aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/pending-3.18/841-rtc_pt7c4338.patch
blob: 83b0232e13f78d1a9e8802920d0bccf3b8efec95 (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
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -567,6 +567,15 @@ config RTC_DRV_S5M
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-s5m.
 
+config RTC_DRV_PT7C4338
+	tristate "Pericom Technology Inc. PT7C4338 RTC"
+	help
+	  If you say yes here you get support for the Pericom Technology
+	  Inc. PT7C4338 RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-pt7c4338.
+
 endif # I2C
 
 comment "SPI RTC drivers"
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_RTC_DRV_PL030)	+= rtc-pl030
 obj-$(CONFIG_RTC_DRV_PL031)	+= rtc-pl031.o
 obj-$(CONFIG_RTC_DRV_PM8XXX)	+= rtc-pm8xxx.o
 obj-$(CONFIG_RTC_DRV_PS3)	+= rtc-ps3.o
+obj-$(CONFIG_RTC_DRV_PT7C4338)	+= rtc-pt7c4338.o
 obj-$(CONFIG_RTC_DRV_PUV3)	+= rtc-puv3.o
 obj-$(CONFIG_RTC_DRV_PXA)	+= rtc-pxa.o
 obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o
--- /dev/null
+++ b/drivers/rtc/rtc-pt7c4338.c
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * Author:	Priyanka Jain <Priyanka.Jain@freescale.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * This file provides Date & Time support (no alarms) for PT7C4338 chip.
+ *
+ * This file is based on drivers/rtc/rtc-ds1307.c
+ *
+ * PT7C4338 chip is manufactured by Pericom Technology Inc.
+ * It is a serial real-time clock which provides
+ * 1)Low-power clock/calendar.
+ * 2)Programmable square-wave output.
+ * It has 56 bytes of nonvolatile RAM.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+/* RTC register addresses */
+#define PT7C4338_REG_SECONDS          0x00
+#define PT7C4338_REG_MINUTES          0x01
+#define PT7C4338_REG_HOURS            0x02
+#define PT7C4338_REG_AMPM             0x02
+#define PT7C4338_REG_DAY              0x03
+#define PT7C4338_REG_DATE             0x04
+#define PT7C4338_REG_MONTH            0x05
+#define PT7C4338_REG_YEAR             0x06
+#define PT7C4338_REG_CTRL_STAT        0x07
+
+/* RTC second register address bit */
+#define PT7C4338_SEC_BIT_CH           0x80	/*Clock Halt (in Register 0)*/
+
+/* RTC control and status register bits */
+#define PT7C4338_CTRL_STAT_BIT_RS0    0x1	/*Rate select 0*/
+#define PT7C4338_CTRL_STAT_BIT_RS1    0x2	/*Rate select 1*/
+#define PT7C4338_CTRL_STAT_BIT_SQWE   0x10	/*Square Wave Enable*/
+#define PT7C4338_CTRL_STAT_BIT_OSF    0x20	/*Oscillator Stop Flag*/
+#define PT7C4338_CTRL_STAT_BIT_OUT    0x80	/*Output Level Control*/
+
+static const struct i2c_device_id pt7c4338_id[] = {
+	{ "pt7c4338", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pt7c4338_id);
+
+struct pt7c4338{
+	struct i2c_client *client;
+	struct rtc_device *rtc;
+};
+
+static int pt7c4338_read_time(struct device *dev, struct rtc_time *time)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret;
+	u8 buf[7];
+	u8 year, month, day, hour, minute, second;
+	u8 week, twelve_hr, am_pm;
+
+	ret = i2c_smbus_read_i2c_block_data(client,
+			PT7C4338_REG_SECONDS, 7, buf);
+	if (ret < 0)
+		return ret;
+	if (ret < 7)
