[U-Boot] [PATCH] rtc: imxdi: Initial support
Benoît Thébaudeau
benoit.thebaudeau at advansee.com
Sat Aug 4 01:06:54 CEST 2012
On Fri, Jul 20, 2012 at 04:24:38 PM, Benoît Thébaudeau wrote:
> Add support for Freescale's i.MX DryIce RTC, present on i.MX25.
>
> Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
> Cc: Wolfgang Denk <wd at denx.de>
> Cc: Stefano Babic <sbabic at denx.de>
> ---
> .../drivers/rtc/Makefile | 1 +
> /dev/null => u-boot-66714b1/drivers/rtc/imxdi.c | 224
> ++++++++++++++++++++
> 2 files changed, 225 insertions(+)
> create mode 100644 u-boot-66714b1/drivers/rtc/imxdi.c
>
> diff --git u-boot-66714b1.orig/drivers/rtc/Makefile
> u-boot-66714b1/drivers/rtc/Makefile
> index faf4fcd..aeeea37 100644
> --- u-boot-66714b1.orig/drivers/rtc/Makefile
> +++ u-boot-66714b1/drivers/rtc/Makefile
> @@ -43,6 +43,7 @@ COBJS-$(CONFIG_RTC_DS164x) += ds164x.o
> COBJS-$(CONFIG_RTC_DS174x) += ds174x.o
> COBJS-$(CONFIG_RTC_DS3231) += ds3231.o
> COBJS-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
> +COBJS-$(CONFIG_RTC_IMXDI) += imxdi.o
> COBJS-$(CONFIG_RTC_ISL1208) += isl1208.o
> COBJS-$(CONFIG_RTC_M41T11) += m41t11.o
> COBJS-$(CONFIG_RTC_M41T60) += m41t60.o
> diff --git u-boot-66714b1/drivers/rtc/imxdi.c
> u-boot-66714b1/drivers/rtc/imxdi.c
> new file mode 100644
> index 0000000..c2be842
> --- /dev/null
> +++ u-boot-66714b1/drivers/rtc/imxdi.c
> @@ -0,0 +1,224 @@
> +/*
> + * (C) Copyright 2009-2012 ADVANSEE
> + * Benoît Thébaudeau <benoit.thebaudeau at 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
> + *
> + * 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 Freescale i.MX DryIce RTC
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <rtc.h>
> +
> +#if defined(CONFIG_CMD_DATE)
> +
> +#include <asm/io.h>
> +#include <asm/arch/imx-regs.h>
> +
> +/* DryIce Register Definitions */
> +
> +#define DTCMR 0x00 /* Time Counter MSB Reg */
> +#define DTCLR 0x04 /* Time Counter LSB Reg */
> +
> +#define DCAMR 0x08 /* Clock Alarm MSB Reg */
> +#define DCALR 0x0c /* Clock Alarm LSB Reg */
> +#define DCAMR_UNSET 0xFFFFFFFF /* doomsday - 1 sec */
> +
> +#define DCR 0x10 /* Control Reg */
> +#define DCR_TCE (1 << 3) /* Time Counter Enable */
> +
> +#define DSR 0x14 /* Status Reg */
> +#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 0x18 /* Interrupt Enable Reg */
> +#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 */
> +
> +/*
> + * 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, IMX_DRYICE_BASE + DSR);
> +
> + /* wait for it to take effect */
> + for (cnt = 0; cnt < 1000; cnt++) {
> + if ((__raw_readl(IMX_DRYICE_BASE + 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.
> + *
> + * This function uses interrupt flags to determine when the
> + * write has completed.
> + */
> +static int di_write_wait(u32 val, int reg)
> +{
> + int cnt;
> + int ret = 0;
> + int rc = 0;
> +
> + /* do the register write */
> + __raw_writel(val, IMX_DRYICE_BASE + reg);
> +
> + /* wait for the write to finish */
> + for (cnt = 0; cnt < 100; cnt++) {
> + if ((__raw_readl(IMX_DRYICE_BASE + DSR) &
> + (DSR_WCF | DSR_WEF)) != 0) {
> + ret = 1;
> + break;
> + }
> + udelay(10);
> + }
> + if (ret == 0)
> + printf("### Warning: RTC - Write-wait timeout "
> + "val = 0x%.8x reg = 0x%.8x\n", val, reg);
> +
> + /* check for write error */
> + if (__raw_readl(IMX_DRYICE_BASE + DSR) & DSR_WEF) {
> + clear_write_error();
> + rc = -1;
> + }
> +
> + return rc;
> +}
> +
> +/*
> + * Initialize dryice hardware
> + */
> +static int di_init(void)
> +{
> + int rc = 0;
> +
> + /* mask all interrupts */
> + __raw_writel(0, IMX_DRYICE_BASE + DIER);
> +
> + /* put dryice into valid state */
> + if (__raw_readl(IMX_DRYICE_BASE + 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(IMX_DRYICE_BASE + 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(IMX_DRYICE_BASE + DTCMR) == 0) {
> + rc = di_write_wait(0, DTCMR);
> + if (rc)
> + goto err;
> + }
> +
> + /* start keeping time */
> + if (!(__raw_readl(IMX_DRYICE_BASE + DCR) & DCR_TCE)) {
> + rc = di_write_wait(__raw_readl(IMX_DRYICE_BASE + DCR) | DCR_TCE,
> + DCR);
> + if (rc)
> + goto err;
> + }
> +
> + return 0;
> +
> +err:
> + return rc;
> +}
> +
> +int rtc_get(struct rtc_time *tmp)
> +{
> + unsigned long now;
> + int rc;
> +
> + rc = di_init();
> + if (rc)
> + goto err;
> +
> + now = __raw_readl(IMX_DRYICE_BASE + DTCMR);
> + to_tm(now, tmp);
> +
> +err:
> + return rc;
> +}
> +
> +int rtc_set(struct rtc_time *tmp)
> +{
> + unsigned long now;
> + int rc;
> +
> + rc = di_init();
> + if (rc)
> + goto err;
> +
> + now = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
> + tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
> + /* 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
>
Ping?
Benoît
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