diff options
Diffstat (limited to 'drivers/rtc/rtc-sh.c')
| -rw-r--r-- | drivers/rtc/rtc-sh.c | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c new file mode 100644 index 000000000..3d7414e5e --- /dev/null +++ b/drivers/rtc/rtc-sh.c @@ -0,0 +1,685 @@ +/* + * SuperH On-Chip RTC Support + * + * Copyright (C) 2006 - 2009 Paul Mundt + * Copyright (C) 2006 Jamie Lenehan + * Copyright (C) 2008 Angelo Castello + * + * Based on the old arch/sh/kernel/cpu/rtc.c by: + * + * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> + * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/kernel.h> +#include <linux/bcd.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/seq_file.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/io.h> +#include <linux/log2.h> +#include <linux/clk.h> +#include <linux/slab.h> +#ifdef CONFIG_SUPERH +#include <asm/rtc.h> +#else +/* Default values for RZ/A RTC */ +#define rtc_reg_size sizeof(u16) +#define RTC_BIT_INVERTED 0 /* no chip bugs */ +#define RTC_CAP_4_DIGIT_YEAR (1 << 0) +#define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR +#endif + +#define DRV_NAME "sh-rtc" + +#define RTC_REG(r) ((r) * rtc_reg_size) + +#define R64CNT RTC_REG(0) + +#define RSECCNT RTC_REG(1) /* RTC sec */ +#define RMINCNT RTC_REG(2) /* RTC min */ +#define RHRCNT RTC_REG(3) /* RTC hour */ +#define RWKCNT RTC_REG(4) /* RTC week */ +#define RDAYCNT RTC_REG(5) /* RTC day */ +#define RMONCNT RTC_REG(6) /* RTC month */ +#define RYRCNT RTC_REG(7) /* RTC year */ +#define RSECAR RTC_REG(8) /* ALARM sec */ +#define RMINAR RTC_REG(9) /* ALARM min */ +#define RHRAR RTC_REG(10) /* ALARM hour */ +#define RWKAR RTC_REG(11) /* ALARM week */ +#define RDAYAR RTC_REG(12) /* ALARM day */ +#define RMONAR RTC_REG(13) /* ALARM month */ +#define RCR1 RTC_REG(14) /* Control */ +#define RCR2 RTC_REG(15) /* Control */ + +/* + * Note on RYRAR and RCR3: Up until this point most of the register + * definitions are consistent across all of the available parts. However, + * the placement of the optional RYRAR and RCR3 (the RYRAR control + * register used to control RYRCNT/RYRAR compare) varies considerably + * across various parts, occasionally being mapped in to a completely + * unrelated address space. For proper RYRAR support a separate resource + * would have to be handed off, but as this is purely optional in + * practice, we simply opt not to support it, thereby keeping the code + * quite a bit more simplified. + */ + +/* ALARM Bits - or with BCD encoded value */ +#define AR_ENB 0x80 /* Enable for alarm cmp */ + +/* Period Bits */ +#define PF_HP 0x100 /* Enable Half Period to support 8,32,128Hz */ +#define PF_COUNT 0x200 /* Half periodic counter */ +#define PF_OXS 0x400 /* Periodic One x Second */ +#define PF_KOU 0x800 /* Kernel or User periodic request 1=kernel */ +#define PF_MASK 0xf00 + +/* RCR1 Bits */ +#define RCR1_CF 0x80 /* Carry Flag */ +#define RCR1_CIE 0x10 /* Carry Interrupt Enable */ +#define RCR1_AIE 0x08 /* Alarm Interrupt Enable */ +#define RCR1_AF 0x01 /* Alarm Flag */ + +/* RCR2 Bits */ +#define RCR2_PEF 0x80 /* PEriodic interrupt Flag */ +#define RCR2_PESMASK 0x70 /* Periodic interrupt Set */ +#define RCR2_RTCEN 0x08 /* ENable RTC */ +#define RCR2_ADJ 0x04 /* ADJustment (30-second) */ +#define RCR2_RESET 0x02 /* Reset bit */ +#define RCR2_START 0x01 /* Start bit */ + +struct sh_rtc { + void __iomem *regbase; + unsigned long regsize; + struct resource *res; + int