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u-boot/drivers/rtc/m41t60.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style 
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

240 lines
6.5 KiB
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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2007
* Larry Johnson, lrj@acm.org
*
* based on rtc/m41t11.c which is ...
*
* (C) Copyright 2002
* Andrew May, Viasat Inc, amay@viasat.com
*/
/*
* STMicroelectronics M41T60 serial access real-time clock
*/
/* #define DEBUG 1 */
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
/*
* Convert between century and "century bits" (CB1 and CB0). These routines
* assume years are in the range 1900 - 2299.
*/
static unsigned char year2cb(unsigned const year)
{
if (year < 1900 || year >= 2300)
printf("M41T60 RTC: year %d out of range\n", year);
return (year / 100) & 0x3;
}
static unsigned cb2year(unsigned const cb)
{
return 1900 + 100 * ((cb + 1) & 0x3);
}
/*
* These are simple defines for the chip local to here so they aren't too
* verbose. DAY/DATE aren't nice but that is how they are on the data sheet.
*/
#define RTC_SEC 0x0
#define RTC_MIN 0x1
#define RTC_HOUR 0x2
#define RTC_DAY 0x3
#define RTC_DATE 0x4
#define RTC_MONTH 0x5
#define RTC_YEAR 0x6
#define RTC_REG_CNT 7
#define RTC_CTRL 0x7
#if defined(DEBUG)
static void rtc_dump(char const *const label)
{
uchar data[8];
if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
printf("I2C read failed in rtc_dump()\n");
return;
}
printf("RTC dump %s: %02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X\n",
label, data[0], data[1], data[2], data[3],
data[4], data[5], data[6], data[7]);
}
#else
#define rtc_dump(label)
#endif
static uchar *rtc_validate(void)
{
/*
* This routine uses the OUT bit and the validity of the time values to
* determine whether there has been an initial power-up since the last
* time the routine was run. It assumes that the OUT bit is not being
* used for any other purpose.
*/
static const uchar daysInMonth[0x13] = {
0x00, 0x31, 0x29, 0x31, 0x30, 0x31, 0x30, 0x31,
0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x31, 0x30, 0x31
};
static uchar data[8];
uchar min, date, month, years;
rtc_dump("begin validate");
if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
printf("I2C read failed in rtc_validate()\n");
return 0;
}
/*
* If the OUT bit is "1", there has been a loss of power, so stop the
* oscillator so it can be "kick-started" as per data sheet.
*/
if (0x00 != (data[RTC_CTRL] & 0x80)) {
printf("M41T60 RTC clock lost power.\n");
data[RTC_SEC] = 0x80;
if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC, 1, data, 1)) {
printf("I2C write failed in rtc_validate()\n");
return 0;
}
}
/*
* If the oscillator is stopped or the date is invalid, then reset the
* OUT bit to "0", reset the date registers, and start the oscillator.
*/
min = data[RTC_MIN] & 0x7F;
date = data[RTC_DATE];
month = data[RTC_MONTH] & 0x3F;
years = data[RTC_YEAR];
if (0x59 < data[RTC_SEC] || 0x09 < (data[RTC_SEC] & 0x0F) ||
0x59 < min || 0x09 < (min & 0x0F) ||
0x23 < data[RTC_HOUR] || 0x09 < (data[RTC_HOUR] & 0x0F) ||
0x07 < data[RTC_DAY] || 0x00 == data[RTC_DAY] ||
0x12 < month ||
0x99 < years || 0x09 < (years & 0x0F) ||
daysInMonth[month] < date || 0x09 < (date & 0x0F) || 0x00 == date ||
(0x29 == date && 0x02 == month &&
((0x00 != (years & 0x03)) ||
(0x00 == years && 0x00 != (data[RTC_MONTH] & 0xC0))))) {
printf("Resetting M41T60 RTC clock.\n");
/*
* Set to 00:00:00 1900-01-01 (Monday)
*/
data[RTC_SEC] = 0x00;
data[RTC_MIN] &= 0x80; /* preserve OFIE bit */
data[RTC_HOUR] = 0x00;
data[RTC_DAY] = 0x02;
data[RTC_DATE] = 0x01;
data[RTC_MONTH] = 0xC1;
data[RTC_YEAR] = 0x00;
data[RTC_CTRL] &= 0x7F; /* reset OUT bit */
if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
printf("I2C write failed in rtc_validate()\n");
return 0;
}
}
return data;
}
int rtc_get(struct rtc_time *tmp)
{
uchar const *const data = rtc_validate();
if (!data)
return -1;
tmp->tm_sec = bcd2bin(data[RTC_SEC] & 0x7F);
tmp->tm_min = bcd2bin(data[RTC_MIN] & 0x7F);
tmp->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3F);
tmp->tm_mday = bcd2bin(data[RTC_DATE] & 0x3F);
tmp->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1F);
tmp->tm_year = cb2year(data[RTC_MONTH] >> 6) + bcd2bin(data[RTC_YEAR]);
tmp->tm_wday = bcd2bin(data[RTC_DAY] & 0x07) - 1;
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);
return 0;
}
int rtc_set(struct rtc_time *tmp)
{
uchar *const data = rtc_validate();
if (!data)
return -1;
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);
data[RTC_SEC] = (data[RTC_SEC] & 0x80) | (bin2bcd(tmp->tm_sec) & 0x7F);
data[RTC_MIN] = (data[RTC_MIN] & 0X80) | (bin2bcd(tmp->tm_min) & 0X7F);
data[RTC_HOUR] = bin2bcd(tmp->tm_hour) & 0x3F;
data[RTC_DATE] = bin2bcd(tmp->tm_mday) & 0x3F;
data[RTC_MONTH] = bin2bcd(tmp->tm_mon) & 0x1F;
data[RTC_YEAR] = bin2bcd(tmp->tm_year % 100);
data[RTC_MONTH] |= year2cb(tmp->tm_year) << 6;
data[RTC_DAY] = bin2bcd(tmp->tm_wday + 1) & 0x07;
if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, RTC_REG_CNT)) {
printf("I2C write failed in rtc_set()\n");
return -1;
}
return 0;
}
void rtc_reset(void)
{
uchar *const data = rtc_validate();
char const *const s = env_get("rtccal");
if (!data)
return;
rtc_dump("begin reset");
/*
* If environmental variable "rtccal" is present, it must be a hex value
* between 0x00 and 0x3F, inclusive. The five least-significan bits
* represent the calibration magnitude, and the sixth bit the sign bit.
* If these do not match the contents of the hardware register, that
* register is updated. The value 0x00 imples no correction. Consult
* the M41T60 documentation for further details.
*/
if (s) {
unsigned long const l = simple_strtoul(s, 0, 16);
if (l <= 0x3F) {
if ((data[RTC_CTRL] & 0x3F) != l) {
printf("Setting RTC calibration to 0x%02lX\n",
l);
data[RTC_CTRL] &= 0xC0;
data[RTC_CTRL] |= (uchar) l;
}
} else
printf("environment parameter \"rtccal\" not valid: "
"ignoring\n");
}
/*
* Turn off frequency test.
*/
data[RTC_CTRL] &= 0xBF;
if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CTRL, 1, data + RTC_CTRL, 1)) {
printf("I2C write failed in rtc_reset()\n");
return;
}
rtc_dump("end reset");
}
#endif /* CONFIG_RTC_M41T60 && CONFIG_SYS_I2C_RTC_ADDR && CONFIG_CMD_DATE */
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