| // SPDX-License-Identifier: GPL-2.0-only |
| /* drivers/rtc/rtc-s3c.c |
| * |
| * Copyright (c) 2010 Samsung Electronics Co., Ltd. |
| * http://www.samsung.com/ |
| * |
| * Copyright (c) 2004,2006 Simtec Electronics |
| * Ben Dooks, <ben@simtec.co.uk> |
| * http://armlinux.simtec.co.uk/ |
| * |
| * S3C2410/S3C2440/S3C24XX Internal RTC Driver |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/string.h> |
| #include <linux/init.h> |
| #include <linux/platform_device.h> |
| #include <linux/interrupt.h> |
| #include <linux/rtc.h> |
| #include <linux/bcd.h> |
| #include <linux/clk.h> |
| #include <linux/log2.h> |
| #include <linux/slab.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/uaccess.h> |
| #include <linux/io.h> |
| |
| #include <asm/irq.h> |
| #include "rtc-s3c.h" |
| |
| struct s3c_rtc { |
| struct device *dev; |
| struct rtc_device *rtc; |
| |
| void __iomem *base; |
| struct clk *rtc_clk; |
| struct clk *rtc_src_clk; |
| bool alarm_enabled; |
| |
| const struct s3c_rtc_data *data; |
| |
| int irq_alarm; |
| spinlock_t alarm_lock; |
| |
| bool wake_en; |
| }; |
| |
| struct s3c_rtc_data { |
| bool needs_src_clk; |
| |
| void (*irq_handler) (struct s3c_rtc *info, int mask); |
| void (*enable) (struct s3c_rtc *info); |
| void (*disable) (struct s3c_rtc *info); |
| }; |
| |
| static int s3c_rtc_enable_clk(struct s3c_rtc *info) |
| { |
| int ret; |
| |
| ret = clk_enable(info->rtc_clk); |
| if (ret) |
| return ret; |
| |
| if (info->data->needs_src_clk) { |
| ret = clk_enable(info->rtc_src_clk); |
| if (ret) { |
| clk_disable(info->rtc_clk); |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| static void s3c_rtc_disable_clk(struct s3c_rtc *info) |
| { |
| if (info->data->needs_src_clk) |
| clk_disable(info->rtc_src_clk); |
| clk_disable(info->rtc_clk); |
| } |
| |
| /* IRQ Handler */ |
| static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) |
| { |
| struct s3c_rtc *info = (struct s3c_rtc *)id; |
| |
| if (info->data->irq_handler) |
| info->data->irq_handler(info, S3C2410_INTP_ALM); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* Update control registers */ |
| static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| unsigned long flags; |
| unsigned int tmp; |
| int ret; |
| |
| dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled); |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; |
| |
| if (enabled) |
| tmp |= S3C2410_RTCALM_ALMEN; |
| |
| writeb(tmp, info->base + S3C2410_RTCALM); |
| |
| spin_lock_irqsave(&info->alarm_lock, flags); |
| |
| if (info->alarm_enabled && !enabled) |
| s3c_rtc_disable_clk(info); |
| else if (!info->alarm_enabled && enabled) |
| ret = s3c_rtc_enable_clk(info); |
| |
| info->alarm_enabled = enabled; |
| spin_unlock_irqrestore(&info->alarm_lock, flags); |
| |
| s3c_rtc_disable_clk(info); |
| |
| return ret; |
| } |
| |
| /* Read time from RTC and convert it from BCD */ |
| static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm) |
| { |
| unsigned int have_retried = 0; |
| int ret; |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| retry_get_time: |
| tm->tm_min = readb(info->base + S3C2410_RTCMIN); |
| tm->tm_hour = readb(info->base + S3C2410_RTCHOUR); |
| tm->tm_mday = readb(info->base + S3C2410_RTCDATE); |
| tm->tm_mon = readb(info->base + S3C2410_RTCMON); |
| tm->tm_year = readb(info->base + S3C2410_RTCYEAR); |
| tm->tm_sec = readb(info->base + S3C2410_RTCSEC); |
| |
| /* |
| * The only way to work out whether the system was mid-update |
| * when we read it is to check the second counter, and if it |
| * is zero, then we re-try the entire read |
| */ |
| if (tm->tm_sec == 0 && !have_retried) { |
| have_retried = 1; |
| goto retry_get_time; |
| } |
| |
| s3c_rtc_disable_clk(info); |
| |
| tm->tm_sec = bcd2bin(tm->tm_sec); |
| tm->tm_min = bcd2bin(tm->tm_min); |
| tm->tm_hour = bcd2bin(tm->tm_hour); |
| tm->tm_mday = bcd2bin(tm->tm_mday); |
| tm->tm_mon = bcd2bin(tm->tm_mon); |
