u-boot/drivers/rtc/imxdi.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

226 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2009-2012 ADVANSEE
* Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
*
* Based on the Linux rtc-imxdi.c driver, which is:
* Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2010 Orex Computed Radiography
*/
/*
* Date & Time support for Freescale i.MX DryIce RTC
*/
#include <common.h>
#include <command.h>
#include <linux/compat.h>
#include <rtc.h>
#if defined(CONFIG_CMD_DATE)
#include <asm/io.h>
#include <asm/arch/imx-regs.h>
/* DryIce Register Definitions */
struct imxdi_regs {
u32 dtcmr; /* Time Counter MSB Reg */
u32 dtclr; /* Time Counter LSB Reg */
u32 dcamr; /* Clock Alarm MSB Reg */
u32 dcalr; /* Clock Alarm LSB Reg */
u32 dcr; /* Control Reg */
u32 dsr; /* Status Reg */
u32 dier; /* Interrupt Enable Reg */
};
#define DCAMR_UNSET 0xFFFFFFFF /* doomsday - 1 sec */
#define DCR_TCE (1 << 3) /* Time Counter Enable */
#define DSR_WBF (1 << 10) /* Write Busy Flag */
#define DSR_WNF (1 << 9) /* Write Next Flag */
#define DSR_WCF (1 << 8) /* Write Complete Flag */
#define DSR_WEF (1 << 7) /* Write Error Flag */
#define DSR_CAF (1 << 4) /* Clock Alarm Flag */
#define DSR_NVF (1 << 1) /* Non-Valid Flag */
#define DSR_SVF (1 << 0) /* Security Violation Flag */
#define DIER_WNIE (1 << 9) /* Write Next Interrupt Enable */
#define DIER_WCIE (1 << 8) /* Write Complete Interrupt Enable */
#define DIER_WEIE (1 << 7) /* Write Error Interrupt Enable */
#define DIER_CAIE (1 << 4) /* Clock Alarm Interrupt Enable */
/* Driver Private Data */
struct imxdi_data {
struct imxdi_regs __iomem *regs;
int init_done;
};
static struct imxdi_data data;
/*
* This function attempts to clear the dryice write-error flag.
*
* A dryice write error is similar to a bus fault and should not occur in
* normal operation. Clearing the flag requires another write, so the root
* cause of the problem may need to be fixed before the flag can be cleared.
*/
static void clear_write_error(void)
{
int cnt;
puts("### Warning: RTC - Register write error!\n");
/* clear the write error flag */
__raw_writel(DSR_WEF, &data.regs->dsr);
/* wait for it to take effect */
for (cnt = 0; cnt < 1000; cnt++) {
if ((__raw_readl(&data.regs->dsr) & DSR_WEF) == 0)
return;
udelay(10);
}
puts("### Error: RTC - Cannot clear write-error flag!\n");
}
/*
* Write a dryice register and wait until it completes.
*
* Use interrupt flags to determine when the write has completed.
*/
#define DI_WRITE_WAIT(val, reg) \
( \
/* do the register write */ \
__raw_writel((val), &data.regs->reg), \
\
di_write_wait((val), #reg) \
)
static int di_write_wait(u32 val, const char *reg)
{
int cnt;
int ret = 0;
int rc = 0;
/* wait for the write to finish */
for (cnt = 0; cnt < 100; cnt++) {
if ((__raw_readl(&data.regs->dsr) & (DSR_WCF | DSR_WEF)) != 0) {
ret = 1;
break;
}
udelay(10);
}
if (ret == 0)
printf("### Warning: RTC - Write-wait timeout "
"val = 0x%.8x reg = %s\n", val, reg);
/* check for write error */
if (__raw_readl(&data.regs->dsr) & DSR_WEF) {
clear_write_error();
rc = -1;
}
return rc;
}
/*
* Initialize dryice hardware
*/
static int di_init(void)
{
int rc = 0;
data.regs = (struct imxdi_regs __iomem *)IMX_DRYICE_BASE;
/* mask all interrupts */
__raw_writel(0, &data.regs->dier);
/* put dryice into valid state */
if (__raw_readl(&data.regs->dsr) & DSR_NVF) {
rc = DI_WRITE_WAIT(DSR_NVF | DSR_SVF, dsr);
if (rc)
goto err;
}
/* initialize alarm */
rc = DI_WRITE_WAIT(DCAMR_UNSET, dcamr);
if (rc)
goto err;
rc = DI_WRITE_WAIT(0, dcalr);
if (rc)
goto err;
/* clear alarm flag */
if (__raw_readl(&data.regs->dsr) & DSR_CAF) {
rc = DI_WRITE_WAIT(DSR_CAF, dsr);
if (rc)
goto err;
}
/* the timer won't count if it has never been written to */
if (__raw_readl(&data.regs->dtcmr) == 0) {
rc = DI_WRITE_WAIT(0, dtcmr);
if (rc)
goto err;
}
/* start keeping time */
if (!(__raw_readl(&data.regs->dcr) & DCR_TCE)) {
rc = DI_WRITE_WAIT(__raw_readl(&data.regs->dcr) | DCR_TCE, dcr);
if (rc)
goto err;
}
data.init_done = 1;
return 0;
err:
return rc;
}
int rtc_get(struct rtc_time *tmp)
{
unsigned long now;
int rc = 0;
if (!data.init_done) {
rc = di_init();
if (rc)
goto err;
}
now = __raw_readl(&data.regs->dtcmr);
rtc_to_tm(now, tmp);
err:
return rc;
}
int rtc_set(struct rtc_time *tmp)
{
unsigned long now;
int rc;
if (!data.init_done) {
rc = di_init();
if (rc)
goto err;
}
now = rtc_mktime(tmp);
/* zero the fractional part first */
rc = DI_WRITE_WAIT(0, dtclr);
if (rc == 0)
rc = DI_WRITE_WAIT(now, dtcmr);
err:
return rc;
}
void rtc_reset(void)
{
di_init();
}
#endif