aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/i2c/chips/rtc8564.c
blob: dd9d42d7b6e75fa58f43a083bd73822b480b3949 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
/*
 *  linux/drivers/i2c/chips/rtc8564.c
 *
 *  Copyright (C) 2002-2004 Stefan Eletzhofer
 *
 *	based on linux/drivers/acron/char/pcf8583.c
 *  Copyright (C) 2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Driver for system3's EPSON RTC 8564 chip
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/rtc.h>		/* get the user-level API */
#include <linux/init.h>

#include "rtc8564.h"

#ifdef DEBUG
# define _DBG(x, fmt, args...) do{ if (debug>=x) printk(KERN_DEBUG"%s: " fmt "\n", __FUNCTION__, ##args); } while(0);
#else
# define _DBG(x, fmt, args...) do { } while(0);
#endif

#define _DBGRTCTM(x, rtctm) if (debug>=x) printk("%s: secs=%d, mins=%d, hours=%d, mday=%d, " \
			"mon=%d, year=%d, wday=%d VL=%d\n", __FUNCTION__, \
			(rtctm).secs, (rtctm).mins, (rtctm).hours, (rtctm).mday, \
			(rtctm).mon, (rtctm).year, (rtctm).wday, (rtctm).vl);

struct rtc8564_data {
	struct i2c_client client;
	u16 ctrl;
};

static inline u8 _rtc8564_ctrl1(struct i2c_client *client)
{
	struct rtc8564_data *data = i2c_get_clientdata(client);
	return data->ctrl & 0xff;
}
static inline u8 _rtc8564_ctrl2(struct i2c_client *client)
{
	struct rtc8564_data *data = i2c_get_clientdata(client);
	return (data->ctrl & 0xff00) >> 8;
}

#define CTRL1(c) _rtc8564_ctrl1(c)
#define CTRL2(c) _rtc8564_ctrl2(c)

#define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10)
#define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10)

static int debug;;
module_param(debug, int, S_IRUGO | S_IWUSR);

static struct i2c_driver rtc8564_driver;

static unsigned short ignore[] = { I2C_CLIENT_END };
static unsigned short normal_addr[] = { 0x51, I2C_CLIENT_END };

static struct i2c_client_address_data addr_data = {
	.normal_i2c		= normal_addr,
	.probe			= ignore,
	.ignore			= ignore,
};

static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem);
static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem);

static int rtc8564_read(struct i2c_client *client, unsigned char adr,
			unsigned char *buf, unsigned char len)
{
	int ret = -EIO;
	unsigned char addr[1] = { adr };
	struct i2c_msg msgs[2] = {
		{client->addr, 0, 1, addr},
		{client->addr, I2C_M_RD, len, buf}
	};

	_DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, buf, len);

	if (!buf) {
		ret = -EINVAL;
		goto done;
	}

	ret = i2c_transfer(client->adapter, msgs, 2);
	if (ret == 2) {
		ret = 0;
	}

done:
	return ret;
}

static int rtc8564_write(struct i2c_client *client, unsigned char adr,
			 unsigned char *data, unsigned char len)
{
	int ret = 0;
	unsigned char _data[16];
	struct i2c_msg wr;
	int i;

	if (!data || len > 15) {
		ret = -EINVAL;
		goto done;
	}

	_DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, data, len);

	_data[0] = adr;
	for (i = 0; i < len; i++) {
		_data[i + 1] = data[i];
		_DBG(5, "data[%d] = 0x%02x (%d)", i, data[i], data[i]);
	}

	wr.addr = client->addr;
	wr.flags = 0;
	wr.len = len + 1;
	wr.buf = _data;

