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