diff options
Diffstat (limited to 'drivers/rtc/rtc-s3c.c')
| -rw-r--r-- | drivers/rtc/rtc-s3c.c | 620 |
1 files changed, 620 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c new file mode 100644 index 000000000..db529733c --- /dev/null +++ b/drivers/rtc/rtc-s3c.c @@ -0,0 +1,620 @@ +// 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 int 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); + + return 0; +} + +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)) { + ret = PTR_ERR(info->rtc_clk); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "failed to find rtc clock\n"); + else + dev_dbg(&pdev->dev, "probe deferred due to missing rtc clk\n"); + return ret; + } + 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 = 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"); |