--- /dev/null
+/*
+ * Dallas DS1302 RTC Support
+ *
+ * Copyright (C) 2002 David McCullough
+ * Copyright (C) 2003 - 2007 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License version 2. See the file "COPYING" in the main directory of
+ * this archive for more details.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+#include <asm/rtc.h>
+
+#define DRV_NAME "rtc-ds1302"
+#define DRV_VERSION "0.1.0"
+
+#define RTC_CMD_READ 0x81 /* Read command */
+#define RTC_CMD_WRITE 0x80 /* Write command */
+
+#define RTC_ADDR_RAM0 0x20 /* Address of RAM0 */
+#define RTC_ADDR_TCR 0x08 /* Address of trickle charge register */
+#define RTC_ADDR_YEAR 0x06 /* Address of year register */
+#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
+#define RTC_ADDR_MON 0x04 /* Address of month register */
+#define RTC_ADDR_DATE 0x03 /* Address of day of month register */
+#define RTC_ADDR_HOUR 0x02 /* Address of hour register */
+#define RTC_ADDR_MIN 0x01 /* Address of minute register */
+#define RTC_ADDR_SEC 0x00 /* Address of second register */
+
+#define RTC_RESET 0x1000
+#define RTC_IODATA 0x0800
+#define RTC_SCLK 0x0400
+
+#ifdef CONFIG_SH_SECUREEDGE5410
+#include <asm/snapgear.h>
+#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
+#define get_dp() SECUREEDGE_READ_IOPORT()
+#else
+#error "Add support for your platform"
+#endif
+
+struct ds1302_rtc {
+ struct rtc_device *rtc_dev;
+ spinlock_t lock;
+};
+
+static void ds1302_sendbits(unsigned int val)
+{
+ int i;
+
+ for (i = 8; (i); i--, val >>= 1) {
+ set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ?
+ RTC_IODATA : 0));
+ set_dp(get_dp() | RTC_SCLK); /* clock high */
+ set_dp(get_dp() & ~RTC_SCLK); /* clock low */
+ }
+}
+
+static unsigned int ds1302_recvbits(void)
+{
+ unsigned int val;
+ int i;
+
+ for (i = 0, val = 0; (i < 8); i++) {
+ val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
+ set_dp(get_dp() | RTC_SCLK); /* clock high */
+ set_dp(get_dp() & ~RTC_SCLK); /* clock low */
+ }
+
+ return val;
+}
+
+static unsigned int ds1302_readbyte(unsigned int addr)
+{
+ unsigned int val;
+
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+
+ set_dp(get_dp() | RTC_RESET);
+ ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
+ val = ds1302_recvbits();
+ set_dp(get_dp() & ~RTC_RESET);
+
+ return val;
+}
+
+static void ds1302_writebyte(unsigned int addr, unsigned int val)
+{
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+ set_dp(get_dp() | RTC_RESET);
+ ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
+ ds1302_sendbits(val);
+ set_dp(get_dp() & ~RTC_RESET);
+}
+
+static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ds1302_rtc *rtc = dev_get_drvdata(dev);
+
+ spin_lock_irq(&rtc->lock);
+
+ tm->tm_sec = BCD2BIN(ds1302_readbyte(RTC_ADDR_SEC));
+ tm->tm_min = BCD2BIN(ds1302_readbyte(RTC_ADDR_MIN));
+ tm->tm_hour = BCD2BIN(ds1302_readbyte(RTC_ADDR_HOUR));
+ tm->tm_wday = BCD2BIN(ds1302_readbyte(RTC_ADDR_DAY));
+ tm->tm_mday = BCD2BIN(ds1302_readbyte(RTC_ADDR_DATE));
+ tm->tm_mon = BCD2BIN(ds1302_readbyte(RTC_ADDR_MON)) - 1;
+ tm->tm_year = BCD2BIN(ds1302_readbyte(RTC_ADDR_YEAR));
+
+ if (tm->tm_year < 70)
+ tm->tm_year += 100;
+
+ spin_unlock_irq(&rtc->lock);
+
+ dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+ "mday=%d, mon=%d, year=%d, wday=%d\n",
