rtc: add rtc-tx4939 driver

Add support for RTC in TX4939 SoC.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig

@@ -705,4 +705,11 @@ config RTC_DRV_STARFIRE
 	  If you say Y here you will get support for the RTC found on
 	  Starfire systems.
 
+config RTC_DRV_TX4939
+	tristate "TX4939 SoC"
+	depends on SOC_TX4939
+	help
+	  Driver for the internal RTC (Realtime Clock) module found on
+	  Toshiba TX4939 SoC.
+
 endif # RTC_CLASS

drivers/rtc/Makefile

@@ -68,6 +68,7 @@ obj-$(CONFIG_RTC_DRV_SH)	+= rtc-sh.o
 obj-$(CONFIG_RTC_DRV_STK17TA8)	+= rtc-stk17ta8.o
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl4030.o
+obj-$(CONFIG_RTC_DRV_TX4939)	+= rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)	+= rtc-vr41xx.o
 obj-$(CONFIG_RTC_DRV_WM8350)	+= rtc-wm8350.o

drivers/rtc/rtc-tx4939.c

@@ -0,0 +1,317 @@
+/*
+ * TX4939 internal RTC driver
+ * Based on RBTX49xx patch from CELF patch archive.
+ *
+ * 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.
+ *
+ * (C) Copyright TOSHIBA CORPORATION 2005-2007
+ */
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <asm/txx9/tx4939.h>
+
+struct tx4939rtc_plat_data {
+	struct rtc_device *rtc;
+	struct tx4939_rtc_reg __iomem *rtcreg;
+};
+
+static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
+{
+	return platform_get_drvdata(to_platform_device(dev));
+}
+
+static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
+{
+	int i = 0;
+
+	__raw_writel(cmd, &rtcreg->ctl);
+	/* This might take 30us (next 32.768KHz clock) */
+	while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
+		/* timeout on approx. 100us (@ GBUS200MHz) */
+		if (i++ > 200 * 100)
+			return -EBUSY;
+		cpu_relax();
+	}
+	return 0;
+}
+
+static int tx4939_rtc_set_mmss(struct device *dev, unsigned long secs)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	int i, ret;
+	unsigned char buf[6];
+
+	buf[0] = 0;
+	buf[1] = 0;
+	buf[2] = secs;
+	buf[3] = secs >> 8;
+	buf[4] = secs >> 16;
+	buf[5] = secs >> 24;
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	__raw_writel(0, &rtcreg->adr);
+	for (i = 0; i < 6; i++)
+		__raw_writel(buf[i], &rtcreg->dat);
+	ret = tx4939_rtc_cmd(rtcreg,
+			     TX4939_RTCCTL_COMMAND_SETTIME |
+			     (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	return ret;
+}
+
+static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	int i, ret;
+	unsigned long sec;
+	unsigned char buf[6];
+
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	ret = tx4939_rtc_cmd(rtcreg,
+			     TX4939_RTCCTL_COMMAND_GETTIME |
+			     (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+	if (ret) {
+		spin_unlock_irq(&pdata->rtc->irq_lock);
+		return ret;
+	}
+	__raw_writel(2, &rtcreg->adr);
+	for (i = 2; i < 6; i++)
+		buf[i] = __raw_readl(&rtcreg->dat);
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
+	rtc_time_to_tm(sec, tm);
+	return rtc_valid_tm(tm);
+}
+
+static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	int i, ret;
+	unsigned long sec;
+	unsigned char buf[6];
+
+	if (alrm->time.tm_sec < 0 ||
+	    alrm->time.tm_min < 0 ||
+	    alrm->time.tm_hour < 0 ||
+	    alrm->time.tm_mday < 0 ||
+	    alrm->time.tm_mon < 0 ||
+	    alrm->time.tm_year < 0)
+		return -EINVAL;
+	rtc_tm_to_time(&alrm->time, &sec);
+	buf[0] = 0;
+	buf[1] = 0;
+	buf[2] = sec;
+	buf[3] = sec >> 8;
+	buf[4] = sec >> 16;
+	buf[5] = sec >> 24;
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	__raw_writel(0, &rtcreg->adr);
+	for (i = 0; i < 6; i++)
+		__raw_writel(buf[i], &rtcreg->dat);
+	ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
+			     (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	return ret;
+}
+
+static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	int i, ret;
+	unsigned long sec;
+	unsigned char buf[6];
+	u32 ctl;
+
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	ret = tx4939_rtc_cmd(rtcreg,
+			     TX4939_RTCCTL_COMMAND_GETALARM |
+			     (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
+	if (ret) {
+		spin_unlock_irq(&pdata->rtc->irq_lock);
+		return ret;
+	}
+	__raw_writel(2, &rtcreg->adr);
+	for (i = 2; i < 6; i++)
+		buf[i] = __raw_readl(&rtcreg->dat);
+	ctl = __raw_readl(&rtcreg->ctl);
+	alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