	ret = i2c_transfer(client->adapter, &wr, 1);
	if (ret == 1) {
		ret = 0;
	}

done:
	return ret;
}

static int rtc8564_attach(struct i2c_adapter *adap, int addr, int kind)
{
	int ret;
	struct i2c_client *new_client;
	struct rtc8564_data *d;
	unsigned char data[10];
	unsigned char ad[1] = { 0 };
	struct i2c_msg ctrl_wr[1] = {
		{addr, 0, 2, data}
	};
	struct i2c_msg ctrl_rd[2] = {
		{addr, 0, 1, ad},
		{addr, I2C_M_RD, 2, data}
	};

	d = kmalloc(sizeof(struct rtc8564_data), GFP_KERNEL);
	if (!d) {
		ret = -ENOMEM;
		goto done;
	}
	memset(d, 0, sizeof(struct rtc8564_data));
	new_client = &d->client;

	strlcpy(new_client->name, "RTC8564", I2C_NAME_SIZE);
	i2c_set_clientdata(new_client, d);
	new_client->flags = I2C_CLIENT_ALLOW_USE;
	new_client->addr = addr;
	new_client->adapter = adap;
	new_client->driver = &rtc8564_driver;

	_DBG(1, "client=%p", new_client);

	/* init ctrl1 reg */
	data[0] = 0;
	data[1] = 0;
	ret = i2c_transfer(new_client->adapter, ctrl_wr, 1);
	if (ret != 1) {
		printk(KERN_INFO "rtc8564: cant init ctrl1\n");
		ret = -ENODEV;
		goto done;
	}

	/* read back ctrl1 and ctrl2 */
	ret = i2c_transfer(new_client->adapter, ctrl_rd, 2);
	if (ret != 2) {
		printk(KERN_INFO "rtc8564: cant read ctrl\n");
		ret = -ENODEV;
		goto done;
	}

	d->ctrl = data[0] | (data[1] << 8);

	_DBG(1, "RTC8564_REG_CTRL1=%02x, RTC8564_REG_CTRL2=%02x",
	     data[0], data[1]);

	ret = i2c_attach_client(new_client);
done:
	if (ret) {
		kfree(d);
	}
	return ret;
}

static int rtc8564_probe(struct i2c_adapter *adap)
{
	return i2c_probe(adap, &addr_data, rtc8564_attach);
}

static int rtc8564_detach(struct i2c_client *client)
{
	i2c_detach_client(client);
	kfree(i2c_get_clientdata(client));
	return 0;
}

static int rtc8564_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
{
	int ret = -EIO;
	unsigned char buf[15];

	_DBG(1, "client=%p, dt=%p", client, dt);

	if (!dt)
		return -EINVAL;

	memset(buf, 0, sizeof(buf));

	ret = rtc8564_read(client, 0, buf, 15);
	if (ret)
		return ret;

	/* century stored in minute alarm reg */
	dt->year = BCD_TO_BIN(buf[RTC8564_REG_YEAR]);
	dt->year += 100 * BCD_TO_BIN(buf[RTC8564_REG_AL_MIN] & 0x3f);
	dt->mday = BCD_TO_BIN(buf[RTC8564_REG_DAY] & 0x3f);
	dt->wday = BCD_TO_BIN(buf[RTC8564_REG_WDAY] & 7);
	dt->mon = BCD_TO_BIN(buf[RTC8564_REG_MON_CENT] & 0x1f);

	dt->secs = BCD_TO_BIN(buf[RTC8564_REG_SEC] & 0x7f);
	dt->vl = (buf[RTC8564_REG_SEC] & 0x80) == 0x80;
	dt->mins = BCD_TO_BIN(buf[RTC8564_REG_MIN] & 0x7f);
	dt->hours = BCD_TO_BIN(buf[RTC8564_REG_HR] & 0x3f);

	_DBGRTCTM(2, *dt);

	return 0;
}

static int
rtc8564_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
{
	int ret, len = 5;
	unsigned char buf[15];

	_DBG(1, "client=%p, dt=%p", client, dt);

	if (!dt)
		return -EINVAL;

