File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
new file mode 100644
index 0000000..f5f4da3
--- /dev/null
+++ b/drivers/macintosh/adb-iop.c
@@ -0,0 +1,286 @@
+/*
+ * I/O Processor (IOP) ADB Driver
+ * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
+ * Based on via-cuda.c by Paul Mackerras.
+ *
+ * 1999-07-01 (jmt) - First implementation for new driver architecture.
+ *
+ * 1999-07-31 (jmt) - First working version.
+ *
+ * TODO:
+ *
+ * o Implement SRQ handling.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+
+#include <asm/macintosh.h> 
+#include <asm/macints.h> 
+#include <asm/mac_iop.h>
+#include <asm/mac_oss.h>
+#include <asm/adb_iop.h>
+
+#include <linux/adb.h> 
+
+/*#define DEBUG_ADB_IOP*/
+
+extern void iop_ism_irq(int, void *);
+
+static struct adb_request *current_req;
+static struct adb_request *last_req;
+#if 0
+static unsigned char reply_buff[16];
+static unsigned char *reply_ptr;
+#endif
+
+static enum adb_iop_state {
+    idle,
+    sending,
+    awaiting_reply
+} adb_iop_state;
+
+static void adb_iop_start(void);
+static int adb_iop_probe(void);
+static int adb_iop_init(void);
+static int adb_iop_send_request(struct adb_request *, int);
+static int adb_iop_write(struct adb_request *);
+static int adb_iop_autopoll(int);
+static void adb_iop_poll(void);
+static int adb_iop_reset_bus(void);
+
+struct adb_driver adb_iop_driver = {
+	"ISM IOP",
+	adb_iop_probe,
+	adb_iop_init,
+	adb_iop_send_request,
+	adb_iop_autopoll,
+	adb_iop_poll,
+	adb_iop_reset_bus
+};
+
+static void adb_iop_end_req(struct adb_request *req, int state)
+{
+	req->complete = 1;
+	current_req = req->next;
+	if (req->done) (*req->done)(req);
+	adb_iop_state = state;
+}
+
+/*
+ * Completion routine for ADB commands sent to the IOP.
+ *
+ * This will be called when a packet has been successfully sent.
+ */
+
+static void adb_iop_complete(struct iop_msg *msg)
+{
+	struct adb_request *req;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	req = current_req;
+	if ((adb_iop_state == sending) && req && req->reply_expected) {
+		adb_iop_state = awaiting_reply;
+	}
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Listen for ADB messages from the IOP.
+ *
+ * This will be called when unsolicited messages (usually replies to TALK
+ * commands or autopoll packets) are received.
+ */
+
+static void adb_iop_listen(struct iop_msg *msg)
+{
+	struct adb_iopmsg *amsg = (struct adb_iopmsg *) msg->message;
+	struct adb_request *req;
+	unsigned long flags;
+#ifdef DEBUG_ADB_IOP
+	int i;
+#endif
+
+	local_irq_save(flags);
+
+	req = current_req;
+
+#ifdef DEBUG_ADB_IOP
+	printk("adb_iop_listen %p: rcvd packet, %d bytes: %02X %02X", req,
+		(uint) amsg->count + 2, (uint) amsg->flags, (uint) amsg->cmd);
+	for (i = 0; i < amsg->count; i++)
+		printk(" %02X", (uint) amsg->data[i]);
+	printk("\n");
+#endif
+
+	/* Handle a timeout. Timeout packets seem to occur even after */
+	/* we've gotten a valid reply to a TALK, so I'm assuming that */
+	/* a "timeout" is actually more like an "end-of-data" signal. */
+	/* We need to send back a timeout packet to the IOP to shut   */
+	/* it up, plus complete the current request, if any.          */
+
+	if (amsg->flags & ADB_IOP_TIMEOUT) {
+		msg->reply[0] = ADB_IOP_TIMEOUT | ADB_IOP_AUTOPOLL;
+		msg->reply[1] = 0;
+		msg->reply[2] = 0;
+		if (req && (adb_iop_state != idle)) {
+			adb_iop_end_req(req, idle);
+		}
+	} else {
+		/* TODO: is it possible for more than one chunk of data  */
+		/*       to arrive before the timeout? If so we need to */
+		/*       use reply_ptr here like the other drivers do.  */
+		if ((adb_iop_state == awaiting_reply) &&
+		    (amsg->flags & ADB_IOP_EXPLICIT)) {
+			req->reply_len = amsg->count + 1;
+			memcpy(req->reply, &amsg->cmd, req->reply_len);
+		} else {
+			adb_input(&amsg->cmd, amsg->count + 1,
+				  amsg->flags & ADB_IOP_AUTOPOLL);
+		}
+		memcpy(msg->reply, msg->message, IOP_MSG_LEN);
+	}
+	iop_complete_message(msg);
+	local_irq_restore(flags);
+}
+
+/*
+ * Start sending an ADB packet, IOP style
+ *
+ * There isn't much to do other than hand the packet over to the IOP
+ * after encapsulating it in an adb_iopmsg.
