// 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.
*
* 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*/
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 = {
.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_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)
{
pr_info("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_poll(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;
}
