aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/sibyte/patches/003-m41t80_smbus.patch
blob: c6a07c6d5b03f4eda48a528da07867b1f5f58e76 (plain)
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
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -6,6 +6,7 @@
  * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
  *
  * 2006 (c) mycable GmbH
+ * Copyright (c) 2008  Maciej W. Rozycki
  *
  * 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
@@ -38,6 +39,8 @@
 #define M41T80_REG_DAY	5
 #define M41T80_REG_MON	6
 #define M41T80_REG_YEAR	7
+#define M41T80_REG_CONTROL	8
+#define M41T80_REG_WATCHDOG	9
 #define M41T80_REG_ALARM_MON	0xa
 #define M41T80_REG_ALARM_DAY	0xb
 #define M41T80_REG_ALARM_HOUR	0xc
@@ -66,7 +69,7 @@
 #define M41T80_FEATURE_WD	(1 << 3)	/* Extra watchdog resolution */
 #define M41T80_FEATURE_SQ_ALT	(1 << 4)	/* RSx bits are in reg 4 */
 
-#define DRV_VERSION "0.05"
+#define DRV_VERSION "0.06"
 
 static const struct i2c_device_id m41t80_id[] = {
 	{ "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
@@ -88,31 +91,88 @@ struct m41t80_data {
 	struct rtc_device *rtc;
 };
 
-static int m41t80_get_datetime(struct i2c_client *client,
-			       struct rtc_time *tm)
+
+static int m41t80_write_block_data(struct i2c_client *client,
+				   u8 reg, u8 num, u8 *buf)
 {
-	u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
-	struct i2c_msg msgs[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1,
-			.buf	= dt_addr,
-		},
-		{
-			.addr	= client->addr,
-			.flags	= I2C_M_RD,
-			.len	= M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
-			.buf	= buf + M41T80_REG_SEC,
-		},
-	};
+	int i, rc;
 
-	if (i2c_transfer(client->adapter, msgs, 2) < 0) {
-		dev_err(&client->dev, "read error\n");
-		return -EIO;
+	if (i2c_check_functionality(client->adapter,
+				    I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
+		i = i2c_smbus_write_i2c_block_data(client, reg, num, buf);
+	} else {
+		for (i = 0; i < num; i++) {
+			rc = i2c_smbus_write_byte_data(client, reg + i,
+						       buf[i]);
+			if (rc < 0) {
+				i = rc;
+				goto out;
+			}
+		}
 	}
+out:
+	return i;
+}
+
+static int m41t80_read_block_data(struct i2c_client *client,
+				  u8 reg, u8 num, u8 *buf)
+{
+	int i, rc;
+
+	if (i2c_check_functionality(client->adapter,
+				    I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+		i = i2c_smbus_read_i2c_block_data(client, reg, num, buf);
+	} else {
+		for (i = 0; i < num; i++) {
+			rc = i2c_smbus_read_byte_data(client, reg + i);
+			if (rc < 0) {
+				i = rc;
+				goto out;
+			}
+			buf[i] = rc;
+		}
+	}
+out:
+	return i;
+}
+
+static int m41t80_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+	u8 buf[M41T80_DATETIME_REG_SIZE];
+	int loops = 2;
+	int sec0, sec1;
+
+	/*
+	 * Time registers are latched by this chip if an I2C block
+	 * transfer is used, but with SMBus-style byte accesses
+	 * this is not the case, so check seconds for a wraparound.
+	 */
+	do {
+		if (m41t80_read_block_data(client, M41T80_REG_SEC,
+					   M41T80_DATETIME_REG_SIZE -
+					   M41T80_REG_SEC,
+					   buf + M41T80_REG_SEC) < 0) {
+			dev_err(&client->dev, "read error\n");
+			return -EIO;
+		}
+		if (i2c_check_functionality(client->adapter,
+					    I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+			sec1 = buf[M41T80_REG_SEC];
+			break;
+		}
+
+		sec0 = buf[M41T80_REG_SEC];
+		sec1 = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
+		if (sec1 < 0) {
+			dev_err(&client->dev, "read error\n");
+			return -EIO;
+		}
+
+		sec0 = bcd2bin(sec0 & 0x7f);
+		sec1 = bcd2bin(sec1 & 0x7f);
+	} while (sec1 < sec0 && --loops);
 
