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/*

 * 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/bootinfo.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 *, struct pt_regs *);

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 pt_regs *regs)

{

        struct adb_request *req;

        uint flags;

        save_flags(flags);

        cli();

        req = current_req;

        if ((adb_iop_state == sending) && req && req->reply_expected) {

                adb_iop_state = awaiting_reply;

        }

        restore_flags(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 pt_regs *regs)

{

        struct adb_iopmsg *amsg = (struct adb_iopmsg *) msg->message;

        struct adb_request *req;

        uint flags;

#ifdef DEBUG_ADB_IOP

        int i;

#endif

        save_flags(flags);

        cli();

        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, regs,

                                  amsg->flags & ADB_IOP_AUTOPOLL);

                }

                memcpy(msg->reply, msg->message, IOP_MSG_LEN);

        }

        iop_complete_message(msg);

        restore_flags(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;

        save_flags(flags);

        cli();

#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;

        restore_flags(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;

        }

        save_flags(flags);

        cli();

        req->next = 0;

        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;

        }

        restore_flags(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, NULL);

}

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;

}