[U-Boot] [PATCH] drivers/rtc: add Marvell Integrated RTC.

[Simon Guinot <simon@sequanux.org>]

Hi Jason,

On Mon, Aug 01, 2011 at 12:48:05AM +0000, Jason Cooper wrote:
> This driver can be used for kirkwood SoCs by enabling CONFIG_RTC_MVINTEG.
> Tested on Global Scale Technologies Dreamplug.
> 
> Signed-off-by: Jason Cooper <u-boot@lakedaemon.net>
> ---
> Changes from v1:
> 	- renamed files to mvrtc.{c,h}
> 	- used proper c-structs for register access
> 	- used existing macros for register access
> 	- removed RFC
> 
>  arch/arm/include/asm/arch-kirkwood/kirkwood.h |    1 +
>  drivers/rtc/Makefile                          |    1 +
>  drivers/rtc/mvrtc.c                           |  157 +++++++++++++++++++++++++
>  drivers/rtc/mvrtc.h                           |   79 +++++++++++++
>  4 files changed, 238 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/rtc/mvrtc.c
>  create mode 100644 drivers/rtc/mvrtc.h
> 
> diff --git a/arch/arm/include/asm/arch-kirkwood/kirkwood.h b/arch/arm/include/asm/arch-kirkwood/kirkwood.h
> index 0104418..3c843a0 100644
> --- a/arch/arm/include/asm/arch-kirkwood/kirkwood.h
> +++ b/arch/arm/include/asm/arch-kirkwood/kirkwood.h
> @@ -50,6 +50,7 @@
>  #define KW_MPP_BASE			(KW_REGISTER(0x10000))
>  #define KW_GPIO0_BASE			(KW_REGISTER(0x10100))
>  #define KW_GPIO1_BASE			(KW_REGISTER(0x10140))
> +#define KW_RTC_BASE			(KW_REGISTER(0x10300))
>  #define KW_NANDF_BASE			(KW_REGISTER(0x10418))
>  #define KW_SPI_BASE			(KW_REGISTER(0x10600))
>  #define KW_CPU_WIN_BASE			(KW_REGISTER(0x20000))
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index e4be4a4..e1591a0 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -55,6 +55,7 @@ COBJS-$(CONFIG_MCFRTC) += mcfrtc.o
>  COBJS-$(CONFIG_RTC_MK48T59) += mk48t59.o
>  COBJS-$(CONFIG_RTC_MPC5200) += mpc5xxx.o
>  COBJS-$(CONFIG_RTC_MPC8xx) += mpc8xx.o
> +COBJS-$(CONFIG_RTC_MVINTEG) += mvrtc.o

What about using CONFIG_RTC_MV ?

>  COBJS-$(CONFIG_RTC_PCF8563) += pcf8563.o
>  COBJS-$(CONFIG_RTC_PL031) += pl031.o
>  COBJS-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
> diff --git a/drivers/rtc/mvrtc.c b/drivers/rtc/mvrtc.c
> new file mode 100644
> index 0000000..0db3b20
> --- /dev/null
> +++ b/drivers/rtc/mvrtc.c
> @@ -0,0 +1,157 @@
> +/*
> + * Copyright (C) 2011
> + * Jason Cooper <u-boot@lakedaemon.net>
> + *
> + * 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 Marvell Integrated RTC
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <rtc.h>
> +#include "mvrtc.h"
> +
> +/* This RTC does not support century, so we assume 20 */
> +#define CENTURY 20
> +
> +int rtc_get(struct rtc_time *t)
> +{
> +	u32 time;
> +	u32 date;
> +	u8  tens;
> +	u8  single;

Maybe you could use the function bcd2bin() and then hide the "tens" and
"single" split.

> +	struct mvrtc_registers *mvrtc_regs;
> +
> +	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
> +
> +	/* read the time register */
> +	time = readl(&mvrtc_regs->time);
> +
> +	/* read the date register */
> +	date = readl(&mvrtc_regs->date);

For example, you could have something like:

t->tm_sec = bcd2bin(time & 0x7f);
t->tm_min = bcd2bin((time >> MVRTC_MIN_SFT) & 0x7f);
t->tm_hour = bcd2bin((time >> MVRTC_HOUR_SFT) & 0x3f); /* 24 hour mode */
...

> +
> +	/* seconds */
> +	tens   = ((time & MVRTC_10SEC_MSK) >> MVRTC_10SEC_SFT);
> +	single = ((time & MVRTC_SEC_MSK)   >> MVRTC_SEC_SFT);
> +	t->tm_sec = 10 * tens + single;
> +
> +	/* minutes */
> +	tens   = ((time & MVRTC_10MIN_MSK) >> MVRTC_10MIN_SFT);
> +	single = ((time & MVRTC_MIN_MSK)   >> MVRTC_MIN_SFT);
> +	t->tm_min = 10 * tens + single;
> +
> +	/* hours */
> +	tens   = ((time & MVRTC_10HOUR_MSK) >> MVRTC_10HOUR_SFT);
> +	single = ((time & MVRTC_HOUR_MSK)   >> MVRTC_HOUR_SFT);
> +	t->tm_hour = 10 * tens + single;

If the RTC operates in 12 hour mode, the code above is wrong.

