275 lines
8.8 KiB
C
275 lines
8.8 KiB
C
/*
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* (C) Copyright 2002 SIXNET, dge@sixnetio.com.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*
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* Date & Time support for DS1306 RTC using software SPI
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*/
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#include <common.h>
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#include <command.h>
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#include <rtc.h>
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#if defined(CONFIG_RTC_DS1306) && (CONFIG_COMMANDS & CFG_CMD_DATE)
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static unsigned int bin2bcd(unsigned int n);
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static unsigned char bcd2bin(unsigned char c);
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static void soft_spi_send(unsigned char n);
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static unsigned char soft_spi_read(void);
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static void init_spi(void);
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/*-----------------------------------------------------------------------
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* Definitions
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*/
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#define PB_SPISCK 0x00000002 /* PB 30 */
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#define PB_SPIMOSI 0x00000004 /* PB 29 */
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#define PB_SPIMISO 0x00000008 /* PB 28 */
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#define PB_SPI_CE 0x00010000 /* PB 15 */
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/* ------------------------------------------------------------------------- */
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/* read clock time from DS1306 and return it in *tmp */
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void rtc_get(struct rtc_time *tmp)
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{
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volatile immap_t *immap = (immap_t *)CFG_IMMR;
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unsigned char spi_byte; /* Data Byte */
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init_spi(); /* set port B for software SPI */
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/* Now we can enable the DS1306 RTC */
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immap->im_cpm.cp_pbdat |= PB_SPI_CE;
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udelay(10);
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/* Shift out the address (0) of the time in the Clock Chip */
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soft_spi_send(0);
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/* Put the clock readings into the rtc_time structure */
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tmp->tm_sec = bcd2bin(soft_spi_read()); /* Read seconds */
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tmp->tm_min = bcd2bin(soft_spi_read()); /* Read minutes */
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/* Hours are trickier */
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spi_byte = soft_spi_read(); /* Read Hours into temporary value */
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if (spi_byte & 0x40) {
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/* 12 hour mode bit is set (time is in 1-12 format) */
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if (spi_byte & 0x20) {
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/* since PM we add 11 to get 0-23 for hours */
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tmp->tm_hour = (bcd2bin(spi_byte & 0x1F)) + 11;
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}
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else {
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/* since AM we subtract 1 to get 0-23 for hours */
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tmp->tm_hour = (bcd2bin(spi_byte & 0x1F)) - 1;
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}
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}
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else {
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/* Otherwise, 0-23 hour format */
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tmp->tm_hour = (bcd2bin(spi_byte & 0x3F));
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}
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soft_spi_read(); /* Read and discard Day of week */
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tmp->tm_mday = bcd2bin(soft_spi_read()); /* Read Day of the Month */
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tmp->tm_mon = bcd2bin(soft_spi_read()); /* Read Month */
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/* Read Year and convert to this century */
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tmp->tm_year = bcd2bin(soft_spi_read()) + 2000;
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/* Now we can disable the DS1306 RTC */
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immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
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udelay(10);
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GregorianDay(tmp); /* Determine the day of week */
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debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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}
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/* ------------------------------------------------------------------------- */
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/* set clock time in DS1306 RTC and in MPC8xx RTC */
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void rtc_set(struct rtc_time *tmp)
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{
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volatile immap_t *immap = (immap_t *)CFG_IMMR;
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init_spi(); /* set port B for software SPI */
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/* Now we can enable the DS1306 RTC */
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immap->im_cpm.cp_pbdat |= PB_SPI_CE; /* Enable DS1306 Chip */
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udelay(10);
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/* First disable write protect in the clock chip control register */
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soft_spi_send(0x8F); /* send address of the control register */
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soft_spi_send(0x00); /* send control register contents */
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/* Now disable the DS1306 to terminate the write */
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immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
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udelay(10);
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/* Now enable the DS1306 to initiate a new write */
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immap->im_cpm.cp_pbdat |= PB_SPI_CE;
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udelay(10);
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/* Next, send the address of the clock time write registers */
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soft_spi_send(0x80); /* send address of the first time register */
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/* Use Burst Mode to send all of the time data to the clock */
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bin2bcd(tmp->tm_sec);
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soft_spi_send(bin2bcd(tmp->tm_sec)); /* Send Seconds */
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soft_spi_send(bin2bcd(tmp->tm_min)); /* Send Minutes */
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soft_spi_send(bin2bcd(tmp->tm_hour)); /* Send Hour */
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soft_spi_send(bin2bcd(tmp->tm_wday)); /* Send Day of the Week */
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soft_spi_send(bin2bcd(tmp->tm_mday)); /* Send Day of Month */
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soft_spi_send(bin2bcd(tmp->tm_mon)); /* Send Month */
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soft_spi_send(bin2bcd(tmp->tm_year - 2000)); /* Send Year */
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/* Now we can disable the Clock chip to terminate the burst write */
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immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
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udelay(10);
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/* Now we can enable the Clock chip to initiate a new write */
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immap->im_cpm.cp_pbdat |= PB_SPI_CE; /* Enable DS1306 Chip */
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udelay(10);
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/* First we Enable write protect in the clock chip control register */
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soft_spi_send(0x8F); /* send address of the control register */
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soft_spi_send(0x40); /* send out Control Register contents */
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/* Now disable the DS1306 */
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immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
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udelay(10);
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/* Set standard MPC8xx clock to the same time so Linux will
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* see the time even if it doesn't have a DS1306 clock driver.