alarm_irq; + int periodic_irq; + int carry_irq; + struct clk *clk; + struct rtc_device *rtc_dev; + spinlock_t lock; + unsigned long capabilities; /* See asm/rtc.h for cap bits */ + unsigned short periodic_freq; +}; + +static int __sh_rtc_interrupt(struct sh_rtc *rtc) +{ + unsigned int tmp, pending; + + tmp = readb(rtc->regbase + RCR1); + pending = tmp & RCR1_CF; + tmp &= ~RCR1_CF; + writeb(tmp, rtc->regbase + RCR1); + + /* Users have requested One x Second IRQ */ + if (pending && rtc->periodic_freq & PF_OXS) + rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF); + + return pending; +} + +static int __sh_rtc_alarm(struct sh_rtc *rtc) +{ + unsigned int tmp, pending; + + tmp = readb(rtc->regbase + RCR1); + pending = tmp & RCR1_AF; + tmp &= ~(RCR1_AF | RCR1_AIE); + writeb(tmp, rtc->regbase + RCR1); + + if (pending) + rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF); + + return pending; +} + +static int __sh_rtc_periodic(struct sh_rtc *rtc) +{ + unsigned int tmp, pending; + + tmp = readb(rtc->regbase + RCR2); + pending = tmp & RCR2_PEF; + tmp &= ~RCR2_PEF; + writeb(tmp, rtc->regbase + RCR2); + + if (!pending) + return 0; + + /* Half period enabled than one skipped and the next notified */ + if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT)) + rtc->periodic_freq &= ~PF_COUNT; + else { + if (rtc->periodic_freq & PF_HP) + rtc->periodic_freq |= PF_COUNT; + rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF); + } + + return pending; +} + +static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id) +{ + struct sh_rtc *rtc = dev_id; + int ret; + + spin_lock(&rtc->lock); + ret = __sh_rtc_interrupt(rtc); + spin_unlock(&rtc->lock); + + return IRQ_RETVAL(ret); +} + +static irqreturn_t sh_rtc_alarm(int irq, void *dev_id) +{ + struct sh_rtc *rtc = dev_id; + int ret; + + spin_lock(&rtc->lock); + ret = __sh_rtc_alarm(rtc); + spin_unlock(&rtc->lock); + + return IRQ_RETVAL(ret); +} + +static irqreturn_t sh_rtc_periodic(int irq, void *dev_id) +{ + struct sh_rtc *rtc = dev_id; + int ret; + + spin_lock(&rtc->lock); + ret = __sh_rtc_periodic(rtc); + spin_unlock(&rtc->lock); + + return IRQ_RETVAL(ret); +} + +static irqreturn_t sh_rtc_shared(int irq, void *dev_id) +{ + struct sh_rtc *rtc = dev_id; + int ret; + + spin_lock(&rtc->lock); + ret = __sh_rtc_interrupt(rtc); + ret |= __sh_rtc_alarm(rtc); + ret |= __sh_rtc_periodic(rtc); + spin_unlock(&rtc->lock); + + return IRQ_RETVAL(ret); +} + +static inline void sh_rtc_setaie(struct device *dev, unsigned int enable) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + + spin_lock_irq(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + + if (enable) + tmp |= RCR1_AIE; + else + tmp &= ~RCR1_AIE; + + writeb(tmp, rtc->regbase + RCR1); + + spin_unlock_irq(&rtc->lock); +} + +static int sh_rtc_proc(struct device *dev, struct seq_file *seq) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + + tmp = readb(rtc->regbase + RCR1); + seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no"); + + tmp = readb(rtc->regbase + RCR2); + seq_printf(seq, "periodic_IRQ\t: %s\n", + (tmp & RCR2_PESMASK) ? "yes" : "no"); + + return 0; +} + +static inline void sh_rtc_setcie(struct device *dev, unsigned int enable) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + + spin_lock_irq(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + + if (!enable) + tmp &= ~RCR1_CIE; + else + tmp |= RCR1_CIE; + + writeb(tmp, rtc->regbase + RCR1); + + spin_unlock_irq(&rtc->lock); +} + +static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + sh_rtc_setaie(dev, enabled); + return 0; +} + +static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int sec128, sec2, yr, yr100, cf_bit; + + do { + unsigned int tmp; + + spin_lock_irq(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + tmp &= ~RCR1_CF; /* Clear CF-bit */ + tmp |= RCR1_CIE; + writeb(tmp, rtc->regbase + RCR1); + + sec128 = readb(rtc->regbase + R64CNT); + + tm->tm_sec = bcd2bin(readb(rtc->regbase + RSECCNT)); + tm->tm_min = bcd2bin(readb(rtc->regbase + RMINCNT)); + tm->tm_hour = bcd2bin(readb(rtc->regbase + RHRCNT)); + tm->tm_wday = bcd2bin(readb(rtc->regbase + RWKCNT)); + tm->tm_mday = bcd2bin(readb(rtc->regbase + RDAYCNT)); + tm->tm_mon = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1; + + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + yr = readw(rtc->regbase + RYRCNT); + yr100 = bcd2bin(yr >> 8); + yr &= 0xff; + } else { + yr = readb(rtc->regbase + RYRCNT); + yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20); + } + + tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900; + + sec2 = readb(rtc->regbase + R64CNT); + cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF; + + spin_unlock_irq(&rtc->lock); + } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0); + +#if RTC_BIT_INVERTED != 0 + if ((sec128 & RTC_BIT_INVERTED)) + tm->tm_sec--; +#endif + + /* only keep the carry interrupt enabled if UIE is on */ + if (!(rtc->periodic_freq & PF_OXS)) + sh_rtc_setcie(dev, 0); + + dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, " + "mday=%d, mon=%d, year=%d, wday=%d\n", + __func__, + tm->tm_sec, tm->tm_min, tm->tm_hour, + tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday); + + return 0; +} + +static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + int year; + + spin_lock_irq(&rtc->lock); + + /* Reset pre-scaler & stop RTC */ + tmp = readb(rtc->regbase + RCR2); + tmp |= RCR2_RESET; + tmp &= ~RCR2_START; + writeb(tmp, rtc->regbase + RCR2); + + writeb(bin2bcd(tm->tm_sec), rtc->regbase + RSECCNT); + writeb(bin2bcd(tm->tm_min), rtc->regbase + RMINCNT); + writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT); + writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT); + writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT); + writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT); + + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) | + bin2bcd(tm->tm_year % 100); + writew(year, rtc->regbase + RYRCNT); + } else { + year = tm->tm_year % 100; + writeb(bin2bcd(year), rtc->regbase + RYRCNT); + } + + /* Start RTC */ + tmp = readb(rtc->regbase + RCR2); + tmp &= ~RCR2_RESET; + tmp |= RCR2_RTCEN | RCR2_START; + writeb(tmp, rtc->regbase + RCR2); + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off) +{ + unsigned int byte; + int value = -1; /* return -1 for ignored values */ + + byte = readb(rtc->regbase + reg_off); + if (byte & AR_ENB) { + byte &= ~AR_ENB; /* strip the enable bit */ + value = bcd2bin(byte); + } + + return value; +} + +static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + struct rtc_time *tm = &wkalrm->time; + + spin_lock_irq(&rtc->lock); + + tm->tm_sec = sh_rtc_read_alarm_value(rtc, RSECAR); + tm->tm_min = sh_rtc_read_alarm_value(rtc, RMINAR); + tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR); + tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR); + tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR); + tm->tm_mon = sh_rtc_read_alarm_value(rtc, RMONAR); + if (tm->tm_mon > 0) + tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */ + + wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0; + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc, + int value, int reg_off) +{ + /* < 0 for a value that is ignored */ + if (value < 0) + writeb(0, rtc->regbase + reg_off); + else + writeb(bin2bcd(value) | AR_ENB, rtc->regbase + reg_off); +} + +static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int rcr1; + struct rtc_time *tm = &wkalrm->time; + int mon; + + spin_lock_irq(&rtc->lock); + + /* disable alarm interrupt and clear the alarm flag */ + rcr1 = readb(rtc->regbase + RCR1); + rcr1 &= ~(RCR1_AF | RCR1_AIE); + writeb(rcr1, rtc->regbase + RCR1); + + /* set alarm time */ + sh_rtc_write_alarm_value(rtc, tm->tm_sec, RSECAR); + sh_rtc_write_alarm_value(rtc, tm->tm_min, RMINAR); + sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR); + sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR); + sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR); + mon = tm->tm_mon; + if (mon >= 0) + mon += 1; + sh_rtc_write_alarm_value(rtc, mon, RMONAR); + + if (wkalrm->enabled) { + rcr1 |= RCR1_AIE; + writeb(rcr1, rtc->regbase + RCR1); + } + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static const struct rtc_class_ops sh_rtc_ops = { + .read_time = sh_rtc_read_time, + .set_time = sh_rtc_set_time, + .read_alarm = sh_rtc_read_alarm, + .set_alarm = sh_rtc_set_alarm, + .proc = sh_rtc_proc, + .alarm_irq_enable = sh_rtc_alarm_irq_enable, +}; + +static int __init sh_rtc_probe(struct platform_device *pdev) +{ + struct sh_rtc *rtc; + struct resource *res; + struct rtc_time r; + char clk_name[6]; + int clk_id, ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (unlikely(!rtc)) + return -ENOMEM; + + spin_lock_init(&rtc->lock); + + /* get periodic/carry/alarm irqs */ + ret = platform_get_irq(pdev, 0); + if (unlikely(ret <= 0)) { + dev_err(&pdev->dev, "No IRQ resource\n"); + return -ENOENT; + } + + rtc->periodic_irq = ret; + rtc->carry_irq = platform_get_irq(pdev, 1); + rtc->alarm_irq = platform_get_irq(pdev, 2); + + res = platform_get_resource(pdev, IORESOURCE_IO, 0); + if (!res) + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(res == NULL)) { + dev_err(&pdev->dev, "No IO resource\n"); + return -ENOENT; + } + + rtc->regsize = resource_size(res); + + rtc->res = devm_request_mem_region(&pdev->dev, res->start, + rtc->regsize, pdev->name); + if (unlikely(!rtc->res)) + return -EBUSY; + + rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start, + rtc->regsize); + if (unlikely(!rtc->regbase)) + return -EINVAL; + + if (!pdev->dev.of_node) { + clk_id = pdev->id; + /* With a single device, the clock id is still "rtc0" */ + if (clk_id < 0) + clk_id = 0; + + snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id); + } else + snprintf(clk_name, sizeof(clk_name), "fck"); + + rtc->clk = devm_clk_get(&pdev->dev, clk_name); + if (IS_ERR(rtc->clk)) { + /* + * No error handling for rtc->clk intentionally, not all + * platforms will have a unique clock for the RTC, and + * the clk API can handle the struct clk pointer being + * NULL. + */ + rtc->clk = NULL; + } + + clk_enable(rtc->clk); + + rtc->capabilities = RTC_DEF_CAPABILITIES; + +#ifdef CONFIG_SUPERH + if (dev_get_platdata(&pdev->dev)) { + struct sh_rtc_platform_info *pinfo = + dev_get_platdata(&pdev->dev); + + /* + * Some CPUs have special capabilities in addition to the + * default set. Add those in here. + */ + rtc->capabilities |= pinfo->capabilities; + } +#endif + + if (rtc->carry_irq <= 0) { + /* register shared periodic/carry/alarm irq */ + ret = devm_request_irq(&pdev->dev, rtc->periodic_irq, + sh_rtc_shared, 0, "sh-rtc", rtc); + if (unlikely(ret)) { + dev_err(&pdev->dev, + "request IRQ failed with %d, IRQ %d\n", ret, + rtc->periodic_irq); + goto err_unmap; + } + } else { + /* register periodic/carry/alarm irqs */ + ret = devm_request_irq(&pdev->dev, rtc->periodic_irq, + sh_rtc_periodic, 0, "sh-rtc period", rtc); + if (unlikely(ret)) { + dev_err(&pdev->dev, + "request period IRQ failed with %d, IRQ %d\n", + ret, rtc->periodic_irq); + goto err_unmap; + } + + ret = devm_request_irq(&pdev->dev, rtc->carry_irq, + sh_rtc_interrupt, 0, "sh-rtc carry", rtc); + if (unlikely(ret)) { + dev_err(&pdev->dev, + "request carry IRQ failed with %d, IRQ %d\n", + ret, rtc->carry_irq); + goto err_unmap; + } + + ret = devm_request_irq(&pdev->dev, rtc->alarm_irq, + sh_rtc_alarm, 0, "sh-rtc alarm", rtc); + if (unlikely(ret)) { + dev_err(&pdev->dev, + "request alarm IRQ failed with %d, IRQ %d\n", + ret, rtc->alarm_irq); + goto err_unmap; + } + } + + platform_set_drvdata(pdev, rtc); + + /* everything disabled by default */ + sh_rtc_setaie(&pdev->dev, 0); + sh_rtc_setcie(&pdev->dev, 0); + + rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh", + &sh_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc->rtc_dev)) { + ret = PTR_ERR(rtc->rtc_dev); + goto err_unmap; + } + + rtc->rtc_dev->max_user_freq = 256; + + /* reset rtc to epoch 0 if time is invalid */ + if (rtc_read_time(rtc->rtc_dev, &r) < 0) { + rtc_time_to_tm(0, &r); + rtc_set_time(rtc->rtc_dev, &r); + } + + device_init_wakeup(&pdev->dev, 1); + return 0; + +err_unmap: + clk_disable(rtc->clk); + + return ret; +} + +static int __exit sh_rtc_remove(struct platform_device *pdev) +{ + struct sh_rtc *rtc = platform_get_drvdata(pdev); + + sh_rtc_setaie(&pdev->dev, 0); + sh_rtc_setcie(&pdev->dev, 0); + + clk_disable(rtc->clk); + + return 0; +} + +static void sh_rtc_set_irq_wake(struct device *dev, int enabled) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + + irq_set_irq_wake(rtc->periodic_irq, enabled); + + if (rtc->carry_irq > 0) { + irq_set_irq_wake(rtc->carry_irq, enabled); + irq_set_irq_wake(rtc->alarm_irq, enabled); + } +} + +static int __maybe_unused sh_rtc_suspend(struct device *dev) +{ + if (device_may_wakeup(dev)) + sh_rtc_set_irq_wake(dev, 1); + + return 0; +} + +static int __maybe_unused sh_rtc_resume(struct device *dev) +{ + if (device_may_wakeup(dev)) + sh_rtc_set_irq_wake(dev, 0); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume); + +static const struct of_device_id sh_rtc_of_match[] = { + { .compatible = "renesas,sh-rtc", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sh_rtc_of_match); + +static struct platform_driver sh_rtc_platform_driver = { + .driver = { + .name = DRV_NAME, + .pm = &sh_rtc_pm_ops, + .of_match_table = sh_rtc_of_match, + }, + .remove = __exit_p(sh_rtc_remove), +}; + +module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe); + +MODULE_DESCRIPTION("SuperH on-chip RTC driver"); +MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, " + "Jamie Lenehan <lenehan@twibble.org>, " + "Angelo Castello <angelo.castello@st.com>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); |