rtc: add EM3027 rtc driver

Add support for EM Microelectronic EM3027 RTC chip. Signed-off-by: Mike Rapoport <mike@compulab.co.il> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: add EM3027 rtc driver
Add support for EM Microelectronic EM3027 RTC chip. Signed-off-by: Mike Rapoport <mike@compulab.co.il> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport · Linus Torvalds
1 parent f77fbdf952
Showing 3 changed files with 171 additions and 0 deletions Side-by-side Diff
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-em3027.c
@@ -361,6 +361,15 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-rx8025.
  
+config RTC_DRV_EM3027
+	tristate "EM Microelectronic EM3027"
+	help
+	  If you say yes here you get support for the EM
+	  Microelectronic EM3027 RTC chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-em3027.
+
 endif # I2C
  
 comment "SPI RTC drivers"
@@ -44,6 +44,7 @@
 obj-$(CONFIG_RTC_DRV_DS3232)	+= rtc-ds3232.o
 obj-$(CONFIG_RTC_DRV_DS3234)	+= rtc-ds3234.o
 obj-$(CONFIG_RTC_DRV_EFI)	+= rtc-efi.o
+obj-$(CONFIG_RTC_DRV_EM3027)	+= rtc-em3027.o
 obj-$(CONFIG_RTC_DRV_EP93XX)	+= rtc-ep93xx.o
 obj-$(CONFIG_RTC_DRV_FM3130)	+= rtc-fm3130.o
 obj-$(CONFIG_RTC_DRV_GENERIC)	+= rtc-generic.o
+/*
+ * An rtc/i2c driver for the EM Microelectronic EM3027
+ * Copyright 2011 CompuLab, Ltd.
+ *
+ * Author: Mike Rapoport <mike@compulab.co.il>
+ *
+ * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * 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.
+ */
+
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+/* Registers */
+#define EM3027_REG_ON_OFF_CTRL	0x00
+#define EM3027_REG_IRQ_CTRL	0x01
+#define EM3027_REG_IRQ_FLAGS	0x02
+#define EM3027_REG_STATUS	0x03
+#define EM3027_REG_RST_CTRL	0x04
+
+#define EM3027_REG_WATCH_SEC	0x08
+#define EM3027_REG_WATCH_MIN	0x09
+#define EM3027_REG_WATCH_HOUR	0x0a
+#define EM3027_REG_WATCH_DATE	0x0b
+#define EM3027_REG_WATCH_DAY	0x0c
+#define EM3027_REG_WATCH_MON	0x0d
+#define EM3027_REG_WATCH_YEAR	0x0e
+
+#define EM3027_REG_ALARM_SEC	0x10
+#define EM3027_REG_ALARM_MIN	0x11
+#define EM3027_REG_ALARM_HOUR	0x12
+#define EM3027_REG_ALARM_DATE	0x13
+#define EM3027_REG_ALARM_DAY	0x14
+#define EM3027_REG_ALARM_MON	0x15
+#define EM3027_REG_ALARM_YEAR	0x16
+
+static struct i2c_driver em3027_driver;
+
+static int em3027_get_time(struct device *dev, struct rtc_time *tm)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	unsigned char addr = EM3027_REG_WATCH_SEC;
+	unsigned char buf[7];
+
+	struct i2c_msg msgs[] = {
+		{client->addr, 0, 1, &addr},		/* setup read addr */
+		{client->addr, I2C_M_RD, 7, buf},	/* read time/date */
+	};
+
+	/* read time/date registers */
+	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
+		dev_err(&client->dev, "%s: read error\n", __func__);
+		return -EIO;
+	}
+
+	tm->tm_sec	= bcd2bin(buf[0]);
+	tm->tm_min	= bcd2bin(buf[1]);
+	tm->tm_hour	= bcd2bin(buf[2]);
+	tm->tm_mday	= bcd2bin(buf[3]);
+	tm->tm_wday	= bcd2bin(buf[4]);
+	tm->tm_mon	= bcd2bin(buf[5]);
+	tm->tm_year	= bcd2bin(buf[6]) + 100;
+
+	return 0;
+}
+
+static int em3027_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned char buf[8];
+
+	struct i2c_msg msg = {
+		client->addr, 0, 8, buf,	/* write time/date */
+	};
+
+	buf[0] = EM3027_REG_WATCH_SEC;
+	buf[1] = bin2bcd(tm->tm_sec);
+	buf[2] = bin2bcd(tm->tm_min);
+	buf[3] = bin2bcd(tm->tm_hour);
+	buf[4] = bin2bcd(tm->tm_mday);
+	buf[5] = bin2bcd(tm->tm_wday);
+	buf[6] = bin2bcd(tm->tm_mon);
