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 | |
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(client: lm8333->client, command: cmd); |
48 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); |
49 | |
50 | return ret; |
51 | } |
52 | |
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(client: lm8333->client, command: cmd, value: val); |
59 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); |
60 | |
61 | return ret; |
62 | } |
63 | |
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(client: lm8333->client, |
70 | command: cmd, length: len, values: buf); |
71 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); |
72 | |
73 | return ret; |
74 | } |
75 | |
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, buf: 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(dev: input, EV_MSC, MSC_SCAN, value: code); |
96 | input_report_key(dev: input, code: lm8333->keycodes[code], value: pressed); |
97 | } |
98 | |
99 | input_sync(dev: input); |
100 | } |
101 | |
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, buf: 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 | |
128 | static int lm8333_probe(struct i2c_client *client) |
129 | { |
130 | const struct lm8333_platform_data *pdata = |
131 | dev_get_platdata(dev: &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(dev: &client->dev, size: 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(dev: input, EV_MSC, MSC_SCAN); |
160 | |
161 | err = matrix_keypad_build_keymap(keymap_data: pdata->matrix_data, NULL, |
162 | LM8333_NUM_ROWS, LM8333_NUM_COLS, |
163 | keymap: lm8333->keycodes, input_dev: input); |
164 | if (err) |
165 | return err; |
166 | |
167 | if (pdata->debounce_time) { |
168 | err = lm8333_write8(lm8333, LM8333_DEBOUNCE, |
169 | val: 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 | val: 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(dev: &client->dev, irq: client->irq, |
182 | NULL, thread_fn: lm8333_irq_thread, |
183 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
184 | devname: "lm8333" , dev_id: 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, data: 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 | |