+ */
+
+static void adb_iop_start(void)
+{
+	unsigned long flags;
+	struct adb_request *req;
+	struct adb_iopmsg amsg;
+#ifdef DEBUG_ADB_IOP
+	int i;
+#endif
+
+	/* get the packet to send */
+	req = current_req;
+	if (!req) return;
+
+	local_irq_save(flags);
+
+#ifdef DEBUG_ADB_IOP
+	printk("adb_iop_start %p: sending packet, %d bytes:", req, req->nbytes);
+	for (i = 0 ; i < req->nbytes ; i++)
+		printk(" %02X", (uint) req->data[i]);
+	printk("\n");
+#endif
+
+	/* The IOP takes MacII-style packets, so */
+	/* strip the initial ADB_PACKET byte.    */
+
+	amsg.flags = ADB_IOP_EXPLICIT;
+	amsg.count = req->nbytes - 2;
+
+	/* amsg.data immediately follows amsg.cmd, effectively making */
+	/* amsg.cmd a pointer to the beginning of a full ADB packet.  */
+	memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);
+
+	req->sent = 1;
+	adb_iop_state = sending;
+	local_irq_restore(flags);
+
+	/* Now send it. The IOP manager will call adb_iop_complete */
+	/* when the packet has been sent.                          */
+
+	iop_send_message(ADB_IOP, ADB_CHAN, req,
+			 sizeof(amsg), (__u8 *) &amsg, adb_iop_complete);
+}
+
+int adb_iop_probe(void)
+{
+	if (!iop_ism_present) return -ENODEV;
+	return 0;
+}
+
+int adb_iop_init(void)
+{
+	printk("adb: IOP ISM driver v0.4 for Unified ADB.\n");
+	iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
+	return 0;
+}
+
+int adb_iop_send_request(struct adb_request *req, int sync)
+{
+	int err;
+
+	err = adb_iop_write(req);
+	if (err) return err;
+
+	if (sync) {
+		while (!req->complete) adb_iop_poll();
+	}
+	return 0;
+}
+
+static int adb_iop_write(struct adb_request *req)
+{
+	unsigned long flags;
+
+	if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
+		req->complete = 1;
+		return -EINVAL;
+	}
+
+	local_irq_save(flags);
+
+	req->next = NULL;
+	req->sent = 0;
+	req->complete = 0;
+	req->reply_len = 0;
+
+	if (current_req != 0) {
+		last_req->next = req;
+		last_req = req;
+	} else {
+		current_req = req;
+		last_req = req;
+	}
+
+	local_irq_restore(flags);
+	if (adb_iop_state == idle) adb_iop_start();
+	return 0;
+}
+
+int adb_iop_autopoll(int devs)
+{
+	/* TODO: how do we enable/disable autopoll? */
+	return 0;
+}
+
+void adb_iop_poll(void)
+{
+	if (adb_iop_state == idle) adb_iop_start();
+	iop_ism_irq(0, (void *) ADB_IOP);
+}
+
+int adb_iop_reset_bus(void)
+{
+	struct adb_request req = {
+		.reply_expected = 0,
+		.nbytes = 2,
+		.data = { ADB_PACKET, 0 },
+	};
+
+	adb_iop_write(&req);
+	while (!req.complete) {
+		adb_iop_poll();
+		schedule();
+	}
+
+	return 0;
+}