+	alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
+	rtc_time_to_tm(sec, &alrm->time);
+	return rtc_valid_tm(&alrm->time);
+}
+
+static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	tx4939_rtc_cmd(pdata->rtcreg,
+		       TX4939_RTCCTL_COMMAND_NOP |
+		       (enabled ? TX4939_RTCCTL_ALME : 0));
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	return 0;
+}
+
+static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
+{
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	unsigned long events = RTC_IRQF;
+
+	spin_lock(&pdata->rtc->irq_lock);
+	if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
+		events |= RTC_AF;
+		tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+	}
+	spin_unlock(&pdata->rtc->irq_lock);
+	rtc_update_irq(pdata->rtc, 1, events);
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops tx4939_rtc_ops = {
+	.read_time		= tx4939_rtc_read_time,
+	.read_alarm		= tx4939_rtc_read_alarm,
+	.set_alarm		= tx4939_rtc_set_alarm,
+	.set_mmss		= tx4939_rtc_set_mmss,
+	.alarm_irq_enable	= tx4939_rtc_alarm_irq_enable,
+};
+
+static ssize_t tx4939_rtc_nvram_read(struct kobject *kobj,
+				     struct bin_attribute *bin_attr,
+				     char *buf, loff_t pos, size_t size)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	ssize_t count;
+
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
+	     count++, size--) {
+		__raw_writel(pos++, &rtcreg->adr);
+		*buf++ = __raw_readl(&rtcreg->dat);
+	}
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	return count;
+}
+
+static ssize_t tx4939_rtc_nvram_write(struct kobject *kobj,
+				      struct bin_attribute *bin_attr,
+				      char *buf, loff_t pos, size_t size)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
+	ssize_t count;
+
+	spin_lock_irq(&pdata->rtc->irq_lock);
+	for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
+	     count++, size--) {
+		__raw_writel(pos++, &rtcreg->adr);
+		__raw_writel(*buf++, &rtcreg->dat);
+	}
+	spin_unlock_irq(&pdata->rtc->irq_lock);
+	return count;
+}
+
+static struct bin_attribute tx4939_rtc_nvram_attr = {
+	.attr = {
+		.name = "nvram",
+		.mode = S_IRUGO | S_IWUSR,
+	},
+	.size = TX4939_RTC_REG_RAMSIZE,
+	.read = tx4939_rtc_nvram_read,
+	.write = tx4939_rtc_nvram_write,
+};
+
+static int __init tx4939_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct tx4939rtc_plat_data *pdata;
+	struct resource *res;
+	int irq, ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENODEV;
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, pdata);
+
+	if (!devm_request_mem_region(&pdev->dev, res->start,
+				     resource_size(res), pdev->name))
+		return -EBUSY;
+	pdata->rtcreg = devm_ioremap(&pdev->dev, res->start,
+				     resource_size(res));
+	if (!pdata->rtcreg)
+		return -EBUSY;
+
+	tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+	if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
+			     IRQF_DISABLED | IRQF_SHARED,
+			     pdev->name, &pdev->dev) < 0) {
+		return -EBUSY;
+	}
+	rtc = rtc_device_register(pdev->name, &pdev->dev,
+				  &tx4939_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	pdata->rtc = rtc;
+	ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
+	if (ret)
+		rtc_device_unregister(rtc);
+	return ret;
+}
+
+static int __exit tx4939_rtc_remove(struct platform_device *pdev)
+{
+	struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
+	struct rtc_device *rtc = pdata->rtc;
+
+	spin_lock_irq(&rtc->irq_lock);
+	tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
+	spin_unlock_irq(&rtc->irq_lock);
+	sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
+	rtc_device_unregister(rtc);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static struct platform_driver tx4939_rtc_driver = {
+	.remove		= __exit_p(tx4939_rtc_remove),
+	.driver		= {
+		.name	= "tx4939rtc",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init tx4939rtc_init(void)
+{
+	return platform_driver_probe(&tx4939_rtc_driver, tx4939_rtc_probe);
+}
+
+static void __exit tx4939rtc_exit(void)
+{
+	platform_driver_unregister(&tx4939_rtc_driver);
+}
+
+module_init(tx4939rtc_init);
+module_exit(tx4939rtc_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("TX4939 internal RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tx4939rtc");