From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> The RTC IP (RTCA-3) available on the Renesas RZ/G3S SoC has calendar count mode and binary count mode (selectable though RCR2.CNTMD) capabilities, alarm capabilities, clock error correction capabilities. It can generate alarm, period, carry interrupts. Add a driver for RTCA-3 IP. The driver implements calendar count mode (as the conversion b/w RTC and system time is simpler, done with bcd2bin(), bin2bcd()), read and set time, read and set alarm, read and set an offset. Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> --- Changes in v4: - disabled all interrupts on the initial setup, function rtca3_initial_setup(); RTCA3_RCR1_PIE interrupt (disabled in this series) is used on alarm setup. - added a comment about the counter clock, when requesting it, to let others know that this should stay on for the full lifetime of the RTC - used RTC_TIMESTAMP_BEGIN_2000 and RTC_TIMESTAMP_BEGIN_2099 - added a comment on rtca3_remove() to mention that the RTC cannot power on the system Changes in v3: - added pm runtime and reset control support; probe() was changed and rtca3_action() was added as for cleanup; VBATTB and RTC shares the clock, reset and PM domain; hw manual doesn't specifies this; it has been detected though reverse engineering - dropped clk member of struct rtca3_priv as it is used only in probe() - renamed rtca3_alarm_irq_enable_helper() to rtca3_alarm_irq_set_helper() and used it all over the places - fixed the issue: Reported-by: kernel test robot <lkp@xxxxxxxxx> Closes: https://lore.kernel.org/oe-kbuild-all/202407191156.wJPjHtKG-lkp@xxxxxxxxx/ - removed __maybe_unused from suspend/resume function and use DEFINE_SIMPLE_DEV_PM_OPS() along with pm_ptr() Changes in v2: - used cleanup.h helpers for locking - updated the MAINTAINERS entry with the new name for RTCA-3 documentation file and a new title (from "RENESAS RZ/G3S RTC DRIVER" to "RENESAS RTCA-3 RTC DRIVER") - used 24 hours mode - changed startup sequence (rtca3_initial_setup()) to avoid stopping the RTC if it's already configured - updated the RTC range to 2000-2099 - updated the compatible with the generic one (renesas,rz-rtca3) in the idea the driver will be also used by the RZ/V2H w/o the necessity to add a new compatible MAINTAINERS | 8 + drivers/rtc/Kconfig | 10 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-renesas-rtca3.c | 899 ++++++++++++++++++++++++++++++++ 4 files changed, 918 insertions(+) create mode 100644 drivers/rtc/rtc-renesas-rtca3.c diff --git a/MAINTAINERS b/MAINTAINERS index 97c4b798e65e..a79f3dac0234 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19633,6 +19633,14 @@ S: Supported F: Documentation/devicetree/bindings/timer/renesas,rz-mtu3.yaml F: drivers/counter/rz-mtu3-cnt.c +RENESAS RTCA-3 RTC DRIVER +M: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> +L: linux-rtc@xxxxxxxxxxxxxxx +L: linux-renesas-soc@xxxxxxxxxxxxxxx +S: Supported +F: Documentation/devicetree/bindings/rtc/renesas,rz-rtca3.yaml +F: drivers/rtc/rtc-renesas-rtca3.c + RENESAS RZ/N1 A5PSW SWITCH DRIVER M: Clément Léger <clement.leger@xxxxxxxxxxx> L: linux-renesas-soc@xxxxxxxxxxxxxxx diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 8d38f55043ca..a1aa6f6b9f88 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1995,6 +1995,16 @@ config RTC_DRV_MA35D1 This driver can also be built as a module, if so, the module will be called "rtc-ma35d1". +config RTC_DRV_RENESAS_RTCA3 + tristate "Renesas RTCA-3 RTC" + depends on ARCH_RENESAS + help + If you say yes here you get support for the Renesas RTCA-3 RTC + available on the Renesas RZ/G3S SoC. + + This driver can also be built as a module, if so, the module + will be called "rtc-rtca3". + comment "HID