1 files changed, 138 insertions, 0 deletions
diff --git a/arch/v850/kernel/rte_cb_leds.c b/arch/v850/kernel/rte_cb_leds.c
new file mode 100644
index 00000000000..b662ad83894
--- /dev/null
+++ b/arch/v850/kernel/rte_cb_leds.c
@@ -0,0 +1,138 @@
+/*
+ * include/asm-v850/rte_cb_leds.c -- Midas lab RTE-CB board LED device support
+ *
+ *  Copyright (C) 2002,03  NEC Electronics Corporation
+ *  Copyright (C) 2002,03  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+
+#include <asm/uaccess.h>
+
+#define LEDS_MINOR	169	/* Minor device number, using misc major.  */
+
+/* The actual LED hardware is write-only, so we hold the contents here too.  */
+static unsigned char leds_image[LED_NUM_DIGITS] = { 0 };
+
+/* Spinlock protecting the above leds.  */
+static DEFINE_SPINLOCK(leds_lock);
+
+/* Common body of LED read/write functions, checks POS and LEN for
+   correctness, declares a variable using IMG_DECL, initialized pointing at
+   the POS position in the LED image buffer, and and iterates COPY_EXPR
+   until BUF is equal to the last buffer position; finally, sets LEN to be
+   the amount actually copied.  IMG should be a variable declaration
+   (without an initializer or a terminating semicolon); POS, BUF, and LEN
+   should all be simple variables.  */
+#define DO_LED_COPY(img_decl, pos, buf, len, copy_expr)			\
+do {									\
+	if (pos > LED_NUM_DIGITS)					\
+		len = 0;						\
+	else {								\
+		if (pos + len > LED_NUM_DIGITS)				\
+			len = LED_NUM_DIGITS - pos;			\
+									\
+		if (len > 0) {						\
+			int _flags;					\
+			const char *_end = buf + len;			\
+			img_decl = &leds_image[pos];			\
+									\
+			spin_lock_irqsave (leds_lock, _flags);		\
+			do						\
+				(copy_expr);				\
+			while (buf != _end);				\
+			spin_unlock_irqrestore (leds_lock, _flags);	\
+		}							\
+	}								\
+} while (0)
+
+/* Read LEN bytes from LEDs at position POS, into BUF.
+   Returns actual amount read.  */
+unsigned read_leds (unsigned pos, char *buf, unsigned len)
+{
+	DO_LED_COPY (const char *img, pos, buf, len, *buf++ = *img++);
+	return len;
+}
+
+/* Write LEN bytes to LEDs at position POS, from BUF.
+   Returns actual amount written.  */
+unsigned write_leds (unsigned pos, const char *buf, unsigned len)
+{
+	/* We write the actual LED values backwards, because
+	   increasing memory addresses reflect LEDs right-to-left. */
+	volatile char *led = &LED (LED_NUM_DIGITS - pos - 1);
+	/* We invert the value written to the hardware, because 1 = off,
+	   and 0 = on.  */
+	DO_LED_COPY (char *img, pos, buf, len,
+		     *led-- = 0xFF ^ (*img++ = *buf++));
+	return len;
+}
+
+
+/* Device functions.  */
+
+static ssize_t leds_dev_read (struct file *file, char *buf, size_t len,
+			      loff_t *pos)
+{
+	char temp_buf[LED_NUM_DIGITS];
+	len = read_leds (*pos, temp_buf, len);
+	if (copy_to_user (buf, temp_buf, len))
+		return -EFAULT;
+	*pos += len;
+	return len;
+}
+
+static ssize_t leds_dev_write (struct file *file, const char *buf, size_t len,
+			       loff_t *pos)
+{
+	char temp_buf[LED_NUM_DIGITS];
+	if (copy_from_user (temp_buf, buf, min_t(size_t, len, LED_NUM_DIGITS)))
+		return -EFAULT;
+	len = write_leds (*pos, temp_buf, len);
+	*pos += len;
+	return len;
+}
+
+static loff_t leds_dev_lseek (struct file *file, loff_t offs, int whence)
+{
+	if (whence == 1)
+		offs += file->f_pos; /* relative */
+	else if (whence == 2)
+		offs += LED_NUM_DIGITS; /* end-relative */
+
+	if (offs < 0 || offs > LED_NUM_DIGITS)
+		return -EINVAL;
+
+	file->f_pos = offs;
+
+	return 0;
+}
+
+static struct file_operations leds_fops = {
+	.read		= leds_dev_read,
+	.write		= leds_dev_write,
+	.llseek		= leds_dev_lseek
+};
+
+static struct miscdevice leds_miscdev = {
+	.name		= "leds",
+	.minor		= LEDS_MINOR,
+	.fops		= &leds_fops
+};
+
+int __init leds_dev_init (void)
+{
+	return misc_register (&leds_miscdev);
+}
+
+__initcall (leds_dev_init);