[PATCH v3 3/4] rtc: rk8xx: Add base support for the RK808 PMIC RTC
elaine.zhang
zhangqing at rock-chips.com
Wed Apr 29 05:27:03 CEST 2020
Hi Sunil,
What scenarios need RTC?
If it is to add hardware driver support, the function is still missing
an alarm.
Direct copy of the kernel is recommended.
About 31 days for november month, I need to explain this hardware Bug:
1、There will be 31 in November after 2016, and there will be no such
problem before 2016.
2、After 2016, each 11.31 will add one more day.
e.g:
Actually 2017-12-3, RTC hardware register: 2017-12-5, two days more
Actually 2019-10-3, RTC hardware register: 2019-10-6, three more days
After 2016, every 11.31 will be an extra day, which should be corrected
back.
Therefore, it is recommended to use the kernel's correction method:
/*
* The Rockchip calendar used by the RK808 counts November with 31
days. We use
* these translation functions to convert its dates to/from the Gregorian
* calendar used by the rest of the world. We arbitrarily define Jan
1st, 2016
* as the day when both calendars were in sync, and treat all other dates
* relative to that.
* NOTE: Other system software (e.g. firmware) that reads the same
hardware must
* implement this exact same conversion algorithm, with the same anchor
date.
*/
static time64_t nov2dec_transitions(struct rtc_time *tm)
{
return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);
}
static void rockchip_to_gregorian(struct rtc_time *tm)
{
/* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */
time64_t time = rtc_tm_to_time64(tm);
rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);
}
static void gregorian_to_rockchip(struct rtc_time *tm)
{
time64_t extra_days = nov2dec_transitions(tm);
time64_t time = rtc_tm_to_time64(tm);
rtc_time64_to_tm(time - extra_days * 86400, tm);
/* Compensate if we went back over Nov 31st (will work up to 2381) */
if (nov2dec_transitions(tm) < extra_days) {
if (tm->tm_mon + 1 == 11)
tm->tm_mday++; /* This may result in 31! */
else
rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);
}
}
在 2020/4/29 上午10:39, Kever Yang 写道:
> +Elaine,
>
> Please help to review this patch.
>
>
> Thanks,
>
> - Kever
>
> On 2020/4/29 上午12:14, sunil at amarulasolutions.com wrote:
>> From: Suniel Mahesh <sunil at amarulasolutions.com>
>>
>> Rockchip RK808 PMIC provides an integrated RTC module. It is
>> commonly used with Rockchip SoCs. Add basic support to access
>> date and time.
>>
>> Signed-off-by: Suniel Mahesh <sunil at amarulasolutions.com>
>> ---
>> Changes for v3:
>> - no changes
>>
>> Changes for v2:
>> - moved corresponding configs which enable rtc into a seperate
>> patch.
>> - changed subject line.
>>
>> Note:
>> 1. The RK808 PMIC RTC has a hardware bug. It counts 31 days
>> for november month and the weeks register counts 0 - 7.
>>
>> 2. This driver does a temporary fix, where as in if date is Nov 31,
>> then it resets the date to Dec 1(this happens only if date cmd is
>> queried
>> from u-boot command line/script). Similarly for the weeks register,
>> 0(sun)
>> - 6(sat). If 7 is encountered then it is reset to zero.
>>
>> 3. u-boot generally loads linux/other binary. Linux has a full fledged
>> driver implemented along with a workaround.
>> https://lkml.org/lkml/2015/12/2/1202
>>
>> 4. Is this change acceptable ? please comment
>> ---
>> drivers/rtc/Kconfig | 8 +++
>> drivers/rtc/Makefile | 1 +
>> drivers/rtc/rk808-rtc.c | 165
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 174 insertions(+)
>> create mode 100644 drivers/rtc/rk808-rtc.c
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index 59e2fc4..a754d1b 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -75,6 +75,14 @@ config RTC_ISL1208
>> This driver supports reading and writing the RTC/calendar and
>> detects
>> total power failures.
