// SPDX-License-Identifier: GPL-2.0
/*
* I/O Processor (IOP) ADB Driver
* Written and (C) 1999 by Joshua M. Thompson ([email protected])
* 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;
}
Codebase Browser
linux