diff options
Diffstat (limited to 'arch/cris/arch-v10/drivers/ds1302.c')
| -rw-r--r-- | arch/cris/arch-v10/drivers/ds1302.c | 602 |
1 files changed, 602 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/drivers/ds1302.c b/arch/cris/arch-v10/drivers/ds1302.c new file mode 100644 index 0000000..fba530f --- /dev/null +++ b/arch/cris/arch-v10/drivers/ds1302.c @@ -0,0 +1,602 @@ +/*!*************************************************************************** +*! +*! FILE NAME : ds1302.c +*! +*! DESCRIPTION: Implements an interface for the DS1302 RTC through Etrax I/O +*! +*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init +*! +*! $Log: ds1302.c,v $ +*! Revision 1.14 2004/08/24 06:48:43 starvik +*! Whitespace cleanup +*! +*! Revision 1.13 2004/05/28 09:26:59 starvik +*! Modified I2C initialization to work in 2.6. +*! +*! Revision 1.12 2004/05/14 07:58:03 starvik +*! Merge of changes from 2.4 +*! +*! Revision 1.10 2004/02/04 09:25:12 starvik +*! Merge of Linux 2.6.2 +*! +*! Revision 1.9 2003/07/04 08:27:37 starvik +*! Merge of Linux 2.5.74 +*! +*! Revision 1.8 2003/04/09 05:20:47 starvik +*! Merge of Linux 2.5.67 +*! +*! Revision 1.6 2003/01/09 14:42:51 starvik +*! Merge of Linux 2.5.55 +*! +*! Revision 1.4 2002/12/11 13:13:57 starvik +*! Added arch/ to v10 specific includes +*! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer) +*! +*! Revision 1.3 2002/11/20 11:56:10 starvik +*! Merge of Linux 2.5.48 +*! +*! Revision 1.2 2002/11/18 13:16:06 starvik +*! Linux 2.5 port of latest 2.4 drivers +*! +*! Revision 1.15 2002/10/11 16:14:33 johana +*! Added CONFIG_ETRAX_DS1302_TRICKLE_CHARGE and initial setting of the +*! trcklecharge register. +*! +*! Revision 1.14 2002/10/10 12:15:38 magnusmn +*! Added support for having the RST signal on bit g0 +*! +*! Revision 1.13 2002/05/29 15:16:08 johana +*! Removed unused variables. +*! +*! Revision 1.12 2002/04/10 15:35:25 johana +*! Moved probe function closer to init function and marked it __init. +*! +*! Revision 1.11 2001/06/14 12:35:52 jonashg +*! The ATA hack is back. It is unfortunately the only way to set g27 to output. +*! +*! Revision 1.9 2001/06/14 10:00:14 jonashg +*! No need for tempudelay to be inline anymore (had to adjust the usec to +*! loops conversion because of this to make it slow enough to be a udelay). +*! +*! Revision 1.8 2001/06/14 08:06:32 jonashg +*! Made tempudelay delay usecs (well, just a tad more). +*! +*! Revision 1.7 2001/06/13 14:18:11 jonashg +*! Only allow processes with SYS_TIME capability to set time and charge. +*! +*! Revision 1.6 2001/06/12 15:22:07 jonashg +*! * Made init function __init. +*! * Parameter to out_byte() is unsigned char. +*! * The magic number 42 has got a name. +*! * Removed comment about /proc (nothing is exported there). +*! +*! Revision 1.5 2001/06/12 14:35:13 jonashg +*! Gave the module a name and added it to printk's. +*! +*! Revision 1.4 2001/05/31 14:53:40 jonashg +*! Made tempudelay() inline so that the watchdog doesn't reset (see +*! function comment). +*! +*! Revision 1.3 2001/03/26 16:03:06 bjornw +*! Needs linux/config.h +*! +*! Revision 1.2 2001/03/20 19:42:00 bjornw +*! Use the ETRAX prefix on the DS1302 options +*! +*! Revision 1.1 2001/03/20 09:13:50 magnusmn +*! Linux 2.4 port +*! +*! Revision 1.10 2000/07/05 15:38:23 bjornw +*! Dont update kernel time when a RTC_SET_TIME is done +*! +*! Revision 1.9 2000/03/02 15:42:59 macce +*! * Hack to make RTC work on all 2100/2400 +*! +*! Revision 1.8 2000/02/23 16:59:18 torbjore +*! added setup of R_GEN_CONFIG when RTC is connected to the generic port. +*! +*! Revision 1.7 2000/01/17 15:51:43 johana +*! Added RTC_SET_CHARGE ioctl to enable trickle charger. +*! +*! Revision 1.6 1999/10/27 13:19:47 bjornw +*! Added update_xtime_from_cmos which reads back the updated