+ __FUNCTION__,
+ tm->tm_sec, tm->tm_min, tm->tm_hour,
+ tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
+
+ if (rtc_valid_tm(tm) < 0)
+ dev_err(dev, "invalid date\n");
+
+ return 0;
+}
+
+static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ds1302_rtc *rtc = dev_get_drvdata(dev);
+
+ spin_lock_irq(&rtc->lock);
+
+ /* Stop RTC */
+ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
+
+ ds1302_writebyte(RTC_ADDR_SEC, BIN2BCD(tm->tm_sec));
+ ds1302_writebyte(RTC_ADDR_MIN, BIN2BCD(tm->tm_min));
+ ds1302_writebyte(RTC_ADDR_HOUR, BIN2BCD(tm->tm_hour));
+ ds1302_writebyte(RTC_ADDR_DAY, BIN2BCD(tm->tm_wday));
+ ds1302_writebyte(RTC_ADDR_DATE, BIN2BCD(tm->tm_mday));
+ ds1302_writebyte(RTC_ADDR_MON, BIN2BCD(tm->tm_mon + 1));
+ ds1302_writebyte(RTC_ADDR_YEAR, BIN2BCD(tm->tm_year % 100));
+
+ /* Start RTC */
+ ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
+
+ spin_unlock_irq(&rtc->lock);
+
+ return 0;
+}
+
+static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd,
+ unsigned long arg)
+{
+ switch (cmd) {
+#ifdef RTC_SET_CHARGE
+ case RTC_SET_CHARGE:
+ {
+ struct ds1302_rtc *rtc = dev_get_drvdata(dev);
+ int tcs_val;
+
+ if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
+ return -EFAULT;
+
+ spin_lock_irq(&rtc->lock);
+ ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
+ spin_unlock_irq(&rtc->lock);
+ return 0;
+ }
+#endif
+ }
+
+ return -ENOIOCTLCMD;
+}
+
+static struct rtc_class_ops ds1302_rtc_ops = {
+ .read_time = ds1302_rtc_read_time,
+ .set_time = ds1302_rtc_set_time,
+ .ioctl = ds1302_rtc_ioctl,
+};
+
+static int __devinit ds1302_rtc_probe(struct platform_device *pdev)
+{
+ struct ds1302_rtc *rtc;
+ int ret;
+
+ /* Reset */
+ set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+
+ /* Write a magic value to the DS1302 RAM, and see if it sticks. */
+ ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
+ if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42)
+ return -ENODEV;
+
+ rtc = kzalloc(sizeof(struct ds1302_rtc), GFP_KERNEL);
+ if (unlikely(!rtc))
+ return -ENOMEM;
+
+ spin_lock_init(&rtc->lock);
+ rtc->rtc_dev = rtc_device_register("ds1302", &pdev->dev,
+ &ds1302_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc->rtc_dev)) {
+ ret = PTR_ERR(rtc->rtc_dev);
+ goto out;
+ }
+
+ platform_set_drvdata(pdev, rtc);
+
+ return 0;
+out:
+ kfree(rtc);
+ return ret;
+}
+
+static int __devexit ds1302_rtc_remove(struct platform_device *pdev)
+{
+ struct ds1302_rtc *rtc = platform_get_drvdata(pdev);
+
+ if (likely(rtc->rtc_dev))
+ rtc_device_unregister(rtc->rtc_dev);
+
+ platform_set_drvdata(pdev, NULL);
+
+ kfree(rtc);
+
+ return 0;
+}
+
+static struct platform_driver ds1302_platform_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = ds1302_rtc_probe,
+ .remove = __devexit_p(ds1302_rtc_remove),
+};
+
+static int __init ds1302_rtc_init(void)
+{
+ return platform_driver_register(&ds1302_platform_driver);
+}
+
+static void __exit ds1302_rtc_exit(void)
+{
+ platform_driver_unregister(&ds1302_platform_driver);
+}
+
+module_init(ds1302_rtc_init);
+module_exit(ds1302_rtc_exit);
+
+MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("Paul Mundt, David McCullough");
+MODULE_LICENSE("GPL v2");
projects / linux-2.6 / commitdiff