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 <[e-mail]>

drivers/rtc/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called rtc-sa1100.
 
+config RTC_DRV_SH
+	tristate "SuperH On-Chip RTC"
+	depends on RTC_CLASS && SUPERH
+	help
+	  Say Y here to enable support for the on-chip RTC found in
+	  most SuperH processors.
+
+ 	  To compile this driver as a module, choose M here: the
+	  module will be called rtc-sh.
+
 config RTC_DRV_VR41XX
 	tristate "NEC VR41XX"
 	depends on RTC_CLASS && CPU_VR41XX

drivers/rtc/Makefile

···
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_AT91)	+= rtc-at91.o
+obj-$(CONFIG_RTC_DRV_SH)	+= rtc-sh.o

drivers/rtc/rtc-sh.c

···
+/*
+ * 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 <[e-mail]>
+ *  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 <[e-mail]>");
+MODULE_LICENSE("GPL");