File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/rtc/rtc-ds1302.c b/drivers/rtc/rtc-ds1302.c
new file mode 100644
index 0000000..6bef7a5
--- /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");