RTC driver for DS1216 chips
RTC driver for Dallas/Maxim DS126 chips used in SNI RM200/RM400
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index bcd1876..6210280 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -280,6 +280,12 @@
This driver can also be built as a module. If so, the module
will be called rtc-cmos.
+config RTC_DRV_DS1216
+ tristate "Dallas DS1216"
+ depends on RTC_CLASS && SNI_RM
+ help
+ If you say yes here you get support for the Dallas DS1216 RTC chips.
+
config RTC_DRV_DS1553
tristate "Dallas DS1553"
depends on RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index ca9166d..3109af9 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -44,3 +44,4 @@
obj-$(CONFIG_RTC_DRV_SH) += rtc-sh.o
obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o
obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o
+obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o
diff --git a/drivers/rtc/rtc-ds1216.c b/drivers/rtc/rtc-ds1216.c
new file mode 100644
index 0000000..83efb88
--- /dev/null
+++ b/drivers/rtc/rtc-ds1216.c
@@ -0,0 +1,226 @@
+/*
+ * Dallas DS1216 RTC driver
+ *
+ * Copyright (c) 2007 Thomas Bogendoerfer
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/bcd.h>
+
+#define DRV_VERSION "0.1"
+
+struct ds1216_regs {
+ u8 tsec;
+ u8 sec;
+ u8 min;
+ u8 hour;
+ u8 wday;
+ u8 mday;
+ u8 month;
+ u8 year;
+};
+
+#define DS1216_HOUR_1224 (1 << 7)
+#define DS1216_HOUR_AMPM (1 << 5)
+
+struct ds1216_priv {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr;
+ size_t size;
+ unsigned long baseaddr;
+};
+
+static const u8 magic[] = {
+ 0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c
+};
+
+/*
+ * Read the 64 bit we'd like to have - It a series
+ * of 64 bits showing up in the LSB of the base register.
+ *
+ */
+static void ds1216_read(u8 __iomem *ioaddr, u8 *buf)
+{
+ unsigned char c;
+ int i, j;
+
+ for (i = 0; i < 8; i++) {
+ c = 0;
+ for (j = 0; j < 8; j++)
+ c |= (readb(ioaddr) & 0x1) << j;
+ buf[i] = c;
+ }
+}
+
+static void ds1216_write(u8 __iomem *ioaddr, const u8 *buf)
+{
+ unsigned char c;
+ int i, j;
+
+ for (i = 0; i < 8; i++) {
+ c = buf[i];
+ for (j = 0; j < 8; j++) {
+ writeb(c, ioaddr);
+ c = c >> 1;
+ }
+ }
+}
+
+static void ds1216_switch_ds_to_clock(u8 __iomem *ioaddr)
+{
+ /* Reset magic pointer */
+ readb(ioaddr);
+ /* Write 64 bit magic to DS1216 */
+ ds1216_write(ioaddr, magic);
+}
+
+static int ds1216_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1216_priv *priv = platform_get_drvdata(pdev);
+ struct ds1216_regs regs;
+
+ ds1216_switch_ds_to_clock(priv->ioaddr);
+ ds1216_read(priv->ioaddr, (u8 *)®s);
+
+ tm->tm_sec = BCD2BIN(regs.sec);
+ tm->tm_min = BCD2BIN(regs.min);
+ if (regs.hour & DS1216_HOUR_1224) {
+ /* AM/PM mode */
+ tm->tm_hour = BCD2BIN(regs.hour & 0x1f);
+ if (regs.hour & DS1216_HOUR_AMPM)
+ tm->tm_hour += 12;
+ } else
+ tm->tm_hour = BCD2BIN(regs.hour & 0x3f);
+ tm->tm_wday = (regs.wday & 7) - 1;
+ tm->tm_mday = BCD2BIN(regs.mday & 0x3f);
+ tm->tm_mon = BCD2BIN(regs.month & 0x1f);