| tm->tm_year = bcd2bin(tm->tm_year); |
| |
| return 0; |
| } |
| |
| /* Convert time to BCD and write it to RTC */ |
| static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm) |
| { |
| int ret; |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC); |
| writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN); |
| writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR); |
| writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE); |
| writeb(bin2bcd(tm->tm_mon), info->base + S3C2410_RTCMON); |
| writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR); |
| |
| s3c_rtc_disable_clk(info); |
| |
| return 0; |
| } |
| |
| static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| int ret; |
| |
| ret = s3c_rtc_read_time(info, tm); |
| if (ret) |
| return ret; |
| |
| /* Convert internal representation to actual date/time */ |
| tm->tm_year += 100; |
| tm->tm_mon -= 1; |
| |
| dev_dbg(dev, "read time %ptR\n", tm); |
| return 0; |
| } |
| |
| static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| struct rtc_time rtc_tm = *tm; |
| |
| dev_dbg(dev, "set time %ptR\n", tm); |
| |
| /* |
| * Convert actual date/time to internal representation. |
| * We get around Y2K by simply not supporting it. |
| */ |
| rtc_tm.tm_year -= 100; |
| rtc_tm.tm_mon += 1; |
| |
| return s3c_rtc_write_time(info, &rtc_tm); |
| } |
| |
| static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| struct rtc_time *alm_tm = &alrm->time; |
| unsigned int alm_en; |
| int ret; |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC); |
| alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN); |
| alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR); |
| alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON); |
| alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE); |
| alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR); |
| |
| alm_en = readb(info->base + S3C2410_RTCALM); |
| |
| s3c_rtc_disable_clk(info); |
| |
| alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0; |
| |
| dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm); |
| |
| /* decode the alarm enable field */ |
| if (alm_en & S3C2410_RTCALM_SECEN) |
| alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); |
| |
| if (alm_en & S3C2410_RTCALM_MINEN) |
| alm_tm->tm_min = bcd2bin(alm_tm->tm_min); |
| |
| if (alm_en & S3C2410_RTCALM_HOUREN) |
| alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); |
| |
| if (alm_en & S3C2410_RTCALM_DAYEN) |
| alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday); |
| |
| if (alm_en & S3C2410_RTCALM_MONEN) { |
| alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon); |
| alm_tm->tm_mon -= 1; |
| } |
| |
| if (alm_en & S3C2410_RTCALM_YEAREN) |
| alm_tm->tm_year = bcd2bin(alm_tm->tm_year); |
| |
| return 0; |
| } |
| |
| static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| struct rtc_time *tm = &alrm->time; |
| unsigned int alrm_en; |
| int ret; |
| |
| dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm); |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; |
| writeb(0x00, info->base + S3C2410_RTCALM); |
| |
| if (tm->tm_sec < 60 && tm->tm_sec >= 0) { |
| alrm_en |= S3C2410_RTCALM_SECEN; |
| writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC); |
| } |
| |
| if (tm->tm_min < 60 && tm->tm_min >= 0) { |
| alrm_en |= S3C2410_RTCALM_MINEN; |
| writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN); |
| } |
| |
| if (tm->tm_hour < 24 && tm->tm_hour >= 0) { |
| alrm_en |= S3C2410_RTCALM_HOUREN; |
| writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR); |
| } |
| |
| if (tm->tm_mon < 12 && tm->tm_mon >= 0) { |
| alrm_en |= S3C2410_RTCALM_MONEN; |
| writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON); |
| } |
| |
| if (tm->tm_mday <= 31 && tm->tm_mday >= 1) { |
| alrm_en |= S3C2410_RTCALM_DAYEN; |
| writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE); |
| } |
| |
| dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en); |
