1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
new file mode 100644
index 000000000..2633bc254
--- /dev/null
+++ b/drivers/macintosh/adb-iop.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_iop.h>
+#include <asm/adb_iop.h>
+#include <asm/unaligned.h>
+
+#include <linux/adb.h>
+
+static struct adb_request *current_req;
+static struct adb_request *last_req;
+static unsigned int autopoll_devs;
+static u8 autopoll_addr;
+
+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);
+
+/* ADB command byte structure */
+#define ADDR_MASK       0xF0
+#define OP_MASK         0x0C
+#define TALK            0x0C
+
+struct adb_driver adb_iop_driver = {
+	.name         = "ISM IOP",
+	.probe        = adb_iop_probe,
+	.init         = adb_iop_init,
+	.send_request = adb_iop_send_request,
+	.autopoll     = adb_iop_autopoll,
+	.poll         = adb_iop_poll,
+	.reset_bus    = adb_iop_reset_bus
+};
+
+static void adb_iop_done(void)
+{
+	struct adb_request *req = current_req;
+
+	adb_iop_state = idle;
+
+	req->complete = 1;
+	current_req = req->next;
+	if (req->done)
+		(*req->done)(req);
+
+	if (adb_iop_state == idle)
+		adb_iop_start();
+}
+
+/*
+ * 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)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	adb_iop_state = awaiting_reply;
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Listen for ADB messages from the IOP.
+ *
+ * This will be called when unsolicited IOP messages are received.
+ * These IOP messages can carry ADB autopoll responses and also occur
+ * after explicit ADB commands.
+ */
+
+static void adb_iop_listen(struct iop_msg *msg)
+{
+	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
+	u8 addr = (amsg->cmd & ADDR_MASK) >> 4;
+	u8 op = amsg->cmd & OP_MASK;
+	unsigned long flags;
+	bool req_done = false;
+
+	local_irq_save(flags);
+
+	/* Responses to Talk commands may be unsolicited as they are
+	 * produced when the IOP polls devices. They are mostly timeouts.
+	 */
+	if (op == TALK && ((1 << addr) & autopoll_devs))
+		autopoll_addr = addr;
+
+	switch (amsg->flags & (ADB_IOP_EXPLICIT |
+			       ADB_IOP_AUTOPOLL |
+			       ADB_IOP_TIMEOUT)) {
+	case ADB_IOP_EXPLICIT:
+	case ADB_IOP_EXPLICIT | ADB_IOP_TIMEOUT:
+		if (adb_iop_state == awaiting_reply) {
+			struct adb_request *req = current_req;
+
+			if (req->reply_expected) {
+				req->reply_len = amsg->count + 1;
+				memcpy(req->reply, &amsg->cmd, req->reply_len);
+			}
+
+			req_done = true;
+		}
+		break;
+	case ADB_IOP_AUTOPOLL:
+		if (((1 << addr) & autopoll_devs) &&
+		    amsg->cmd == ADB_READREG(addr, 0))
+			adb_input(&amsg->cmd, amsg->count + 1, 1);
+		break;
+	}
+	msg->reply[0] = autopoll_addr ? ADB_IOP_AUTOPOLL : 0;
+	msg->reply[1] = 0;
+	msg->reply[2] = autopoll_addr ? ADB_READREG(autopoll_addr, 0) : 0;
+	iop_complete_message(msg);
+
+	if (req_done)
+		adb_iop_done();
+
+	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)
+{
+	struct adb_request *req;
+	struct adb_iopmsg amsg;
+
+	/* get the packet to send */
+	req = current_req;
+	if (!req)
+		return;
+
+	/* 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;
+
+	/* Now send it. The IOP manager will call adb_iop_complete
+	 * when the message has been sent.
+	 */
+	iop_send_message(ADB_IOP, ADB_CHAN, req, sizeof(amsg), (__u8 *)&amsg,
+			 adb_iop_complete);
+}
+
+static int adb_iop_probe(void)
+{
+	if (!iop_ism_present)
+		return -ENODEV;
+	return 0;
+}
+
+static int adb_iop_init(void)
+{
+	pr_info("adb: IOP ISM driver v0.4 for Unified ADB\n");
+	iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
+	return 0;
+}
+
+static 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;
+	}
+
+	req->next = NULL;
+	req->sent = 0;
+	req->complete = 0;
+	req->reply_len = 0;
+
+	local_irq_save(flags);
+
+	if (current_req) {
+		last_req->next = req;
+		last_req = req;
+	} else {
+		current_req = req;
+		last_req = req;
+	}
+
+	if (adb_iop_state == idle)
+		adb_iop_start();
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static void adb_iop_set_ap_complete(struct iop_msg *msg)
+{
+	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
+
+	autopoll_devs = get_unaligned_be16(amsg->data);
+	if (autopoll_devs & (1 << autopoll_addr))
+		return;
+	autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;
+}
+
+static int adb_iop_autopoll(int devs)
+{
+	struct adb_iopmsg amsg;
+	unsigned long flags;
+	unsigned int mask = (unsigned int)devs & 0xFFFE;
+
+	local_irq_save(flags);
+
+	amsg.flags = ADB_IOP_SET_AUTOPOLL | (mask ? ADB_IOP_AUTOPOLL : 0);
+	amsg.count = 2;
+	amsg.cmd = 0;
+	put_unaligned_be16(mask, amsg.data);
+
+	iop_send_message(ADB_IOP, ADB_CHAN, NULL, sizeof(amsg), (__u8 *)&amsg,
+			 adb_iop_set_ap_complete);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static void adb_iop_poll(void)
+{
+	iop_ism_irq_poll(ADB_IOP);
+}
+
+static int adb_iop_reset_bus(void)
+{
+	struct adb_request req;
+
+	/* Command = 0, Address = ignored */
+	adb_request(&req, NULL, ADBREQ_NOSEND, 1, ADB_BUSRESET);
+	adb_iop_send_request(&req, 1);
+
+	/* Don't want any more requests during the Global Reset low time. */
+	mdelay(3);
+
+	return 0;
+}