Initial import

1 files changed, 255 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds1302.c b/drivers/rtc/rtc-ds1302.c
new file mode 100644
index 000000000..6bef7a523
--- /dev/null
+++ b/drivers/rtc/rtc-ds1302.c
@@ -0,0 +1,255 @@
+/*
+ * 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/rtc.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+
+#define DRV_NAME	"rtc-ds1302"
+#define DRV_VERSION	"0.1.1"
+
+#define	RTC_CMD_READ	0x81		/* Read command */
+#define	RTC_CMD_WRITE	0x80		/* Write command */
+
+#define	RTC_CMD_WRITE_ENABLE	0x00		/* Write enable */
+#define	RTC_CMD_WRITE_DISABLE	0x80		/* Write disable */
+
+#define RTC_ADDR_RAM0	0x20		/* Address of RAM0 */
+#define RTC_ADDR_TCR	0x08		/* Address of trickle charge register */
+#define	RTC_ADDR_CTRL	0x07		/* Address of control 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 */
+
+#ifdef CONFIG_SH_SECUREEDGE5410
+#include <asm/rtc.h>
+#include <mach/secureedge5410.h>
+
+#define	RTC_RESET	0x1000
+#define	RTC_IODATA	0x0800
+#define	RTC_SCLK	0x0400
+
+#define set_dp(x)	SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
+#define get_dp()	SECUREEDGE_READ_IOPORT()
+#define ds1302_set_tx()
+#define ds1302_set_rx()
+
+static inline int ds1302_hw_init(void)
+{
+	return 0;
+}
+
+static inline void ds1302_reset(void)
+{
+	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
+}
+
+static inline void ds1302_clock(void)
+{
+	set_dp(get_dp() | RTC_SCLK);	/* clock high */
+	set_dp(get_dp() & ~RTC_SCLK);	/* clock low */
+}
+
+static inline void ds1302_start(void)
+{
+	set_dp(get_dp() | RTC_RESET);
+}
+
+static inline void ds1302_stop(void)
+{
+	set_dp(get_dp() & ~RTC_RESET);
+}
+
+static inline void ds1302_txbit(int bit)
+{
+	set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0));
+}
+
+static inline int ds1302_rxbit(void)
+{
+	return !!(get_dp() & RTC_IODATA);
+}
+
+#else
+#error "Add support for your platform"
+#endif
+
+static void ds1302_sendbits(unsigned int val)
+{
+	int i;
+
+	ds1302_set_tx();
+
+	for (i = 8; (i); i--, val >>= 1) {
+		ds1302_txbit(val & 0x1);
+		ds1302_clock();
+	}
+}
+
+static unsigned int ds1302_recvbits(void)
+{
+	unsigned int val;
+	int i;
+
+	ds1302_set_rx();
+
+	for (i = 0, val = 0; (i < 8); i++) {
+		val |= (ds1302_rxbit() << i);
+		ds1302_clock();
+	}
+
+	return val;
+}
+
+static unsigned int ds1302_readbyte(unsigned int addr)
+{
+	unsigned int val;
+
+	ds1302_reset();
+
+	ds1302_start();
+	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
+	val = ds1302_recvbits();
+	ds1302_stop();
+
+	return val;
+}
+
+static void ds1302_writebyte(unsigned int addr, unsigned int val)
+{
+	ds1302_reset();
+
+	ds1302_start();
+	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
+	ds1302_sendbits(val);
+	ds1302_stop();
+}
+
+static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	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;
+
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
+
+	return rtc_valid_tm(tm);
+}
+
+static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_ENABLE);
+	/* 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);
+
+	ds1302_writebyte(RTC_ADDR_CTRL, RTC_CMD_WRITE_DISABLE);
+
+	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:
+	{
+		int tcs_val;
+
+		if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
+			return -EFAULT;
+
+		ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
+		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 __init ds1302_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+
+	if (ds1302_hw_init()) {
+		dev_err(&pdev->dev, "Failed to init communication channel");
+		return -EINVAL;
+	}
+
+	/* Reset */
+	ds1302_reset();
+
+	/* 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) {
+		dev_err(&pdev->dev, "Failed to probe");
+		return -ENODEV;
+	}
+
+	rtc = devm_rtc_device_register(&pdev->dev, "ds1302",
+					   &ds1302_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	platform_set_drvdata(pdev, rtc);
+
+	return 0;
+}
+
+static struct platform_driver ds1302_platform_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+	},
+};
+
+module_platform_driver_probe(ds1302_platform_driver, ds1302_rtc_probe);
+
+MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("Paul Mundt, David McCullough");
+MODULE_LICENSE("GPL v2");