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path: root/drivers/i2c/chips/ds1337.c
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Diffstat (limited to 'drivers/i2c/chips/ds1337.c')
-rw-r--r--drivers/i2c/chips/ds1337.c410
1 files changed, 0 insertions, 410 deletions
diff --git a/drivers/i2c/chips/ds1337.c b/drivers/i2c/chips/ds1337.c
deleted file mode 100644
index ec17d6b684a2..000000000000
--- a/drivers/i2c/chips/ds1337.c
+++ /dev/null
@@ -1,410 +0,0 @@
1/*
2 * linux/drivers/i2c/chips/ds1337.c
3 *
4 * Copyright (C) 2005 James Chapman <jchapman@katalix.com>
5 *
6 * based on linux/drivers/acorn/char/pcf8583.c
7 * Copyright (C) 2000 Russell King
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * Driver for Dallas Semiconductor DS1337 and DS1339 real time clock chip
14 */
15
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/i2c.h>
20#include <linux/string.h>
21#include <linux/rtc.h> /* get the user-level API */
22#include <linux/bcd.h>
23#include <linux/list.h>
24
25/* Device registers */
26#define DS1337_REG_HOUR 2
27#define DS1337_REG_DAY 3
28#define DS1337_REG_DATE 4
29#define DS1337_REG_MONTH 5
30#define DS1337_REG_CONTROL 14
31#define DS1337_REG_STATUS 15
32
33/* FIXME - how do we export these interface constants? */
34#define DS1337_GET_DATE 0
35#define DS1337_SET_DATE 1
36
37/*
38 * Functions declaration
39 */
40static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };
41
42I2C_CLIENT_INSMOD_1(ds1337);
43
44static int ds1337_attach_adapter(struct i2c_adapter *adapter);
45static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind);
46static void ds1337_init_client(struct i2c_client *client);
47static int ds1337_detach_client(struct i2c_client *client);
48static int ds1337_command(struct i2c_client *client, unsigned int cmd,
49 void *arg);
50
51/*
52 * Driver data (common to all clients)
53 */
54static struct i2c_driver ds1337_driver = {
55 .driver = {
56 .name = "ds1337",
57 },
58 .attach_adapter = ds1337_attach_adapter,
59 .detach_client = ds1337_detach_client,
60 .command = ds1337_command,
61};
62
63/*
64 * Client data (each client gets its own)
65 */
66struct ds1337_data {
67 struct i2c_client client;
68 struct list_head list;
69};
70
71/*
72 * Internal variables
73 */
74static LIST_HEAD(ds1337_clients);
75
76static inline int ds1337_read(struct i2c_client *client, u8 reg, u8 *value)
77{
78 s32 tmp = i2c_smbus_read_byte_data(client, reg);
79
80 if (tmp < 0)
81 return -EIO;
82
83 *value = tmp;
84
85 return 0;
86}
87
88/*
89 * Chip access functions
90 */
91static int ds1337_get_datetime(struct i2c_client *client, struct rtc_time *dt)
92{
93 int result;
94 u8 buf[7];
95 u8 val;
96 struct i2c_msg msg[2];
97 u8 offs = 0;
98
99 if (!dt) {
100 dev_dbg(&client->dev, "%s: EINVAL: dt=NULL\n", __FUNCTION__);
101 return -EINVAL;
102 }
103
104 msg[0].addr = client->addr;
105 msg[0].flags = 0;
106 msg[0].len = 1;
107 msg[0].buf = &offs;
108
109 msg[1].addr = client->addr;
110 msg[1].flags = I2C_M_RD;
111 msg[1].len = sizeof(buf);
112 msg[1].buf = &buf[0];
113
114 result = i2c_transfer(client->adapter, msg, 2);
115
116 dev_dbg(&client->dev, "%s: [%d] %02x %02x %02x %02x %02x %02x %02x\n",
117 __FUNCTION__, result, buf[0], buf[1], buf[2], buf[3],
118 buf[4], buf[5], buf[6]);
119
120 if (result == 2) {
121 dt->tm_sec = BCD2BIN(buf[0]);
122 dt->tm_min = BCD2BIN(buf[1]);
123 val = buf[2] & 0x3f;
124 dt->tm_hour = BCD2BIN(val);
125 dt->tm_wday = BCD2BIN(buf[3]) - 1;
126 dt->tm_mday = BCD2BIN(buf[4]);
127 val = buf[5] & 0x7f;
128 dt->tm_mon = BCD2BIN(val) - 1;
129 dt->tm_year = BCD2BIN(buf[6]);
130 if (buf[5] & 0x80)
131 dt->tm_year += 100;
132
133 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, "
134 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
