1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LM8333 keypad driver
4 * Copyright (C) 2012 Wolfram Sang, Pengutronix <kernel@pengutronix.de>
5 */
6
7#include <linux/module.h>
8#include <linux/slab.h>
9#include <linux/irq.h>
10#include <linux/i2c.h>
11#include <linux/interrupt.h>
12#include <linux/input/matrix_keypad.h>
13#include <linux/input/lm8333.h>
14
15#define LM8333_FIFO_READ		0x20
16#define LM8333_DEBOUNCE			0x22
17#define LM8333_READ_INT			0xD0
18#define LM8333_ACTIVE			0xE4
19#define LM8333_READ_ERROR		0xF0
20
21#define LM8333_KEYPAD_IRQ		(1 << 0)
22#define LM8333_ERROR_IRQ		(1 << 3)
23
24#define LM8333_ERROR_KEYOVR		0x04
25#define LM8333_ERROR_FIFOOVR		0x40
26
27#define LM8333_FIFO_TRANSFER_SIZE	16
28
29#define LM8333_NUM_ROWS		8
30#define LM8333_NUM_COLS		16
31#define LM8333_ROW_SHIFT	4
32
33struct lm8333 {
34	struct i2c_client *client;
35	struct input_dev *input;
36	unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT];
37};
38
39/* The accessors try twice because the first access may be needed for wakeup */
40#define LM8333_READ_RETRIES 2
41
42int lm8333_read8(struct lm8333 *lm8333, u8 cmd)
43{
44	int retries = 0, ret;
45
46	do {
47		ret = i2c_smbus_read_byte_data(lm8333->client, cmd);
48	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
49
50	return ret;
51}
52
53int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val)
54{
55	int retries = 0, ret;
56
57	do {
58		ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val);
59	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
60
61	return ret;
62}
63
64int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf)
65{
66	int retries = 0, ret;
67
68	do {
69		ret = i2c_smbus_read_i2c_block_data(lm8333->client,
70						    cmd, len, buf);
71	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
72
73	return ret;
74}
75
76static void lm8333_key_handler(struct lm8333 *lm8333)
77{
78	struct input_dev *input = lm8333->input;
79	u8 keys[LM8333_FIFO_TRANSFER_SIZE];
80	u8 code, pressed;
81	int i, ret;
82
83	ret = lm8333_read_block(lm8333, LM8333_FIFO_READ,
84				LM8333_FIFO_TRANSFER_SIZE, keys);
85	if (ret != LM8333_FIFO_TRANSFER_SIZE) {
86		dev_err(&lm8333->client->dev,
87			"Error %d while reading FIFO\n", ret);
88		return;
89	}
90
91	for (i = 0; i < LM8333_FIFO_TRANSFER_SIZE && keys[i]; i++) {
92		pressed = keys[i] & 0x80;
93		code = keys[i] & 0x7f;
94
95		input_event(input, EV_MSC, MSC_SCAN, code);
96		input_report_key(input, lm8333->keycodes[code], pressed);
97	}
98
99	input_sync(input);
100}
101
102static irqreturn_t lm8333_irq_thread(int irq, void *data)
103{
104	struct lm8333 *lm8333 = data;
105	u8 status = lm8333_read8(lm8333, LM8333_READ_INT);
106
107	if (!status)
108		return IRQ_NONE;
109
110	if (status & LM8333_ERROR_IRQ) {
111		u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR);
112
113		if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) {
114			u8 dummy[LM8333_FIFO_TRANSFER_SIZE];
115
116			lm8333_read_block(lm8333, LM8333_FIFO_READ,
117					LM8333_FIFO_TRANSFER_SIZE, dummy);
118		}
119		dev_err(&lm8333->client->dev, "Got error %02x\n", err);
120	}
121
122	if (status & LM8333_KEYPAD_IRQ)
123		lm8333_key_handler(lm8333);
124
125	return IRQ_HANDLED;
126}
127
128static int lm8333_probe(struct i2c_client *client,
129				  const struct i2c_device_id *id)
130{
131	const struct lm8333_platform_data *pdata =
132			dev_get_platdata(&client->dev);
133	struct lm8333 *lm8333;
134	struct input_dev *input;
135	int err, active_time;
136
137	if (!pdata)
138		return -EINVAL;
139
140	active_time = pdata->active_time ?: 500;
141	if (active_time / 3 <= pdata->debounce_time / 3) {
142		dev_err(&client->dev, "Active time not big enough!\n");
143		return -EINVAL;
144	}
145
146	lm8333 = kzalloc(sizeof(*lm8333), GFP_KERNEL);
147	input = input_allocate_device();
148	if (!lm8333 || !input) {
149		err = -ENOMEM;
150		goto free_mem;
151	}
152
153	lm8333->client = client;
154	lm8333->input = input;
155
156	input->name = client->name;
157	input->dev.parent = &client->dev;
158	input->id.bustype = BUS_I2C;
159
160	input_set_capability(input, EV_MSC, MSC_SCAN);
161
162	err = matrix_keypad_build_keymap(pdata->matrix_data, NULL,
163					 LM8333_NUM_ROWS, LM8333_NUM_COLS,
164					 lm8333->keycodes, input);
165	if (err)
166		goto free_mem;
167
168	if (pdata->debounce_time) {
169		err = lm8333_write8(lm8333, LM8333_DEBOUNCE,
170				    pdata->debounce_time / 3);
171		if (err)
172			dev_warn(&client->dev, "Unable to set debounce time\n");
173	}
174
175	if (pdata->active_time) {
176		err = lm8333_write8(lm8333, LM8333_ACTIVE,
177				    pdata->active_time / 3);
178		if (err)
179			dev_warn(&client->dev, "Unable to set active time\n");
180	}
181
182	err = request_threaded_irq(client->irq, NULL, lm8333_irq_thread,
183				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
184				   "lm8333", lm8333);
185	if (err)
186		goto free_mem;
187
188	err = input_register_device(input);
189	if (err)
190		goto free_irq;
191
192	i2c_set_clientdata(client, lm8333);
193	return 0;
194
195 free_irq:
196	free_irq(client->irq, lm8333);
197 free_mem:
198	input_free_device(input);
199	kfree(lm8333);
200	return err;
201}
202
203static int lm8333_remove(struct i2c_client *client)
204{
205	struct lm8333 *lm8333 = i2c_get_clientdata(client);
206
207	free_irq(client->irq, lm8333);
208	input_unregister_device(lm8333->input);
209	kfree(lm8333);
210
211	return 0;
212}
213
214static const struct i2c_device_id lm8333_id[] = {
215	{ "lm8333", 0 },
216	{ }
217};
218MODULE_DEVICE_TABLE(i2c, lm8333_id);
219
220static struct i2c_driver lm8333_driver = {
221	.driver = {
222		.name		= "lm8333",
223	},
224	.probe		= lm8333_probe,
225	.remove		= lm8333_remove,
226	.id_table	= lm8333_id,
227};
228module_i2c_driver(lm8333_driver);
229
230MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
231MODULE_DESCRIPTION("LM8333 keyboard driver");
232MODULE_LICENSE("GPL v2");
233