Gitiles
Code Review Sign In
gerrit.cesnet.cz / github / trini / u-boot / 7f33899221e4235900760add69ffbb5f66f1229d / . / drivers / rtc / pt7c4338.c
blob: b1eb7d8781881871425de35a2ec056ee3fbc920e [file] [log] [blame]
Priyanka Jain09344532010-10-26 14:52:19 +0530[diff] [blame]1/*
2 * Copyright 2010 Freescale Semiconductor, Inc.
3 *
4 * Author: Priyanka Jain <Priyanka.Jain@freescale.com>
5 *
Wolfgang Denk1a459662013-07-08 09:37:19 +0200[diff] [blame]6 * SPDX-License-Identifier: GPL-2.0+
Priyanka Jain09344532010-10-26 14:52:19 +0530[diff] [blame]7 */
8
9/*
10 * This file provides Date & Time support (no alarms) for PT7C4338 chip.
11 *
12 * This file is based on drivers/rtc/ds1337.c
13 *
14 * PT7C4338 chip is manufactured by Pericom Technology Inc.
15 * It is a serial real-time clock which provides
16 * 1)Low-power clock/calendar.
17 * 2)Programmable square-wave output.
18 * It has 56 bytes of nonvolatile RAM.
19 */
20
21#include <common.h>
22#include <command.h>
23#include <rtc.h>
24#include <i2c.h>
25
26/* RTC register addresses */
27#define RTC_SEC_REG_ADDR 0x0
28#define RTC_MIN_REG_ADDR 0x1
29#define RTC_HR_REG_ADDR 0x2
30#define RTC_DAY_REG_ADDR 0x3
31#define RTC_DATE_REG_ADDR 0x4
32#define RTC_MON_REG_ADDR 0x5
33#define RTC_YR_REG_ADDR 0x6
34#define RTC_CTL_STAT_REG_ADDR 0x7
35
36/* RTC second register address bit */
37#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
38
39/* RTC control and status register bits */
40#define RTC_CTL_STAT_BIT_RS0 0x1 /* Rate select 0 */
41#define RTC_CTL_STAT_BIT_RS1 0x2 /* Rate select 1 */
42#define RTC_CTL_STAT_BIT_SQWE 0x10 /* Square Wave Enable */
43#define RTC_CTL_STAT_BIT_OSF 0x20 /* Oscillator Stop Flag */
44#define RTC_CTL_STAT_BIT_OUT 0x80 /* Output Level Control */
45
46/* RTC reset value */
47#define RTC_PT7C4338_RESET_VAL \
48 (RTC_CTL_STAT_BIT_RS0 | RTC_CTL_STAT_BIT_RS1 | RTC_CTL_STAT_BIT_OUT)
49
50/****** Helper functions ****************************************/
51static u8 rtc_read(u8 reg)
52{
53 return i2c_reg_read(CONFIG_SYS_I2C_RTC_ADDR, reg);
54}
55
56static void rtc_write(u8 reg, u8 val)
57{
58 i2c_reg_write(CONFIG_SYS_I2C_RTC_ADDR, reg, val);
59}
60/****************************************************************/
61
62/* Get the current time from the RTC */
63int rtc_get(struct rtc_time *tmp)
64{
65 int ret = 0;
66 u8 sec, min, hour, mday, wday, mon, year, ctl_stat;
67
68 ctl_stat = rtc_read(RTC_CTL_STAT_REG_ADDR);
69 sec = rtc_read(RTC_SEC_REG_ADDR);
70 min = rtc_read(RTC_MIN_REG_ADDR);
71 hour = rtc_read(RTC_HR_REG_ADDR);
72 wday = rtc_read(RTC_DAY_REG_ADDR);
73 mday = rtc_read(RTC_DATE_REG_ADDR);
74 mon = rtc_read(RTC_MON_REG_ADDR);
75 year = rtc_read(RTC_YR_REG_ADDR);
76 debug("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
77 "hr: %02x min: %02x sec: %02x control_status: %02x\n",
78 year, mon, mday, wday, hour, min, sec, ctl_stat);
79
80 if (ctl_stat & RTC_CTL_STAT_BIT_OSF) {
81 printf("### Warning: RTC oscillator has stopped\n");
82 /* clear the OSF flag */
83 rtc_write(RTC_CTL_STAT_REG_ADDR,
84 rtc_read(RTC_CTL_STAT_REG_ADDR)\
85 & ~RTC_CTL_STAT_BIT_OSF);
86 ret = -1;
87 }
88
89 tmp->tm_sec = bcd2bin(sec & 0x7F);
90 tmp->tm_min = bcd2bin(min & 0x7F);
91 tmp->tm_hour = bcd2bin(hour & 0x3F);
92 tmp->tm_mday = bcd2bin(mday & 0x3F);
93 tmp->tm_mon = bcd2bin(mon & 0x1F);
94 tmp->tm_year = bcd2bin(year) + 2000;
95 tmp->tm_wday = bcd2bin((wday - 1) & 0x07);
96 tmp->tm_yday = 0;
97 tmp->tm_isdst = 0;
98 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
99 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
100 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
101
102 return ret;
103}
104
105/* Set the RTC */
106int rtc_set(struct rtc_time *tmp)
107{
108 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
109 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
110 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
111
112 rtc_write(RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100));
113 rtc_write(RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon));
114 rtc_write(RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday + 1));
115 rtc_write(RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday));
116 rtc_write(RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour));
117 rtc_write(RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min));
118 rtc_write(RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec));
119
120 return 0;
121}
122
123/* Reset the RTC */
124void rtc_reset(void)
125{
126 rtc_write(RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
127 rtc_write(RTC_CTL_STAT_REG_ADDR, RTC_PT7C4338_RESET_VAL);
128}