135 __FUNCTION__, dt->tm_sec, dt->tm_min,
136 dt->tm_hour, dt->tm_mday,
137 dt->tm_mon, dt->tm_year, dt->tm_wday);
138
139 return 0;
140 }
141
142 dev_err(&client->dev, "error reading data! %d\n", result);
143 return -EIO;
144}
145
146static int ds1337_set_datetime(struct i2c_client *client, struct rtc_time *dt)
147{
148 int result;
149 u8 buf[8];
150 u8 val;
151 struct i2c_msg msg[1];
152
153 if (!dt) {
154 dev_dbg(&client->dev, "%s: EINVAL: dt=NULL\n", __FUNCTION__);
155 return -EINVAL;
156 }
157
158 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
159 "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__,
160 dt->tm_sec, dt->tm_min, dt->tm_hour,
161 dt->tm_mday, dt->tm_mon, dt->tm_year, dt->tm_wday);
162
163 buf[0] = 0; /* reg offset */
164 buf[1] = BIN2BCD(dt->tm_sec);
165 buf[2] = BIN2BCD(dt->tm_min);
166 buf[3] = BIN2BCD(dt->tm_hour);
167 buf[4] = BIN2BCD(dt->tm_wday + 1);
168 buf[5] = BIN2BCD(dt->tm_mday);
169 buf[6] = BIN2BCD(dt->tm_mon + 1);
170 val = dt->tm_year;
171 if (val >= 100) {
172 val -= 100;
173 buf[6] |= (1 << 7);
174 }
175 buf[7] = BIN2BCD(val);
176
177 msg[0].addr = client->addr;
178 msg[0].flags = 0;
179 msg[0].len = sizeof(buf);
180 msg[0].buf = &buf[0];
181
182 result = i2c_transfer(client->adapter, msg, 1);
183 if (result == 1)
184 return 0;
185
186 dev_err(&client->dev, "error writing data! %d\n", result);
187 return -EIO;
188}
189
190static int ds1337_command(struct i2c_client *client, unsigned int cmd,
191 void *arg)
192{
193 dev_dbg(&client->dev, "%s: cmd=%d\n", __FUNCTION__, cmd);
194
195 switch (cmd) {
196 case DS1337_GET_DATE:
197 return ds1337_get_datetime(client, arg);
198
199 case DS1337_SET_DATE:
200 return ds1337_set_datetime(client, arg);
201
202 default:
203 return -EINVAL;
204 }
205}
206
207/*
208 * Public API for access to specific device. Useful for low-level
209 * RTC access from kernel code.
210 */
211int ds1337_do_command(int bus, int cmd, void *arg)
212{
213 struct list_head *walk;
214 struct list_head *tmp;
215 struct ds1337_data *data;
216
217 list_for_each_safe(walk, tmp, &ds1337_clients) {
218 data = list_entry(walk, struct ds1337_data, list);
219 if (data->client.adapter->nr == bus)
220 return ds1337_command(&data->client, cmd, arg);
221 }
222
223 return -ENODEV;
224}
225
226static int ds1337_attach_adapter(struct i2c_adapter *adapter)
227{
228 return i2c_probe(adapter, &addr_data, ds1337_detect);
229}
230
231/*
232 * The following function does more than just detection. If detection
233 * succeeds, it also registers the new chip.
234 */
235static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind)
236{
237 struct i2c_client *new_client;
238 struct ds1337_data *data;
239 int err = 0;
240 const char *name = "";
241
242 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
243 I2C_FUNC_I2C))
244 goto exit;
245
246 if (!(data = kzalloc(sizeof(struct ds1337_data), GFP_KERNEL))) {
247 err = -ENOMEM;
248 goto exit;
249 }
250 INIT_LIST_HEAD(&data->list);
251
252 /* The common I2C client data is placed right before the
253 * DS1337-specific data.
254 */
255 new_client = &data->client;
256 i2c_set_clientdata(new_client, data);
257 new_client->addr = address;
258 new_client->adapter = adapter;
259 new_client->driver = &ds1337_driver;
260 new_client->flags = 0;
261
262 /*
263 * Now we do the remaining detection. A negative kind means that
264 * the driver was loaded with no force parameter (default), so we
265 * must both detect and identify the chip. A zero kind means that
266 * the driver was loaded with the force parameter, the detection
267 * step shall be skipped. A positive kind means that the driver
268 * was loaded with the force parameter and a given kind of chip is
269 * requested, so both the detection and the identification steps
270 * are skipped.
