1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Driver for keys on TCA6416 I2C IO expander |
4 | * |
5 | * Copyright (C) 2010 Texas Instruments |
6 | * |
7 | * Author : Sriramakrishnan.A.G. <srk@ti.com> |
8 | */ |
9 | |
10 | #include <linux/types.h> |
11 | #include <linux/module.h> |
12 | #include <linux/init.h> |
13 | #include <linux/delay.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/interrupt.h> |
16 | #include <linux/workqueue.h> |
17 | #include <linux/gpio.h> |
18 | #include <linux/i2c.h> |
19 | #include <linux/input.h> |
20 | #include <linux/tca6416_keypad.h> |
21 | |
22 | #define TCA6416_INPUT 0 |
23 | #define TCA6416_OUTPUT 1 |
24 | #define TCA6416_INVERT 2 |
25 | #define TCA6416_DIRECTION 3 |
26 | |
27 | #define TCA6416_POLL_INTERVAL 100 /* msec */ |
28 | |
29 | static const struct i2c_device_id tca6416_id[] = { |
30 | { "tca6416-keys" , 16, }, |
31 | { "tca6408-keys" , 8, }, |
32 | { } |
33 | }; |
34 | MODULE_DEVICE_TABLE(i2c, tca6416_id); |
35 | |
36 | struct tca6416_drv_data { |
37 | struct input_dev *input; |
38 | struct tca6416_button data[]; |
39 | }; |
40 | |
41 | struct tca6416_keypad_chip { |
42 | uint16_t reg_output; |
43 | uint16_t reg_direction; |
44 | uint16_t reg_input; |
45 | |
46 | struct i2c_client *client; |
47 | struct input_dev *input; |
48 | int io_size; |
49 | int irqnum; |
50 | u16 pinmask; |
51 | bool use_polling; |
52 | struct tca6416_button buttons[]; |
53 | }; |
54 | |
55 | static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val) |
56 | { |
57 | int error; |
58 | |
59 | error = chip->io_size > 8 ? |
60 | i2c_smbus_write_word_data(client: chip->client, command: reg << 1, value: val) : |
61 | i2c_smbus_write_byte_data(client: chip->client, command: reg, value: val); |
62 | if (error < 0) { |
63 | dev_err(&chip->client->dev, |
64 | "%s failed, reg: %d, val: %d, error: %d\n" , |
65 | __func__, reg, val, error); |
66 | return error; |
67 | } |
68 | |
69 | return 0; |
70 | } |
71 | |
72 | static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val) |
73 | { |
74 | int retval; |
75 | |
76 | retval = chip->io_size > 8 ? |
77 | i2c_smbus_read_word_data(client: chip->client, command: reg << 1) : |
78 | i2c_smbus_read_byte_data(client: chip->client, command: reg); |
79 | if (retval < 0) { |
80 | dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n" , |
81 | __func__, reg, retval); |
82 | return retval; |
83 | } |
84 | |
85 | *val = (u16)retval; |
86 | return 0; |
87 | } |
88 | |
89 | static void tca6416_keys_scan(struct input_dev *input) |
90 | { |
91 | struct tca6416_keypad_chip *chip = input_get_drvdata(dev: input); |
92 | u16 reg_val, val; |
93 | int error, i, pin_index; |
94 | |
95 | error = tca6416_read_reg(chip, TCA6416_INPUT, val: ®_val); |
96 | if (error) |
97 | return; |
98 | |
99 | reg_val &= chip->pinmask; |
100 | |
101 | /* Figure out which lines have changed */ |
102 | val = reg_val ^ chip->reg_input; |
103 | chip->reg_input = reg_val; |
104 | |
105 | for (i = 0, pin_index = 0; i < 16; i++) { |
106 | if (val & (1 << i)) { |
107 | struct tca6416_button *button = &chip->buttons[pin_index]; |
108 | unsigned int type = button->type ?: EV_KEY; |
109 | int state = ((reg_val & (1 << i)) ? 1 : 0) |
110 | ^ button->active_low; |
111 | |
112 | input_event(dev: input, type, code: button->code, value: !!state); |
113 | input_sync(dev: input); |
114 | } |
115 | |
116 | if (chip->pinmask & (1 << i)) |
117 | pin_index++; |
118 | } |
119 | } |
120 | |
121 | /* |
122 | * This is threaded IRQ handler and this can (and will) sleep. |
123 | */ |
124 | static irqreturn_t tca6416_keys_isr(int irq, void *dev_id) |
125 | { |
126 | tca6416_keys_scan(input: dev_id); |
127 | |
128 | return IRQ_HANDLED; |
129 | } |
130 | |
131 | static int tca6416_keys_open(struct input_dev *dev) |
132 | { |
133 | struct tca6416_keypad_chip *chip = input_get_drvdata(dev); |
134 | |
135 | if (!chip->use_polling) { |
136 | /* Get initial device state in case it has switches */ |
137 | tca6416_keys_scan(input: dev); |
138 | enable_irq(irq: chip->client->irq); |
139 | } |
140 | |
141 | return 0; |
142 | } |
143 | |
144 | static void tca6416_keys_close(struct input_dev *dev) |
145 | { |
146 | struct tca6416_keypad_chip *chip = input_get_drvdata(dev); |
147 | |
148 | if (!chip->use_polling) |
149 | disable_irq(irq: chip->client->irq); |
150 | } |
151 | |
152 | static int tca6416_setup_registers(struct tca6416_keypad_chip *chip) |
153 | { |
154 | int error; |
155 | |
156 | error = tca6416_read_reg(chip, TCA6416_OUTPUT, val: &chip->reg_output); |
157 | if (error) |
158 | return error; |
159 | |
160 | error = tca6416_read_reg(chip, TCA6416_DIRECTION, val: &chip->reg_direction); |
