[PATCH] RTC subsystem: EP93XX driver

This patch adds a driver for the RTC embedded in the Cirrus Logic EP93XX
family of processors.

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ep93xx.c b/drivers/rtc/rtc-ep93xx.c
new file mode 100644
index 000000000000..0dd80ea686a9
--- /dev/null
+++ b/drivers/rtc/rtc-ep93xx.c
@@ -0,0 +1,162 @@
+/*
+ * A driver for the RTC embedded in the Cirrus Logic EP93XX processors
+ * Copyright (c) 2006 Tower Technologies
+ *
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * 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 <asm/hardware.h>
+
+#define EP93XX_RTC_REG(x)       (EP93XX_RTC_BASE + (x))
+#define EP93XX_RTC_DATA         EP93XX_RTC_REG(0x0000)
+#define EP93XX_RTC_LOAD         EP93XX_RTC_REG(0x000C)
+#define EP93XX_RTC_SWCOMP       EP93XX_RTC_REG(0x0108)
+
+#define DRV_VERSION "0.2"
+
+static int ep93xx_get_swcomp(struct device *dev, unsigned short *preload,
+                                unsigned short *delete)
+{
+        unsigned short comp = __raw_readl(EP93XX_RTC_SWCOMP);
+
+        if (preload)
+                *preload = comp & 0xffff;
+
+        if (delete)
+                *delete = (comp >> 16) & 0x1f;
+
+        return 0;
+}
+
+static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        unsigned long time = __raw_readl(EP93XX_RTC_DATA);
+
+        rtc_time_to_tm(time, tm);
+        return 0;
+}
+
+static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
+{
+        __raw_writel(secs + 1, EP93XX_RTC_LOAD);
+        return 0;
+}
+
+static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        int err;
+        unsigned long secs;
+
+        err = rtc_tm_to_time(tm, &secs);
+        if (err != 0)
+                return err;
+
+        return ep93xx_rtc_set_mmss(dev, secs);
+}
+
+static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+        unsigned short preload, delete;
+
+        ep93xx_get_swcomp(dev, &preload, &delete);
+
+        seq_printf(seq, "24hr\t\t: yes\n");
+        seq_printf(seq, "preload\t\t: %d\n", preload);
+        seq_printf(seq, "delete\t\t: %d\n", delete);
+
+        return 0;
+}
+
+static struct rtc_class_ops ep93xx_rtc_ops = {
+        .read_time      = ep93xx_rtc_read_time,
+        .set_time       = ep93xx_rtc_set_time,
+        .set_mmss       = ep93xx_rtc_set_mmss,
+        .proc           = ep93xx_rtc_proc,
+};
+
+static ssize_t ep93xx_sysfs_show_comp_preload(struct device *dev,
+                        struct device_attribute *attr, char *buf)
+{
+        unsigned short preload;
+
+        ep93xx_get_swcomp(dev, &preload, NULL);
+
+        return sprintf(buf, "%d\n", preload);
+}
+static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_sysfs_show_comp_preload, NULL);
+
+static ssize_t ep93xx_sysfs_show_comp_delete(struct device *dev,
+                        struct device_attribute *attr, char *buf)
+{
+        unsigned short delete;
+
+        ep93xx_get_swcomp(dev, NULL, &delete);
+
+        return sprintf(buf, "%d\n", delete);
+}
+static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_sysfs_show_comp_delete, NULL);
+
+
+static int __devinit ep93xx_rtc_probe(struct platform_device *dev)
+{
+        struct rtc_device *rtc = rtc_device_register("ep93xx",
+                                &dev->dev, &ep93xx_rtc_ops, THIS_MODULE);
+
+        if (IS_ERR(rtc)) {
+                dev_err(&dev->dev, "unable to register\n");
+                return PTR_ERR(rtc);
+        }
+
+        platform_set_drvdata(dev, rtc);
+
+        device_create_file(&dev->dev, &dev_attr_comp_preload);
+        device_create_file(&dev->dev, &dev_attr_comp_delete);
+
+        return 0;
+}
+
+static int __devexit ep93xx_rtc_remove(struct platform_device *dev)
+{
+        struct rtc_device *rtc = platform_get_drvdata(dev);
+
+        if (rtc)
+                rtc_device_unregister(rtc);
+
+        platform_set_drvdata(dev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver ep93xx_rtc_platform_driver = {
+        .driver         = {
+                .name   = "ep93xx-rtc",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = ep93xx_rtc_probe,
+        .remove         = __devexit_p(ep93xx_rtc_remove),
+};
+
+static int __init ep93xx_rtc_init(void)
+{
+        return platform_driver_register(&ep93xx_rtc_platform_driver);
+}
+
+static void __exit ep93xx_rtc_exit(void)
+{
+        platform_driver_unregister(&ep93xx_rtc_platform_driver);
+}
+
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_DESCRIPTION("EP93XX RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(ep93xx_rtc_init);
+module_exit(ep93xx_rtc_exit);