| |
| writeb(alrm_en, info->base + S3C2410_RTCALM); |
| |
| s3c_rtc_setaie(dev, alrm->enabled); |
| |
| s3c_rtc_disable_clk(info); |
| |
| return 0; |
| } |
| |
| static const struct rtc_class_ops s3c_rtcops = { |
| .read_time = s3c_rtc_gettime, |
| .set_time = s3c_rtc_settime, |
| .read_alarm = s3c_rtc_getalarm, |
| .set_alarm = s3c_rtc_setalarm, |
| .alarm_irq_enable = s3c_rtc_setaie, |
| }; |
| |
| static void s3c24xx_rtc_enable(struct s3c_rtc *info) |
| { |
| unsigned int con, tmp; |
| |
| con = readw(info->base + S3C2410_RTCCON); |
| /* re-enable the device, and check it is ok */ |
| if ((con & S3C2410_RTCCON_RTCEN) == 0) { |
| dev_info(info->dev, "rtc disabled, re-enabling\n"); |
| |
| tmp = readw(info->base + S3C2410_RTCCON); |
| writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON); |
| } |
| |
| if (con & S3C2410_RTCCON_CNTSEL) { |
| dev_info(info->dev, "removing RTCCON_CNTSEL\n"); |
| |
| tmp = readw(info->base + S3C2410_RTCCON); |
| writew(tmp & ~S3C2410_RTCCON_CNTSEL, |
| info->base + S3C2410_RTCCON); |
| } |
| |
| if (con & S3C2410_RTCCON_CLKRST) { |
| dev_info(info->dev, "removing RTCCON_CLKRST\n"); |
| |
| tmp = readw(info->base + S3C2410_RTCCON); |
| writew(tmp & ~S3C2410_RTCCON_CLKRST, |
| info->base + S3C2410_RTCCON); |
| } |
| } |
| |
| static void s3c24xx_rtc_disable(struct s3c_rtc *info) |
| { |
| unsigned int con; |
| |
| con = readw(info->base + S3C2410_RTCCON); |
| con &= ~S3C2410_RTCCON_RTCEN; |
| writew(con, info->base + S3C2410_RTCCON); |
| |
| con = readb(info->base + S3C2410_TICNT); |
| con &= ~S3C2410_TICNT_ENABLE; |
| writeb(con, info->base + S3C2410_TICNT); |
| } |
| |
| static void s3c6410_rtc_disable(struct s3c_rtc *info) |
| { |
| unsigned int con; |
| |
| con = readw(info->base + S3C2410_RTCCON); |
| con &= ~S3C64XX_RTCCON_TICEN; |
| con &= ~S3C2410_RTCCON_RTCEN; |
| writew(con, info->base + S3C2410_RTCCON); |
| } |
| |
| static void s3c_rtc_remove(struct platform_device *pdev) |
| { |
| struct s3c_rtc *info = platform_get_drvdata(pdev); |
| |
| s3c_rtc_setaie(info->dev, 0); |
| |
| if (info->data->needs_src_clk) |
| clk_unprepare(info->rtc_src_clk); |
| clk_unprepare(info->rtc_clk); |
| } |
| |
| static int s3c_rtc_probe(struct platform_device *pdev) |
| { |
| struct s3c_rtc *info = NULL; |
| int ret; |
| |
| info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); |
| if (!info) |
| return -ENOMEM; |
| |
| info->dev = &pdev->dev; |
| info->data = of_device_get_match_data(&pdev->dev); |
| if (!info->data) { |
| dev_err(&pdev->dev, "failed getting s3c_rtc_data\n"); |
| return -EINVAL; |
| } |
| spin_lock_init(&info->alarm_lock); |
| |
| platform_set_drvdata(pdev, info); |
| |
| info->irq_alarm = platform_get_irq(pdev, 0); |
| if (info->irq_alarm < 0) |
| return info->irq_alarm; |
| |
| dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm); |
| |
| /* get the memory region */ |
| info->base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(info->base)) |
| return PTR_ERR(info->base); |
| |
| info->rtc_clk = devm_clk_get(&pdev->dev, "rtc"); |
| if (IS_ERR(info->rtc_clk)) |
| return dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_clk), |
| "failed to find rtc clock\n"); |
| ret = clk_prepare_enable(info->rtc_clk); |
| if (ret) |
| return ret; |
| |
| if (info->data->needs_src_clk) { |
| info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src"); |
| if (IS_ERR(info->rtc_src_clk)) { |
| ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk), |
| "failed to find rtc source clock\n"); |
| goto err_src_clk; |
| } |
| ret = clk_prepare_enable(info->rtc_src_clk); |
| if (ret) |
| goto err_src_clk; |
| } |
| |
| /* disable RTC enable bits potentially set by the bootloader */ |
| if (info->data->disable) |
| info->data->disable(info); |
| |
| /* check to see if everything is setup correctly */ |
| if (info->data->enable) |
| info->data->enable(info); |
| |
| dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n", |
