From: Suniel Mahesh sunil@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@amarulasolutions.com --- 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@amarulasolutions.com + * + * Based on code from Linux kernel: + * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd + * Author: Chris Zhong zyw@rock-chips.com + * Author: Zhang Qing zhangqing@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); + 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); + } + + if (tm->tm_wday == 7) { + tm->tm_wday = 0; + 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, +};