From c79e1c1ce9e5c1ddf6fac631e4741999f8a0cc58 Mon Sep 17 00:00:00 2001 From: Andy Fleming Date: Wed, 21 Oct 2015 18:59:06 -0500 Subject: [PATCH] rtc: Add MCP79411 support to DS1307 rtc driver The code is from Adrian Cox, and is patterned after similar support in Linux (drivers/rtc/rtc-ds1307.c:1121-1135). This chip is used on the Cyrus board from Varisys. Signed-off-by: Andy Fleming Reviewed-by: York Sun --- drivers/rtc/Makefile | 2 +- drivers/rtc/ds1307.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 3092de1d9c..fc38a3f309 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -4,7 +4,6 @@ # # SPDX-License-Identifier: GPL-2.0+ # - #ccflags-y += -DDEBUG obj-$(CONFIG_DM_RTC) += rtc-uclass.o @@ -37,6 +36,7 @@ obj-$(CONFIG_RTC_M48T35A) += m48t35ax.o obj-$(CONFIG_RTC_MAX6900) += max6900.o obj-$(CONFIG_RTC_MC13XXX) += mc13xxx-rtc.o obj-$(CONFIG_RTC_MC146818) += mc146818.o +obj-$(CONFIG_RTC_MCP79411) += ds1307.o obj-$(CONFIG_MCFRTC) += mcfrtc.o obj-$(CONFIG_RTC_MK48T59) += mk48t59.o obj-$(CONFIG_RTC_MPC5200) += mpc5xxx.o diff --git a/drivers/rtc/ds1307.c b/drivers/rtc/ds1307.c index 03ab1a8c5d..3be1da6873 100644 --- a/drivers/rtc/ds1307.c +++ b/drivers/rtc/ds1307.c @@ -58,6 +58,10 @@ #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ +/* MCP7941X-specific bits */ +#define MCP7941X_BIT_ST 0x80 +#define MCP7941X_BIT_VBATEN 0x08 + static uchar rtc_read (uchar reg); static void rtc_write (uchar reg, uchar val); @@ -69,6 +73,9 @@ int rtc_get (struct rtc_time *tmp) int rel = 0; uchar sec, min, hour, mday, wday, mon, year; +#ifdef CONFIG_RTC_MCP79411 +read_rtc: +#endif sec = rtc_read (RTC_SEC_REG_ADDR); min = rtc_read (RTC_MIN_REG_ADDR); hour = rtc_read (RTC_HR_REG_ADDR); @@ -81,6 +88,7 @@ int rtc_get (struct rtc_time *tmp) "hr: %02x min: %02x sec: %02x\n", year, mon, mday, wday, hour, min, sec); +#ifdef CONFIG_RTC_DS1307 if (sec & RTC_SEC_BIT_CH) { printf ("### Warning: RTC oscillator has stopped\n"); /* clear the CH flag */ @@ -88,6 +96,23 @@ int rtc_get (struct rtc_time *tmp) rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); rel = -1; } +#endif + +#ifdef CONFIG_RTC_MCP79411 + /* make sure that the backup battery is enabled */ + if (!(wday & MCP7941X_BIT_VBATEN)) { + rtc_write(RTC_DAY_REG_ADDR, + wday | MCP7941X_BIT_VBATEN); + } + + /* clock halted? turn it on, so clock can tick. */ + if (!(sec & MCP7941X_BIT_ST)) { + rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST); + printf("Started RTC\n"); + goto read_rtc; + } +#endif + tmp->tm_sec = bcd2bin (sec & 0x7F); tmp->tm_min = bcd2bin (min & 0x7F); @@ -121,11 +146,20 @@ int rtc_set (struct rtc_time *tmp) rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); +#ifdef CONFIG_RTC_MCP79411 + rtc_write (RTC_DAY_REG_ADDR, + bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN); +#else rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); +#endif rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); +#ifdef CONFIG_RTC_MCP79411 + rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST); +#else rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); +#endif return 0; } -- 2.39.5