u-boot/drivers/rtc/s35392a.c
Tom Rini d678a59d2d Revert "Merge patch series "arm: dts: am62-beagleplay: Fix Beagleplay Ethernet""
When bringing in the series 'arm: dts: am62-beagleplay: Fix Beagleplay
Ethernet"' I failed to notice that b4 noticed it was based on next and
so took that as the base commit and merged that part of next to master.

This reverts commit c8ffd1356d, reversing
changes made to 2ee6f3a5f7.

Reported-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Tom Rini <trini@konsulko.com>
2024-05-19 08:16:36 -06:00

375 lines
8.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* SII Semiconductor Corporation S35392A RTC driver.
*
* Copyright (c) 2017, General Electric Company
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <command.h>
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <linux/bitrev.h>
#include <rtc.h>
#include <linux/delay.h>
#define S35390A_CHIP_ADDR 0x30
#define S35390A_CMD_STATUS1 0x0
#define S35390A_CMD_STATUS2 0x1
#define S35390A_CMD_TIME1 0x2
#define S35390A_CMD_TIME2 0x3
#define S35390A_CMD_INT2_REG1 0x5
#define S35390A_BYTE_YEAR 0
#define S35390A_BYTE_MONTH 1
#define S35390A_BYTE_DAY 2
#define S35390A_BYTE_WDAY 3
#define S35390A_BYTE_HOURS 4
#define S35390A_BYTE_MINS 5
#define S35390A_BYTE_SECS 6
/* flags for STATUS1 */
#define S35390A_FLAG_POC 0x01
#define S35390A_FLAG_BLD 0x02
#define S35390A_FLAG_INT2 0x04
#define S35390A_FLAG_24H 0x40
#define S35390A_FLAG_RESET 0x80
/*
* If either BLD or POC is set, then the chip has lost power long enough for
* the time value to become invalid.
*/
#define S35390A_LOW_VOLTAGE (S35390A_FLAG_POC | S35390A_FLAG_BLD)
/*---------------------------------------------------------------------*/
#undef DEBUG_RTC
#ifdef DEBUG_RTC
#define DEBUGR(fmt, args...) printf(fmt, ##args)
#else
#define DEBUGR(fmt, args...)
#endif
/*---------------------------------------------------------------------*/
#ifdef CONFIG_DM_RTC
#define DEV_TYPE struct udevice
#else
/* Local udevice */
struct ludevice {
u8 chip;
};
#define DEV_TYPE struct ludevice
struct ludevice dev;
#endif
#define msleep(a) udelay(a * 1000)
int lowvoltage;
static int s35392a_rtc_reset(DEV_TYPE *dev);
static int s35392a_rtc_read(DEV_TYPE *dev, u8 reg, u8 *buf, int len)
{
int ret;
#ifdef CONFIG_DM_RTC
ret = dm_i2c_read(dev, reg, buf, len);
#else
(void)dev;
ret = i2c_read(S35390A_CHIP_ADDR | reg, 0, -1, buf, len);
#endif
return ret;
}
static int s35392a_rtc_write(DEV_TYPE *dev, u8 reg, u8 *buf, int len)
{
int ret;
#ifdef CONFIG_DM_RTC
ret = dm_i2c_write(dev, reg, buf, len);
#else
(void)dev;
ret = i2c_write(S35390A_CHIP_ADDR | reg, 0, 0, buf, len);
#endif
return ret;
}
static int s35392a_rtc_read8(DEV_TYPE *dev, unsigned int reg)
{
u8 val;
int ret;
ret = s35392a_rtc_read(dev, reg, &val, sizeof(val));
return ret < 0 ? ret : val;
}
static int s35392a_rtc_write8(DEV_TYPE *dev, unsigned int reg, int val)
{
int ret;
u8 lval = val;
ret = s35392a_rtc_write(dev, reg, &lval, sizeof(lval));
return ret < 0 ? ret : 0;
}
static int validate_time(const struct rtc_time *tm)
{
if ((tm->tm_year < 2000) || (tm->tm_year > 2099))
return -EINVAL;
if ((tm->tm_mon < 1) || (tm->tm_mon > 12))
return -EINVAL;
if ((tm->tm_mday < 1) || (tm->tm_mday > 31))
return -EINVAL;
if ((tm->tm_wday < 0) || (tm->tm_wday > 6))
return -EINVAL;
if ((tm->tm_hour < 0) || (tm->tm_hour > 23))
return -EINVAL;
if ((tm->tm_min < 0) || (tm->tm_min > 59))
return -EINVAL;
if ((tm->tm_sec < 0) || (tm->tm_sec > 59))
return -EINVAL;
return 0;
}
void s35392a_rtc_init(DEV_TYPE *dev)
{
int status;
status = s35392a_rtc_read8(dev, S35390A_CMD_STATUS1);
if (status < 0)
goto error;
DEBUGR("init: S35390A_CMD_STATUS1: 0x%x\n", status);
lowvoltage = status & S35390A_LOW_VOLTAGE ? 1 : 0;
if (status & S35390A_FLAG_POC)
/*
* Do not communicate for 0.5 seconds since the power-on
* detection circuit is in operation.
*/
msleep(500);
else if (!lowvoltage)
/*