Sensor RTC drivers" config RTC_DRV_HID_SENSOR_TIME diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 8ee79cb18322..1e19e97d7c51 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -158,6 +158,7 @@ obj-$(CONFIG_RTC_DRV_RX8025) += rtc-rx8025.o obj-$(CONFIG_RTC_DRV_RX8111) += rtc-rx8111.o obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o obj-$(CONFIG_RTC_DRV_RZN1) += rtc-rzn1.o +obj-$(CONFIG_RTC_DRV_RENESAS_RTCA3) += rtc-renesas-rtca3.o obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o obj-$(CONFIG_RTC_DRV_S3C) += rtc-s3c.o obj-$(CONFIG_RTC_DRV_S5M) += rtc-s5m.o diff --git a/drivers/rtc/rtc-renesas-rtca3.c b/drivers/rtc/rtc-renesas-rtca3.c new file mode 100644 index 000000000000..c8efccf3e552 --- /dev/null +++ b/drivers/rtc/rtc-renesas-rtca3.c @@ -0,0 +1,899 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * On-Chip RTC Support available on RZ/G3S SoC + * + * Copyright (C) 2024 Renesas Electronics Corp. + */ +#include <linux/bcd.h> +#include <linux/cleanup.h> +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/iopoll.h> +#include <linux/interrupt.h> +#include <linux/jiffies.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> +#include <linux/rtc.h> + +/* Counter registers. */ +#define RTCA3_RSECCNT 0x2 +#define RTCA3_RSECCNT_SEC GENMASK(6, 0) +#define RTCA3_RMINCNT 0x4 +#define RTCA3_RMINCNT_MIN GENMASK(6, 0) +#define RTCA3_RHRCNT 0x6 +#define RTCA3_RHRCNT_HR GENMASK(5, 0) +#define RTCA3_RHRCNT_PM BIT(6) +#define RTCA3_RWKCNT 0x8 +#define RTCA3_RWKCNT_WK GENMASK(2, 0) +#define RTCA3_RDAYCNT 0xa +#define RTCA3_RDAYCNT_DAY GENMASK(5, 0) +#define RTCA3_RMONCNT 0xc +#define RTCA3_RMONCNT_MONTH GENMASK(4, 0) +#define RTCA3_RYRCNT 0xe +#define RTCA3_RYRCNT_YEAR GENMASK(7, 0) + +/* Alarm registers. */ +#define RTCA3_RSECAR 0x10 +#define RTCA3_RSECAR_SEC GENMASK(6, 0) +#define RTCA3_RMINAR 0x12 +#define RTCA3_RMINAR_MIN GENMASK(6, 0) +#define RTCA3_RHRAR 0x14 +#define RTCA3_RHRAR_HR GENMASK(5, 0) +#define RTCA3_RHRAR_PM BIT(6) +#define RTCA3_RWKAR 0x16 +#define RTCA3_RWKAR_DAYW GENMASK(2, 0) +#define RTCA3_RDAYAR 0x18 +#define RTCA3_RDAYAR_DATE GENMASK(5, 0) +#define RTCA3_RMONAR 0x1a +#define RTCA3_RMONAR_MON GENMASK(4, 0) +#define RTCA3_RYRAR 0x1c +#define RTCA3_RYRAR_YR GENMASK(7, 0) +#define RTCA3_RYRAREN 0x1e + +/* Alarm enable bit (for all alarm registers). */ +#define RTCA3_AR_ENB BIT(7) + +/* Control registers. */ +#define RTCA3_RCR1 0x22 +#define RTCA3_RCR1_AIE BIT(0) +#define RTCA3_RCR1_CIE BIT(1) +#define RTCA3_RCR1_PIE BIT(2) +#define RTCA3_RCR1_PES GENMASK(7, 4) +#define RTCA3_RCR1_PES_1_64_SEC 0x8 +#define RTCA3_RCR2 0x24 +#define RTCA3_RCR2_START BIT(0) +#define RTCA3_RCR2_RESET BIT(1) +#define RTCA3_RCR2_AADJE BIT(4) +#define RTCA3_RCR2_ADJP BIT(5) +#define RTCA3_RCR2_HR24 BIT(6) +#define RTCA3_RCR2_CNTMD BIT(7) +#define RTCA3_RSR 0x20 +#define RTCA3_RSR_AF BIT(0) +#define RTCA3_RSR_CF BIT(1) +#define RTCA3_RSR_PF BIT(2) +#define RTCA3_RADJ 0x2e +#define RTCA3_RADJ_ADJ GENMASK(5, 0) +#define RTCA3_RADJ_ADJ_MAX 0x3f +#define RTCA3_RADJ_PMADJ GENMASK(7, 6) +#define RTCA3_RADJ_PMADJ_NONE 0 +#define RTCA3_RADJ_PMADJ_ADD 1 +#define RTCA3_RADJ_PMADJ_SUB 2 + +/* Polling operation timeouts. */ +#define RTCA3_DEFAULT_TIMEOUT_US 150 +#define RTCA3_IRQSET_TIMEOUT_US 5000 +#define RTCA3_START_TIMEOUT_US 150000 +#define RTCA3_RESET_TIMEOUT_US 200000 + +/** + * enum rtca3_alrm_set_step - RTCA3 alarm set steps + * @RTCA3_ALRM_SSTEP_DONE: alarm setup done step + * @RTCA3_ALRM_SSTEP_IRQ: two 1/64 periodic IRQs were generated step + * @RTCA3_ALRM_SSTEP_INIT: alarm setup initialization step + */ +enum rtca3_alrm_set_step { + RTCA3_ALRM_SSTEP_DONE = 0, + RTCA3_ALRM_SSTEP_IRQ = 1, + RTCA3_ALRM_SSTEP_INIT = 3, +}; + +/** + * struct rtca3_ppb_per_cycle - PPB