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