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0bf25a45 WS |
1 | /* |
2 | * LM8333 keypad driver | |
3 | * Copyright (C) 2012 Wolfram Sang, Pengutronix <w.sang@pengutronix.de> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License. | |
8 | */ | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/irq.h> | |
13 | #include <linux/i2c.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/input/matrix_keypad.h> | |
16 | #include <linux/input/lm8333.h> | |
17 | ||
18 | #define LM8333_FIFO_READ 0x20 | |
19 | #define LM8333_DEBOUNCE 0x22 | |
20 | #define LM8333_READ_INT 0xD0 | |
21 | #define LM8333_ACTIVE 0xE4 | |
22 | #define LM8333_READ_ERROR 0xF0 | |
23 | ||
24 | #define LM8333_KEYPAD_IRQ (1 << 0) | |
25 | #define LM8333_ERROR_IRQ (1 << 3) | |
26 | ||
27 | #define LM8333_ERROR_KEYOVR 0x04 | |
28 | #define LM8333_ERROR_FIFOOVR 0x40 | |
29 | ||
30 | #define LM8333_FIFO_TRANSFER_SIZE 16 | |
31 | ||
0bf25a45 | 32 | #define LM8333_NUM_ROWS 8 |
1932811f DT |
33 | #define LM8333_NUM_COLS 16 |
34 | #define LM8333_ROW_SHIFT 4 | |
0bf25a45 WS |
35 | |
36 | struct lm8333 { | |
37 | struct i2c_client *client; | |
38 | struct input_dev *input; | |
39 | unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT]; | |
40 | }; | |
41 | ||
42 | /* The accessors try twice because the first access may be needed for wakeup */ | |
43 | #define LM8333_READ_RETRIES 2 | |
44 | ||
45 | int lm8333_read8(struct lm8333 *lm8333, u8 cmd) | |
46 | { | |
47 | int retries = 0, ret; | |
48 | ||
49 | do { | |
50 | ret = i2c_smbus_read_byte_data(lm8333->client, cmd); | |
51 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); | |
52 | ||
53 | return ret; | |
54 | } | |
55 | ||
56 | int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val) | |
57 | { | |
58 | int retries = 0, ret; | |
59 | ||
60 | do { | |
61 | ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val); | |
62 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); | |
63 | ||
64 | return ret; | |
65 | } | |
66 | ||
67 | int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf) | |
68 | { | |
69 | int retries = 0, ret; | |
70 | ||
71 | do { | |
72 | ret = i2c_smbus_read_i2c_block_data(lm8333->client, | |
73 | cmd, len, buf); | |
74 | } while (ret < 0 && retries++ < LM8333_READ_RETRIES); | |
75 | ||
76 | return ret; | |
77 | } | |
78 | ||
79 | static void lm8333_key_handler(struct lm8333 *lm8333) | |
80 | { | |
81 | struct input_dev *input = lm8333->input; | |
82 | u8 keys[LM8333_FIFO_TRANSFER_SIZE]; | |
83 | u8 code, pressed; | |
84 | int i, ret; | |
85 | ||
86 | ret = lm8333_read_block(lm8333, LM8333_FIFO_READ, | |
87 | LM8333_FIFO_TRANSFER_SIZE, keys); | |
88 | if (ret != LM8333_FIFO_TRANSFER_SIZE) { | |
89 | dev_err(&lm8333->client->dev, | |
90 | "Error %d while reading FIFO\n", ret); | |
91 | return; | |
92 | } | |
93 | ||
954bd6d1 | 94 | for (i = 0; i < LM8333_FIFO_TRANSFER_SIZE && keys[i]; i++) { |
0bf25a45 WS |
95 | pressed = keys[i] & 0x80; |
96 | code = keys[i] & 0x7f; | |
97 | ||
98 | input_event(input, EV_MSC, MSC_SCAN, code); | |
99 | input_report_key(input, lm8333->keycodes[code], pressed); | |
100 | } | |
101 | ||
102 | input_sync(input); | |
103 | } | |
104 | ||
105 | static irqreturn_t lm8333_irq_thread(int irq, void *data) | |
106 | { | |
107 | struct lm8333 *lm8333 = data; | |
108 | u8 status = lm8333_read8(lm8333, LM8333_READ_INT); | |
109 | ||
110 | if (!status) | |
111 | return IRQ_NONE; | |
112 | ||
113 | if (status & LM8333_ERROR_IRQ) { | |
114 | u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR); | |
115 | ||
116 | if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) { | |
117 | u8 dummy[LM8333_FIFO_TRANSFER_SIZE]; | |
118 | ||
