1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Machine dependent access functions for RTC registers.
4 */
5 #ifndef _ASM_MC146818RTC_H
6 #define _ASM_MC146818RTC_H
7
8 #include <linux/io.h>
9 #include <linux/kernel.h>
10
11 #define RTC_IRQ BUILD_BUG_ON(1)
12
13 #ifndef RTC_PORT
14 #define RTC_PORT(x) (0x70 + (x))
15 #define RTC_ALWAYS_BCD 1 /* RTC operates in binary mode */
16 #endif
17
18 /*
19 * The yet supported machines all access the RTC index register via
20 * an ISA port access but the way to access the date register differs ...
21 */
22 #define CMOS_READ(addr) ({ \
23 outb_p((addr),RTC_PORT(0)); \
24 inb_p(RTC_PORT(1)); \
25 })
26 #define CMOS_WRITE(val, addr) ({ \
27 outb_p((addr),RTC_PORT(0)); \
28 outb_p((val),RTC_PORT(1)); \
29 })
30
31 #endif /* _ASM_MC146818RTC_H */