RTC into the kernel. +*! /dev/rtc calls it now. +*! +*! Revision 1.5 1999/10/27 12:39:37 bjornw +*! Disabled superuser check. Anyone can now set the time. +*! +*! Revision 1.4 1999/09/02 13:27:46 pkj +*! Added shadow for R_PORT_PB_CONFIG. +*! Renamed port_g_shadow to port_g_data_shadow. +*! +*! Revision 1.3 1999/09/02 08:28:06 pkj +*! Made it possible to select either port PB or the generic port for the RST +*! signal line to the DS1302 RTC. +*! Also make sure the RST bit is configured as output on Port PB (if used). +*! +*! Revision 1.2 1999/09/01 14:47:20 bjornw +*! Added support for /dev/rtc operations with ioctl RD_TIME and SET_TIME to read +*! and set the date. Register as major 121. +*! +*! Revision 1.1 1999/09/01 09:45:29 bjornw +*! Implemented a DS1302 RTC driver. +*! +*! +*! --------------------------------------------------------------------------- +*! +*! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN +*! +*! $Id: ds1302.c,v 1.14 2004/08/24 06:48:43 starvik Exp $ +*! +*!***************************************************************************/ + +#include <linux/config.h> + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/miscdevice.h> +#include <linux/delay.h> +#include <linux/bcd.h> + +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/arch/svinto.h> +#include <asm/io.h> +#include <asm/rtc.h> + +#define RTC_MAJOR_NR 121 /* local major, change later */ + +static const char ds1302_name[] = "ds1302"; + +/* The DS1302 might be connected to different bits on different products. + * It has three signals - SDA, SCL and RST. RST and SCL are always outputs, + * but SDA can have a selected direction. + * For now, only PORT_PB is hardcoded. + */ + +/* The RST bit may be on either the Generic Port or Port PB. */ +#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT +#define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x) +#define TK_RST_DIR(x) +#else +#define TK_RST_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x) +#define TK_RST_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_RSTBIT, x) +#endif + + +#define TK_SDA_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SDABIT, x) +#define TK_SCL_OUT(x) REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x) + +#define TK_SDA_IN() ((*R_PORT_PB_READ >> CONFIG_ETRAX_DS1302_SDABIT) & 1) +/* 1 is out, 0 is in */ +#define TK_SDA_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SDABIT, x) +#define TK_SCL_DIR(x) REG_SHADOW_SET(R_PORT_PB_DIR, port_pb_dir_shadow, CONFIG_ETRAX_DS1302_SCLBIT, x) + + +/* + * The reason for tempudelay and not udelay is that loops_per_usec + * (used in udelay) is not set when functions here are called from time.c + */ + +static void tempudelay(int usecs) +{ + volatile int loops; + + for(loops = usecs * 12; loops > 0; loops--) + /* nothing */; +} + + +/* Send 8 bits. */ +static void +out_byte(unsigned char x) +{ + int i; + TK_SDA_DIR(1); + for (i = 8; i--;) { + /* The chip latches incoming bits on the rising edge of SCL. */ + TK_SCL_OUT(0); + TK_SDA_OUT(x & 1); + tempudelay(1); + TK_SCL_OUT(1); + tempudelay(1); + x >>= 1; + } + TK_SDA_DIR(0); +} + +static unsigned char +in_byte(void) +{ + unsigned char x = 0; + int i; + + /* Read byte. Bits come LSB first, on the falling edge of SCL. + * Assume SDA is in input direction already. + */ + TK_SDA_DIR(0); + + for (i = 8; i--;) { + TK_SCL_OUT(0); + tempudelay(1); + x >>= 1; + x |= (TK_SDA_IN() << 7); + TK_SCL_OUT(1); + tempudelay(1); + } + + return x; +} + +/* Prepares for a transaction by de-activating RST (active-low). */ + +static void +start(void) +{ + TK_SCL_OUT(0); + tempudelay(1); + TK_RST_OUT(0); + tempudelay(5); + TK_RST_OUT(1); +} + +/* Ends a transaction by taking RST active again. */ + +static void +stop(void) +{ + tempudelay(2); + TK_RST_OUT(0); +} + +/* Enable