From 53e84b672c1a8190af2b376c35c7a39cf1214f59 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 23 Jul 2008 21:30:36 -0700 Subject: rtc: ds1305/ds1306 driver Support the Dallas/Maxim DS1305 and DS1306 RTC chips. These use SPI, and support alarms, NVRAM, and a trickle charger for use when their backup power supply is a supercap or rechargeable cell. This basic driver doesn't yet support suspend/resume or wakealarms. Signed-off-by: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/spi/ds1305.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/linux/spi/ds1305.h (limited to 'include') diff --git a/include/linux/spi/ds1305.h b/include/linux/spi/ds1305.h new file mode 100644 index 00000000000..287ec830eab --- /dev/null +++ b/include/linux/spi/ds1305.h @@ -0,0 +1,35 @@ +#ifndef __LINUX_SPI_DS1305_H +#define __LINUX_SPI_DS1305_H + +/* + * One-time configuration for ds1305 and ds1306 RTC chips. + * + * Put a pointer to this in spi_board_info.platform_data if you want to + * be sure that Linux (re)initializes this as needed ... after losing + * backup power, and potentially on the first boot. + */ +struct ds1305_platform_data { + + /* Trickle charge configuration: it's OK to leave out the MAGIC + * bitmask; mask in either DS1 or DS2, and then one of 2K/4k/8K. + */ +#define DS1305_TRICKLE_MAGIC 0xa0 +#define DS1305_TRICKLE_DS2 0x08 /* two diodes */ +#define DS1305_TRICKLE_DS1 0x04 /* one diode */ +#define DS1305_TRICKLE_2K 0x01 /* 2 KOhm resistance */ +#define DS1305_TRICKLE_4K 0x02 /* 4 KOhm resistance */ +#define DS1305_TRICKLE_8K 0x03 /* 8 KOhm resistance */ + u8 trickle; + + /* set only on ds1306 parts */ + bool is_ds1306; + + /* ds1306 only: enable 1 Hz output */ + bool en_1hz; + + /* REVISIT: the driver currently expects nINT0 to be wired + * as the alarm IRQ. ALM1 may also need to be set up ... + */ +}; + +#endif /* __LINUX_SPI_DS1305_H */ -- cgit v1.2.3