libreCMC/target/linux/generic/patches-4.4/840-rtc7301.patch

--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1132,6 +1132,15 @@ config RTC_DRV_ZYNQMP
 	  If you say yes here you get support for the RTC controller found on
 	  Xilinx Zynq Ultrascale+ MPSoC.
 
+config RTC_DRV_RTC7301
+	tristate "Epson RTC-7301 SF/DG"
+	help
+	  If you say Y here you will get support for the
+	  Epson RTC-7301 SF/DG RTC chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-7301.
+
 comment "on-CPU RTC drivers"
 
 config RTC_DRV_DAVINCI
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -125,6 +125,7 @@ obj-$(CONFIG_RTC_DRV_RP5C01)	+= rtc-rp5c
 obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o
 obj-$(CONFIG_RTC_DRV_RS5C348)	+= rtc-rs5c348.o
 obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o
+obj-$(CONFIG_RTC_DRV_RTC7301)	+= rtc-rtc7301.o
 obj-$(CONFIG_RTC_DRV_RV3029C2)	+= rtc-rv3029c2.o
 obj-$(CONFIG_RTC_DRV_RV8803)	+= rtc-rv8803.o
 obj-$(CONFIG_RTC_DRV_RX4581)	+= rtc-rx4581.o
--- /dev/null
+++ b/drivers/rtc/rtc-rtc7301.c
@@ -0,0 +1,219 @@
+/*
+ * Driver for Epson RTC-7301SF/DG
+ *
+ * Copyright (C) 2009 Jose Vasconcellos
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/bcd.h>
+
+#define RTC_NAME "rtc7301"
+#define RTC_VERSION "0.1"
+
+/* Epson RTC-7301 register addresses */
+#define RTC7301_SEC		0x00
+#define RTC7301_SEC10		0x01
+#define RTC7301_MIN		0x02
+#define RTC7301_MIN10		0x03
+#define RTC7301_HOUR		0x04
+#define RTC7301_HOUR10		0x05
+#define RTC7301_WEEKDAY		0x06
+#define RTC7301_DAY		0x07
+#define RTC7301_DAY10		0x08
+#define RTC7301_MON		0x09
+#define RTC7301_MON10		0x0A
+#define RTC7301_YEAR		0x0B
+#define RTC7301_YEAR10		0x0C
+#define RTC7301_YEAR100		0x0D
+#define RTC7301_YEAR1000	0x0E
+#define RTC7301_CTRLREG		0x0F
+
+static uint8_t __iomem *rtc7301_base;
+
+#define read_reg(offset) (readb(rtc7301_base + offset) & 0xf)
+#define write_reg(offset, data) writeb(data, rtc7301_base + (offset))
+
+#define rtc7301_isbusy() (read_reg(RTC7301_CTRLREG) & 1)
+
+static void rtc7301_init_settings(void)
+{
+	int i;
+
+	write_reg(RTC7301_CTRLREG, 2);
+	write_reg(RTC7301_YEAR1000, 2);
+	udelay(122);
+
+	/* bank 1 */
+	write_reg(RTC7301_CTRLREG, 6);
+	for (i=0; i<15; i++)
+		write_reg(i, 0);
+
+	/* bank 2 */
+	write_reg(RTC7301_CTRLREG, 14);
+	for (i=0; i<15; i++)
+		write_reg(i, 0);
+	write_reg(RTC7301_CTRLREG, 0);
+}
+
+static int rtc7301_get_datetime(struct device *dev, struct rtc_time *dt)
+{
+	int cnt;
+	uint8_t buf[16];
+
+	cnt = 0;
+	while (rtc7301_isbusy()) {
+		udelay(244);
+		if (cnt++ > 100) {
+			dev_err(dev, "%s: timeout error %x\n", __func__, rtc7301_base[RTC7301_CTRLREG]);
+			return -EIO;
+		}
+	}
+
+	for (cnt=0; cnt<16; cnt++)
+		buf[cnt] = read_reg(cnt);
+
+	if (buf[RTC7301_SEC10] & 8) {
+		dev_err(dev, "%s: RTC not set\n", __func__);
+		return -EINVAL;
+	}
+
+	memset(dt, 0, sizeof(*dt));
+
+	dt->tm_sec =  buf[RTC7301_SEC] + buf[RTC7301_SEC10]*10;
+	dt->tm_min =  buf[RTC7301_MIN] + buf[RTC7301_MIN10]*10;