per cycle + * @ten_sec: PPB per cycle in 10 seconds adjutment mode + * @sixty_sec: PPB per cycle in 60 seconds adjustment mode + */ +struct rtca3_ppb_per_cycle { + int ten_sec; + int sixty_sec; +}; + +/** + * struct rtca3_priv - RTCA3 private data structure + * @base: base address + * @rtc_dev: RTC device + * @rstc: reset control + * @set_alarm_completion: alarm setup completion + * @alrm_sstep: alarm setup step (see enum rtca3_alrm_set_step) + * @lock: device lock + * @ppb: ppb per cycle for each the available adjustment modes + * @wakeup_irq: wakeup IRQ + */ +struct rtca3_priv { + void __iomem *base; + struct rtc_device *rtc_dev; + struct reset_control *rstc; + struct completion set_alarm_completion; + atomic_t alrm_sstep; + spinlock_t lock; + struct rtca3_ppb_per_cycle ppb; + int wakeup_irq; +}; + +static void rtca3_byte_update_bits(struct rtca3_priv *priv, u8 off, u8 mask, u8 val) +{ + u8 tmp; + + tmp = readb(priv->base + off); + tmp &= ~mask; + tmp |= (val & mask); + writeb(tmp, priv->base + off); +} + +static u8 rtca3_alarm_handler_helper(struct rtca3_priv *priv) +{ + u8 val, pending; + + val = readb(priv->base + RTCA3_RSR); + pending = val & RTCA3_RSR_AF; + writeb(val & ~pending, priv->base + RTCA3_RSR); + + if (pending) + rtc_update_irq(priv->rtc_dev, 1, RTC_AF | RTC_IRQF); + + return pending; +} + +static irqreturn_t rtca3_alarm_handler(int irq, void *dev_id) +{ + struct rtca3_priv *priv = dev_id; + u8 pending; + + guard(spinlock)(&priv->lock); + + pending = rtca3_alarm_handler_helper(priv); + + return IRQ_RETVAL(pending); +} + +static irqreturn_t rtca3_periodic_handler(int irq, void *dev_id) +{ + struct rtca3_priv *priv = dev_id; + u8 val, pending; + + guard(spinlock)(&priv->lock); + + val = readb(priv->base + RTCA3_RSR); + pending = val & RTCA3_RSR_PF; + + if (pending) { + writeb(val & ~pending, priv->base + RTCA3_RSR); + + if (atomic_read(&priv->alrm_sstep) > RTCA3_ALRM_SSTEP_IRQ) { + /* Alarm setup in progress. */ + atomic_dec(&priv->alrm_sstep); + + if (atomic_read(&priv->alrm_sstep) == RTCA3_ALRM_SSTEP_IRQ) { + /* + * We got 2 * 1/64 periodic interrupts. Disable + * interrupt and let alarm setup continue. + */ + rtca3_byte_update_bits(priv, RTCA3_RCR1, + RTCA3_RCR1_PIE, 0); + readb_poll_timeout_atomic(priv->base + RTCA3_RCR1, val, + !(val & RTCA3_RCR1_PIE), + 10, RTCA3_DEFAULT_TIMEOUT_US); + complete(&priv->set_alarm_completion); + } + } + } + + return IRQ_RETVAL(pending); +} + +static void rtca3_prepare_cntalrm_regs_for_read(struct rtca3_priv *priv, bool cnt) +{ + /* Offset b/w time and alarm registers. */ + u8 offset = cnt ? 0 : 0xe; + + /* + * According to HW manual (section 22.6.4. Notes on writing to and + * reading from registers) after writing to count registers, alarm + * registers, year alarm enable register, bits RCR2.AADJE, AADJP, + * and HR24 register, we need to do 3 empty reads before being + * able to fetch the registers content. + */ + for (u8 i = 0; i < 3; i++) { + readb(priv->base + RTCA3_RSECCNT + offset); + readb(priv->base + RTCA3_RMINCNT + offset); + readb(priv->base + RTCA3_RHRCNT + offset); + readb(priv->base + RTCA3_RWKCNT + offset); + readb(priv->base + RTCA3_RDAYCNT + offset); + readw(priv->base + RTCA3_RYRCNT + offset); + if (!cnt) + readb(priv->base + RTCA3_RYRAREN); + } +} + +static int rtca3_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + u8 sec, min, hour, wday, mday, month, tmp; + u8 trials = 0; + u32 year100; + u16 year; + + guard(spinlock_irqsave)(&priv->lock); + + tmp = readb(priv->base + RTCA3_RCR2); + if (!