patch-2.1.51 linux/drivers/macintosh/adb.c

• Lines: 170
• Date: Sat Aug 16 09:53:08 1997
• Orig file: v2.1.50/linux/drivers/macintosh/adb.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.50/linux/drivers/macintosh/adb.c linux/drivers/macintosh/adb.c
@@ -0,0 +1,169 @@
+/*
+ * Device driver for the /dev/adb device on macintoshes.
+ *
+ * Copyright (C) 1996 Paul Mackerras.
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/malloc.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <asm/prom.h>
+#include <asm/cuda.h>
+#include <asm/uaccess.h>
+
+#define ADB_MAJOR	56	/* major number for /dev/adb */
+
+extern void adbdev_init(void);
+
+struct adbdev_state {
+	struct cuda_request req;
+};
+
+static struct wait_queue *adb_wait;
+
+static int adb_wait_reply(struct adbdev_state *state, struct file *file)
+{
+	int ret = 0;
+	struct wait_queue wait = { current, NULL };
+
+	add_wait_queue(&adb_wait, &wait);
+	current->state = TASK_INTERRUPTIBLE;
+
+	while (!state->req.got_reply) {
+		if (file->f_flags & O_NONBLOCK) {
+			ret = -EAGAIN;
+			break;
+		}
+		if (current->signal & ~current->blocked) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		schedule();
+	}
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&adb_wait, &wait);
+
+	return ret;
+}
+
+static void adb_write_done(struct cuda_request *req)
+{
+	if (!req->got_reply) {
+		req->reply_len = 0;
+		req->got_reply = 1;
+	}
+	wake_up_interruptible(&adb_wait);
+}
+
+static int adb_open(struct inode *inode, struct file *file)
+{
+	struct adbdev_state *state;
+
+	if (MINOR(inode->i_rdev) > 0)
+		return -ENXIO;
+	state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
+	if (state == 0)
+		return -ENOMEM;
+	file->private_data = state;
+	state->req.reply_expected = 0;
+	return 0;
+}
+
+static int adb_release(struct inode *inode, struct file *file)
+{
+	struct adbdev_state *state = file->private_data;
+
+	if (state) {
+		file->private_data = NULL;
+		if (state->req.reply_expected && !state->req.got_reply)
+			if (adb_wait_reply(state, file))
+				return 0;
+		kfree(state);
+	}
+	return 0;
+}
+
+static long long adb_lseek(struct inode *inode, struct file *file,
+			   long long offset, int origin)
+{
+	return -ESPIPE;
+}
+
+static long adb_read(struct inode *inode, struct file *file,
+		     char *buf, unsigned long count)
+{
+	int ret;
+	struct adbdev_state *state = file->private_data;
+
+	if (count < 2)
+		return -EINVAL;
+	if (count > sizeof(state->req.reply))
+		count = sizeof(state->req.reply);
+	ret = verify_area(VERIFY_WRITE, buf, count);
+	if (ret)
+		return ret;
+
+	if (!state->req.reply_expected)
+		return 0;
+
+	ret = adb_wait_reply(state, file);
+	if (ret)
+		return ret;
+
+	ret = state->req.reply_len;
+	copy_to_user(buf, state->req.reply, ret);
+	state->req.reply_expected = 0;
+
+	return ret;
+}
+
+static long adb_write(struct inode *inode, struct file *file,
+		      const char *buf, unsigned long count)
+{
+	int ret;
+	struct adbdev_state *state = file->private_data;
+
+	if (count < 2 || count > sizeof(state->req.data))
+		return -EINVAL;
+	ret = verify_area(VERIFY_READ, buf, count);
+	if (ret)
+		return ret;
+
+	if (state->req.reply_expected && !state->req.got_reply) {
+		/* A previous request is still being processed.
+		   Wait for it to finish. */
+		ret = adb_wait_reply(state, file);
+		if (ret)
+			return ret;
+	}
+
+	state->req.nbytes = count;
+	state->req.done = adb_write_done;
+	copy_from_user(state->req.data, buf, count);
+	state->req.reply_expected = 1;
+	state->req.got_reply = 0;
+	cuda_send_request(&state->req);
+
+	return count;
+}
+
+static struct file_operations adb_fops = {
+	adb_lseek,
+	adb_read,
+	adb_write,
+	NULL,		/* no readdir */
+	NULL,		/* no poll yet */
+	NULL,		/* no ioctl yet */
+	NULL,		/* no mmap */
+	adb_open,
+	adb_release
+};
+
+void adbdev_init()
+{
+	if (register_chrdev(ADB_MAJOR, "adb", &adb_fops))
+		printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
+}