+	dt->tm_hour = buf[RTC7301_HOUR] + buf[RTC7301_HOUR10]*10;
+
+	dt->tm_mday = buf[RTC7301_DAY] + buf[RTC7301_DAY10]*10;
+	dt->tm_mon =  buf[RTC7301_MON] + buf[RTC7301_MON10]*10 - 1;
+	dt->tm_year = buf[RTC7301_YEAR] + buf[RTC7301_YEAR10]*10 +
+		      buf[RTC7301_YEAR100]*100 +
+		      ((buf[RTC7301_YEAR1000] & 3)*1000) - 1900;
+
+	/* the rtc device may contain illegal values on power up
+	 * according to the data sheet. make sure they are valid.
+	 */
+
+	return rtc_valid_tm(dt);
+}
+
+static int rtc7301_set_datetime(struct device *dev, struct rtc_time *dt)
+{
+	int data;
+
+	data = dt->tm_year + 1900;
+	if (data >= 2100 || data < 1900)
+		return -EINVAL;
+
+	write_reg(RTC7301_CTRLREG, 2);
+       	udelay(122);
+
+	data = bin2bcd(dt->tm_sec);
+	write_reg(RTC7301_SEC, data);
+	write_reg(RTC7301_SEC10, (data >> 4));
+
+	data = bin2bcd(dt->tm_min);
+	write_reg(RTC7301_MIN, data );
+	write_reg(RTC7301_MIN10, (data >> 4));
+
+	data = bin2bcd(dt->tm_hour);
+	write_reg(RTC7301_HOUR, data);
+	write_reg(RTC7301_HOUR10, (data >> 4));
+
+	data = bin2bcd(dt->tm_mday);
+	write_reg(RTC7301_DAY, data);
+	write_reg(RTC7301_DAY10, (data>> 4));
+
+	data = bin2bcd(dt->tm_mon + 1);
+	write_reg(RTC7301_MON, data);
+	write_reg(RTC7301_MON10, (data >> 4));
+
+	data = bin2bcd(dt->tm_year % 100);
+	write_reg(RTC7301_YEAR, data);
+	write_reg(RTC7301_YEAR10, (data >> 4));
+	data = bin2bcd((1900 + dt->tm_year) / 100);
+	write_reg(RTC7301_YEAR100, data);
+
+	data = bin2bcd(dt->tm_wday);
+	write_reg(RTC7301_WEEKDAY, data);
+
+	write_reg(RTC7301_CTRLREG, 0);
+
+	return 0;
+}
+
+static const struct rtc_class_ops rtc7301_rtc_ops = {
+	.read_time	= rtc7301_get_datetime,
+	.set_time	= rtc7301_set_datetime,
+};
+
+static int rtc7301_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOENT;
+
+	rtc7301_base = ioremap_nocache(res->start, 0x1000 /*res->end - res->start + 1*/);
+	if (!rtc7301_base)
+		return -EINVAL;
+
+	rtc = rtc_device_register(RTC_NAME, &pdev->dev,
+				&rtc7301_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		iounmap(rtc7301_base);
+		return PTR_ERR(rtc);
+	}
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc7301_init_settings();
+	return 0;
+}
+
+static int rtc7301_remove(struct platform_device *pdev)
+{
+	struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+	if (rtc)
+		rtc_device_unregister(rtc);
+	if (rtc7301_base)
+		iounmap(rtc7301_base);
+	return 0;
+}
+
+static struct platform_driver rtc7301_driver = {
+	.driver = {
+		.name	= RTC_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe	= rtc7301_probe,
+	.remove = rtc7301_remove,
+};
+
+static __init int rtc7301_init(void)
+{
+	return platform_driver_register(&rtc7301_driver);
+}
+module_init(rtc7301_init);
+
+static __exit void rtc7301_exit(void)
+{
+	platform_driver_unregister(&rtc7301_driver);
+}
+module_exit(rtc7301_exit);
+
+MODULE_DESCRIPTION("Epson 7301 RTC driver");
+MODULE_AUTHOR("Jose Vasconcellos <jvasco@verizon.net>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" RTC_NAME);
+MODULE_VERSION(RTC_VERSION);