(tmp & RTCA3_RCR2_START)) + return -EINVAL; + + do { + /* Clear carry interrupt. */ + rtca3_byte_update_bits(priv, RTCA3_RSR, RTCA3_RSR_CF, 0); + + /* Read counters. */ + sec = readb(priv->base + RTCA3_RSECCNT); + min = readb(priv->base + RTCA3_RMINCNT); + hour = readb(priv->base + RTCA3_RHRCNT); + wday = readb(priv->base + RTCA3_RWKCNT); + mday = readb(priv->base + RTCA3_RDAYCNT); + month = readb(priv->base + RTCA3_RMONCNT); + year = readw(priv->base + RTCA3_RYRCNT); + + tmp = readb(priv->base + RTCA3_RSR); + + /* + * We cannot generate carries due to reading 64Hz counter as + * the driver doesn't implement carry, thus, carries will be + * generated once per seconds. Add a timeout of 5 trials here + * to avoid infinite loop, if any. + */ + } while ((tmp & RTCA3_RSR_CF) && ++trials < 5); + + if (trials >= 5) + return -ETIMEDOUT; + + tm->tm_sec = bcd2bin(FIELD_GET(RTCA3_RSECCNT_SEC, sec)); + tm->tm_min = bcd2bin(FIELD_GET(RTCA3_RMINCNT_MIN, min)); + tm->tm_hour = bcd2bin(FIELD_GET(RTCA3_RHRCNT_HR, hour)); + tm->tm_wday = bcd2bin(FIELD_GET(RTCA3_RWKCNT_WK, wday)); + tm->tm_mday = bcd2bin(FIELD_GET(RTCA3_RDAYCNT_DAY, mday)); + tm->tm_mon = bcd2bin(FIELD_GET(RTCA3_RMONCNT_MONTH, month)) - 1; + year = FIELD_GET(RTCA3_RYRCNT_YEAR, year); + year100 = bcd2bin((year == 0x99) ? 0x19 : 0x20); + tm->tm_year = (year100 * 100 + bcd2bin(year)) - 1900; + + return 0; +} + +static int rtca3_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + u8 rcr2, tmp; + int ret; + + guard(spinlock_irqsave)(&priv->lock); + + /* Stop the RTC. */ + rcr2 = readb(priv->base + RTCA3_RCR2); + writeb(rcr2 & ~RTCA3_RCR2_START, priv->base + RTCA3_RCR2); + ret = readb_poll_timeout_atomic(priv->base + RTCA3_RCR2, tmp, + !(tmp & RTCA3_RCR2_START), + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + + /* Update time. */ + writeb(bin2bcd(tm->tm_sec), priv->base + RTCA3_RSECCNT); + writeb(bin2bcd(tm->tm_min), priv->base + RTCA3_RMINCNT); + writeb(bin2bcd(tm->tm_hour), priv->base + RTCA3_RHRCNT); + writeb(bin2bcd(tm->tm_wday), priv->base + RTCA3_RWKCNT); + writeb(bin2bcd(tm->tm_mday), priv->base + RTCA3_RDAYCNT); + writeb(bin2bcd(tm->tm_mon + 1), priv->base + RTCA3_RMONCNT); + writew(bin2bcd(tm->tm_year % 100), priv->base + RTCA3_RYRCNT); + + /* Make sure we can read back the counters. */ + rtca3_prepare_cntalrm_regs_for_read(priv, true); + + /* Start RTC. */ + writeb(rcr2 | RTCA3_RCR2_START, priv->base + RTCA3_RCR2); + return readb_poll_timeout_atomic(priv->base + RTCA3_RCR2, tmp, + (tmp & RTCA3_RCR2_START), + 10, RTCA3_DEFAULT_TIMEOUT_US); +} + +static int rtca3_alarm_irq_set_helper(struct rtca3_priv *priv, + u8 interrupts, + unsigned int enabled) +{ + u8 tmp, val; + + if (enabled) { + /* + * AIE, CIE, PIE bit indexes in RSR corresponds with + * those on RCR1. Same interrupts mask can be used. + */ + rtca3_byte_update_bits(priv, RTCA3_RSR, interrupts, 0); + val = interrupts; + } else { + val = 0; + } + + rtca3_byte_update_bits(priv, RTCA3_RCR1, interrupts, val); + return readb_poll_timeout_atomic(priv->base + RTCA3_RCR1, tmp, + ((tmp & interrupts) == val), + 10, RTCA3_IRQSET_TIMEOUT_US); +} + +static int rtca3_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + + guard(spinlock_irqsave)(&priv->lock); + + return rtca3_alarm_irq_set_helper(priv, RTCA3_RCR1_AIE, enabled); +} + +static int rtca3_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + u8 sec, min, hour, wday, mday, month; + struct rtc_time *tm = &wkalrm->time; + u32 year100; + u16 year; + + guard(spinlock_irqsave)(&priv->lock); + + sec = readb(priv->base + RTCA3_RSECAR); + min = readb(priv->base + RTCA3_RMINAR); + hour = readb(priv->base + RTCA3_RHRAR); + wday = readb(priv->base + RTCA3_RWKAR); + mday = readb(priv->base + RTCA3_RDAYAR); + month = readb(priv->base + RTCA3_RMONAR); + year = readw(priv->base + RTCA3_RYRAR); + + tm->tm_sec = bcd2bin(FIELD_GET(RTCA3_RSECAR_SEC, sec)); + tm->tm_min = bcd2bin(FIELD_GET(RTCA3_RMINAR_MIN, min)); + tm->tm_hour = bcd2bin(FIELD_GET(RTCA3_RHRAR_HR, hour)); + tm->tm_wday = bcd2bin(FIELD_GET(RTCA3_RWKAR_DAYW, wday)); + tm->tm_mday = bcd2bin(FIELD_GET(RTCA3_RDAYAR_DATE, mday)); + tm->tm_mon = bcd2bin(FIELD_GET(RTCA3_RMONAR_MON, month)) - 1; + year = FIELD_GET(RTCA3_RYRAR_YR, year); + year100 = bcd2bin((year == 0x99) ? 