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* This helps with experimenting with standard kernels.
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*/
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{
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ulong tim;
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tim = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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immap->im_sitk.sitk_rtck = KAPWR_KEY;
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immap->im_sit.sit_rtc = tim;
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}
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debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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}
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/* ------------------------------------------------------------------------- */
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void rtc_reset(void)
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{
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return; /* nothing to do */
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}
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/* ------------------------------------------------------------------------- */
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static unsigned char bcd2bin(unsigned char n)
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{
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return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
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}
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/* ------------------------------------------------------------------------- */
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static unsigned int bin2bcd(unsigned int n)
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{
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return (((n / 10) << 4) | (n % 10));
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}
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/* ------------------------------------------------------------------------- */
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/* Initialize Port B for software SPI */
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static void init_spi(void) {
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volatile immap_t *immap = (immap_t *)CFG_IMMR;
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/* Force output pins to begin at logic 0 */
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immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
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/* Set these 3 signals as outputs */
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immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
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immap->im_cpm.cp_pbdir &= ~PB_SPIMISO; /* Make MISO pin an input */
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udelay(10);
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}
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/* ------------------------------------------------------------------------- */
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/* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
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static void soft_spi_send(unsigned char n)
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{
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volatile immap_t *immap = (immap_t *)CFG_IMMR;
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unsigned char bitpos; /* bit position to receive */
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unsigned char i; /* Loop Control */
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/* bit position to send, start with most significant bit */
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bitpos = 0x80;
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/* Send 8 bits to software SPI */
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for (i = 0; i < 8; i++) { /* Loop for 8 bits */
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immap->im_cpm.cp_pbdat |= PB_SPISCK; /* Raise SCK */
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if (n & bitpos)
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immap->im_cpm.cp_pbdat |= PB_SPIMOSI; /* Set MOSI to 1 */
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else
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immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI; /* Set MOSI to 0 */
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udelay(10);
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immap->im_cpm.cp_pbdat &= ~PB_SPISCK; /* Lower SCK */
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udelay(10);
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bitpos >>= 1; /* Shift for next bit position */
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}
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}
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/* ------------------------------------------------------------------------- */
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/* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
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static unsigned char soft_spi_read(void)
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{
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volatile immap_t *immap = (immap_t *)CFG_IMMR;
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unsigned char spi_byte = 0; /* Return value, assume success */
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unsigned char bitpos; /* bit position to receive */
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unsigned char i; /* Loop Control */
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/* bit position to receive, start with most significant bit */
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bitpos = 0x80;
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/* Read 8 bits here */
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for (i = 0; i < 8; i++) { /* Do 8 bits in loop */
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immap->im_cpm.cp_pbdat |= PB_SPISCK; /* Raise SCK */
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udelay(10);
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if (immap->im_cpm.cp_pbdat & PB_SPIMISO) /* Get a bit of data */
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spi_byte |= bitpos; /* Set data accordingly */
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immap->im_cpm.cp_pbdat &= ~PB_SPISCK; /* Lower SCK */
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udelay(10);
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bitpos >>= 1; /* Shift for next bit position */
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}
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return spi_byte; /* Return the byte read */
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}
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/* ------------------------------------------------------------------------- */
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#endif
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