diff options
Diffstat (limited to 'drivers/rtc/rtc-rzn1.c')
| -rw-r--r-- | drivers/rtc/rtc-rzn1.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c new file mode 100644 index 000000000000..6b2139a09ae2 --- /dev/null +++ b/drivers/rtc/rtc-rzn1.c @@ -0,0 +1,243 @@ +// 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 const struct rtc_class_ops rzn1_rtc_ops = { + .read_time = rzn1_rtc_read_time, + .set_time = rzn1_rtc_set_time, +}; + +static int rzn1_rtc_probe(struct platform_device *pdev) +{ + struct rzn1_rtc *rtc; + 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"); + + rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtcdev)) + return PTR_ERR(rtc); + + rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099; + rtc->rtcdev->ops = &rzn1_rtc_ops; + clear_bit(RTC_FEATURE_ALARM, rtc->rtcdev->features); + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features); + + devm_pm_runtime_enable(&pdev->dev); + 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_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", + .owner = THIS_MODULE, + .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"); |