0x19 : 0x20); + tm->tm_year = (year100 * 100 + bcd2bin(year)) - 1900; + + wkalrm->enabled = !!(readb(priv->base + RTCA3_RCR1) & RTCA3_RCR1_AIE); + + return 0; +} + +static int rtca3_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + struct rtc_time *tm = &wkalrm->time; + u8 rcr1, tmp; + int ret; + + scoped_guard(spinlock_irqsave, &priv->lock) { + tmp = readb(priv->base + RTCA3_RCR2); + if (!(tmp & RTCA3_RCR2_START)) + return -EPERM; + + /* Disable AIE to prevent false interrupts. */ + rcr1 = readb(priv->base + RTCA3_RCR1); + rcr1 &= ~RTCA3_RCR1_AIE; + writeb(rcr1, priv->base + RTCA3_RCR1); + ret = readb_poll_timeout_atomic(priv->base + RTCA3_RCR1, tmp, + !(tmp & RTCA3_RCR1_AIE), + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + + /* Set the time and enable the alarm. */ + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_sec), priv->base + RTCA3_RSECAR); + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_min), priv->base + RTCA3_RMINAR); + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_hour), priv->base + RTCA3_RHRAR); + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_wday), priv->base + RTCA3_RWKAR); + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_mday), priv->base + RTCA3_RDAYAR); + writeb(RTCA3_AR_ENB | bin2bcd(tm->tm_mon + 1), priv->base + RTCA3_RMONAR); + + writew(bin2bcd(tm->tm_year % 100), priv->base + RTCA3_RYRAR); + writeb(RTCA3_AR_ENB, priv->base + RTCA3_RYRAREN); + + /* Make sure we can read back the counters. */ + rtca3_prepare_cntalrm_regs_for_read(priv, false); + + /* Need to wait for 2 * 1/64 periodic interrupts to be generated. */ + atomic_set(&priv->alrm_sstep, RTCA3_ALRM_SSTEP_INIT); + reinit_completion(&priv->set_alarm_completion); + + /* Enable periodic interrupt. */ + rcr1 |= RTCA3_RCR1_PIE; + writeb(rcr1, priv->base + RTCA3_RCR1); + ret = readb_poll_timeout_atomic(priv->base + RTCA3_RCR1, tmp, + (tmp & RTCA3_RCR1_PIE), + 10, RTCA3_IRQSET_TIMEOUT_US); + } + + if (ret) + goto setup_failed; + + /* Wait for the 2 * 1/64 periodic interrupts. */ + ret = wait_for_completion_interruptible_timeout(&priv->set_alarm_completion, + msecs_to_jiffies(500)); + if (ret <= 0) { + ret = -ETIMEDOUT; + goto setup_failed; + } + + scoped_guard(spinlock_irqsave, &priv->lock) { + ret = rtca3_alarm_irq_set_helper(priv, RTCA3_RCR1_AIE, wkalrm->enabled); + atomic_set(&priv->alrm_sstep, RTCA3_ALRM_SSTEP_DONE); + } + + return ret; + +setup_failed: + scoped_guard(spinlock_irqsave, &priv->lock) { + /* + * Disable PIE to avoid interrupt storm in case HW needed more than + * specified timeout for setup. + */ + writeb(rcr1 & ~RTCA3_RCR1_PIE, priv->base + RTCA3_RCR1); + readb_poll_timeout_atomic(priv->base + RTCA3_RCR1, tmp, !(tmp & ~RTCA3_RCR1_PIE), + 10, RTCA3_DEFAULT_TIMEOUT_US); + atomic_set(&priv->alrm_sstep, RTCA3_ALRM_SSTEP_DONE); + } + + return ret; +} + +static int rtca3_read_offset(struct device *dev, long *offset) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + u8 val, radj, cycles; + u32 ppb_per_cycle; + + scoped_guard(spinlock_irqsave, &priv->lock) { + radj = readb(priv->base + RTCA3_RADJ); + val = readb(priv->base + RTCA3_RCR2); + } + + cycles = FIELD_GET(RTCA3_RADJ_ADJ, radj); + + if (!cycles) { + *offset = 0; + return 0; + } + + if (val & RTCA3_RCR2_ADJP) + ppb_per_cycle = priv->ppb.ten_sec; + else + ppb_per_cycle = priv->ppb.sixty_sec; + + *offset = cycles * ppb_per_cycle; + val = FIELD_GET(RTCA3_RADJ_PMADJ, radj); + if (val == RTCA3_RADJ_PMADJ_SUB) + *offset = -(*offset); + + return 0; +} + +static int rtca3_set_offset(struct device *dev, long offset) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + int cycles, cycles10, cycles60; + u8 radj, adjp, tmp; + int ret; + + /* + * Automatic time error adjustment could be set at intervals of 10 + * or 60 seconds. + */ + cycles10 = DIV_ROUND_CLOSEST(offset, priv->ppb.ten_sec); + cycles60 = DIV_ROUND_CLOSEST(offset, priv->ppb.sixty_sec); + + /* We can set b/w 1 and 63 clock cycles. */ + if (cycles60 >= -RTCA3_RADJ_ADJ_MAX && + cycles60 <= RTCA3_RADJ_ADJ_MAX) { + cycles = cycles60; + adjp = 0; + } else if (cycles10 >= -RTCA3_RADJ_ADJ_MAX && + cycles10 <= RTCA3_RADJ_ADJ_MAX) { + cycles = cycles10; + adjp = RTCA3_RCR2_ADJP; + } else { + return -ERANGE; + } + + radj = FIELD_PREP(RTCA3_RADJ_ADJ, abs(cycles)); + if (!cycles) + radj |= FIELD_PREP(RTCA3_RADJ_PMADJ, RTCA3_RADJ_PMADJ_NONE); + else if (cycles > 0) + radj |= FIELD_PREP(RTCA3_RADJ_PMADJ, RTCA3_RADJ_PMADJ_ADD); + else + radj |= FIELD_PREP(RTCA3_RADJ_PMADJ, RTCA3_RADJ_PMADJ_SUB); + + guard(spinlock_irqsave)(&priv->lock); + + tmp = readb(priv->base + RTCA3_RCR2); + + if ((tmp & RTCA3_RCR2_ADJP) != adjp) { + /* RADJ.PMADJ need to be set to zero before setting RCR2.ADJP. */ + writeb(0, priv->base + RTCA3_RADJ); + ret = readb_poll_timeout_atomic(priv->base + RTCA3_RADJ, tmp, !tmp, + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + + rtca3_byte_update_bits(priv, RTCA3_RCR2, RTCA3_RCR2_ADJP, adjp); + ret = readb_poll_timeout_atomic(priv->base + RTCA3_RCR2, tmp, + ((tmp & RTCA3_RCR2_ADJP) == adjp), + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + } + + writeb(radj, priv->base + RTCA3_RADJ); + return readb_poll_timeout_atomic(priv->base + RTCA3_RADJ, tmp, (tmp == radj), + 10, RTCA3_DEFAULT_TIMEOUT_US); +} + +static const struct rtc_class_ops rtca3_ops = { + .read_time = rtca3_read_time, + .set_time = rtca3_set_time, + .read_alarm = rtca3_read_alarm, + .set_alarm = rtca3_set_alarm, + .alarm_irq_enable = rtca3_alarm_irq_enable, + .set_offset = rtca3_set_offset, + .read_offset = rtca3_read_offset, +}; + +static int rtca3_initial_setup(struct clk *clk, struct rtca3_priv *priv) +{ + unsigned long osc32k_rate; + u8 val, tmp, mask; + u32 sleep_us; + int ret; + + osc32k_rate = clk_get_rate(clk); + if (!osc32k_rate) + return -EINVAL; + + sleep_us = DIV_ROUND_UP_ULL(1000000ULL, osc32k_rate) * 6; + + priv->ppb.ten_sec = DIV_ROUND_CLOSEST_ULL(1000000000ULL, (osc32k_rate * 10)); + priv->ppb.sixty_sec = DIV_ROUND_CLOSEST_ULL(1000000000ULL, (osc32k_rate * 60)); + + /* + * According to HW manual (section 22.4.2. Clock and count mode setting procedure) + * we need to wait at least 6 cycles of the 32KHz clock after clock was enabled. + */ + usleep_range(sleep_us, sleep_us + 10); + + /* Disable all interrupts. */ + mask = RTCA3_RCR1_AIE | RTCA3_RCR1_CIE | RTCA3_RCR1_PIE; + ret = rtca3_alarm_irq_set_helper(priv, mask, 0); + if (ret) + return ret; + + mask = RTCA3_RCR2_START | RTCA3_RCR2_HR24; + val = readb(priv->base + RTCA3_RCR2); + /* Nothing to do if already started in 24 hours and calendar count mode. */ + if ((val & mask) == mask) + return 0; + + /* Reconfigure the RTC in 24 hours and calendar count mode. */ + mask = RTCA3_RCR2_START | RTCA3_RCR2_CNTMD; + writeb(0, priv->base + RTCA3_RCR2); + ret = readb_poll_timeout(priv->base + RTCA3_RCR2, tmp, !(tmp & mask), + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + + /* + * Set 24 hours mode. According to HW manual (section 22.3.19. RTC Control + * Register 2) this needs to be done separate from stop operation. + */ + mask = RTCA3_RCR2_HR24; + val = RTCA3_RCR2_HR24; + writeb(val, priv->base + RTCA3_RCR2); + ret = readb_poll_timeout(priv->base + RTCA3_RCR2, tmp, (tmp & mask), + 10, RTCA3_DEFAULT_TIMEOUT_US); + if (ret) + return ret; + + /* Execute reset. */ + mask = RTCA3_RCR2_RESET; + writeb(val | RTCA3_RCR2_RESET, priv->base + RTCA3_RCR2); + ret = readb_poll_timeout(priv->base + RTCA3_RCR2, tmp, !