rtc: New RTC driver for SuperH On-Chip RTC.

This replaces the old SH RTC driver, and allows us to
clean quite a lot of things up on the board-specific
side.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 467 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c
new file mode 100644
index 000000000000..d2ce0c8bb8f3
--- /dev/null
+++ b/drivers/rtc/rtc-sh.c
@@ -0,0 +1,467 @@
+/*
+ * SuperH On-Chip RTC Support
+ *
+ * Copyright (C) 2006  Paul Mundt
+ *
+ * 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/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 <asm/io.h>
+
+#ifdef CONFIG_CPU_SH3
+#define rtc_reg_size            sizeof(u16)
+#define RTC_BIT_INVERTED        0       /* No bug on SH7708, SH7709A */
+#elif defined(CONFIG_CPU_SH4)
+#define rtc_reg_size            sizeof(u32)
+#define RTC_BIT_INVERTED        0x40    /* bug on SH7750, SH7750S */
+#endif
+
+#define RTC_REG(r)      ((r) * rtc_reg_size)
+
+#define R64CNT          RTC_REG(0)
+#define RSECCNT         RTC_REG(1)
+#define RMINCNT         RTC_REG(2)
+#define RHRCNT          RTC_REG(3)
+#define RWKCNT          RTC_REG(4)
+#define RDAYCNT         RTC_REG(5)
+#define RMONCNT         RTC_REG(6)
+#define RYRCNT          RTC_REG(7)
+#define RSECAR          RTC_REG(8)
+#define RMINAR          RTC_REG(9)
+#define RHRAR           RTC_REG(10)
+#define RWKAR           RTC_REG(11)
+#define RDAYAR          RTC_REG(12)
+#define RMONAR          RTC_REG(13)
+#define RCR1            RTC_REG(14)
+#define RCR2            RTC_REG(15)
+
+/* 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;
+        unsigned int alarm_irq, periodic_irq, carry_irq;
+        struct rtc_device *rtc_dev;
+        spinlock_t lock;
+};
+
+static irqreturn_t sh_rtc_interrupt(int irq, void *id, struct pt_regs *regs)
+{
+        struct platform_device *pdev = id;
+        struct sh_rtc *rtc = platform_get_drvdata(pdev);
+        unsigned int tmp, events = 0;
+
+        spin_lock(&rtc->lock);
+
+        tmp = readb(rtc->regbase + RCR1);
+
+        if (tmp & RCR1_AF)
+                events |= RTC_AF | RTC_IRQF;
+
+        tmp &= ~(RCR1_CF | RCR1_AF);
+
+        writeb(tmp, rtc->regbase + RCR1);
+
+        rtc_update_irq(&rtc->rtc_dev->class_dev, 1, events);
+
+        spin_unlock(&rtc->lock);
+
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t sh_rtc_periodic(int irq, void *id, struct pt_regs *regs)
+{
+        struct sh_rtc *rtc = dev_get_drvdata(id);
+
+        spin_lock(&rtc->lock);
+
+        rtc_update_irq(&rtc->rtc_dev->class_dev, 1, RTC_PF | RTC_IRQF);
+
+        spin_unlock(&rtc->lock);
+
+        return IRQ_HANDLED;
+}
+
+static inline void sh_rtc_setpie(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 + RCR2);
+
+        if (enable) {
+                tmp &= ~RCR2_PESMASK;
+                tmp |= RCR2_PEF | (2 << 4);
+        } else
+                tmp &= ~(RCR2_PESMASK | RCR2_PEF);
+
+        writeb(tmp, rtc->regbase + RCR2);
+
+        spin_unlock_irq(&rtc->lock);
+}
+
+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_open(struct device *dev)
+{
+        struct sh_rtc *rtc = dev_get_drvdata(dev);
+        unsigned int tmp;
+        int ret;
+
+        tmp = readb(rtc->regbase + RCR1);
+        tmp &= ~RCR1_CF;
+        tmp |= RCR1_CIE;
+        writeb(tmp, rtc->regbase + RCR1);
+
+        ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, SA_INTERRUPT,
+                          "sh-rtc period", dev);
+        if (unlikely(ret)) {
+                dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
+                        ret, rtc->periodic_irq);
+                return ret;
+        }
+
+        ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, SA_INTERRUPT,
+                          "sh-rtc carry", dev);
+        if (unlikely(ret)) {
+                dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
+                        ret, rtc->carry_irq);
+                free_irq(rtc->periodic_irq, dev);
+                goto err_bad_carry;
+        }
+
+        ret = request_irq(rtc->alarm_irq, sh_rtc_interrupt, SA_INTERRUPT,
+                          "sh-rtc alarm", dev);
+        if (unlikely(ret)) {
+                dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
+                        ret, rtc->alarm_irq);
+                goto err_bad_alarm;
+        }
+
+        return 0;
+
+err_bad_alarm:
+        free_irq(rtc->carry_irq, dev);
+err_bad_carry:
+        free_irq(rtc->periodic_irq, dev);
+
+        return ret;
+}
+
+static void sh_rtc_release(struct device *dev)
+{
+        struct sh_rtc *rtc = dev_get_drvdata(dev);
+
+        sh_rtc_setpie(dev, 0);
+
+        free_irq(rtc->periodic_irq, dev);
+        free_irq(rtc->carry_irq, dev);
+        free_irq(rtc->alarm_irq, dev);
+}
+
+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, "alarm_IRQ\t: %s\n",
+                   (tmp & RCR1_AIE) ? "yes" : "no");
+        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_PEF) ? "yes" : "no");
+
+        return 0;
+}
+
+static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+        unsigned int ret = -ENOIOCTLCMD;
+
+        switch (cmd) {
+        case RTC_PIE_OFF:
+        case RTC_PIE_ON:
+                sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
+                ret = 0;
+                break;