	_DBGRTCTM(2, *dt);

	buf[RTC8564_REG_CTRL1] = CTRL1(client) | RTC8564_CTRL1_STOP;
	buf[RTC8564_REG_CTRL2] = CTRL2(client);
	buf[RTC8564_REG_SEC] = BIN_TO_BCD(dt->secs);
	buf[RTC8564_REG_MIN] = BIN_TO_BCD(dt->mins);
	buf[RTC8564_REG_HR] = BIN_TO_BCD(dt->hours);

	if (datetoo) {
		len += 5;
		buf[RTC8564_REG_DAY] = BIN_TO_BCD(dt->mday);
		buf[RTC8564_REG_WDAY] = BIN_TO_BCD(dt->wday);
		buf[RTC8564_REG_MON_CENT] = BIN_TO_BCD(dt->mon) & 0x1f;
		/* century stored in minute alarm reg */
		buf[RTC8564_REG_YEAR] = BIN_TO_BCD(dt->year % 100);
		buf[RTC8564_REG_AL_MIN] = BIN_TO_BCD(dt->year / 100);
	}

	ret = rtc8564_write(client, 0, buf, len);
	if (ret) {
		_DBG(1, "error writing data! %d", ret);
	}

	buf[RTC8564_REG_CTRL1] = CTRL1(client);
	ret = rtc8564_write(client, 0, buf, 1);
	if (ret) {
		_DBG(1, "error writing data! %d", ret);
	}

	return ret;
}

static int rtc8564_get_ctrl(struct i2c_client *client, unsigned int *ctrl)
{
	struct rtc8564_data *data = i2c_get_clientdata(client);

	if (!ctrl)
		return -1;

	*ctrl = data->ctrl;
	return 0;
}

static int rtc8564_set_ctrl(struct i2c_client *client, unsigned int *ctrl)
{
	struct rtc8564_data *data = i2c_get_clientdata(client);
	unsigned char buf[2];

	if (!ctrl)
		return -1;

	buf[0] = *ctrl & 0xff;
	buf[1] = (*ctrl & 0xff00) >> 8;
	data->ctrl = *ctrl;

	return rtc8564_write(client, 0, buf, 2);
}

static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem)
{

	if (!mem)
		return -EINVAL;

	return rtc8564_read(client, mem->loc, mem->data, mem->nr);
}

static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem)
{

	if (!mem)
		return -EINVAL;

	return rtc8564_write(client, mem->loc, mem->data, mem->nr);
}

static int
rtc8564_command(struct i2c_client *client, unsigned int cmd, void *arg)
{

	_DBG(1, "cmd=%d", cmd);

	switch (cmd) {
	case RTC_GETDATETIME:
		return rtc8564_get_datetime(client, arg);

	case RTC_SETTIME:
		return rtc8564_set_datetime(client, arg, 0);

	case RTC_SETDATETIME:
		return rtc8564_set_datetime(client, arg, 1);

	case RTC_GETCTRL:
		return rtc8564_get_ctrl(client, arg);

	case RTC_SETCTRL:
		return rtc8564_set_ctrl(client, arg);

	case MEM_READ:
		return rtc8564_read_mem(client, arg);

	case MEM_WRITE:
		return rtc8564_write_mem(client, arg);

	default:
		return -EINVAL;
	}
}

static struct i2c_driver rtc8564_driver = {
	.owner		= THIS_MODULE,
	.name		= "RTC8564",
	.id		= I2C_DRIVERID_RTC8564,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter = rtc8564_probe,
	.detach_client	= rtc8564_detach,
	.command	= rtc8564_command
};

static __init int rtc8564_init(void)
{
	return i2c_add_driver(&rtc8564_driver);
}

static __exit void rtc8564_exit(void)
{
	i2c_del_driver(&rtc8564_driver);
}

MODULE_AUTHOR("Stefan Eletzhofer <Stefan.Eletzhofer@eletztrick.de>");
MODULE_DESCRIPTION("EPSON RTC8564 Driver");
MODULE_LICENSE("GPL");

module_init(rtc8564_init);
module_exit(rtc8564_exit);