COLS 10
44 /* TCA8418 register offsets */
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
92 /* TCA8418 bit definitions */
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)
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)
108 /* TCA8418 register masks */
109 #define KEY_LCK_EC_KEC 0x7
110 #define KEY_EVENT_CODE 0x7f
111 #define KEY_EVENT_VALUE 0x80
114 static const struct i2c_device_id tca8418_id[] = {
115 { TCA8418_NAME, 8418, },
118 MODULE_DEVICE_TABLE(i2c, tca8418_id);
121 static const struct of_device_id tca8418_dt_ids[] __devinitconst = {
122 { .compatible = "ti,tca8418", },
125 MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
128 struct tca8418_keypad {
130 unsigned int row_shift;
132 struct i2c_client *client;
133 struct input_dev *input;
135 /* Flexible array member, must be at end of struct */
136 unsigned short keymap[];
140 * Write a byte to the TCA8418
142 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
147 error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
149 dev_err(&keypad_data->client->dev,
150 "%s failed, reg: %d, val: %d, error: %d\n",
151 __func__, reg, val, error);
159 * Read a byte from the TCA8418
161 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
166 error = i2c_smbus_read_byte_data(keypad_data->client, reg);
168 dev_err(&keypad_data->client->dev,
169 "%s failed, reg: %d, error: %d\n",
170 __func__, reg, error);
179 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
184 /* Initial read of the key event FIFO */
185 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
187 /* Assume that key code 0 signifies empty FIFO */
188 while (error >= 0 && reg > 0) {
189 state = reg & KEY_EVENT_VALUE;
190 code = reg & KEY_EVENT_CODE;
192 row = code / TCA8418_MAX_COLS;
193 col = code % TCA8418_MAX_COLS;
195 row = (col) ? row : row - 1;
196 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
198 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
199 input_event(keypad_data->input, EV_MSC, MSC_SCAN, code);
200 input_report_key(keypad_data->input,
201 keypad_data->keymap[code], state);
203 /* Read for next loop */
204 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
208 dev_err(&keypad_data->client->dev,
209 "unable to read REG_KEY_EVENT_A\n");
211 input_sync(keypad_data->input);
215 * Threaded IRQ handler and this can (and will) sleep.
217 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
219 struct tca8418_keypad *keypad_data = dev_id;
223 error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®);
225 dev_err(&keypad_data->client->dev,
226 "unable to read REG_INT_STAT\n");
230 if (reg & INT_STAT_OVR_FLOW_INT)
231 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
233 if (reg & INT_STAT_K_INT)
234 tca8418_read_keypad(keypad_data);
237 /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
239 error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
241 dev_err(&keypad_data->client->dev,
242 "unable to clear REG_INT_STAT\n");
248 * Configure the TCA8418 for keypad operation
250 static int tca8418_configure(struct tca8418_keypad *keypad_data,
255 /* Write config register, if this fails assume device not present */
256 error = tca8418_write_byte(keypad_data, REG_CFG,
257 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
262 /* Assemble a mask for row and column registers */
264 reg += (~(~0 << cols)) << 8;
266 /* Set registers to keypad mode */
267 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
268 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
269 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
271 /* Enable column debouncing */
272 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
273 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
274 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
279 static int tca8418_keypad_probe(struct i2c_client *client,
280 const struct i2c_device_id *id)
282 const struct tca8418_keypad_platform_data *pdata =
283 client->dev.platform_data;
284 struct tca8418_keypad *keypad_data;
285 struct input_dev *input;
286 const struct matrix_keymap_data *keymap_data = NULL;
287 u32 rows = 0, cols = 0;
289 bool irq_is_gpio = false;
290 int error, row_shift, max_keys;
292 /* Copy the platform data */
294 if (!pdata->keymap_data) {
295 dev_err(&client->dev, "no keymap data defined\n");
298 keymap_data = pdata->keymap_data;
302 irq_is_gpio = pdata->irq_is_gpio;
304 struct device_node *np = client->dev.of_node;
305 of_property_read_u32(np, "keypad,num-rows", &rows);
306 of_property_read_u32(np, "keypad,num-columns", &cols);
307 rep = of_property_read_bool(np, "keypad,autorepeat");
310 if (!rows || rows > TCA8418_MAX_ROWS) {
311 dev_err(&client->dev, "invalid rows\n");
315 if (!cols || cols > TCA8418_MAX_COLS) {
316 dev_err(&client->dev, "invalid columns\n");
320 /* Check i2c driver capabilities */
321 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
322 dev_err(&client->dev, "%s adapter not supported\n",
323 dev_driver_string(&client->adapter->dev));
327 row_shift = get_count_order(cols);
328 max_keys = rows << row_shift;
330 /* Allocate memory for keypad_data, keymap and input device */
331 keypad_data = kzalloc(sizeof(*keypad_data) +
332 max_keys * sizeof(keypad_data->keymap[0]), GFP_KERNEL);
336 keypad_data->client = client;
337 keypad_data->row_shift = row_shift;
339 /* Initialize the chip or fail if chip isn't present */
340 error = tca8418_configure(keypad_data, rows, cols);
344 /* Configure input device */
345 input = input_allocate_device();
350 keypad_data->input = input;
352 input->name = client->name;
353 input->dev.parent = &client->dev;
355 input->id.bustype = BUS_I2C;
356 input->id.vendor = 0x0001;
357 input->id.product = 0x001;
358 input->id.version = 0x0001;
360 error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
361 keypad_data->keymap, input);
363 dev_dbg(&client->dev, "Failed to build keymap\n");
368 __set_bit(EV_REP, input->evbit);
369 input_set_capability(input, EV_MSC, MSC_SCAN);
371 input_set_drvdata(input, keypad_data);
374 client->irq = gpio_to_irq(client->irq);
376 error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler,
377 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
378 client->name, keypad_data);
380 dev_dbg(&client->dev,
381 "Unable to claim irq %d; error %d\n",
386 error = input_register_device(input);
388 dev_dbg(&client->dev,
389 "Unable to register input device, error: %d\n", error);
393 i2c_set_clientdata(client, keypad_data);
397 free_irq(client->irq, keypad_data);
399 input_free_device(input);
405 static int tca8418_keypad_remove(struct i2c_client *client)
407 struct tca8418_keypad *keypad_data = i2c_get_clientdata(client);
409 free_irq(keypad_data->client->irq, keypad_data);
411 input_unregister_device(keypad_data->input);
418 static struct i2c_driver tca8418_keypad_driver = {
420 .name = TCA8418_NAME,
421 .owner = THIS_MODULE,
422 .of_match_table = of_match_ptr(tca8418_dt_ids),
424 .probe = tca8418_keypad_probe,
425 .remove = tca8418_keypad_remove,
426 .id_table = tca8418_id,
429 static int __init tca8418_keypad_init(void)
431 return i2c_add_driver(&tca8418_keypad_driver);
433 subsys_initcall(tca8418_keypad_init);
435 static void __exit tca8418_keypad_exit(void)
437 i2c_del_driver(&tca8418_keypad_driver);
439 module_exit(tca8418_keypad_exit);
441 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
442 MODULE_DESCRIPTION("Keypad driver for TCA8418");
443 MODULE_LICENSE("GPL");