| readw(info->base + S3C2410_RTCCON)); |
| |
| device_init_wakeup(&pdev->dev, 1); |
| |
| info->rtc = devm_rtc_allocate_device(&pdev->dev); |
| if (IS_ERR(info->rtc)) { |
| ret = PTR_ERR(info->rtc); |
| goto err_nortc; |
| } |
| |
| info->rtc->ops = &s3c_rtcops; |
| info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; |
| info->rtc->range_max = RTC_TIMESTAMP_END_2099; |
| |
| ret = devm_rtc_register_device(info->rtc); |
| if (ret) |
| goto err_nortc; |
| |
| ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq, |
| 0, "s3c2410-rtc alarm", info); |
| if (ret) { |
| dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret); |
| goto err_nortc; |
| } |
| |
| s3c_rtc_disable_clk(info); |
| |
| return 0; |
| |
| err_nortc: |
| if (info->data->disable) |
| info->data->disable(info); |
| |
| if (info->data->needs_src_clk) |
| clk_disable_unprepare(info->rtc_src_clk); |
| err_src_clk: |
| clk_disable_unprepare(info->rtc_clk); |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| |
| static int s3c_rtc_suspend(struct device *dev) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| int ret; |
| |
| ret = s3c_rtc_enable_clk(info); |
| if (ret) |
| return ret; |
| |
| if (info->data->disable) |
| info->data->disable(info); |
| |
| if (device_may_wakeup(dev) && !info->wake_en) { |
| if (enable_irq_wake(info->irq_alarm) == 0) |
| info->wake_en = true; |
| else |
| dev_err(dev, "enable_irq_wake failed\n"); |
| } |
| |
| return 0; |
| } |
| |
| static int s3c_rtc_resume(struct device *dev) |
| { |
| struct s3c_rtc *info = dev_get_drvdata(dev); |
| |
| if (info->data->enable) |
| info->data->enable(info); |
| |
| s3c_rtc_disable_clk(info); |
| |
| if (device_may_wakeup(dev) && info->wake_en) { |
| disable_irq_wake(info->irq_alarm); |
| info->wake_en = false; |
| } |
| |
| return 0; |
| } |
| #endif |
| static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume); |
| |
| static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask) |
| { |
| rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF); |
| } |
| |
| static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask) |
| { |
| rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF); |
| writeb(mask, info->base + S3C2410_INTP); |
| } |
| |
| static struct s3c_rtc_data const s3c2410_rtc_data = { |
| .irq_handler = s3c24xx_rtc_irq, |
| .enable = s3c24xx_rtc_enable, |
| .disable = s3c24xx_rtc_disable, |
| }; |
| |
| static struct s3c_rtc_data const s3c2416_rtc_data = { |
| .irq_handler = s3c24xx_rtc_irq, |
| .enable = s3c24xx_rtc_enable, |
| .disable = s3c24xx_rtc_disable, |
| }; |
| |
| static struct s3c_rtc_data const s3c2443_rtc_data = { |
| .irq_handler = s3c24xx_rtc_irq, |
| .enable = s3c24xx_rtc_enable, |
| .disable = s3c24xx_rtc_disable, |
| }; |
| |
| static struct s3c_rtc_data const s3c6410_rtc_data = { |
| .needs_src_clk = true, |
| .irq_handler = s3c6410_rtc_irq, |
| .enable = s3c24xx_rtc_enable, |
| .disable = s3c6410_rtc_disable, |
| }; |
| |
| static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = { |
| { |
| .compatible = "samsung,s3c2410-rtc", |
| .data = &s3c2410_rtc_data, |
| }, { |
| .compatible = "samsung,s3c2416-rtc", |
| .data = &s3c2416_rtc_data, |
| }, { |
| .compatible = "samsung,s3c2443-rtc", |
| .data = &s3c2443_rtc_data, |
| }, { |
| .compatible = "samsung,s3c6410-rtc", |
| .data = &s3c6410_rtc_data, |
| }, { |
| .compatible = "samsung,exynos3250-rtc", |
| .data = &s3c6410_rtc_data, |
| }, |
| { /* sentinel */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match); |
| |
| static struct platform_driver s3c_rtc_driver = { |
| .probe = s3c_rtc_probe, |
| .remove_new = s3c_rtc_remove, |
| .driver = { |
| .name = "s3c-rtc", |
| .pm = &s3c_rtc_pm_ops, |
| .of_match_table = of_match_ptr(s3c_rtc_dt_match), |
| }, |
| }; |
| module_platform_driver(s3c_rtc_driver); |
| |
| MODULE_DESCRIPTION("Samsung S3C RTC Driver"); |
| MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:s3c2410-rtc"); |