rtc: Add TI BQ4802 RTC driver.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/rtc/Kconfig

@@ -414,6 +414,15 @@ config RTC_DRV_M48T59
 	  This driver can also be built as a module, if so, the module
 	  will be called "rtc-m48t59".
 
+config RTC_DRV_BQ4802
+	tristate "TI BQ4802"
+	help
+	  If you say Y here you will get support for the TI
+	  BQ4802 RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-bq4802.
+
 config RTC_DRV_V3020
 	tristate "EM Microelectronic V3020"
 	help

drivers/rtc/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_RTC_DRV_M41T80)	+= rtc-m41t80.o
 obj-$(CONFIG_RTC_DRV_M41T94)	+= rtc-m41t94.o
 obj-$(CONFIG_RTC_DRV_M48T59)	+= rtc-m48t59.o
 obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
+obj-$(CONFIG_RTC_DRV_BQ4802)	+= rtc-bq4802.o
 obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o

drivers/rtc/rtc-bq4802.c

+/* rtc-bq4802.c: TI BQ4802 RTC driver.
+ *
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
+MODULE_DESCRIPTION("TI BQ4802 RTC driver");
+MODULE_LICENSE("GPL");
+
+struct bq4802 {
+	void __iomem		*regs;
+	struct rtc_device	*rtc;
+	spinlock_t		lock;
+	struct resource		*r;
+	u8 (*read)(struct bq4802 *, int);
+	void (*write)(struct bq4802 *, int, u8);
+};
+
+static u8 bq4802_read_io(struct bq4802 *p, int off)
+{
+	return inb(p->regs + off);
+}
+
+static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
+{
+	return outb(val, p->regs + off);
+}
+
+static u8 bq4802_read_mem(struct bq4802 *p, int off)
+{
+	return readb(p->regs + off);
+}
+
+static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
+{
+	return writeb(val, p->regs + off);
+}
+
+static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bq4802 *p = platform_get_drvdata(pdev);
+	unsigned long flags;
+	unsigned int century;
+	u8 val;
+
+	spin_lock_irqsave(&p->lock, flags);
+
+	val = p->read(p, 0x0e);
+	p->write(p, 0xe, val | 0x08);
+
+	tm->tm_sec = p->read(p, 0x00);
+	tm->tm_min = p->read(p, 0x02);
+	tm->tm_hour = p->read(p, 0x04);
+	tm->tm_mday = p->read(p, 0x06);
+	tm->tm_mon = p->read(p, 0x09);
+	tm->tm_year = p->read(p, 0x0a);
+	tm->tm_wday = p->read(p, 0x08);
+	century = p->read(p, 0x0f);
+
+	p->write(p, 0x0e, val);
+
+	spin_unlock_irqrestore(&p->lock, flags);
+
+	BCD_TO_BIN(tm->tm_sec);
+	BCD_TO_BIN(tm->tm_min);
+	BCD_TO_BIN(tm->tm_hour);
+	BCD_TO_BIN(tm->tm_mday);
+	BCD_TO_BIN(tm->tm_mon);
+	BCD_TO_BIN(tm->tm_year);
+	BCD_TO_BIN(tm->tm_wday);
+	BCD_TO_BIN(century);
+
+	tm->tm_year += (century * 100);
+	tm->tm_year -= 1900;
+
+	tm->tm_mon--;
+
+	return 0;
+}
+
+static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bq4802 *p = platform_get_drvdata(pdev);
+	u8 sec, min, hrs, day, mon, yrs, century, val;
+	unsigned long flags;
+	unsigned int year;
+
+	year = tm->tm_year + 1900;
+	century = year / 100;
+	yrs = year % 100;
+
+	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
+	day = tm->tm_mday;
+	hrs = tm->tm_hour;
+	min = tm->tm_min;
+	sec = tm->tm_sec;
+
+	BIN_TO_BCD(sec);
+	BIN_TO_BCD(min);
+	BIN_TO_BCD(hrs);
+	BIN_TO_BCD(day);
+	BIN_TO_BCD(mon);
+	BIN_TO_BCD(yrs);
+	BIN_TO_BCD(century);
+
+	spin_lock_irqsave(&p->lock, flags);
+
+	val = p->read(p, 0x0e);
+	p->write(p, 0x0e, val | 0x08);
+
+	p->write(p, 0x00, sec);
+	p->write(p, 0x02, min);
+	p->write(p, 0x04, hrs);
+	p->write(p, 0x06, day);
+	p->write(p, 0x09, mon);
+	p->write(p, 0x0a, yrs);
+	p->write(p, 0x0f, century);
+
+	p->write(p, 0x0e, val);
+
+	spin_unlock_irqrestore(&p->lock, flags);
+
+	return 0;
+}
+
+static const struct rtc_class_ops bq4802_ops = {
+	.read_time	= bq4802_read_time,
+	.set_time	= bq4802_set_time,
+};
+
+static int __devinit bq4802_probe(struct platform_device *pdev)
+{
+	struct bq4802 *p = kzalloc(sizeof(*p), GFP_KERNEL);
+	int err = -ENOMEM;
+
+	if (!p)
+		goto out;
+
+	spin_lock_init(&p->lock);
+
+	p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!p->r) {
+		p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
+		err = -EINVAL;
+		if (!p->r)
+			goto out_free;
+	}
+	if (p->r->flags & IORESOURCE_IO) {
+		p->regs = (void __iomem *) p->r->start;
+		p->read = bq4802_read_io;
+		p->write = bq4802_write_io;
+	} else if (p->r->flags & IORESOURCE_MEM) {
+		p->regs = ioremap(p->r->start, resource_size(p->r));
+		p->read = bq4802_read_mem;
+		p->write = bq4802_write_mem;
+	} else {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	p->rtc = rtc_device_register("bq4802", &pdev->dev,
+				     &bq4802_ops, THIS_MODULE);
+	if (IS_ERR(p->rtc)) {
+		err = PTR_ERR(p->rtc);
+		goto out_iounmap;
+	}
+
+	platform_set_drvdata(pdev, p);
+	err = 0;
+out:
+	return err;
+
+out_iounmap:
+	if (p->r->flags & IORESOURCE_MEM)
+		iounmap(p->regs);
+out_free:
+	kfree(p);
+	goto out;
+}
+
+static int __devexit bq4802_remove(struct platform_device *pdev)
+{
+	struct bq4802 *p = platform_get_drvdata(pdev);
+
+	rtc_device_unregister(p->rtc);
+	if (p->r->flags & IORESOURCE_MEM)
+		iounmap(p->regs);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(p);
+
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:rtc-bq4802");
+
+static struct platform_driver bq4802_driver = {
+	.driver		= {
+		.name	= "rtc-bq4802",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= bq4802_probe,
+	.remove		= __devexit_p(bq4802_remove),
+};
+
+static int __init bq4802_init(void)
+{
+	return platform_driver_register(&bq4802_driver);
+}
+
+static void __exit bq4802_exit(void)
+{
+	platform_driver_unregister(&bq4802_driver);
+}
+
+module_init(bq4802_init);
+module_exit(bq4802_exit);