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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/rtc/rtc-rzn1.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/rtc/rtc-rzn1.c')
-rw-r--r-- | drivers/rtc/rtc-rzn1.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c new file mode 100644 index 000000000..0d36bc501 --- /dev/null +++ b/drivers/rtc/rtc-rzn1.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Renesas RZ/N1 Real Time Clock interface for Linux + * + * Copyright: + * - 2014 Renesas Electronics Europe Limited + * - 2022 Schneider Electric + * + * Authors: + * - Michel Pollet <michel.pollet@bp.renesas.com>, <buserror@gmail.com> + * - Miquel Raynal <miquel.raynal@bootlin.com> + */ + +#include <linux/bcd.h> +#include <linux/init.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/rtc.h> + +#define RZN1_RTC_CTL0 0x00 +#define RZN1_RTC_CTL0_SLSB_SUBU 0 +#define RZN1_RTC_CTL0_SLSB_SCMP BIT(4) +#define RZN1_RTC_CTL0_AMPM BIT(5) +#define RZN1_RTC_CTL0_CE BIT(7) + +#define RZN1_RTC_CTL1 0x04 +#define RZN1_RTC_CTL1_ALME BIT(4) + +#define RZN1_RTC_CTL2 0x08 +#define RZN1_RTC_CTL2_WAIT BIT(0) +#define RZN1_RTC_CTL2_WST BIT(1) +#define RZN1_RTC_CTL2_WUST BIT(5) +#define RZN1_RTC_CTL2_STOPPED (RZN1_RTC_CTL2_WAIT | RZN1_RTC_CTL2_WST) + +#define RZN1_RTC_SEC 0x14 +#define RZN1_RTC_MIN 0x18 +#define RZN1_RTC_HOUR 0x1c +#define RZN1_RTC_WEEK 0x20 +#define RZN1_RTC_DAY 0x24 +#define RZN1_RTC_MONTH 0x28 +#define RZN1_RTC_YEAR 0x2c + +#define RZN1_RTC_SUBU 0x38 +#define RZN1_RTC_SUBU_DEV BIT(7) +#define RZN1_RTC_SUBU_DECR BIT(6) + +#define RZN1_RTC_ALM 0x40 +#define RZN1_RTC_ALH 0x44 +#define RZN1_RTC_ALW 0x48 + +#define RZN1_RTC_SECC 0x4c +#define RZN1_RTC_MINC 0x50 +#define RZN1_RTC_HOURC 0x54 +#define RZN1_RTC_WEEKC 0x58 +#define RZN1_RTC_DAYC 0x5c +#define RZN1_RTC_MONTHC 0x60 +#define RZN1_RTC_YEARC 0x64 + +struct rzn1_rtc { + struct rtc_device *rtcdev; + void __iomem *base; +}; + +static void rzn1_rtc_get_time_snapshot(struct rzn1_rtc *rtc, struct rtc_time *tm) +{ + tm->tm_sec = readl(rtc->base + RZN1_RTC_SECC); + tm->tm_min = readl(rtc->base + RZN1_RTC_MINC); + tm->tm_hour = readl(rtc->base + RZN1_RTC_HOURC); + tm->tm_wday = readl(rtc->base + RZN1_RTC_WEEKC); + tm->tm_mday = readl(rtc->base + RZN1_RTC_DAYC); + tm->tm_mon = readl(rtc->base + RZN1_RTC_MONTHC); + tm->tm_year = readl(rtc->base + RZN1_RTC_YEARC); +} + +static unsigned int rzn1_rtc_tm_to_wday(struct rtc_time *tm) +{ + time64_t time; + unsigned int days; + u32 secs; + + time = rtc_tm_to_time64(tm); + days = div_s64_rem(time, 86400, &secs); + + /* day of the week, 1970-01-01 was a Thursday */ + return (days + 4) % 7; +} + +static int rzn1_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + u32 val, secs; + + /* + * The RTC was not started or is stopped and thus does not carry the + * proper time/date. + */ + val = readl(rtc->base + RZN1_RTC_CTL2); + if (val & RZN1_RTC_CTL2_STOPPED) + return -EINVAL; + + rzn1_rtc_get_time_snapshot(rtc, tm); + secs = readl(rtc->base + RZN1_RTC_SECC); + if (tm->tm_sec != secs) + rzn1_rtc_get_time_snapshot(rtc, tm); + + tm->tm_sec = bcd2bin(tm->tm_sec); + tm->tm_min = bcd2bin(tm->tm_min); + tm->tm_hour = bcd2bin(tm->tm_hour); + tm->tm_wday = bcd2bin(tm->tm_wday); + tm->tm_mday = bcd2bin(tm->tm_mday); + tm->tm_mon = bcd2bin(tm->tm_mon); + tm->tm_year = bcd2bin(tm->tm_year); + + return 0; +} + +static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + u32 val; + int ret; + + tm->tm_sec = bin2bcd(tm->tm_sec); + tm->tm_min = bin2bcd(tm->tm_min); + tm->tm_hour = bin2bcd(tm->tm_hour); + tm->tm_wday = bin2bcd(rzn1_rtc_tm_to_wday(tm)); + tm->tm_mday = bin2bcd(tm->tm_mday); + tm->tm_mon = bin2bcd(tm->tm_mon); + tm->tm_year = bin2bcd(tm->tm_year); + + val = readl(rtc->base + RZN1_RTC_CTL2); + if (!