(tmp & mask), + 10, RTCA3_RESET_TIMEOUT_US); + if (ret) + return ret; + + /* + * According to HW manual (section 22.6.3. Notes on writing to and reading + * from registers) after reset we need to wait 6 clock cycles before + * writing to RTC registers. + */ + usleep_range(sleep_us, sleep_us + 10); + + /* Set no adjustment. */ + writeb(0, priv->base + RTCA3_RADJ); + ret = readb_poll_timeout(priv->base + RTCA3_RADJ, tmp, !tmp, 10, + RTCA3_DEFAULT_TIMEOUT_US); + + /* Start the RTC and enable automatic time error adjustment. */ + mask = RTCA3_RCR2_START | RTCA3_RCR2_AADJE; + val |= RTCA3_RCR2_START | RTCA3_RCR2_AADJE; + writeb(val, priv->base + RTCA3_RCR2); + ret = readb_poll_timeout(priv->base + RTCA3_RCR2, tmp, ((tmp & mask) == mask), + 10, RTCA3_START_TIMEOUT_US); + if (ret) + return ret; + + /* + * According to HW manual (section 22.6.4. Notes on writing to and reading + * from registers) we need to wait 1/128 seconds while the clock is operating + * (RCR2.START bit = 1) to be able to read the counters after a return from + * reset. + */ + usleep_range(8000, 9000); + + /* Set period interrupt to 1/64 seconds. It is necessary for alarm setup. */ + val = FIELD_PREP(RTCA3_RCR1_PES, RTCA3_RCR1_PES_1_64_SEC); + rtca3_byte_update_bits(priv, RTCA3_RCR1, RTCA3_RCR1_PES, val); + return readb_poll_timeout(priv->base + RTCA3_RCR1, tmp, ((tmp & RTCA3_RCR1_PES) == val), + 10, RTCA3_DEFAULT_TIMEOUT_US); +} + +static int rtca3_request_irqs(struct platform_device *pdev, struct rtca3_priv *priv) +{ + struct device *dev = &pdev->dev; + int ret, irq; + + irq = platform_get_irq_byname(pdev, "alarm"); + if (irq < 0) + return dev_err_probe(dev, irq, "Failed to get alarm IRQ!\n"); + + ret = devm_request_irq(dev, irq, rtca3_alarm_handler, 0, "rtca3-alarm", priv); + if (ret) + return dev_err_probe(dev, ret, "Failed to request alarm IRQ!\n"); + priv->wakeup_irq = irq; + + irq = platform_get_irq_byname(pdev, "period"); + if (irq < 0) + return dev_err_probe(dev, irq, "Failed to get period IRQ!\n"); + + ret = devm_request_irq(dev, irq, rtca3_periodic_handler, 0, "rtca3-period", priv); + if (ret) + return dev_err_probe(dev, ret, "Failed to request period IRQ!\n"); + + /* + * Driver doesn't implement carry handler. Just get the IRQ here + * for backward compatibility, in case carry support will be added later. + */ + irq = platform_get_irq_byname(pdev, "carry"); + if (irq < 0) + return dev_err_probe(dev, irq, "Failed to get carry IRQ!\n"); + + return 0; +} + +static void rtca3_action(void *data) +{ + struct device *dev = data; + struct rtca3_priv *priv = dev_get_drvdata(dev); + int ret; + + ret = reset_control_assert(priv->rstc); + if (ret) + dev_err(dev, "Failed to de-assert reset!"); + + ret = pm_runtime_put_sync(dev); + if (ret < 0) + dev_err(dev, "Failed to runtime suspend!"); +} + +static int rtca3_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rtca3_priv *priv; + struct clk *clk; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + ret = devm_pm_runtime_enable(dev); + if (ret) + return ret; + + priv->rstc = devm_reset_control_get_shared(dev, NULL); + if (IS_ERR(priv->rstc)) + return PTR_ERR(priv->rstc); + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return ret; + + ret = reset_control_deassert(priv->rstc); + if (ret) { + pm_runtime_put_sync(dev); + return ret; + } + + dev_set_drvdata(dev, priv); + ret = devm_add_action_or_reset(dev, rtca3_action, dev); + if (ret) + return ret; + + /* + * This must be an always-on clock to keep the RTC running even after + * driver is unbinded. + */ + clk = devm_clk_get_enabled(dev, "counter"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + spin_lock_init(&priv->lock); + atomic_set(&priv->alrm_sstep, RTCA3_ALRM_SSTEP_DONE); + init_completion(&priv->set_alarm_completion); + + ret = rtca3_initial_setup(clk, priv); + if (ret) + return dev_err_probe(dev, ret, "Failed to setup the RTC!