271 *
272 * For detection, we read registers that are most likely to cause
273 * detection failure, i.e. those that have more bits with fixed
274 * or reserved values.
275 */
276
277 /* Default to an DS1337 if forced */
278 if (kind == 0)
279 kind = ds1337;
280
281 if (kind < 0) { /* detection and identification */
282 u8 data;
283
284 /* Check that status register bits 6-2 are zero */
285 if ((ds1337_read(new_client, DS1337_REG_STATUS, &data) < 0) ||
286 (data & 0x7c))
287 goto exit_free;
288
289 /* Check for a valid day register value */
290 if ((ds1337_read(new_client, DS1337_REG_DAY, &data) < 0) ||
291 (data == 0) || (data & 0xf8))
292 goto exit_free;
293
294 /* Check for a valid date register value */
295 if ((ds1337_read(new_client, DS1337_REG_DATE, &data) < 0) ||
296 (data == 0) || (data & 0xc0) || ((data & 0x0f) > 9) ||
297 (data >= 0x32))
298 goto exit_free;
299
300 /* Check for a valid month register value */
301 if ((ds1337_read(new_client, DS1337_REG_MONTH, &data) < 0) ||
302 (data == 0) || (data & 0x60) || ((data & 0x0f) > 9) ||
303 ((data >= 0x13) && (data <= 0x19)))
304 goto exit_free;
305
306 /* Check that control register bits 6-5 are zero */
307 if ((ds1337_read(new_client, DS1337_REG_CONTROL, &data) < 0) ||
308 (data & 0x60))
309 goto exit_free;
310
311 kind = ds1337;
312 }
313
314 if (kind == ds1337)
315 name = "ds1337";
316
317 /* We can fill in the remaining client fields */
318 strlcpy(new_client->name, name, I2C_NAME_SIZE);
319
320 /* Tell the I2C layer a new client has arrived */
321 if ((err = i2c_attach_client(new_client)))
322 goto exit_free;
323
324 /* Initialize the DS1337 chip */
325 ds1337_init_client(new_client);
326
327 /* Add client to local list */
328 list_add(&data->list, &ds1337_clients);
329
330 return 0;
331
332exit_free:
333 kfree(data);
334exit:
335 return err;
336}
337
338static void ds1337_init_client(struct i2c_client *client)
339{
340 u8 status, control;
341
342 /* On some boards, the RTC isn't configured by boot firmware.
343 * Handle that case by starting/configuring the RTC now.
344 */
345 status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
346 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
347
348 if ((status & 0x80) || (control & 0x80)) {
349 /* RTC not running */
350 u8 buf[1+16]; /* First byte is interpreted as address */
351 struct i2c_msg msg[1];
352
353 dev_dbg(&client->dev, "%s: RTC not running!\n", __FUNCTION__);
354
355 /* Initialize all, including STATUS and CONTROL to zero */
356 memset(buf, 0, sizeof(buf));
357
358 /* Write valid values in the date/time registers */
359 buf[1+DS1337_REG_DAY] = 1;
360 buf[1+DS1337_REG_DATE] = 1;
361 buf[1+DS1337_REG_MONTH] = 1;
362
363 msg[0].addr = client->addr;
364 msg[0].flags = 0;
365 msg[0].len = sizeof(buf);
366 msg[0].buf = &buf[0];
367
368 i2c_transfer(client->adapter, msg, 1);
369 } else {
370 /* Running: ensure that device is set in 24-hour mode */
371 s32 val;
372
373 val = i2c_smbus_read_byte_data(client, DS1337_REG_HOUR);
374 if ((val >= 0) && (val & (1 << 6)))
375 i2c_smbus_write_byte_data(client, DS1337_REG_HOUR,
376 val & 0x3f);
377 }
378}
379
380static int ds1337_detach_client(struct i2c_client *client)
381{
382 int err;
383 struct ds1337_data *data = i2c_get_clientdata(client);
384
385 if ((err = i2c_detach_client(client)))
386 return err;
387
388 list_del(&data->list);
389 kfree(data);
390 return 0;
391}
392
393static int __init ds1337_init(void)
394{
395 return i2c_add_driver(&ds1337_driver);
396}
397
398static void __exit ds1337_exit(void)
399{
400 i2c_del_driver(&ds1337_driver);
401}
402
403MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
404MODULE_DESCRIPTION("DS1337 RTC driver");
405MODULE_LICENSE("GPL");
406
407EXPORT_SYMBOL_GPL(ds1337_do_command);
408
409module_init(ds1337_init);
410module_exit(ds1337_exit);
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