>> +config RTC_RK808
>> + bool "Enable Rockchip RK8XX RTC driver"
>> + depends on DM_RTC && PMIC_RK8XX
>> + default y
>> + help
>> + Basic support for Rockchip RK808 PMIC Real Time Clock devices for
>> + time and date.
>> +
>> config RTC_RV3029
>> bool "Enable RV3029 driver"
>> depends on DM_RTC
>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>> index 12eb449..63e2c34 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -44,6 +44,7 @@ obj-$(CONFIG_RTC_PCF8563) += pcf8563.o
>> obj-$(CONFIG_RTC_PCF2127) += pcf2127.o
>> obj-$(CONFIG_RTC_PL031) += pl031.o
>> obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
>> +obj-$(CONFIG_RTC_RK808) += rk808-rtc.o
>> obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o
>> obj-$(CONFIG_RTC_RV3029) += rv3029.o
>> obj-$(CONFIG_RTC_RV8803) += rv8803.o
>> diff --git a/drivers/rtc/rk808-rtc.c b/drivers/rtc/rk808-rtc.c
>> new file mode 100644
>> index 0000000..b63cced
>> --- /dev/null
>> +++ b/drivers/rtc/rk808-rtc.c
>> @@ -0,0 +1,165 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * RTC driver for Rockchip RK808 PMIC.
>> + *
>> + * Copyright (C) 2020 Amarula Solutions(India).
>> + * Suniel Mahesh <sunil at amarulasolutions.com>
>> + *
>> + * Based on code from Linux kernel:
>> + * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
>> + * Author: Chris Zhong <zyw at rock-chips.com>
>> + * Author: Zhang Qing <zhangqing at rock-chips.com>
>> + *
>> + * Date & Time support (no alarms and interrupts)
>> + */
>> +
>> +#include <command.h>
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <i2c.h>
>> +#include <rtc.h>
>> +#include <power/rk8xx_pmic.h>
>> +#include <power/pmic.h>
>> +
>> +/* RTC_CTRL_REG bitfields */
>> +#define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)
>> +
>> +/* RK808 has a shadowed register for saving a "frozen" RTC time.
>> + * When user setting "GET_TIME" to 1, the time will save in this
>> shadowed
>> + * register. If set "READSEL" to 1, user read rtc time register,
>> actually
>> + * get the time of that moment. If we need the real time, clr this bit.
>> + */
>> +
>> +#define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6)
>> +#define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7)
>> +#define RTC_STATUS_MASK 0xFE
>> +
>> +#define SECONDS_REG_MSK 0x7F
>> +#define MINUTES_REG_MAK 0x7F
>> +#define HOURS_REG_MSK 0x3F
>> +#define DAYS_REG_MSK 0x3F
>> +#define MONTHS_REG_MSK 0x1F
>> +#define YEARS_REG_MSK 0xFF
>> +#define WEEKS_REG_MSK 0x7
>> +
>> +/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
>> +
>> +#define NUM_TIME_REGS (REG_WEEKS - REG_SECONDS + 1)
>> +
>> +static int rk808_rtc_set(struct udevice *dev, const struct rtc_time
>> *tm)
>> +{
>> + u8 rtc_data[NUM_TIME_REGS];
>> +
>> + debug("RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
>> + tm->tm_year, tm->tm_mon, tm->tm_mday,
>> + tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
>> +
>> + rtc_data[0] = bin2bcd(tm->tm_sec);
>> + rtc_data[1] = bin2bcd(tm->tm_min);
>> + rtc_data[2] = bin2bcd(tm->tm_hour);
>> + rtc_data[3] = bin2bcd(tm->tm_mday);
>> + rtc_data[4] = bin2bcd(tm->tm_mon);
>> + rtc_data[5] = bin2bcd(tm->tm_year - 2000);
>> + rtc_data[6] = bin2bcd(tm->tm_wday);
>> +
>> +/* Stop RTC while updating the RTC registers */
>> + pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,
>> + BIT_RTC_CTRL_REG_STOP_RTC_M);
It's usually used as(The same below):