-	tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
+	tm->tm_sec = sec1;
 	tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
 	tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
 	tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
@@ -127,39 +187,16 @@ static int m41t80_get_datetime(struct i2
 /* Sets the given date and time to the real time clock. */
 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
-	u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
-	u8 *buf = &wbuf[1];
-	u8 dt_addr[1] = { M41T80_REG_SEC };
-	struct i2c_msg msgs_in[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1,
-			.buf	= dt_addr,
-		},
-		{
-			.addr	= client->addr,
-			.flags	= I2C_M_RD,
-			.len	= M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
-			.buf	= buf + M41T80_REG_SEC,
-		},
-	};
-	struct i2c_msg msgs[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1 + M41T80_DATETIME_REG_SIZE,
-			.buf	= wbuf,
-		 },
-	};
+	u8 buf[M41T80_DATETIME_REG_SIZE];
 
 	/* Read current reg values into buf[1..7] */
-	if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
+	if (m41t80_read_block_data(client, M41T80_REG_SEC,
+				   M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
+				   buf + M41T80_REG_SEC) < 0) {
 		dev_err(&client->dev, "read error\n");
 		return -EIO;
 	}
 
-	wbuf[0] = 0; /* offset into rtc's regs */
 	/* Merge time-data and register flags into buf[0..7] */
 	buf[M41T80_REG_SSEC] = 0;
 	buf[M41T80_REG_SEC] =
@@ -177,7 +214,8 @@ static int m41t80_set_datetime(struct i2
 	/* assume 20YY not 19YY */
 	buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
 
-	if (i2c_transfer(client->adapter, msgs, 1) != 1) {
+	if (m41t80_write_block_data(client, M41T80_REG_SSEC,
+				    M41T80_DATETIME_REG_SIZE, buf) < 0) {
 		dev_err(&client->dev, "write error\n");
 		return -EIO;
 	}
@@ -251,34 +289,11 @@ err:
 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
-	u8 *buf = &wbuf[1];
+	u8 buf[M41T80_ALARM_REG_SIZE];
 	u8 *reg = buf - M41T80_REG_ALARM_MON;
-	u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
-	struct i2c_msg msgs_in[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1,
-			.buf	= dt_addr,
-		},
-		{
-			.addr	= client->addr,
-			.flags	= I2C_M_RD,
-			.len	= M41T80_ALARM_REG_SIZE,
-			.buf	= buf,
-		},
-	};
-	struct i2c_msg msgs[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1 + M41T80_ALARM_REG_SIZE,
-			.buf	= wbuf,
-		 },
-	};
 
-	if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
+	if (m41t80_read_block_data(client, M41T80_REG_ALARM_MON,
+				   M41T80_ALARM_REG_SIZE, buf) < 0) {
 		dev_err(&client->dev, "read error\n");
 		return -EIO;
 	}
@@ -288,7 +303,6 @@ static int m41t80_rtc_set_alarm(struct d
 	reg[M41T80_REG_ALARM_MIN] = 0;
 	reg[M41T80_REG_ALARM_SEC] = 0;
 
-	wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
 	reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
 		bin2bcd(t->time.tm_sec) : 0x80;
 	reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
@@ -302,7 +316,8 @@ static int m41t80_rtc_set_alarm(struct d
 	else
 		reg[M41T80_REG_ALARM_DAY] |= 0x40;
 
