rtc: Add an RTC driver for the Ricoh RP5C01

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>

drivers/rtc/Kconfig

@@ -518,6 +518,16 @@ config RTC_DRV_BQ4802
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-bq4802.
 
+config RTC_DRV_RP5C01
+	tristate "Ricoh RP5C01"
+	help
+	  If you say yes here you get support for the Ricoh RP5C01
+	  timekeeping chip. It is used in some Amiga models (e.g. A3000
+	  and A4000).
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-rp5c01.
+
 config RTC_DRV_V3020
 	tristate "EM Microelectronic V3020"
 	help

drivers/rtc/Makefile

@@ -60,6 +60,7 @@ obj-$(CONFIG_RTC_DRV_PL031)	+= rtc-pl031.o
 obj-$(CONFIG_RTC_DRV_GENERIC)	+= rtc-generic.o
 obj-$(CONFIG_RTC_DRV_PXA)	+= rtc-pxa.o
 obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o
+obj-$(CONFIG_RTC_DRV_RP5C01)	+= rtc-rp5c01.o
 obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o
 obj-$(CONFIG_RTC_DRV_RS5C348)	+= rtc-rs5c348.o
 obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o

drivers/rtc/rtc-rp5c01.c

+/*
+ *  Ricoh RP5C01 RTC Driver
+ *
+ *  Copyright 2009 Geert Uytterhoeven
+ *
+ *  Based on the A3000 TOD code in arch/m68k/amiga/config.c
+ *  Copyright (C) 1993 Hamish Macdonald
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+
+enum {
+	RP5C01_1_SECOND		= 0x0,	/* MODE 00 */
+	RP5C01_10_SECOND	= 0x1,	/* MODE 00 */
+	RP5C01_1_MINUTE		= 0x2,	/* MODE 00 and MODE 01 */
+	RP5C01_10_MINUTE	= 0x3,	/* MODE 00 and MODE 01 */
+	RP5C01_1_HOUR		= 0x4,	/* MODE 00 and MODE 01 */
+	RP5C01_10_HOUR		= 0x5,	/* MODE 00 and MODE 01 */
+	RP5C01_DAY_OF_WEEK	= 0x6,	/* MODE 00 and MODE 01 */
+	RP5C01_1_DAY		= 0x7,	/* MODE 00 and MODE 01 */
+	RP5C01_10_DAY		= 0x8,	/* MODE 00 and MODE 01 */
+	RP5C01_1_MONTH		= 0x9,	/* MODE 00 */
+	RP5C01_10_MONTH		= 0xa,	/* MODE 00 */
+	RP5C01_1_YEAR		= 0xb,	/* MODE 00 */
+	RP5C01_10_YEAR		= 0xc,	/* MODE 00 */
+
+	RP5C01_12_24_SELECT	= 0xa,	/* MODE 01 */
+	RP5C01_LEAP_YEAR	= 0xb,	/* MODE 01 */
+
+	RP5C01_MODE		= 0xd,	/* all modes */
+	RP5C01_TEST		= 0xe,	/* all modes */
+	RP5C01_RESET		= 0xf,	/* all modes */
+};
+
+#define RP5C01_12_24_SELECT_12	(0 << 0)
+#define RP5C01_12_24_SELECT_24	(1 << 0)
+
+#define RP5C01_10_HOUR_AM	(0 << 1)
+#define RP5C01_10_HOUR_PM	(1 << 1)
+
+#define RP5C01_MODE_TIMER_EN	(1 << 3)	/* timer enable */
+#define RP5C01_MODE_ALARM_EN	(1 << 2)	/* alarm enable */
+
+#define RP5C01_MODE_MODE_MASK	(3 << 0)
+#define RP5C01_MODE_MODE00	(0 << 0)	/* time */
+#define RP5C01_MODE_MODE01	(1 << 0)	/* alarm, 12h/24h, leap year */
+#define RP5C01_MODE_RAM_BLOCK10	(2 << 0)	/* RAM 4 bits x 13 */
+#define RP5C01_MODE_RAM_BLOCK11	(3 << 0)	/* RAM 4 bits x 13 */
+
+#define RP5C01_RESET_1HZ_PULSE	(1 << 3)
+#define RP5C01_RESET_16HZ_PULSE	(1 << 2)
+#define RP5C01_RESET_SECOND	(1 << 1)	/* reset divider stages for */
+						/* seconds or smaller units */
+#define RP5C01_RESET_ALARM	(1 << 0)	/* reset all alarm registers */
+
+
+struct rp5c01_priv {
+	u32 __iomem *regs;
+	struct rtc_device *rtc;
+};
+
+static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
+				       unsigned int reg)
+{
+	return __raw_readl(&priv->regs[reg]) & 0xf;
+}
+
+static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
+				unsigned int reg)
+{
+	return __raw_writel(val, &priv->regs[reg]);
+}
+
+static void rp5c01_lock(struct rp5c01_priv *priv)
+{
+	rp5c01_write(priv, RP5C01_MODE_MODE00, RP5C01_MODE);
+}
+
+static void rp5c01_unlock(struct rp5c01_priv *priv)
+{
+	rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