(val & RZN1_RTC_CTL2_STOPPED)) { + /* Hold the counter if it was counting up */ + writel(RZN1_RTC_CTL2_WAIT, rtc->base + RZN1_RTC_CTL2); + + /* Wait for the counter to stop: two 32k clock cycles */ + usleep_range(61, 100); + ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val, + val & RZN1_RTC_CTL2_WST, 0, 100); + if (ret) + return ret; + } + + writel(tm->tm_sec, rtc->base + RZN1_RTC_SEC); + writel(tm->tm_min, rtc->base + RZN1_RTC_MIN); + writel(tm->tm_hour, rtc->base + RZN1_RTC_HOUR); + writel(tm->tm_wday, rtc->base + RZN1_RTC_WEEK); + writel(tm->tm_mday, rtc->base + RZN1_RTC_DAY); + writel(tm->tm_mon, rtc->base + RZN1_RTC_MONTH); + writel(tm->tm_year, rtc->base + RZN1_RTC_YEAR); + writel(0, rtc->base + RZN1_RTC_CTL2); + + return 0; +} + +static irqreturn_t rzn1_rtc_alarm_irq(int irq, void *dev_id) +{ + struct rzn1_rtc *rtc = dev_id; + + rtc_update_irq(rtc->rtcdev, 1, RTC_AF | RTC_IRQF); + + return IRQ_HANDLED; +} + +static int rzn1_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + u32 ctl1 = readl(rtc->base + RZN1_RTC_CTL1); + + if (enable) + ctl1 |= RZN1_RTC_CTL1_ALME; + else + ctl1 &= ~RZN1_RTC_CTL1_ALME; + + writel(ctl1, rtc->base + RZN1_RTC_CTL1); + + return 0; +} + +static int rzn1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + struct rtc_time *tm = &alrm->time; + unsigned int min, hour, wday, delta_days; + time64_t alarm; + u32 ctl1; + int ret; + + ret = rzn1_rtc_read_time(dev, tm); + if (ret) + return ret; + + min = readl(rtc->base + RZN1_RTC_ALM); + hour = readl(rtc->base + RZN1_RTC_ALH); + wday = readl(rtc->base + RZN1_RTC_ALW); + + tm->tm_sec = 0; + tm->tm_min = bcd2bin(min); + tm->tm_hour = bcd2bin(hour); + delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7; + tm->tm_wday = fls(wday) - 1; + + if (delta_days) { + alarm = rtc_tm_to_time64(tm) + (delta_days * 86400); + rtc_time64_to_tm(alarm, tm); + } + + ctl1 = readl(rtc->base + RZN1_RTC_CTL1); + alrm->enabled = !!(ctl1 & RZN1_RTC_CTL1_ALME); + + return 0; +} + +static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + struct rtc_time *tm = &alrm->time, tm_now; + unsigned long alarm, farest; + unsigned int days_ahead, wday; + int ret; + + ret = rzn1_rtc_read_time(dev, &tm_now); + if (ret) + return ret; + + /* We cannot set alarms more than one week ahead */ + farest = rtc_tm_to_time64(&tm_now) + (7 * 86400); + alarm = rtc_tm_to_time64(tm); + if (time_after(alarm, farest)) + return -ERANGE; + + /* Convert alarm day into week day */ + days_ahead = tm->tm_mday - tm_now.tm_mday; + wday = (tm_now.tm_wday + days_ahead) % 7; + + writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM); + writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH); + writel(BIT(wday), rtc->base + RZN1_RTC_ALW); + + rzn1_rtc_alarm_irq_enable(dev, alrm->enabled); + + return 0; +} + +static int rzn1_rtc_read_offset(struct device *dev, long *offset) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + unsigned int ppb_per_step; + bool subtract; + u32 val; + + val = readl(rtc->base + RZN1_RTC_SUBU); + ppb_per_step = val & RZN1_RTC_SUBU_DEV ? 