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authorDavid S. Miller <davem@davemloft.net>2008-08-29 12:29:53 +0400
committerDavid S. Miller <davem@davemloft.net>2008-08-30 01:16:49 +0400
commitcca4c231028405950a15f5a27d7326d18d909784 (patch)
treeeda3009102cb3a2cf66a8194a49290bcefb9b773 /drivers/rtc/rtc-bq4802.c
parentda86783dda5ad8c64b945157108d1ace7aa79bbf (diff)
downloadlinux-cca4c231028405950a15f5a27d7326d18d909784.tar.xz
rtc: Add TI BQ4802 RTC driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/rtc/rtc-bq4802.c')
-rw-r--r--drivers/rtc/rtc-bq4802.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bq4802.c b/drivers/rtc/rtc-bq4802.c
new file mode 100644
index 000000000000..541580cb6df4
--- /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);