pmic_clrsetbits(dev->parent, REG_RTC_CTRL, BIT_RTC_CTRL_REG_STOP_RTC_M,
+ BIT_RTC_CTRL_REG_STOP_RTC_M);
>> + pmic_write(dev->parent, REG_SECONDS, rtc_data, NUM_TIME_REGS);
>> +
>> +/* Start RTC again */
>> + pmic_clrsetbits(dev->parent, REG_RTC_CTRL,
>> + BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
>> + return 0;
>> +}
>> +
>> +static int rk808_rtc_get(struct udevice *dev, struct rtc_time *tm)
>> +{
>> + u8 rtc_data[NUM_TIME_REGS];
>> +
>> +/* Force an update of the shadowed registers right now */
>> + pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,
>> + BIT_RTC_CTRL_REG_RTC_GET_TIME);
>> +
>> +/*
>> + * After we set the GET_TIME bit, the rtc time can't be read
>> + * immediately. So we should wait up to 31.25 us, about one cycle of
>> + * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
>> + * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
>> + */
>> + pmic_clrsetbits(dev->parent, REG_RTC_CTRL,
>> + BIT_RTC_CTRL_REG_RTC_GET_TIME, 0);
>> + pmic_read(dev->parent, REG_SECONDS, rtc_data, NUM_TIME_REGS);
>> +
>> + tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
>> + tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
>> + tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
>> + tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
>> + tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK));
>> + tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 2000;
>> + tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
>> +/*
>> + * RK808 PMIC RTC h/w counts/has 31 days in november. This is corrected
>> + * when date cmd is invoked on prompt. checks for the current day and
>> + * if it is 31 November, then adjusts it to 1 December.
>> + *
>> + * h/w also has weeks register which counts from 0 to 7(0(sun)-6(sat)).
>> + * 7 is an unknown state, reset it back to 0(sun).
>> + */
>> + if (tm->tm_mon == 11 && tm->tm_mday == 31) {
>> + debug("correcting Nov 31st to Dec 1st (HW bug)\n");
>> + tm->tm_mon += 1;
>> + tm->tm_mday = 1;
>> + if (tm->tm_wday == 7)
>> + tm->tm_wday = 0;
>> + rk808_rtc_set(dev, tm);
>> + }
Error use.
>> +
>> + if (tm->tm_wday == 7) {
>> + tm->tm_wday = 0;
No problems were found in the kernel.
Please describe your problem in detail.
Our RTC weeks_reg is:
Bit 3-0 WEEK: Set the second digit of the RTC weeks.
Note BCD coding from 1 to 7
>> + rk808_rtc_set(dev, tm);
>> + }
>> +
>> + debug("RTC date/time %4d-%02d-%02d(%d) %02d:%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;
>> +}
>> +
>> +static int rk808_rtc_reset(struct udevice *dev)
>> +{
>> +/* Not needed */
>> + return 0;
>> +}
>> +
>> +static int rk808_rtc_init(struct udevice *dev)
>> +{
>> + struct rtc_time tm;
>> +
>> +/* start rtc running by default, and use shadowed timer. */
>> + pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,
>> + BIT_RTC_CTRL_REG_RTC_READSEL_M);
>> + pmic_reg_write(dev->parent, REG_RTC_STATUS, RTC_STATUS_MASK);
>> +/* set init time */
>> + rk808_rtc_get(dev, &tm);
>> + return 0;
>> +}
>> +
>> +static int rk808_rtc_probe(struct udevice *dev)
>> +{
>> + rk808_rtc_init(dev);
>> + return 0;
>> +}
>> +
>> +static const struct rtc_ops rk808_rtc_ops = {
>> + .get = rk808_rtc_get,
>> + .set = rk808_rtc_set,
>> + .reset = rk808_rtc_reset,
>> +};
>> +
>> +U_BOOT_DRIVER(rk808_rtc) = {
>> + .name = "rk808_rtc",
>> + .id = UCLASS_RTC,
>> + .ops = &rk808_rtc_ops,
>> + .probe = rk808_rtc_probe,
>> +};
>
>
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