+	buf[7] = bin2bcd(tm->tm_year % 100);
+
+	/* write time/date registers */
+	if ((i2c_transfer(client->adapter, &msg, 1)) != 1) {
+		dev_err(&client->dev, "%s: write error\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static const struct rtc_class_ops em3027_rtc_ops = {
+	.read_time = em3027_get_time,
+	.set_time = em3027_set_time,
+};
+
+static int em3027_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct rtc_device *rtc;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	rtc = rtc_device_register(em3027_driver.driver.name, &client->dev,
+				  &em3027_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	i2c_set_clientdata(client, rtc);
+
+	return 0;
+}
+
+static int em3027_remove(struct i2c_client *client)
+{
+	struct rtc_device *rtc = i2c_get_clientdata(client);
+
+	if (rtc)
+		rtc_device_unregister(rtc);
+
+	return 0;
+}
+
+static struct i2c_device_id em3027_id[] = {
+	{ "em3027", 0 },
+	{ }
+};
+
+static struct i2c_driver em3027_driver = {
+	.driver = {
+		   .name = "rtc-em3027",
+	},
+	.probe = &em3027_probe,
+	.remove = &em3027_remove,
+	.id_table = em3027_id,
+};
+
+static int __init em3027_init(void)
+{
+	return i2c_add_driver(&em3027_driver);
+}
+
+static void __exit em3027_exit(void)
+{
+	i2c_del_driver(&em3027_driver);
+}
+
+MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
+MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");
+MODULE_LICENSE("GPL");
+
+module_init(em3027_init);
+module_exit(em3027_exit);
...	...	@@ -361,6 +361,15 @@
361	361	This driver can also be built as a module. If so, the module
362	362	will be called rtc-rx8025.
363	363
	364	+config RTC_DRV_EM3027
	365	+ tristate "EM Microelectronic EM3027"
	366	+ help
	367	+ If you say yes here you get support for the EM
	368	+ Microelectronic EM3027 RTC chips.
	369	+
	370	+ This driver can also be built as a module. If so, the module
	371	+ will be called rtc-em3027.
	372	+
364	373	endif # I2C
365	374
366	375	comment "SPI RTC drivers"
...	...	@@ -44,6 +44,7 @@
44	44	obj-$(CONFIG_RTC_DRV_DS3232) += rtc-ds3232.o
45	45	obj-$(CONFIG_RTC_DRV_DS3234) += rtc-ds3234.o
46	46	obj-$(CONFIG_RTC_DRV_EFI) += rtc-efi.o
	47	+obj-$(CONFIG_RTC_DRV_EM3027) += rtc-em3027.o
47	48	obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
48	49	obj-$(CONFIG_RTC_DRV_FM3130) += rtc-fm3130.o
49	50	obj-$(CONFIG_RTC_DRV_GENERIC) += rtc-generic.o
	1	+/*
	2	+ * An rtc/i2c driver for the EM Microelectronic EM3027
	3	+ * Copyright 2011 CompuLab, Ltd.
	4	+ *
	5	+ * Author: Mike Rapoport <mike@compulab.co.il>
	6	+ *
	7	+ * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it>
	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	+
	14	+#include <linux/i2c.h>
	15	+#include <linux/rtc.h>
	16	+#include <linux/bcd.h>
	17	+
	18	+/* Registers */
	19	+#define EM3027_REG_ON_OFF_CTRL 0x00
	20	+#define EM3027_REG_IRQ_CTRL 0x01
	21	+#define EM3027_REG_IRQ_FLAGS 0x02
	22	+#define EM3027_REG_STATUS 0x03
	23	+#define EM3027_REG_RST_CTRL 0x04
	24	+
	25	+#define EM3027_REG_WATCH_SEC 0x08
	26	+#define EM3027_REG_WATCH_MIN 0x09
	27	+#define EM3027_REG_WATCH_HOUR 0x0a
	28	+#define EM3027_REG_WATCH_DATE 0x0b
	29	+#define EM3027_REG_WATCH_DAY 0x0c
	30	+#define EM3027_REG_WATCH_MON 0x0d
	31	+#define EM3027_REG_WATCH_YEAR 0x0e
	32	+
	33	+#define EM3027_REG_ALARM_SEC 0x10
	34	+#define EM3027_REG_ALARM_MIN 0x11
	35	+#define EM3027_REG_ALARM_HOUR 0x12
	36	+#define EM3027_REG_ALARM_DATE 0x13