119 | lm8333_read_block(lm8333, LM8333_FIFO_READ, | |
120 | LM8333_FIFO_TRANSFER_SIZE, dummy); | |
121 | } | |
122 | dev_err(&lm8333->client->dev, "Got error %02x\n", err); | |
123 | } | |
124 | ||
125 | if (status & LM8333_KEYPAD_IRQ) | |
126 | lm8333_key_handler(lm8333); | |
127 | ||
128 | return IRQ_HANDLED; | |
129 | } | |
130 | ||
131 | static int __devinit lm8333_probe(struct i2c_client *client, | |
132 | const struct i2c_device_id *id) | |
133 | { | |
134 | const struct lm8333_platform_data *pdata = client->dev.platform_data; | |
135 | struct lm8333 *lm8333; | |
136 | struct input_dev *input; | |
137 | int err, active_time; | |
138 | ||
139 | if (!pdata) | |
140 | return -EINVAL; | |
141 | ||
142 | active_time = pdata->active_time ?: 500; | |
143 | if (active_time / 3 <= pdata->debounce_time / 3) { | |
144 | dev_err(&client->dev, "Active time not big enough!\n"); | |
145 | return -EINVAL; | |
146 | } | |
147 | ||
148 | lm8333 = kzalloc(sizeof(*lm8333), GFP_KERNEL); | |
149 | input = input_allocate_device(); | |
150 | if (!lm8333 || !input) { | |
151 | err = -ENOMEM; | |
152 | goto free_mem; | |
153 | } | |
154 | ||
155 | lm8333->client = client; | |
156 | lm8333->input = input; | |
157 | ||
158 | input->name = client->name; | |
159 | input->dev.parent = &client->dev; | |
160 | input->id.bustype = BUS_I2C; | |
161 | ||
0bf25a45 WS |
162 | input_set_capability(input, EV_MSC, MSC_SCAN); |
163 | ||
1932811f DT |
164 | err = matrix_keypad_build_keymap(pdata->matrix_data, NULL, |
165 | LM8333_NUM_ROWS, LM8333_NUM_COLS, | |
166 | lm8333->keycodes, input); | |
167 | if (err) | |
168 | goto free_mem; | |
0bf25a45 WS |
169 | |
170 | if (pdata->debounce_time) { | |
171 | err = lm8333_write8(lm8333, LM8333_DEBOUNCE, | |
172 | pdata->debounce_time / 3); | |
173 | if (err) | |
174 | dev_warn(&client->dev, "Unable to set debounce time\n"); | |
175 | } | |
176 | ||
177 | if (pdata->active_time) { | |
178 | err = lm8333_write8(lm8333, LM8333_ACTIVE, | |
179 | pdata->active_time / 3); | |
180 | if (err) | |
181 | dev_warn(&client->dev, "Unable to set active time\n"); | |
182 | } | |
183 | ||
184 | err = request_threaded_irq(client->irq, NULL, lm8333_irq_thread, | |
185 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, | |
186 | "lm8333", lm8333); | |
187 | if (err) | |
188 | goto free_mem; | |
189 | ||
190 | err = input_register_device(input); | |
191 | if (err) | |
192 | goto free_irq; | |
193 | ||
194 | i2c_set_clientdata(client, lm8333); | |
195 | return 0; | |
196 | ||
197 | free_irq: | |
198 | free_irq(client->irq, lm8333); | |
199 | free_mem: | |
200 | input_free_device(input); | |
201 | kfree(lm8333); | |
202 | return err; | |
203 | } | |
204 | ||
205 | static int __devexit lm8333_remove(struct i2c_client *client) | |
206 | { | |
207 | struct lm8333 *lm8333 = i2c_get_clientdata(client); | |
208 | ||
209 | free_irq(client->irq, lm8333); | |
210 | input_unregister_device(lm8333->input); | |
211 | kfree(lm8333); | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
216 | static const struct i2c_device_id lm8333_id[] = { | |
217 | { "lm8333", 0 }, | |
218 | { } | |
219 | }; | |
220 | MODULE_DEVICE_TABLE(i2c, lm8333_id); | |
221 | ||
222 | static struct i2c_driver lm8333_driver = { | |
223 | .driver = { | |
224 | .name = "lm8333", | |
225 | .owner = THIS_MODULE, | |
226 | }, | |
227 | .probe = lm8333_probe, | |
228 | .remove = __devexit_p(lm8333_remove), | |
229 | .id_table = lm8333_id, | |
230 | }; | |
231 | module_i2c_driver(lm8333_driver); | |
232 | ||
233 | MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); | |
234 | MODULE_DESCRIPTION("LM8333 keyboard driver"); | |
235 | MODULE_LICENSE("GPL v2"); |