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
113 struct tca8418_keypad {
115 unsigned int row_shift;
117 struct i2c_client *client;
118 struct input_dev *input;
120 /* Flexible array member, must be at end of struct */
121 unsigned short keymap[];
125 * Write a byte to the TCA8418
127 static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
132 error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
134 dev_err(&keypad_data->client->dev,
135 "%s failed, reg: %d, val: %d, error: %d\n",
136 __func__, reg, val, error);
144 * Read a byte from the TCA8418
146 static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
151 error = i2c_smbus_read_byte_data(keypad_data->client, reg);
153 dev_err(&keypad_data->client->dev,
154 "%s failed, reg: %d, error: %d\n",
155 __func__, reg, error);
164 static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
169 /* Initial read of the key event FIFO */
170 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
172 /* Assume that key code 0 signifies empty FIFO */
173 while (error >= 0 && reg > 0) {
174 state = reg & KEY_EVENT_VALUE;
175 code = reg & KEY_EVENT_CODE;
177 row = code / TCA8418_MAX_COLS;
178 col = code % TCA8418_MAX_COLS;
180 row = (col) ? row : row - 1;
181 col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
183 code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
184 input_event(keypad_data->input, EV_MSC, MSC_SCAN, code);
185 input_report_key(keypad_data->input,
186 keypad_data->keymap[code], state);
188 /* Read for next loop */
189 error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
193 dev_err(&keypad_data->client->dev,
194 "unable to read REG_KEY_EVENT_A\n");
196 input_sync(keypad_data->input);
200 * Threaded IRQ handler and this can (and will) sleep.
202 static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
204 struct tca8418_keypad *keypad_data = dev_id;
208 error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®);
210 dev_err(&keypad_data->client->dev,
211 "unable to read REG_INT_STAT\n");
218 if (reg & INT_STAT_OVR_FLOW_INT)
219 dev_warn(&keypad_data->client->dev, "overflow occurred\n");
221 if (reg & INT_STAT_K_INT)
222 tca8418_read_keypad(keypad_data);
224 /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
226 error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
228 dev_err(&keypad_data->client->dev,
229 "unable to clear REG_INT_STAT\n");
235 * Configure the TCA8418 for keypad operation
237 static int tca8418_configure(struct tca8418_keypad *keypad_data,
242 /* Write config register, if this fails assume device not present */
243 error = tca8418_write_byte(keypad_data, REG_CFG,
244 CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
249 /* Assemble a mask for row and column registers */
251 reg += (~(~0 << cols)) << 8;
253 /* Set registers to keypad mode */
254 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
255 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
256 error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
258 /* Enable column debouncing */
259 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
260 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
261 error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
266 static int tca8418_keypad_probe(struct i2c_client *client,
267 const struct i2c_device_id *id)
269 struct device *dev = &client->dev;
270 const struct tca8418_keypad_platform_data *pdata =
271 dev_get_platdata(dev);
272 struct tca8418_keypad *keypad_data;
273 struct input_dev *input;
274 const struct matrix_keymap_data *keymap_data = NULL;
275 u32 rows = 0, cols = 0;
277 bool irq_is_gpio = false;
278 int error, row_shift, max_keys;
280 /* Copy the platform data */
282 if (!pdata->keymap_data) {
283 dev_err(dev, "no keymap data defined\n");
286 keymap_data = pdata->keymap_data;
290 irq_is_gpio = pdata->irq_is_gpio;
292 struct device_node *np = dev->of_node;
293 of_property_read_u32(np, "keypad,num-rows", &rows);
294 of_property_read_u32(np, "keypad,num-columns", &cols);
295 rep = of_property_read_bool(np, "keypad,autorepeat");
298 if (!rows || rows > TCA8418_MAX_ROWS) {
299 dev_err(dev, "invalid rows\n");
303 if (!cols || cols > TCA8418_MAX_COLS) {
304 dev_err(dev, "invalid columns\n");
308 /* Check i2c driver capabilities */
309 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
310 dev_err(dev, "%s adapter not supported\n",
311 dev_driver_string(&client->adapter->dev));
315 row_shift = get_count_order(cols);
316 max_keys = rows << row_shift;
318 /* Allocate memory for keypad_data, keymap and input device */
319 keypad_data = kzalloc(sizeof(*keypad_data) +
320 max_keys * sizeof(keypad_data->keymap[0]), GFP_KERNEL);
324 keypad_data->client = client;
325 keypad_data->row_shift = row_shift;
327 /* Initialize the chip or fail if chip isn't present */
328 error = tca8418_configure(keypad_data, rows, cols);
332 /* Configure input device */
333 input = input_allocate_device();
338 keypad_data->input = input;
340 input->name = client->name;
341 input->dev.parent = &client->dev;
343 input->id.bustype = BUS_I2C;
344 input->id.vendor = 0x0001;
345 input->id.product = 0x001;
346 input->id.version = 0x0001;
348 error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
349 keypad_data->keymap, input);
351 dev_dbg(dev, "Failed to build keymap\n");
356 __set_bit(EV_REP, input->evbit);
357 input_set_capability(input, EV_MSC, MSC_SCAN);
359 input_set_drvdata(input, keypad_data);
362 client->irq = gpio_to_irq(client->irq);
364 error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler,
365 IRQF_TRIGGER_FALLING |
368 client->name, keypad_data);
370 dev_dbg(dev, "Unable to claim irq %d; error %d\n",
375 error = input_register_device(input);
377 dev_dbg(dev, "Unable to register input device, error: %d\n",
382 i2c_set_clientdata(client, keypad_data);
386 free_irq(client->irq, keypad_data);
388 input_free_device(input);
394 static int tca8418_keypad_remove(struct i2c_client *client)
396 struct tca8418_keypad *keypad_data = i2c_get_clientdata(client);
398 free_irq(keypad_data->client->irq, keypad_data);
400 input_unregister_device(keypad_data->input);
407 static const struct i2c_device_id tca8418_id[] = {
408 { TCA8418_NAME, 8418, },
411 MODULE_DEVICE_TABLE(i2c, tca8418_id);
414 static const struct of_device_id tca8418_dt_ids[] __devinitconst = {
415 { .compatible = "ti,tca8418", },
418 MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
421 static struct i2c_driver tca8418_keypad_driver = {
423 .name = TCA8418_NAME,
424 .owner = THIS_MODULE,
425 .of_match_table = of_match_ptr(tca8418_dt_ids),
427 .probe = tca8418_keypad_probe,
428 .remove = tca8418_keypad_remove,
429 .id_table = tca8418_id,
432 static int __init tca8418_keypad_init(void)
434 return i2c_add_driver(&tca8418_keypad_driver);
436 subsys_initcall(tca8418_keypad_init);
438 static void __exit tca8418_keypad_exit(void)
440 i2c_del_driver(&tca8418_keypad_driver);
442 module_exit(tca8418_keypad_exit);
444 MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
445 MODULE_DESCRIPTION("Keypad driver for TCA8418");
446 MODULE_LICENSE("GPL");