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/i2c.h>
8 #include <linux/input.h>
9 #include <linux/input/matrix_keypad.h>
10 #include <linux/input/lm8333.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/slab.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
33 struct 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
lm8333_read8(struct lm8333 * lm8333,u8 cmd)42 int 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
lm8333_write8(struct lm8333 * lm8333,u8 cmd,u8 val)53 int 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
lm8333_read_block(struct lm8333 * lm8333,u8 cmd,u8 len,u8 * buf)64 int 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
lm8333_key_handler(struct lm8333 * lm8333)76 static 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
lm8333_irq_thread(int irq,void * data)102 static 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
lm8333_probe(struct i2c_client * client)128 static int lm8333_probe(struct i2c_client *client)
129 {
130 const struct lm8333_platform_data *pdata =
131 dev_get_platdata(&client->dev);
132 struct lm8333 *lm8333;
133 struct input_dev *input;
134 int err, active_time;
135
136 if (!pdata)
137 return -EINVAL;
138
139 active_time = pdata->active_time ?: 500;
140 if (active_time / 3 <= pdata->debounce_time / 3) {
141 dev_err(&client->dev, "Active time not big enough!\n");
142 return -EINVAL;
143 }
144
145 lm8333 = devm_kzalloc(&client->dev, sizeof(*lm8333), GFP_KERNEL);
146 if (!lm8333)
147 return -ENOMEM;
148
149 input = devm_input_allocate_device(&client->dev);
150 if (!input)
151 return -ENOMEM;
152
153 lm8333->client = client;
154 lm8333->input = input;
155
156 input->name = client->name;
157 input->id.bustype = BUS_I2C;
158
159 input_set_capability(input, EV_MSC, MSC_SCAN);
160
161 err = matrix_keypad_build_keymap(pdata->matrix_data, NULL,
162 LM8333_NUM_ROWS, LM8333_NUM_COLS,
163 lm8333->keycodes, input);
164 if (err)
165 return err;
166
167 if (pdata->debounce_time) {
168 err = lm8333_write8(lm8333, LM8333_DEBOUNCE,
169 pdata->debounce_time / 3);
170 if (err)
171 dev_warn(&client->dev, "Unable to set debounce time\n");
172 }
173
174 if (pdata->active_time) {
175 err = lm8333_write8(lm8333, LM8333_ACTIVE,
176 pdata->active_time / 3);
177 if (err)
178 dev_warn(&client->dev, "Unable to set active time\n");
179 }
180
181 err = devm_request_threaded_irq(&client->dev, client->irq,
182 NULL, lm8333_irq_thread,
183 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
184 "lm8333", lm8333);
185 if (err)
186 return err;
187
188 err = input_register_device(input);
189 if (err)
190 return err;
191
192 i2c_set_clientdata(client, lm8333);
193 return 0;
194 }
195
196 static const struct i2c_device_id lm8333_id[] = {
197 { "lm8333", 0 },
198 { }
199 };
200 MODULE_DEVICE_TABLE(i2c, lm8333_id);
201
202 static struct i2c_driver lm8333_driver = {
203 .driver = {
204 .name = "lm8333",
205 },
206 .probe = lm8333_probe,
207 .id_table = lm8333_id,
208 };
209 module_i2c_driver(lm8333_driver);
210
211 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
212 MODULE_DESCRIPTION("LM8333 keyboard driver");
213 MODULE_LICENSE("GPL v2");
214