blob: 26e2c1ee60dbda8e4c816c0b2fa62e3dcd392d1c [file] [log] [blame]
Priyanka Jain09344532010-10-26 14:52:19 +05301/*
2 * Copyright 2010 Freescale Semiconductor, Inc.
3 *
4 * Author: Priyanka Jain <Priyanka.Jain@freescale.com>
5 *
6 * See file CREDITS for list of people who contributed to this
7 * project.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * MA 02111-1307 USA
23 */
24
25/*
26 * This file provides Date & Time support (no alarms) for PT7C4338 chip.
27 *
28 * This file is based on drivers/rtc/ds1337.c
29 *
30 * PT7C4338 chip is manufactured by Pericom Technology Inc.
31 * It is a serial real-time clock which provides
32 * 1)Low-power clock/calendar.
33 * 2)Programmable square-wave output.
34 * It has 56 bytes of nonvolatile RAM.
35 */
36
37#include <common.h>
38#include <command.h>
39#include <rtc.h>
40#include <i2c.h>
41
42/* RTC register addresses */
43#define RTC_SEC_REG_ADDR 0x0
44#define RTC_MIN_REG_ADDR 0x1
45#define RTC_HR_REG_ADDR 0x2
46#define RTC_DAY_REG_ADDR 0x3
47#define RTC_DATE_REG_ADDR 0x4
48#define RTC_MON_REG_ADDR 0x5
49#define RTC_YR_REG_ADDR 0x6
50#define RTC_CTL_STAT_REG_ADDR 0x7
51
52/* RTC second register address bit */
53#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
54
55/* RTC control and status register bits */
56#define RTC_CTL_STAT_BIT_RS0 0x1 /* Rate select 0 */
57#define RTC_CTL_STAT_BIT_RS1 0x2 /* Rate select 1 */
58#define RTC_CTL_STAT_BIT_SQWE 0x10 /* Square Wave Enable */
59#define RTC_CTL_STAT_BIT_OSF 0x20 /* Oscillator Stop Flag */
60#define RTC_CTL_STAT_BIT_OUT 0x80 /* Output Level Control */
61
62/* RTC reset value */
63#define RTC_PT7C4338_RESET_VAL \
64 (RTC_CTL_STAT_BIT_RS0 | RTC_CTL_STAT_BIT_RS1 | RTC_CTL_STAT_BIT_OUT)
65
66/****** Helper functions ****************************************/
67static u8 rtc_read(u8 reg)
68{
69 return i2c_reg_read(CONFIG_SYS_I2C_RTC_ADDR, reg);
70}
71
72static void rtc_write(u8 reg, u8 val)
73{
74 i2c_reg_write(CONFIG_SYS_I2C_RTC_ADDR, reg, val);
75}
76/****************************************************************/
77
78/* Get the current time from the RTC */
79int rtc_get(struct rtc_time *tmp)
80{
81 int ret = 0;
82 u8 sec, min, hour, mday, wday, mon, year, ctl_stat;
83
84 ctl_stat = rtc_read(RTC_CTL_STAT_REG_ADDR);
85 sec = rtc_read(RTC_SEC_REG_ADDR);
86 min = rtc_read(RTC_MIN_REG_ADDR);
87 hour = rtc_read(RTC_HR_REG_ADDR);
88 wday = rtc_read(RTC_DAY_REG_ADDR);
89 mday = rtc_read(RTC_DATE_REG_ADDR);
90 mon = rtc_read(RTC_MON_REG_ADDR);
91 year = rtc_read(RTC_YR_REG_ADDR);
92 debug("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
93 "hr: %02x min: %02x sec: %02x control_status: %02x\n",
94 year, mon, mday, wday, hour, min, sec, ctl_stat);
95
96 if (ctl_stat & RTC_CTL_STAT_BIT_OSF) {
97 printf("### Warning: RTC oscillator has stopped\n");
98 /* clear the OSF flag */
99 rtc_write(RTC_CTL_STAT_REG_ADDR,
100 rtc_read(RTC_CTL_STAT_REG_ADDR)\
101 & ~RTC_CTL_STAT_BIT_OSF);
102 ret = -1;
103 }
104
105 tmp->tm_sec = bcd2bin(sec & 0x7F);
106 tmp->tm_min = bcd2bin(min & 0x7F);
107 tmp->tm_hour = bcd2bin(hour & 0x3F);
108 tmp->tm_mday = bcd2bin(mday & 0x3F);
109 tmp->tm_mon = bcd2bin(mon & 0x1F);
110 tmp->tm_year = bcd2bin(year) + 2000;
111 tmp->tm_wday = bcd2bin((wday - 1) & 0x07);
112 tmp->tm_yday = 0;
113 tmp->tm_isdst = 0;
114 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
115 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
116 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
117
118 return ret;
119}
120
121/* Set the RTC */
122int rtc_set(struct rtc_time *tmp)
123{
124 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
125 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
126 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
127
128 rtc_write(RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100));
129 rtc_write(RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon));
130 rtc_write(RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday + 1));
131 rtc_write(RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday));
132 rtc_write(RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour));
133 rtc_write(RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min));
134 rtc_write(RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec));
135
136 return 0;
137}
138
139/* Reset the RTC */
140void rtc_reset(void)
141{
142 rtc_write(RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
143 rtc_write(RTC_CTL_STAT_REG_ADDR, RTC_PT7C4338_RESET_VAL);
144}