diff options
Diffstat (limited to 'arch/mips/tx4938/common/rtc_rx5c348.c')
| -rw-r--r-- | arch/mips/tx4938/common/rtc_rx5c348.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/mips/tx4938/common/rtc_rx5c348.c b/arch/mips/tx4938/common/rtc_rx5c348.c new file mode 100644 index 00000000000..d249edbb6af --- /dev/null +++ b/arch/mips/tx4938/common/rtc_rx5c348.c @@ -0,0 +1,202 @@ +/* + * 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; +} |