161 | if (error) |
162 | return error; |
163 | |
164 | /* ensure that keypad pins are set to input */ |
165 | error = tca6416_write_reg(chip, TCA6416_DIRECTION, |
166 | val: chip->reg_direction | chip->pinmask); |
167 | if (error) |
168 | return error; |
169 | |
170 | error = tca6416_read_reg(chip, TCA6416_DIRECTION, val: &chip->reg_direction); |
171 | if (error) |
172 | return error; |
173 | |
174 | error = tca6416_read_reg(chip, TCA6416_INPUT, val: &chip->reg_input); |
175 | if (error) |
176 | return error; |
177 | |
178 | chip->reg_input &= chip->pinmask; |
179 | |
180 | return 0; |
181 | } |
182 | |
183 | static int tca6416_keypad_probe(struct i2c_client *client) |
184 | { |
185 | const struct i2c_device_id *id = i2c_client_get_device_id(client); |
186 | struct tca6416_keys_platform_data *pdata; |
187 | struct tca6416_keypad_chip *chip; |
188 | struct input_dev *input; |
189 | int error; |
190 | int i; |
191 | |
192 | /* Check functionality */ |
193 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_BYTE)) { |
194 | dev_err(&client->dev, "%s adapter not supported\n" , |
195 | dev_driver_string(&client->adapter->dev)); |
196 | return -ENODEV; |
197 | } |
198 | |
199 | pdata = dev_get_platdata(dev: &client->dev); |
200 | if (!pdata) { |
201 | dev_dbg(&client->dev, "no platform data\n" ); |
202 | return -EINVAL; |
203 | } |
204 | |
205 | chip = devm_kzalloc(dev: &client->dev, |
206 | struct_size(chip, buttons, pdata->nbuttons), |
207 | GFP_KERNEL); |
208 | if (!chip) |
209 | return -ENOMEM; |
210 | |
211 | input = devm_input_allocate_device(&client->dev); |
212 | if (!input) |
213 | return -ENOMEM; |
214 | |
215 | chip->client = client; |
216 | chip->input = input; |
217 | chip->io_size = id->driver_data; |
218 | chip->pinmask = pdata->pinmask; |
219 | chip->use_polling = pdata->use_polling; |
220 | |
221 | input->phys = "tca6416-keys/input0" ; |
222 | input->name = client->name; |
223 | |
224 | input->open = tca6416_keys_open; |
225 | input->close = tca6416_keys_close; |
226 | |
227 | input->id.bustype = BUS_HOST; |
228 | input->id.vendor = 0x0001; |
229 | input->id.product = 0x0001; |
230 | input->id.version = 0x0100; |
231 | |
232 | /* Enable auto repeat feature of Linux input subsystem */ |
233 | if (pdata->rep) |
234 | __set_bit(EV_REP, input->evbit); |
235 | |
236 | for (i = 0; i < pdata->nbuttons; i++) { |
237 | unsigned int type; |
238 | |
239 | chip->buttons[i] = pdata->buttons[i]; |
240 | type = (pdata->buttons[i].type) ?: EV_KEY; |
241 | input_set_capability(dev: input, type, code: pdata->buttons[i].code); |
242 | } |
243 | |
244 | input_set_drvdata(dev: input, data: chip); |
245 | |
246 | /* |
247 | * Initialize cached registers from their original values. |
248 | * we can't share this chip with another i2c master. |
249 | */ |
250 | error = tca6416_setup_registers(chip); |
251 | if (error) |
252 | return error; |
253 | |
254 | if (chip->use_polling) { |
255 | error = input_setup_polling(dev: input, poll_fn: tca6416_keys_scan); |
256 | if (error) { |
257 | dev_err(&client->dev, "Failed to setup polling\n" ); |
258 | return error; |
259 | } |
260 | |
261 | input_set_poll_interval(dev: input, TCA6416_POLL_INTERVAL); |
262 | } else { |
263 | error = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, |
264 | NULL, thread_fn: tca6416_keys_isr, |
265 | IRQF_TRIGGER_FALLING | |
266 | IRQF_ONESHOT | |
267 | IRQF_NO_AUTOEN, |
268 | devname: "tca6416-keypad" , dev_id: input); |
269 | if (error) { |
270 | dev_dbg(&client->dev, |
271 | "Unable to claim irq %d; error %d\n" , |
272 | client->irq, error); |
273 | return error; |
274 | } |
275 | } |
276 | |
277 | error = input_register_device(input); |
278 | if (error) { |
279 | dev_dbg(&client->dev, |
280 | "Unable to register input device, error: %d\n" , error); |
281 | return error; |
282 | } |
283 | |
284 | i2c_set_clientdata(client, data: chip); |
285 | |
286 | return 0; |
287 | } |
288 | |
289 | static struct i2c_driver tca6416_keypad_driver = { |
290 | .driver = { |
291 | .name = "tca6416-keypad" , |
292 | }, |
293 | .probe = tca6416_keypad_probe, |
294 | .id_table = tca6416_id, |
295 | }; |
296 | |
297 | static int __init tca6416_keypad_init(void) |
298 | { |
299 | return i2c_add_driver(&tca6416_keypad_driver); |
300 | } |
301 | |
302 | subsys_initcall(tca6416_keypad_init); |
303 | |
304 | static void __exit tca6416_keypad_exit(void) |
305 | { |
306 | i2c_del_driver(driver: &tca6416_keypad_driver); |
307 | } |
308 | module_exit(tca6416_keypad_exit); |
309 | |
310 | MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>" ); |
311 | MODULE_DESCRIPTION("Keypad driver over tca6416 IO expander" ); |
312 | MODULE_LICENSE("GPL" ); |
313 | |