+		return -EIO;
+
+	second = buf[0];
+	minute = buf[1];
+	hour = buf[2];
+	week = buf[3];
+	day = buf[4];
+	month = buf[5];
+	year = buf[6];
+
+	/* Extract additional information for AM/PM */
+	twelve_hr = hour & 0x40;
+	am_pm = hour & 0x20;
+
+	/* Write to rtc_time structure */
+	time->tm_sec = bcd2bin(second & 0x7f);
+	time->tm_min = bcd2bin(minute & 0x7f);
+	if (twelve_hr) {
+		/* Convert to 24 hr */
+		if (am_pm)
+			time->tm_hour = bcd2bin(hour & 0x10) + 12;
+		else
+			time->tm_hour = bcd2bin(hour & 0xBF);
+	} else {
+		time->tm_hour = bcd2bin(hour);
+	}
+
+	time->tm_wday = bcd2bin(week & 0x07) - 1;
+	time->tm_mday = bcd2bin(day & 0x3f);
+	time->tm_mon = bcd2bin(month & 0x1F) - 1;
+	/* assume 20YY not 19YY */
+	time->tm_year = bcd2bin(year) + 100;
+
+	return 0;
+}
+
+static int pt7c4338_set_time(struct device *dev, struct rtc_time *time)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	u8 buf[7];
+
+	/* Extract time from rtc_time and load into pt7c4338*/
+	buf[0] = bin2bcd(time->tm_sec);
+	buf[1] = bin2bcd(time->tm_min);
+	buf[2] = bin2bcd(time->tm_hour);
+	buf[3] = bin2bcd(time->tm_wday + 1); /* Day of the week */
+	buf[4] = bin2bcd(time->tm_mday); /* Date */
+	buf[5] = bin2bcd(time->tm_mon + 1);
+
+	/* assume 20YY not 19YY */
+	if (time->tm_year >= 100)
+		buf[6] = bin2bcd(time->tm_year - 100);
+	else
+		buf[6] = bin2bcd(time->tm_year);
+
+	return i2c_smbus_write_i2c_block_data(client,
+					PT7C4338_REG_SECONDS, 7, buf);
+}
+
+static const struct rtc_class_ops pt7c4338_rtc_ops = {
+	.read_time = pt7c4338_read_time,
+	.set_time = pt7c4338_set_time,
+};
+
+static int pt7c4338_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct pt7c4338 *pt7c4338;
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	int ret;
+
+	pt7c4338 = kzalloc(sizeof(struct pt7c4338), GFP_KERNEL);
+	if (!pt7c4338)
+		return -ENOMEM;
+
+	pt7c4338->client = client;
+	i2c_set_clientdata(client, pt7c4338);
+	pt7c4338->rtc = rtc_device_register(client->name, &client->dev,
+					&pt7c4338_rtc_ops, THIS_MODULE);
+	if (IS_ERR(pt7c4338->rtc)) {
+		ret = PTR_ERR(pt7c4338->rtc);
+		dev_err(&client->dev, "unable to register the class device\n");
+		goto out_free;
+	}
+
+	return 0;
+out_free:
+	i2c_set_clientdata(client, NULL);
+	kfree(pt7c4338);
+	return ret;
+}
+
+static int pt7c4338_remove(struct i2c_client *client)
+{
+	struct pt7c4338 *pt7c4338 = i2c_get_clientdata(client);
+
+	rtc_device_unregister(pt7c4338->rtc);
+	i2c_set_clientdata(client, NULL);
+	kfree(pt7c4338);
+	return 0;
+}
+
+static struct i2c_driver pt7c4338_driver = {
+	.driver = {
+		.name = "rtc-pt7c4338",
+		.owner = THIS_MODULE,
+	},
+	.probe = pt7c4338_probe,
+	.remove = pt7c4338_remove,
+	.id_table = pt7c4338_id,
+};
+
+static int __init pt7c4338_init(void)
+{
+	return i2c_add_driver(&pt7c4338_driver);
+}
+
+static void __exit pt7c4338_exit(void)
+{
+	i2c_del_driver(&pt7c4338_driver);
+}
+
+module_init(pt7c4338_init);
+module_exit(pt7c4338_exit);
+
+MODULE_AUTHOR("Priyanka Jain <Priyanka.Jain@freescale.com>");
+MODULE_DESCRIPTION("pericom Technology Inc. PT7C4338 RTC Driver");
+MODULE_LICENSE("GPL");