> +
> +	/* day */
> +	t->tm_wday = ((time & MVRTC_DAY_MSK) >> MVRTC_DAY_SFT);
> +	t->tm_wday--;
> +
> +	/* date */
> +	tens   = ((date & MVRTC_10DATE_MSK) >> MVRTC_10DATE_SFT);
> +	single = ((date & MVRTC_DATE_MSK)   >> MVRTC_DATE_SFT);
> +	t->tm_mday = 10 * tens + single;
> +
> +	/* month */
> +	tens   = ((date & MVRTC_10MON_MSK) >> MVRTC_10MON_SFT);
> +	single = ((date & MVRTC_MON_MSK)   >> MVRTC_MON_SFT);
> +	t->tm_mon = 10 * tens + single;
> +
> +	/* year */
> +	tens   = ((date & MVRTC_10YEAR_MSK) >> MVRTC_10YEAR_SFT);
> +	single = ((date & MVRTC_YEAR_MSK)   >> MVRTC_YEAR_SFT);
> +	t->tm_year = (CENTURY * 100) + (10 * tens) + single;
> +
> +	/* not supported in this RTC */
> +	t->tm_yday  = 0;
> +	t->tm_isdst = 0;
> +
> +	return 0;
> +}
> +
> +int rtc_set(struct rtc_time *t)
> +{
> +	u32 time = 0;
> +	u32 date = 0;
> +	u32 tens;
> +	u32 single;
> +	struct mvrtc_registers *mvrtc_regs;
> +
> +	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
> +
> +	/* seconds */
> +	tens   = t->tm_sec / 10;
> +	single = t->tm_sec % 10;

Again, you could use the function bin2bcd() and then get ride of this
"tens" and "single" split.

> +	time |= ((tens   << MVRTC_10SEC_SFT) & MVRTC_10SEC_MSK) |
> +		((single << MVRTC_SEC_SFT)   & MVRTC_SEC_MSK);

For example, here you could have:

time |= bin2bcd(tm->tm_sec) << MVRTC_SEC_SFT;

> +
> +	/* minutes */
> +	tens   = t->tm_min / 10;
> +	single = t->tm_min % 10;
> +	time |= ((tens   << MVRTC_10MIN_SFT) & MVRTC_10MIN_MSK) |
> +		((single << MVRTC_MIN_SFT)   & MVRTC_MIN_MSK);
> +
> +	/* hours (24) */
> +	tens   = t->tm_hour / 10;
> +	single = t->tm_hour % 10;
> +	time |= ((tens   << MVRTC_10HOUR_SFT) & MVRTC_10HOUR_MSK) |
> +		((single << MVRTC_HOUR_SFT)   & MVRTC_HOUR_MSK);
> +
> +	/* day */
> +	single = t->tm_wday + 1;
> +	time |= ((single << MVRTC_DAY_SFT) & MVRTC_DAY_MSK);
> +
> +	/* date */
> +	tens   = t->tm_mday / 10;
> +	single = t->tm_mday % 10;
> +	date |= ((tens   << MVRTC_10DATE_SFT) & MVRTC_10DATE_MSK) |
> +		((single << MVRTC_DATE_SFT)   & MVRTC_DATE_MSK);
> +
> +	/* month */
> +	tens   = t->tm_mon / 10;
> +	single = t->tm_mon % 10;
> +	date |= ((tens   << MVRTC_10MON_SFT) & MVRTC_10MON_MSK) |
> +		((single << MVRTC_MON_SFT)   & MVRTC_MON_MSK);
> +
> +	/* year */
> +	if ((t->tm_year / 100) != CENTURY)
> +		printf("Warning: Only century %d supported.\n", CENTURY);
> +	tens   = (t->tm_year % 100) / 10;
> +	single = (t->tm_year % 100) % 10;
> +	date |= ((tens   << MVRTC_10YEAR_SFT) & MVRTC_10YEAR_MSK) |
> +		((single << MVRTC_YEAR_SFT)   & MVRTC_YEAR_MSK);
> +
> +	/* write the time register */
> +	writel(time, &mvrtc_regs->time);
> +
> +	/* write the date register */
> +	writel(date, &mvrtc_regs->date);
> +
> +	return 0;
> +}
> +
> +void rtc_reset(void)
> +{
> +	/* no init routine for this RTC needed */

In the Linux driver, there is also a check to ensure that the RTC is
ticking. Maybe it could be useful here too, just to let know the RTC is 
functional (or not).

Regards,

Simon
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