writing. */ + +static void +ds1302_wenable(void) +{ + start(); + out_byte(0x8e); /* Write control register */ + out_byte(0x00); /* Disable write protect bit 7 = 0 */ + stop(); +} + +/* Disable writing. */ + +static void +ds1302_wdisable(void) +{ + start(); + out_byte(0x8e); /* Write control register */ + out_byte(0x80); /* Disable write protect bit 7 = 0 */ + stop(); +} + + + +/* Read a byte from the selected register in the DS1302. */ + +unsigned char +ds1302_readreg(int reg) +{ + unsigned char x; + + start(); + out_byte(0x81 | (reg << 1)); /* read register */ + x = in_byte(); + stop(); + + return x; +} + +/* Write a byte to the selected register. */ + +void +ds1302_writereg(int reg, unsigned char val) +{ +#ifndef CONFIG_ETRAX_RTC_READONLY + int do_writereg = 1; +#else + int do_writereg = 0; + + if (reg == RTC_TRICKLECHARGER) + do_writereg = 1; +#endif + + if (do_writereg) { + ds1302_wenable(); + start(); + out_byte(0x80 | (reg << 1)); /* write register */ + out_byte(val); + stop(); + ds1302_wdisable(); + } +} + +void +get_rtc_time(struct rtc_time *rtc_tm) +{ + unsigned long flags; + + local_irq_save(flags); + local_irq_disable(); + + rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); + rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); + rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); + rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); + rtc_tm->tm_mon = CMOS_READ(RTC_MONTH); + rtc_tm->tm_year = CMOS_READ(RTC_YEAR); + + local_irq_restore(flags); + + BCD_TO_BIN(rtc_tm->tm_sec); + BCD_TO_BIN(rtc_tm->tm_min); + BCD_TO_BIN(rtc_tm->tm_hour); + BCD_TO_BIN(rtc_tm->tm_mday); + BCD_TO_BIN(rtc_tm->tm_mon); + BCD_TO_BIN(rtc_tm->tm_year); + + /* + * Account for differences between how the RTC uses the values + * and how they are defined in a struct rtc_time; + */ + + if (rtc_tm->tm_year <= 69) + rtc_tm->tm_year += 100; + + rtc_tm->tm_mon--; +} + +static unsigned char days_in_mo[] = + {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; + +/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */ + +static int +rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, + unsigned long arg) +{ + unsigned long flags; + + switch(cmd) { + case RTC_RD_TIME: /* read the time/date from RTC */ + { + struct rtc_time rtc_tm; + + memset(&rtc_tm, 0, sizeof (struct rtc_time)); + get_rtc_time(&rtc_tm); + if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time))) + return -EFAULT; + return 0; + } + + case RTC_SET_TIME: /* set the RTC */ + { + struct rtc_time rtc_tm; + unsigned char mon, day, hrs, min, sec, leap_yr; + unsigned int yrs; + + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time))) + return -EFAULT; + + yrs = rtc_tm.tm_year + 1900; + mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ + day = rtc_tm.tm_mday; + hrs = rtc_tm.tm_hour; + min = rtc_tm.tm_min; + sec = rtc_tm.tm_sec; + + + if ((yrs < 1970) || (yrs > 2069)) + return -EINVAL; + + leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); + + if ((mon > 12) || (day == 0)) + return -EINVAL; + + if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) + return -EINVAL; + + if ((hrs >= 24) || (min >= 60) || (sec >= 60)) + return -EINVAL; + + if (yrs >= 2000) + yrs -= 2000; /* RTC (0, 1, ... 69) */ + else + yrs -= 1900; /* RTC (70, 71, ... 