+        case RTC_AIE_OFF:
+        case RTC_AIE_ON:
+                sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
+                ret = 0;
+                break;
+        }
+
+        return ret;
+}
+
+static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct sh_rtc *rtc = platform_get_drvdata(pdev);
+        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));
+
+#if defined(CONFIG_CPU_SH4)
+                yr  = readw(rtc->regbase + RYRCNT);
+                yr100 = BCD2BIN(yr >> 8);
+                yr &= 0xff;
+#else
+                yr  = readb(rtc->regbase + RYRCNT);
+                yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
+#endif
+
+                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
+
+        dev_dbg(&dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+                "mday=%d, mon=%d, year=%d, wday=%d\n",
+                __FUNCTION__,
+                tm->tm_sec, tm->tm_min, tm->tm_hour,
+                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+        if (rtc_valid_tm(tm) < 0)
+                dev_err(dev, "invalid date\n");
+
+        return 0;
+}
+
+static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct sh_rtc *rtc = platform_get_drvdata(pdev);
+        unsigned int tmp;
+        int year;
+
+        spin_lock_irq(&rtc->lock);
+
+        /* Reset pre-scaler & stop RTC */
+        tmp = readb(rtc->regbase + RCR2);
+        tmp |= RCR2_RESET;
+        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),  rtc->regbase + RMONCNT);
+
+#ifdef CONFIG_CPU_SH3
+        year = tm->tm_year % 100;
+        writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
+#else
+        year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
+                BIN2BCD(tm->tm_year % 100);
+        writew(year, rtc->regbase + RYRCNT);
+#endif
+
+        /* 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 struct rtc_class_ops sh_rtc_ops = {
+        .open           = sh_rtc_open,
+        .release        = sh_rtc_release,
+        .ioctl          = sh_rtc_ioctl,
+        .read_time      = sh_rtc_read_time,
+        .set_time       = sh_rtc_set_time,
+        .proc           = sh_rtc_proc,
+};
+
+static int __devinit sh_rtc_probe(struct platform_device *pdev)
+{
+        struct sh_rtc *rtc;
+        struct resource *res;
+        int ret = -ENOENT;
+
+        rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
+        if (unlikely(!rtc))
+                return -ENOMEM;
+
+        spin_lock_init(&rtc->lock);
+
+        rtc->periodic_irq = platform_get_irq(pdev, 0);
+        if (unlikely(rtc->periodic_irq < 0)) {
+                dev_err(&pdev->dev, "No IRQ for period\n");
+                goto err_badres;
+        }
+
+        rtc->carry_irq = platform_get_irq(pdev, 1);
+        if (unlikely(rtc->carry_irq < 0)) {
+                dev_err(&pdev->dev, "No IRQ for carry\n");
+                goto err_badres;
+        }
+
+        rtc->alarm_irq = platform_get_irq(pdev, 2);
+        if (unlikely(rtc->alarm_irq < 0)) {
+                dev_err(&pdev->dev, "No IRQ for alarm\n");
+                goto err_badres;
+        }
+
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (unlikely(res == NULL)) {
+                dev_err(&pdev->dev, "No IO resource\n");
+                goto err_badres;
+        }
+
+        rtc->regsize = res->end - res->start + 1;
+
+        rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
+        if (unlikely(!rtc->res)) {
+                ret = -EBUSY;
+                goto err_badres;
+        }
+
+        rtc->regbase = (void __iomem *)rtc->res->start;
+        if (unlikely(!rtc->regbase)) {
+                ret = -EINVAL;
+                goto err_badmap;
+        }
+
+        rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
+                                           &sh_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc)) {
+                ret = PTR_ERR(rtc->rtc_dev);
+                goto err_badmap;
+        }
+
+        platform_set_drvdata(pdev, rtc);
+
+        return 0;
+
+err_badmap:
+        release_resource(rtc->res);
+err_badres:
+        kfree(rtc);
+
+        return ret;
+}
+
+static int __devexit sh_rtc_remove(struct platform_device *pdev)
+{
+        struct sh_rtc *rtc = platform_get_drvdata(pdev);
+
+        if (likely(rtc->rtc_dev))
+                rtc_device_unregister(rtc->rtc_dev);
+
+        sh_rtc_setpie(&pdev->dev, 0);
+        sh_rtc_setaie(&pdev->dev, 0);
+
+        release_resource(rtc->res);
+
+        platform_set_drvdata(pdev, NULL);
+
+        kfree(rtc);
+
+        return 0;
+}
+static struct platform_driver sh_rtc_platform_driver = {
+        .driver         = {
+                .name   = "sh-rtc",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = sh_rtc_probe,
+        .remove         = __devexit_p(sh_rtc_remove),
+};
+
+static int __init sh_rtc_init(void)
+{
+        return platform_driver_register(&sh_rtc_platform_driver);
+}
+
+static void __exit sh_rtc_exit(void)
+{
+        platform_driver_unregister(&sh_rtc_platform_driver);
+}
+
+module_init(sh_rtc_init);
+module_exit(sh_rtc_exit);
+
+MODULE_DESCRIPTION("SuperH on-chip RTC driver");
+MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
+MODULE_LICENSE("GPL");