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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
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
