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/*
* RTC routines for RICOH Rx5C348 SPI chip.
* Copyright (C) 2000-2001 Toshiba Corporation
*
* 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
* terms of the GNU General Public License version 2. This program is
* licensed "as is" without any warranty of any kind, whether express
* or implied.
*
* Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/rtc.h>
#include <linux/time.h>
#include <asm/time.h>
#include <asm/tx4938/spi.h>
#define EPOCH 2000
/* registers */
#define Rx5C348_REG_SECOND 0
#define Rx5C348_REG_MINUTE 1
#define Rx5C348_REG_HOUR 2
#define Rx5C348_REG_WEEK 3
#define Rx5C348_REG_DAY 4
#define Rx5C348_REG_MONTH 5
#define Rx5C348_REG_YEAR 6
#define Rx5C348_REG_ADJUST 7
#define Rx5C348_REG_ALARM_W_MIN 8
#define Rx5C348_REG_ALARM_W_HOUR 9
#define Rx5C348_REG_ALARM_W_WEEK 10
#define Rx5C348_REG_ALARM_D_MIN 11
#define Rx5C348_REG_ALARM_D_HOUR 12
#define Rx5C348_REG_CTL1 14
#define Rx5C348_REG_CTL2 15
/* register bits */
#define Rx5C348_BIT_PM 0x20 /* REG_HOUR */
#define Rx5C348_BIT_Y2K 0x80 /* REG_MONTH */
#define Rx5C348_BIT_24H 0x20 /* REG_CTL1 */
#define Rx5C348_BIT_XSTP 0x10 /* REG_CTL2 */
/* commands */
#define Rx5C348_CMD_W(addr) (((addr) << 4) | 0x08) /* single write */
#define Rx5C348_CMD_R(addr) (((addr) << 4) | 0x0c) /* single read */
#define Rx5C348_CMD_MW(addr) (((addr) << 4) | 0x00) /* burst write */
#define Rx5C348_CMD_MR(addr) (((addr) << 4) | 0x04) /* burst read */
static struct spi_dev_desc srtc_dev_desc = {
.baud = 1000000, /* 1.0Mbps @ Vdd 2.0V */
.tcss = 31,
.tcsh = 1,
.tcsr = 62,
/* 31us for Tcss (62us for Tcsr) is required for carry operation) */
.byteorder = 1, /* MSB-First */
.polarity = 0, /* High-Active */
.phase = 1, /* Shift-Then-Sample */
};
static int srtc_chipid;
static int srtc_24h;
static inline int
spi_rtc_io(unsigned char *inbuf, unsigned char *outbuf, unsigned int count)
{
unsigned char *inbufs[1], *outbufs[1];
unsigned int incounts[2], outcounts[2];
inbufs[0] = inbuf;
incounts[0] = count;
incounts[1] = 0;
outbufs[0] = outbuf;
outcounts[0] = count;
outcounts[1] = 0;
return txx9_spi_io(srtc_chipid, &srtc_dev_desc,
inbufs, incounts, outbufs, outcounts, 0);
}
/*
* Conversion between binary and BCD.
*/
#ifndef BCD_TO_BIN
#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
#endif
#ifndef BIN_TO_BCD
#define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
#endif
/* RTC-dependent code for time.c */
static int
rtc_rx5c348_set_time(unsigned long t)
{
unsigned char inbuf[8];
struct rtc_time tm;
u8 year, month, day, hour, minute, second, century;
/* convert */
to_tm(t, &tm);
year = tm.tm_year % 100;
month = tm.tm_mon+1; /* tm_mon starts from 0 to 11 */
day = tm.tm_mday;
hour = tm.tm_hour;
minute = tm.tm_min;
second = tm.tm_sec;
century = tm.tm_year / 100;
inbuf[0] = Rx5C348_CMD_MW(Rx5C348_REG_SECOND);
BIN_TO_BCD(second);
inbuf[1] = second;
BIN_TO_BCD(minute);
inbuf[2] = minute;
if (srtc_24h) {
BIN_TO_BCD(hour);
inbuf[3] = hour;
} else {
/* hour 0 is AM12, noon is PM12 */
inbuf[3] = 0;
if (hour >= 12)
inbuf[3] = Rx5C348_BIT_PM;
hour = (hour + 11) % 12 + 1;
BIN_TO_BCD(hour);
inbuf[3] |= hour;
}
inbuf[4] = 0; /* ignore week */
BIN_TO_BCD(day);
inbuf[5] = day;
BIN_TO_BCD(month);
inbuf[6] = month;
if (century >= 20)
inbuf[6] |= Rx5C348_BIT_Y2K;
BIN_TO_BCD(year);
inbuf[7] = year;
/* write in one transfer to avoid data inconsistency */
return spi_rtc_io(inbuf, NULL, 8);
}
static unsigned long
rtc_rx5c348_get_time(void)
{
unsigned char inbuf[8], outbuf[8];
unsigned int year, month, day, hour, minute, second;
inbuf[0] = Rx5C348_CMD_MR(Rx5C348_REG_SECOND);
memset(inbuf + 1, 0, 7);
/* read in one transfer to avoid data inconsistency */
if (spi_rtc_io(inbuf, outbuf, 8))
return 0;
second = outbuf[1];
BCD_TO_BIN(second);
minute = outbuf[2];
BCD_TO_BIN(minute);
if (srtc_24h) {
hour = outbuf[3];
BCD_TO_BIN(hour);
} else {
hour = outbuf[3] & ~Rx5C348_BIT_PM;
BCD_TO_BIN(hour);
hour %= 12;
if (outbuf[3] & Rx5C348_BIT_PM)
hour += 12;
}
day = outbuf[5];
BCD_TO_BIN(day);
month = outbuf[6] & ~Rx5C348_BIT_Y2K;
BCD_TO_BIN(month);
year = outbuf[7];
BCD_TO_BIN(year);
year += EPOCH;
return mktime(year, month, day, hour, minute, second);
}
void __init
rtc_rx5c348_init(int chipid)
{
unsigned char inbuf[2], outbuf[2];
srtc_chipid = chipid;
/* turn on RTC if it is not on */
inbuf[0] = Rx5C348_CMD_R(Rx5C348_REG_CTL2);
inbuf[1] = 0;
spi_rtc_io(inbuf, outbuf, 2);
if (outbuf[1] & Rx5C348_BIT_XSTP) {
inbuf[0] = Rx5C348_CMD_W(Rx5C348_REG_CTL2);
inbuf[1] = 0;
spi_rtc_io(inbuf, NULL, 2);
}
inbuf[0] = Rx5C348_CMD_R(Rx5C348_REG_CTL1);
inbuf[1] = 0;
spi_rtc_io(inbuf, outbuf, 2);
if (outbuf[1] & Rx5C348_BIT_24H)
srtc_24h = 1;
/* set the function pointers */
rtc_get_time = rtc_rx5c348_get_time;
rtc_set_time = rtc_rx5c348_set_time;
}
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