-	if (i2c_transfer(client->adapter, msgs, 1) != 1) {
+	if (m41t80_write_block_data(client, M41T80_REG_ALARM_MON,
+				    M41T80_ALARM_REG_SIZE, buf) < 0) {
 		dev_err(&client->dev, "write error\n");
 		return -EIO;
 	}
@@ -322,24 +337,10 @@ static int m41t80_rtc_read_alarm(struct 
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
-	u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
 	u8 *reg = buf - M41T80_REG_ALARM_MON;
-	struct i2c_msg msgs[] = {
-		{
-			.addr	= client->addr,
-			.flags	= 0,
-			.len	= 1,
-			.buf	= dt_addr,
-		},
-		{
-			.addr	= client->addr,
-			.flags	= I2C_M_RD,
-			.len	= M41T80_ALARM_REG_SIZE + 1,
-			.buf	= buf,
-		},
-	};
 
-	if (i2c_transfer(client->adapter, msgs, 2) < 0) {
+	if (m41t80_read_block_data(client, M41T80_REG_ALARM_MON,
+				   M41T80_ALARM_REG_SIZE + 1, buf) < 0) {
 		dev_err(&client->dev, "read error\n");
 		return -EIO;
 	}
@@ -512,26 +513,16 @@ static int boot_flag;
  */
 static void wdt_ping(void)
 {
-	unsigned char i2c_data[2];
-	struct i2c_msg msgs1[1] = {
-		{
-			.addr	= save_client->addr,
-			.flags	= 0,
-			.len	= 2,
-			.buf	= i2c_data,
-		},
-	};
-	struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
+	u8 wdt = 0x80;				/* WDS = 1 (0x80)  */
 
-	i2c_data[0] = 0x09;		/* watchdog register */
+	struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
 
 	if (wdt_margin > 31)
-		i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
+		/* mulitplier = WD_TIMO / 4, resolution = 4s (0x3)  */
+		wdt |= (wdt_margin & 0xfc) | 0x3;
 	else
-		/*
-		 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
-		 */
-		i2c_data[1] = wdt_margin<<2 | 0x82;
+		/* mulitplier = WD_TIMO, resolution = 1s (0x2)  */
+		wdt |= wdt_margin << 2 | 0x2;
 
 	/*
 	 * M41T65 has three bits for watchdog resolution.  Don't set bit 7, as
@@ -540,7 +531,7 @@ static void wdt_ping(void)
 	if (clientdata->features & M41T80_FEATURE_WD)
 		i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
 
-	i2c_transfer(save_client->adapter, msgs1, 1);
+	i2c_smbus_write_byte_data(save_client, M41T80_REG_WATCHDOG, wdt);
 }
 
 /**
@@ -550,36 +541,8 @@ static void wdt_ping(void)
  */
 static void wdt_disable(void)
 {
-	unsigned char i2c_data[2], i2c_buf[0x10];
-	struct i2c_msg msgs0[2] = {
-		{
-			.addr	= save_client->addr,
-			.flags	= 0,
-			.len	= 1,
-			.buf	= i2c_data,
-		},
-		{
-			.addr	= save_client->addr,
-			.flags	= I2C_M_RD,
-			.len	= 1,
-			.buf	= i2c_buf,
-		},
-	};
-	struct i2c_msg msgs1[1] = {
-		{
-			.addr	= save_client->addr,
-			.flags	= 0,
-			.len	= 2,
-			.buf	= i2c_data,
-		},
-	};
-
-	i2c_data[0] = 0x09;
-	i2c_transfer(save_client->adapter, msgs0, 2);
-
-	i2c_data[0] = 0x09;
-	i2c_data[1] = 0x00;
-	i2c_transfer(save_client->adapter, msgs1, 1);
+	i2c_smbus_read_byte_data(save_client, M41T80_REG_WATCHDOG);
+	i2c_smbus_write_byte_data(save_client, M41T80_REG_WATCHDOG, 0);
 }
 
 /**
@@ -772,8 +735,8 @@ static int m41t80_probe(struct i2c_clien
 	struct rtc_time tm;
 	struct m41t80_data *clientdata = NULL;
 
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
-				     | I2C_FUNC_SMBUS_BYTE_DATA)) {
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA)) {
 		rc = -ENODEV;
 		goto exit;
 	}