+		     RP5C01_MODE);
+}
+
+static int rp5c01_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rp5c01_priv *priv = dev_get_drvdata(dev);
+
+	rp5c01_lock(priv);
+
+	tm->tm_sec  = rp5c01_read(priv, RP5C01_10_SECOND) * 10 +
+		      rp5c01_read(priv, RP5C01_1_SECOND);
+	tm->tm_min  = rp5c01_read(priv, RP5C01_10_MINUTE) * 10 +
+		      rp5c01_read(priv, RP5C01_1_MINUTE);
+	tm->tm_hour = rp5c01_read(priv, RP5C01_10_HOUR) * 10 +
+		      rp5c01_read(priv, RP5C01_1_HOUR);
+	tm->tm_mday = rp5c01_read(priv, RP5C01_10_DAY) * 10 +
+		      rp5c01_read(priv, RP5C01_1_DAY);
+	tm->tm_wday = rp5c01_read(priv, RP5C01_DAY_OF_WEEK);
+	tm->tm_mon  = rp5c01_read(priv, RP5C01_10_MONTH) * 10 +
+		      rp5c01_read(priv, RP5C01_1_MONTH) - 1;
+	tm->tm_year = rp5c01_read(priv, RP5C01_10_YEAR) * 10 +
+		      rp5c01_read(priv, RP5C01_1_YEAR);
+	if (tm->tm_year <= 69)
+		tm->tm_year += 100;
+
+	rp5c01_unlock(priv);
+
+	return rtc_valid_tm(tm);
+}
+
+static int rp5c01_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rp5c01_priv *priv = dev_get_drvdata(dev);
+
+	rp5c01_lock(priv);
+
+	rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND);
+	rp5c01_write(priv, tm->tm_sec % 10, RP5C01_1_SECOND);
+	rp5c01_write(priv, tm->tm_min / 10, RP5C01_10_MINUTE);
+	rp5c01_write(priv, tm->tm_min % 10, RP5C01_1_MINUTE);
+	rp5c01_write(priv, tm->tm_hour / 10, RP5C01_10_HOUR);
+	rp5c01_write(priv, tm->tm_hour % 10, RP5C01_1_HOUR);
+	rp5c01_write(priv, tm->tm_mday / 10, RP5C01_10_DAY);
+	rp5c01_write(priv, tm->tm_mday % 10, RP5C01_1_DAY);
+	if (tm->tm_wday != -1)
+		rp5c01_write(priv, tm->tm_wday, RP5C01_DAY_OF_WEEK);
+	rp5c01_write(priv, (tm->tm_mon + 1) / 10, RP5C01_10_MONTH);
+	rp5c01_write(priv, (tm->tm_mon + 1) % 10, RP5C01_1_MONTH);
+	if (tm->tm_year >= 100)
+		tm->tm_year -= 100;
+	rp5c01_write(priv, tm->tm_year / 10, RP5C01_10_YEAR);
+	rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR);
+
+	rp5c01_unlock(priv);
+	return 0;
+}
+
+static const struct rtc_class_ops rp5c01_rtc_ops = {
+	.read_time	= rp5c01_read_time,
+	.set_time	= rp5c01_set_time,
+};
+
+static int __init rp5c01_rtc_probe(struct platform_device *dev)
+{
+	struct resource *res;
+	struct rp5c01_priv *priv;
+	struct rtc_device *rtc;
+	int error;
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regs = ioremap(res->start, resource_size(res));
+	if (!priv->regs) {
+		error = -ENOMEM;
+		goto out_free_priv;
+	}
+
+	rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops,
+				  THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		error = PTR_ERR(rtc);
+		goto out_unmap;
+	}
+
+	priv->rtc = rtc;
+	platform_set_drvdata(dev, priv);
+	return 0;
+
+out_unmap:
+	iounmap(priv->regs);
+out_free_priv:
+	kfree(priv);
+	return error;
+}
+
+static int __exit rp5c01_rtc_remove(struct platform_device *dev)
+{
+	struct rp5c01_priv *priv = platform_get_drvdata(dev);
+
+	rtc_device_unregister(priv->rtc);
+	iounmap(priv->regs);
+	kfree(priv);
+	return 0;
+}
+
+static struct platform_driver rp5c01_rtc_driver = {
+	.driver	= {
+		.name	= "rtc-rp5c01",
+		.owner	= THIS_MODULE,
+	},
+	.remove	= __exit_p(rp5c01_rtc_remove),
+};
+
+static int __init rp5c01_rtc_init(void)
+{
+	return platform_driver_probe(&rp5c01_rtc_driver, rp5c01_rtc_probe);
+}
+
+static void __exit rp5c01_rtc_fini(void)
+{
+	platform_driver_unregister(&rp5c01_rtc_driver);
+}
+
+module_init(rp5c01_rtc_init);
+module_exit(rp5c01_rtc_fini);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Ricoh RP5C01 RTC driver");
+MODULE_ALIAS("platform:rtc-rp5c01");