* If both POC and BLD are unset everything is fine.
*/
return;
if (lowvoltage)
printf("RTC low voltage detected\n");
if (!s35392a_rtc_reset(dev))
return;
error:
printf("Error RTC init.\n");
}
/* Get the current time from the RTC */
static int s35392a_rtc_get(DEV_TYPE *dev, struct rtc_time *tm)
{
u8 date[7];
int ret, i;
if (lowvoltage) {
DEBUGR("RTC low voltage detected\n");
return -EINVAL;
}
ret = s35392a_rtc_read(dev, S35390A_CMD_TIME1, date, sizeof(date));
if (ret < 0) {
DEBUGR("Error reading date from RTC\n");
return -EIO;
}
/* This chip returns the bits of each byte in reverse order */
for (i = 0; i < 7; ++i)
date[i] = bitrev8(date[i]);
tm->tm_sec = bcd2bin(date[S35390A_BYTE_SECS]);
tm->tm_min = bcd2bin(date[S35390A_BYTE_MINS]);
tm->tm_hour = bcd2bin(date[S35390A_BYTE_HOURS] & ~S35390A_FLAG_24H);
tm->tm_wday = bcd2bin(date[S35390A_BYTE_WDAY]);
tm->tm_mday = bcd2bin(date[S35390A_BYTE_DAY]);
tm->tm_mon = bcd2bin(date[S35390A_BYTE_MONTH]);
tm->tm_year = bcd2bin(date[S35390A_BYTE_YEAR]) + 2000;
DEBUGR("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
/* Set the RTC */
static int s35392a_rtc_set(DEV_TYPE *dev, const struct rtc_time *tm)
{
int i, ret;
int status;
u8 date[7];
DEBUGR("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
ret = validate_time(tm);
if (ret < 0)
return -EINVAL;
/* We support only 24h mode */
ret = s35392a_rtc_read8(dev, S35390A_CMD_STATUS1);
if (ret < 0)
return -EIO;
status = ret;
ret = s35392a_rtc_write8(dev, S35390A_CMD_STATUS1,
status | S35390A_FLAG_24H);
if (ret < 0)
return -EIO;
date[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 2000);
date[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon);
date[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
date[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
date[S35390A_BYTE_HOURS] = bin2bcd(tm->tm_hour);
date[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
date[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
/* This chip expects the bits of each byte to be in reverse order */
for (i = 0; i < 7; ++i)
date[i] = bitrev8(date[i]);
ret = s35392a_rtc_write(dev, S35390A_CMD_TIME1, date, sizeof(date));
if (ret < 0) {
DEBUGR("Error writing date to RTC\n");
return -EIO;
}
/* Now we have time. Reset the low voltage status */
lowvoltage = 0;
return 0;
}
/* Reset the RTC. */
static int s35392a_rtc_reset(DEV_TYPE *dev)
{
int buf;
int ret;
unsigned int initcount = 0;
buf = S35390A_FLAG_RESET;
initialize:
ret = s35392a_rtc_write8(dev, S35390A_CMD_STATUS1, buf);
if (ret < 0)
return -EIO;
ret = s35392a_rtc_read8(dev, S35390A_CMD_STATUS1);
if (ret < 0)
return -EIO;
buf = ret;
if (!lowvoltage)
lowvoltage = buf & S35390A_LOW_VOLTAGE ? 1 : 0;
if (buf & S35390A_LOW_VOLTAGE) {
/* Try up to five times to reset the chip */
if (initcount < 5) {
++initcount;
goto initialize;
} else {
return -EIO;
}
}
return 0;
}
#ifndef CONFIG_DM_RTC
int rtc_get(struct rtc_time *tm)
{
return s35392a_rtc_get(&dev, tm);
}
int rtc_set(struct rtc_time *tm)
{
return s35392a_rtc_set(&dev, tm);
}
void rtc_reset(void)
{
s35392a_rtc_reset(&dev);
}
void rtc_init(void)
{
s35392a_rtc_init(&dev);
}
#else
static int s35392a_probe(struct udevice *dev)
{
#if defined(CONFIG_DM_RTC)
/* 3-bit "command", or register, is encoded within the device address.
*/
i2c_set_chip_offset_len(dev, 0);
i2c_set_chip_addr_offset_mask(dev, 0x7);
#endif
s35392a_rtc_init(dev);
return 0;
}
static const struct rtc_ops s35392a_rtc_ops = {
.get = s35392a_rtc_get,
.set = s35392a_rtc_set,
.read8 = s35392a_rtc_read8,
.write8 = s35392a_rtc_write8,
.reset = s35392a_rtc_reset,
};
static const struct udevice_id s35392a_rtc_ids[] = {
{ .compatible = "sii,s35392a-rtc" },
{ .compatible = "sii,s35392a" },
{ .compatible = "s35392a" },
{ }
};
U_BOOT_DRIVER(s35392a_rtc) = {
.name = "s35392a_rtc",
.id = UCLASS_RTC,
.probe = s35392a_probe,
.of_match = s35392a_rtc_ids,
.ops = &s35392a_rtc_ops,
};
#endif