99) */ + + BIN_TO_BCD(sec); + BIN_TO_BCD(min); + BIN_TO_BCD(hrs); + BIN_TO_BCD(day); + BIN_TO_BCD(mon); + BIN_TO_BCD(yrs); + + local_irq_save(flags); + local_irq_disable(); + CMOS_WRITE(yrs, RTC_YEAR); + CMOS_WRITE(mon, RTC_MONTH); + CMOS_WRITE(day, RTC_DAY_OF_MONTH); + CMOS_WRITE(hrs, RTC_HOURS); + CMOS_WRITE(min, RTC_MINUTES); + CMOS_WRITE(sec, RTC_SECONDS); + local_irq_restore(flags); + + /* Notice that at this point, the RTC is updated but + * the kernel is still running with the old time. + * You need to set that separately with settimeofday + * or adjtimex. + */ + return 0; + } + + case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */ + { + int tcs_val; + + if (!capable(CAP_SYS_TIME)) + return -EPERM; + + if(copy_from_user(&tcs_val, (int*)arg, sizeof(int))) + return -EFAULT; + + tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F); + ds1302_writereg(RTC_TRICKLECHARGER, tcs_val); + return 0; + } + case RTC_VLOW_RD: + { + /* TODO: + * Implement voltage low detection support + */ + printk(KERN_WARNING "DS1302: RTC Voltage Low detection" + " is not supported\n"); + return 0; + } + case RTC_VLOW_SET: + { + /* TODO: + * Nothing to do since Voltage Low detection is not supported + */ + return 0; + } + default: + return -ENOIOCTLCMD; + } +} + +static void +print_rtc_status(void) +{ + struct rtc_time tm; + + get_rtc_time(&tm); + + /* + * There is no way to tell if the luser has the RTC set for local + * time or for Universal Standard Time (GMT). Probably local though. + */ + + printk(KERN_INFO "rtc_time\t: %02d:%02d:%02d\n", + tm.tm_hour, tm.tm_min, tm.tm_sec); + printk(KERN_INFO "rtc_date\t: %04d-%02d-%02d\n", + tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday); +} + +/* The various file operations we support. */ + +static struct file_operations rtc_fops = { + .owner = THIS_MODULE, + .ioctl = rtc_ioctl, +}; + +/* Probe for the chip by writing something to its RAM and try reading it back. */ + +#define MAGIC_PATTERN 0x42 + +static int __init +ds1302_probe(void) +{ + int retval, res; + + TK_RST_DIR(1); + TK_SCL_DIR(1); + TK_SDA_DIR(0); + + /* Try to talk to timekeeper. */ + + ds1302_wenable(); + start(); + out_byte(0xc0); /* write RAM byte 0 */ + out_byte(MAGIC_PATTERN); /* write something magic */ + start(); + out_byte(0xc1); /* read RAM byte 0 */ + + if((res = in_byte()) == MAGIC_PATTERN) { + stop(); + ds1302_wdisable(); + printk(KERN_INFO "%s: RTC found.\n", ds1302_name); + printk(KERN_INFO "%s: SDA, SCL, RST on PB%i, PB%i, %s%i\n", + ds1302_name, + CONFIG_ETRAX_DS1302_SDABIT, + CONFIG_ETRAX_DS1302_SCLBIT, +#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT + "GENIO", +#else + "PB", +#endif + CONFIG_ETRAX_DS1302_RSTBIT); + print_rtc_status(); + retval = 1; + } else { + stop(); + retval = 0; + } + + return retval; +} + + +/* Just probe for the RTC and register the device to handle the ioctl needed. */ + +int __init +ds1302_init(void) +{ + i2c_init(); + + if (!ds1302_probe()) { +#ifdef CONFIG_ETRAX_DS1302_RST_ON_GENERIC_PORT +#if CONFIG_ETRAX_DS1302_RSTBIT == 27 + /* + * The only way to set g27 to output is to enable ATA. + * + * Make sure that R_GEN_CONFIG is setup correct. + */ + genconfig_shadow = ((genconfig_shadow & + ~IO_MASK(R_GEN_CONFIG, ata)) | + (IO_STATE(R_GEN_CONFIG, ata, select))); + *R_GEN_CONFIG = genconfig_shadow; +#elif CONFIG_ETRAX_DS1302_RSTBIT == 0 + + /* Set the direction of this bit to out. */ + genconfig_shadow = ((genconfig_shadow & + ~IO_MASK(R_GEN_CONFIG, g0dir)) | + (IO_STATE(R_GEN_CONFIG, g0dir, out))); + *R_GEN_CONFIG = genconfig_shadow; +#endif + if (!ds1302_probe()) { + printk(KERN_WARNING "%s: RTC not found.\n", ds1302_name); + return -1; + } +#else + printk(KERN_WARNING "%s: RTC not found.\n", ds1302_name); + return -1; +#endif + } + /* Initialise trickle charger */ + ds1302_writereg(RTC_TRICKLECHARGER, + RTC_TCR_PATTERN |(CONFIG_ETRAX_DS1302_TRICKLE_CHARGE & 0x0F)); + /* Start clock by resetting CLOCK_HALT */ + ds1302_writereg(RTC_SECONDS, (ds1302_readreg(RTC_SECONDS) & 0x7F)); + return 0; +} + +static int __init ds1302_register(void) +{ + ds1302_init(); + if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) { + printk(KERN_INFO "%s: unable to get major %d for rtc\n", + ds1302_name, RTC_MAJOR_NR); + return -1; + } + return 0; + +} + +module_init(ds1302_register); |