+ tm->tm_year = BCD2BIN(regs.year);
+ if (tm->tm_year < 70)
+ tm->tm_year += 100;
+ return 0;
+}
+
+static int ds1216_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ds1216_priv *priv = platform_get_drvdata(pdev);
+ struct ds1216_regs regs;
+
+ ds1216_switch_ds_to_clock(priv->ioaddr);
+ ds1216_read(priv->ioaddr, (u8 *)®s);
+
+ regs.tsec = 0; /* clear 0.1 and 0.01 seconds */
+ regs.sec = BIN2BCD(tm->tm_sec);
+ regs.min = BIN2BCD(tm->tm_min);
+ regs.hour &= DS1216_HOUR_1224;
+ if (regs.hour && tm->tm_hour > 12) {
+ regs.hour |= DS1216_HOUR_AMPM;
+ tm->tm_hour -= 12;
+ }
+ regs.hour |= BIN2BCD(tm->tm_hour);
+ regs.wday &= ~7;
+ regs.wday |= tm->tm_wday;
+ regs.mday = BIN2BCD(tm->tm_mday);
+ regs.month = BIN2BCD(tm->tm_mon);
+ regs.year = BIN2BCD(tm->tm_year % 100);
+
+ ds1216_switch_ds_to_clock(priv->ioaddr);
+ ds1216_write(priv->ioaddr, (u8 *)®s);
+ return 0;
+}
+
+static const struct rtc_class_ops ds1216_rtc_ops = {
+ .read_time = ds1216_rtc_read_time,
+ .set_time = ds1216_rtc_set_time,
+};
+
+static int __devinit ds1216_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ struct resource *res;
+ struct ds1216_priv *priv;
+ int ret = 0;
+ u8 dummy[8];
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+ priv = kzalloc(sizeof *priv, GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->size = res->end - res->start + 1;
+ if (!request_mem_region(res->start, priv->size, pdev->name)) {
+ ret = -EBUSY;
+ goto out;
+ }
+ priv->baseaddr = res->start;
+ priv->ioaddr = ioremap(priv->baseaddr, priv->size);
+ if (!priv->ioaddr) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ rtc = rtc_device_register("ds1216", &pdev->dev,
+ &ds1216_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ ret = PTR_ERR(rtc);
+ goto out;
+ }
+ priv->rtc = rtc;
+ platform_set_drvdata(pdev, priv);
+
+ /* dummy read to get clock into a known state */
+ ds1216_read(priv->ioaddr, dummy);
+ return 0;
+
+out:
+ if (priv->rtc)
+ rtc_device_unregister(priv->rtc);
+ if (priv->ioaddr)
+ iounmap(priv->ioaddr);
+ if (priv->baseaddr)
+ release_mem_region(priv->baseaddr, priv->size);
+ kfree(priv);
+ return ret;
+}
+
+static int __devexit ds1216_rtc_remove(struct platform_device *pdev)
+{
+ struct ds1216_priv *priv = platform_get_drvdata(pdev);
+
+ rtc_device_unregister(priv->rtc);
+ iounmap(priv->ioaddr);
+ release_mem_region(priv->baseaddr, priv->size);
+ kfree(priv);
+ return 0;
+}
+
+static struct platform_driver ds1216_rtc_platform_driver = {
+ .driver = {
+ .name = "rtc-ds1216",
+ .owner = THIS_MODULE,
+ },
+ .probe = ds1216_rtc_probe,
+ .remove = __devexit_p(ds1216_rtc_remove),
+};
+
+static int __init ds1216_rtc_init(void)
+{
+ return platform_driver_register(&ds1216_rtc_platform_driver);
+}
+
+static void __exit ds1216_rtc_exit(void)
+{
+ platform_driver_unregister(&ds1216_rtc_platform_driver);
+}
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
+MODULE_DESCRIPTION("DS1216 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(ds1216_rtc_init);
+module_exit(ds1216_rtc_exit);