\n"); + + ret = rtca3_request_irqs(pdev, priv); + if (ret) + return ret; + + device_init_wakeup(&pdev->dev, 1); + + priv->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(priv->rtc_dev)) + return PTR_ERR(priv->rtc_dev); + + priv->rtc_dev->ops = &rtca3_ops; + priv->rtc_dev->max_user_freq = 256; + priv->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000; + priv->rtc_dev->range_max = RTC_TIMESTAMP_END_2099; + + return devm_rtc_register_device(priv->rtc_dev); +} + +static void rtca3_remove(struct platform_device *pdev) +{ + struct rtca3_priv *priv = platform_get_drvdata(pdev); + + guard(spinlock_irqsave)(&priv->lock); + + /* + * Disable alarm, periodic interrupts. The RTC device cannot + * power up the system. + */ + rtca3_alarm_irq_set_helper(priv, RTCA3_RCR1_AIE | RTCA3_RCR1_PIE, 0); +} + +static int rtca3_suspend(struct device *dev) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + + if (!device_may_wakeup(dev)) + return 0; + + /* Alarm setup in progress. */ + if (atomic_read(&priv->alrm_sstep) != RTCA3_ALRM_SSTEP_DONE) + return -EBUSY; + + enable_irq_wake(priv->wakeup_irq); + + return 0; +} + +static int rtca3_clean_alarm(struct rtca3_priv *priv) +{ + struct rtc_device *rtc_dev = priv->rtc_dev; + time64_t alarm_time, now; + struct rtc_wkalrm alarm; + struct rtc_time tm; + u8 pending; + int ret; + + ret = rtc_read_alarm(rtc_dev, &alarm); + if (ret) + return ret; + + if (!alarm.enabled) + return 0; + + ret = rtc_read_time(rtc_dev, &tm); + if (ret) + return ret; + + alarm_time = rtc_tm_to_time64(&alarm.time); + now = rtc_tm_to_time64(&tm); + if (alarm_time >= now) + return 0; + + /* + * Heuristically, it has been determined that when returning from deep + * sleep state the RTCA3_RSR.AF is zero even though the alarm expired. + * Call again the rtc_update_irq() if alarm helper detects this. + */ + + guard(spinlock_irqsave)(&priv->lock); + + pending = rtca3_alarm_handler_helper(priv); + if (!pending) + rtc_update_irq(priv->rtc_dev, 1, RTC_AF | RTC_IRQF); + + return 0; +} + +static int rtca3_resume(struct device *dev) +{ + struct rtca3_priv *priv = dev_get_drvdata(dev); + + if (!device_may_wakeup(dev)) + return 0; + + disable_irq_wake(priv->wakeup_irq); + + /* + * According to the HW manual (section 22.6.4 Notes on writing to + * and reading from registers) we need to wait 1/128 seconds while + * RCR2.START = 1 to be able to read the counters after a return from low + * power consumption state. + */ + mdelay(8); + + /* + * The alarm cannot wake the system from deep sleep states. In case + * we return from deep sleep states and the alarm expired we need + * to disable it to avoid failures when setting another alarm. + */ + return rtca3_clean_alarm(priv); +} + +static DEFINE_SIMPLE_DEV_PM_OPS(rtca3_pm_ops, rtca3_suspend, rtca3_resume); + +static const struct of_device_id rtca3_of_match[] = { + { .compatible = "renesas,rz-rtca3", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rtca3_of_match); + +static struct platform_driver rtca3_platform_driver = { + .driver = { + .name = "rtc-rtca3", + .pm = pm_ptr(&rtca3_pm_ops), + .of_match_table = rtca3_of_match, + }, + .probe = rtca3_probe, + .remove_new = rtca3_remove, +}; +module_platform_driver(rtca3_platform_driver); + +MODULE_DESCRIPTION("Renesas RTCA-3 RTC driver"); +MODULE_AUTHOR("Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.39.2
