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Wolfram Sang0bf25a42012-04-03 13:39:44 -07001/*
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
Wolfram Sang0bf25a42012-04-03 13:39:44 -070032#define LM8333_NUM_ROWS 8
Dmitry Torokhov19328112012-05-10 22:37:08 -070033#define LM8333_NUM_COLS 16
34#define LM8333_ROW_SHIFT 4
Wolfram Sang0bf25a42012-04-03 13:39:44 -070035
36struct 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
45int 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
56int 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
67int 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
79static 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
Alan Cox954bd6d2012-06-27 12:02:07 +010094 for (i = 0; i < LM8333_FIFO_TRANSFER_SIZE && keys[i]; i++) {
Wolfram Sang0bf25a42012-04-03 13:39:44 -070095 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
105static 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
131static 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
Wolfram Sang0bf25a42012-04-03 13:39:44 -0700162 input_set_capability(input, EV_MSC, MSC_SCAN);
163
Dmitry Torokhov19328112012-05-10 22:37:08 -0700164 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;
Wolfram Sang0bf25a42012-04-03 13:39:44 -0700169
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
205static 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
216static const struct i2c_device_id lm8333_id[] = {
217 { "lm8333", 0 },
218 { }
219};
220MODULE_DEVICE_TABLE(i2c, lm8333_id);
221
222static struct i2c_driver lm8333_driver = {
223 .driver = {
224 .name = "lm8333",
225 .owner = THIS_MODULE,
226 },
227 .probe = lm8333_probe,
Bill Pemberton1cb0aa82012-11-23 21:27:39 -0800228 .remove = lm8333_remove,
Wolfram Sang0bf25a42012-04-03 13:39:44 -0700229 .id_table = lm8333_id,
230};
231module_i2c_driver(lm8333_driver);
232
233MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
234MODULE_DESCRIPTION("LM8333 keyboard driver");
235MODULE_LICENSE("GPL v2");