diff options
Diffstat (limited to 'drivers/rtc/ds1306.c')
| -rw-r--r-- | drivers/rtc/ds1306.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/drivers/rtc/ds1306.c b/drivers/rtc/ds1306.c new file mode 100644 index 0000000000..89e433dabd --- /dev/null +++ b/drivers/rtc/ds1306.c @@ -0,0 +1,438 @@ +/* + * (C) Copyright 2002 SIXNET, dge@sixnetio.com. + * + * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net> + * Stephan Linz <linz@li-pro.net> + * + * 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 SPI: + * + * - SXNI855T: it uses its own soft SPI here in this file + * - all other: use the external spi_xfer() function + * (see include/spi.h) + */ + +#include <common.h> +#include <command.h> +#include <rtc.h> +#include <spi.h> + +#if defined(CONFIG_RTC_DS1306) && defined(CONFIG_CMD_DATE) + +#define RTC_SECONDS 0x00 +#define RTC_MINUTES 0x01 +#define RTC_HOURS 0x02 +#define RTC_DAY_OF_WEEK 0x03 +#define RTC_DATE_OF_MONTH 0x04 +#define RTC_MONTH 0x05 +#define RTC_YEAR 0x06 + +#define RTC_SECONDS_ALARM0 0x07 +#define RTC_MINUTES_ALARM0 0x08 +#define RTC_HOURS_ALARM0 0x09 +#define RTC_DAY_OF_WEEK_ALARM0 0x0a + +#define RTC_SECONDS_ALARM1 0x0b +#define RTC_MINUTES_ALARM1 0x0c +#define RTC_HOURS_ALARM1 0x0d +#define RTC_DAY_OF_WEEK_ALARM1 0x0e + +#define RTC_CONTROL 0x0f +#define RTC_STATUS 0x10 +#define RTC_TRICKLE_CHARGER 0x11 + +#define RTC_USER_RAM_BASE 0x20 + +/* + * External table of chip select functions (see the appropriate board + * support for the actual definition of the table). + */ +extern spi_chipsel_type spi_chipsel[]; +extern int spi_chipsel_cnt; + +static unsigned int bin2bcd (unsigned int n); +static unsigned char bcd2bin (unsigned char c); + +/* ************************************************************************* */ +#ifdef CONFIG_SXNI855T /* !!! SHOULD BE CHANGED TO NEW CODE !!! */ + +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); +} + +/* ------------------------------------------------------------------------- */ + +/* 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 */ +} + +/* ------------------------------------------------------------------------- */ + +void rtc_reset (void) +{ + return; /* nothing to do */ +} + +#else /* not CONFIG_SXNI855T */ +/* ************************************************************************* */ + +static unsigned char rtc_read (unsigned char reg); +static void rtc_write (unsigned char reg, unsigned char val); + +/* read clock time from DS1306 and return it in *tmp */ +void rtc_get (struct rtc_time *tmp) +{ + unsigned char sec, min, hour, mday, wday, mon, year; + + sec = rtc_read (RTC_SECONDS); + min = rtc_read (RTC_MINUTES); + hour = rtc_read (RTC_HOURS); + mday = rtc_read (RTC_DATE_OF_MONTH); + wday = rtc_read (RTC_DAY_OF_WEEK); + mon = rtc_read (RTC_MONTH); + year = rtc_read (RTC_YEAR); + + debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x\n", + year, mon, mday, wday, hour, min, sec); + debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n", + rtc_read (RTC_DAY_OF_WEEK_ALARM0), + rtc_read (RTC_HOURS_ALARM0), + rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0)); + debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n", + rtc_read (RTC_DAY_OF_WEEK_ALARM1), + rtc_read (RTC_HOURS_ALARM1), + rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1)); + + tmp->tm_sec = bcd2bin (sec & 0x7F); /* convert Seconds */ + tmp->tm_min = bcd2bin (min & 0x7F); /* convert Minutes */ + + /* convert Hours */ + tmp->tm_hour = (hour & 0x40) + ? ((hour & 0x20) /* 12 hour mode */ + ? bcd2bin (hour & 0x1F) + 11 /* PM */ + : bcd2bin (hour & 0x1F) - 1 /* AM */ + ) + : bcd2bin (hour & 0x3F); /* 24 hour mode */ + + tmp->tm_mday = bcd2bin (mday & 0x3F); /* convert Day of the Month */ + tmp->tm_mon = bcd2bin (mon & 0x1F); /* convert Month */ + tmp->tm_year = bcd2bin (year) + 2000; /* convert Year */ + tmp->tm_wday = bcd2bin (wday & 0x07) - 1; /* convert Day of the Week */ + tmp->tm_yday = 0; + tmp->tm_isdst = 0; + + 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 from *tmp in DS1306 RTC */ +void rtc_set (struct rtc_time *tmp) +{ + 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); + + rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec)); + rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min)); + rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour)); + rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1)); + rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday)); + rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon)); + rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000)); +} + +/* ------------------------------------------------------------------------- */ + +/* reset the DS1306 */ +void rtc_reset (void) +{ + /* clear the control register */ + rtc_write (RTC_CONTROL, 0x00); /* 1st step: reset WP */ + rtc_write (RTC_CONTROL, 0x00); /* 2nd step: reset 1Hz, AIE1, AIE0 */ + + /* reset all alarms */ + rtc_write (RTC_SECONDS_ALARM0, 0x00); + rtc_write (RTC_SECONDS_ALARM1, 0x00); + rtc_write (RTC_MINUTES_ALARM0, 0x00); + rtc_write (RTC_MINUTES_ALARM1, 0x00); + rtc_write (RTC_HOURS_ALARM0, 0x00); + rtc_write (RTC_HOURS_ALARM1, 0x00); + rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00); + rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00); +} + +/* ------------------------------------------------------------------------- */ + +static unsigned char rtc_read (unsigned char reg) +{ + unsigned char dout[2]; /* SPI Output Data Bytes */ + unsigned char din[2]; /* SPI Input Data Bytes */ + + dout[0] = reg; + + if (spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din) != 0) { + return 0; + } else { + return din[1]; + } +} + +/* ------------------------------------------------------------------------- */ + +static void rtc_write (unsigned char reg, unsigned char val) +{ + unsigned char dout[2]; /* SPI Output Data Bytes */ + unsigned char din[2]; /* SPI Input Data Bytes */ + + dout[0] = 0x80 | reg; + dout[1] = val; + + spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din); +} + +#endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */ + +/* ------------------------------------------------------------------------- */ + +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)); +} +/* ------------------------------------------------------------------------- */ + +#endif |