	37	+#define EM3027_REG_ALARM_DAY 0x14
	38	+#define EM3027_REG_ALARM_MON 0x15
	39	+#define EM3027_REG_ALARM_YEAR 0x16
	40	+
	41	+static struct i2c_driver em3027_driver;
	42	+
	43	+static int em3027_get_time(struct device dev, struct rtc_time tm)
	44	+{
	45	+ struct i2c_client *client = to_i2c_client(dev);
	46	+
	47	+ unsigned char addr = EM3027_REG_WATCH_SEC;
	48	+ unsigned char buf[7];
	49	+
	50	+ struct i2c_msg msgs[] = {
	51	+ {client->addr, 0, 1, &addr}, /* setup read addr */
	52	+ {client->addr, I2C_M_RD, 7, buf}, /* read time/date */
	53	+ };
	54	+
	55	+ /* read time/date registers */
	56	+ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
	57	+ dev_err(&client->dev, "%s: read error\n", __func__);
	58	+ return -EIO;
	59	+ }
	60	+
	61	+ tm->tm_sec = bcd2bin(buf[0]);
	62	+ tm->tm_min = bcd2bin(buf[1]);
	63	+ tm->tm_hour = bcd2bin(buf[2]);
	64	+ tm->tm_mday = bcd2bin(buf[3]);
	65	+ tm->tm_wday = bcd2bin(buf[4]);
	66	+ tm->tm_mon = bcd2bin(buf[5]);
	67	+ tm->tm_year = bcd2bin(buf[6]) + 100;
	68	+
	69	+ return 0;
	70	+}
	71	+
	72	+static int em3027_set_time(struct device dev, struct rtc_time tm)
	73	+{
	74	+ struct i2c_client *client = to_i2c_client(dev);
	75	+ unsigned char buf[8];
	76	+
	77	+ struct i2c_msg msg = {
	78	+ client->addr, 0, 8, buf, /* write time/date */
	79	+ };
	80	+
	81	+ buf[0] = EM3027_REG_WATCH_SEC;
	82	+ buf[1] = bin2bcd(tm->tm_sec);
	83	+ buf[2] = bin2bcd(tm->tm_min);
	84	+ buf[3] = bin2bcd(tm->tm_hour);
	85	+ buf[4] = bin2bcd(tm->tm_mday);
	86	+ buf[5] = bin2bcd(tm->tm_wday);
	87	+ buf[6] = bin2bcd(tm->tm_mon);
	88	+ buf[7] = bin2bcd(tm->tm_year % 100);
	89	+
	90	+ /* write time/date registers */
	91	+ if ((i2c_transfer(client->adapter, &msg, 1)) != 1) {
	92	+ dev_err(&client->dev, "%s: write error\n", __func__);
	93	+ return -EIO;
	94	+ }
	95	+
	96	+ return 0;
	97	+}
	98	+
	99	+static const struct rtc_class_ops em3027_rtc_ops = {
	100	+ .read_time = em3027_get_time,
	101	+ .set_time = em3027_set_time,
	102	+};
	103	+
	104	+static int em3027_probe(struct i2c_client *client,
	105	+ const struct i2c_device_id *id)
	106	+{
	107	+ struct rtc_device *rtc;
	108	+
	109	+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	110	+ return -ENODEV;
	111	+
	112	+ rtc = rtc_device_register(em3027_driver.driver.name, &client->dev,
	113	+ &em3027_rtc_ops, THIS_MODULE);
	114	+ if (IS_ERR(rtc))
	115	+ return PTR_ERR(rtc);
	116	+
	117	+ i2c_set_clientdata(client, rtc);
	118	+
	119	+ return 0;
	120	+}
	121	+
	122	+static int em3027_remove(struct i2c_client *client)
	123	+{
	124	+ struct rtc_device *rtc = i2c_get_clientdata(client);
	125	+
	126	+ if (rtc)
	127	+ rtc_device_unregister(rtc);
	128	+
	129	+ return 0;
	130	+}
	131	+
	132	+static struct i2c_device_id em3027_id[] = {
	133	+ { "em3027", 0 },
	134	+ { }
	135	+};
	136	+
	137	+static struct i2c_driver em3027_driver = {
	138	+ .driver = {
	139	+ .name = "rtc-em3027",
	140	+ },
	141	+ .probe = &em3027_probe,
	142	+ .remove = &em3027_remove,
	143	+ .id_table = em3027_id,
	144	+};
	145	+
	146	+static int __init em3027_init(void)
	147	+{
	148	+ return i2c_add_driver(&em3027_driver);
	149	+}
	150	+
	151	+static void __exit em3027_exit(void)
	152	+{
	153	+ i2c_del_driver(&em3027_driver);
	154	+}
	155	+
	156	+MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
	157	+MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");
	158	+MODULE_LICENSE("GPL");
	159	+
	160	+module_init(em3027_init);
	161	+module_exit(em3027_exit);