rtc: Add TI BQ4802 RTC driver.

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

3 files changed, 239 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 8cb158d7744..5d600ff8d2d 100644
--- a/drivers/rtc/Kconfig
+++ b/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
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 18622ef84ca..fed42c2f82f 100644
--- a/drivers/rtc/Makefile
+++ b/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
diff --git a/drivers/rtc/rtc-bq4802.c b/drivers/rtc/rtc-bq4802.c
new file mode 100644
index 00000000000..541580cb6df
--- /dev/null
+++ b/drivers/rtc/rtc-bq4802.c
@@ -0,0 +1,229 @@
+/* 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);