1017 : 3051; + subtract = val & RZN1_RTC_SUBU_DECR; + val &= 0x3F; + + if (!val) + *offset = 0; + else if (subtract) + *offset = -(((~val) & 0x3F) + 1) * ppb_per_step; + else + *offset = (val - 1) * ppb_per_step; + + return 0; +} + +static int rzn1_rtc_set_offset(struct device *dev, long offset) +{ + struct rzn1_rtc *rtc = dev_get_drvdata(dev); + int stepsh, stepsl, steps; + u32 subu = 0, ctl2; + int ret; + + /* + * Check which resolution mode (every 20 or 60s) can be used. + * Between 2 and 124 clock pulses can be added or substracted. + * + * In 20s mode, the minimum resolution is 2 / (32768 * 20) which is + * close to 3051 ppb. In 60s mode, the resolution is closer to 1017. + */ + stepsh = DIV_ROUND_CLOSEST(offset, 1017); + stepsl = DIV_ROUND_CLOSEST(offset, 3051); + + if (stepsh >= -0x3E && stepsh <= 0x3E) { + /* 1017 ppb per step */ + steps = stepsh; + subu |= RZN1_RTC_SUBU_DEV; + } else if (stepsl >= -0x3E && stepsl <= 0x3E) { + /* 3051 ppb per step */ + steps = stepsl; + } else { + return -ERANGE; + } + + if (!steps) + return 0; + + if (steps > 0) { + subu |= steps + 1; + } else { + subu |= RZN1_RTC_SUBU_DECR; + subu |= (~(-steps - 1)) & 0x3F; + } + + ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, ctl2, + !(ctl2 & RZN1_RTC_CTL2_WUST), 100, 2000000); + if (ret) + return ret; + + writel(subu, rtc->base + RZN1_RTC_SUBU); + + return 0; +} + +static const struct rtc_class_ops rzn1_rtc_ops = { + .read_time = rzn1_rtc_read_time, + .set_time = rzn1_rtc_set_time, + .read_alarm = rzn1_rtc_read_alarm, + .set_alarm = rzn1_rtc_set_alarm, + .alarm_irq_enable = rzn1_rtc_alarm_irq_enable, + .read_offset = rzn1_rtc_read_offset, + .set_offset = rzn1_rtc_set_offset, +}; + +static int rzn1_rtc_probe(struct platform_device *pdev) +{ + struct rzn1_rtc *rtc; + int alarm_irq; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + platform_set_drvdata(pdev, rtc); + + rtc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rtc->base)) + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n"); + + alarm_irq = platform_get_irq(pdev, 0); + if (alarm_irq < 0) + return alarm_irq; + + rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtcdev)) + return PTR_ERR(rtc->rtcdev); + + rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099; + rtc->rtcdev->ops = &rzn1_rtc_ops; + set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtcdev->features); + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features); + + ret = devm_pm_runtime_enable(&pdev->dev); + if (ret < 0) + return ret; + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) + return ret; + + /* + * Ensure the clock counter is enabled. + * Set 24-hour mode and possible oscillator offset compensation in SUBU mode. + */ + writel(RZN1_RTC_CTL0_CE | RZN1_RTC_CTL0_AMPM | RZN1_RTC_CTL0_SLSB_SUBU, + rtc->base + RZN1_RTC_CTL0); + + /* Disable all interrupts */ + writel(0, rtc->base + RZN1_RTC_CTL1); + + ret = devm_request_irq(&pdev->dev, alarm_irq, rzn1_rtc_alarm_irq, 0, + dev_name(&pdev->dev), rtc); + if (ret) { + dev_err(&pdev->dev, "RTC timer interrupt not available\n"); + goto dis_runtime_pm; + } + + ret = devm_rtc_register_device(rtc->rtcdev); + if (ret) + goto dis_runtime_pm; + + return 0; + +dis_runtime_pm: + pm_runtime_put(&pdev->dev); + + return ret; +} + +static int rzn1_rtc_remove(struct platform_device *pdev) +{ + pm_runtime_put(&pdev->dev); + + return 0; +} + +static const struct of_device_id rzn1_rtc_of_match[] = { + { .compatible = "renesas,rzn1-rtc" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rzn1_rtc_of_match); + +static struct platform_driver rzn1_rtc_driver = { + .probe = rzn1_rtc_probe, + .remove = rzn1_rtc_remove, + .driver = { + .name = "rzn1-rtc", + .of_match_table = rzn1_rtc_of_match, + }, +}; +module_platform_driver(rzn1_rtc_driver); + +MODULE_AUTHOR("Michel Pollet <Michel.Pollet@bp.renesas.com"); +MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com"); +MODULE_DESCRIPTION("RZ/N1 RTC driver"); +MODULE_LICENSE("GPL"); |