adb.c

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/*
 * Device driver for the Apple Desktop Bus
 * and the /dev/adb device on macintoshes.
 *
 * Copyright (C) 1996 Paul Mackerras.
 *
 * Modified to declare controllers as structures, added
 * client notification of bus reset and handles PowerBook
 * sleep, by Benjamin Herrenschmidt.
 *
 * To do:
 *
 * - /proc/adb to list the devices and infos
 * - more /dev/adb to allow userland to receive the
 *   flow of auto-polling datas from a given device.
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/pmu.h>
#include <linux/notifier.h>
#include <linux/wait.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#ifdef CONFIG_PPC
#include <asm/prom.h>
#include <asm/hydra.h>
#endif

EXPORT_SYMBOL(adb_controller);
EXPORT_SYMBOL(adb_client_list);

extern struct adb_driver via_macii_driver;
extern struct adb_driver via_maciisi_driver;
extern struct adb_driver via_cuda_driver;
extern struct adb_driver adb_iop_driver;
extern struct adb_driver via_pmu_driver;
extern struct adb_driver macio_adb_driver;

static struct adb_driver *adb_driver_list[] = {
#ifdef CONFIG_ADB_MACII
	&via_macii_driver,
#endif
#ifdef CONFIG_ADB_MACIISI
	&via_maciisi_driver,
#endif
#ifdef CONFIG_ADB_CUDA
	&via_cuda_driver,
#endif
#ifdef CONFIG_ADB_IOP
	&adb_iop_driver,
#endif
#ifdef CONFIG_ADB_PMU
	&via_pmu_driver,
#endif
#ifdef CONFIG_ADB_MACIO
	&macio_adb_driver,
#endif
	NULL
};

struct adb_driver *adb_controller;
struct notifier_block *adb_client_list = NULL;
static int adb_got_sleep = 0;
static int adb_inited = 0;

#ifdef CONFIG_PMAC_PBOOK
static int adb_notify_sleep(struct pmu_sleep_notifier *self, int when);
static struct pmu_sleep_notifier adb_sleep_notifier = {
	adb_notify_sleep,
	SLEEP_LEVEL_ADB,
};
#endif

static int adb_scan_bus(void);

static struct adb_handler {
	void (*handler)(unsigned char *, int, struct pt_regs *, int);
	int original_address;
	int handler_id;
} adb_handler[16];

#if 0
static void printADBreply(struct adb_request *req)
{
        int i;

        printk("adb reply (%d)", req->reply_len);
        for(i = 0; i < req->reply_len; i++)
                printk(" %x", req->reply[i]);
        printk("\n");

}
#endif

static int adb_scan_bus(void)
{
	int i, highFree=0, noMovement;
	int devmask = 0;
	struct adb_request req;
	
	/* assumes adb_handler[] is all zeroes at this point */
	for (i = 1; i < 16; i++) {
		/* see if there is anything at address i */
		adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
                            (i << 4) | 0xf);
		if (req.reply_len > 1)
			/* one or more devices at this address */
			adb_handler[i].original_address = i;
		else if (i > highFree)
			highFree = i;
	}

	/* Note we reset noMovement to 0 each time we move a device */
	for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
		for (i = 1; i < 16; i++) {
			if (adb_handler[i].original_address == 0)
				continue;
			/*
			 * Send a "talk register 3" command to address i
			 * to provoke a collision if there is more than
			 * one device at this address.
			 */
			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
				    (i << 4) | 0xf);
			/*
			 * Move the device(s) which didn't detect a
			 * collision to address `highFree'.  Hopefully
			 * this only moves one device.
			 */
			adb_request(&req, NULL, ADBREQ_SYNC, 3,
				    (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
			/*
			 * See if anybody actually moved. This is suggested
			 * by HW TechNote 01:
			 *
			 * http://developer.apple.com/technotes/hw/hw_01.html
			 */
			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
				    (highFree << 4) | 0xf);
			if (req.reply_len <= 1) continue;
			/*
			 * Test whether there are any device(s) left
			 * at address i.
			 */
			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
				    (i << 4) | 0xf);
			if (req.reply_len > 1) {
				/*
				 * There are still one or more devices
				 * left at address i.  Register the one(s)
				 * we moved to `highFree', and find a new
				 * value for highFree.
				 */
				adb_handler[highFree].original_address =
					adb_handler[i].original_address;
				while (highFree > 0 &&
				       adb_handler[highFree].original_address)
					highFree--;
				if (highFree <= 0)
					break;

				noMovement = 0;
			}
			else {
				/*
				 * No devices left at address i; move the
				 * one(s) we moved to `highFree' back to i.
				 */
				adb_request(&req, NULL, ADBREQ_SYNC, 3,
					    (highFree << 4) | 0xb,
					    (i | 0x60), 0xfe);
			}
		}	
	}

	/* Now fill in the handler_id field of the adb_handler entries. */
	printk(KERN_DEBUG "adb devices:");
	for (i = 1; i < 16; i++) {
		if (adb_handler[i].original_address == 0)
			continue;
		adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
			    (i << 4) | 0xf);
		adb_handler[i].handler_id = req.reply[2];
		printk(" [%d]: %d %x", i, adb_handler[i].original_address,
		       adb_handler[i].handler_id);
		devmask |= 1 << i;
	}
	printk("\n");
	return devmask;
}

int __init adb_init(void)
{
	struct adb_driver *driver;
	int i;

#ifdef CONFIG_PPC
	if ( (_machine != _MACH_chrp) && (_machine != _MACH_Pmac) )
		return 0;
#endif
#ifdef CONFIG_MAC
	if (!MACH_IS_MAC)
		return 0;
#endif

	/* xmon may do early-init */
	if (adb_inited)
		return 0;
	adb_inited = 1;
		
	adb_controller = NULL;

	i = 0;
	while ((driver = adb_driver_list[i++]) != NULL) {
		if (!driver->probe()) {
			adb_controller = driver;
			break;
		}
	}
	if ((adb_controller == NULL) || adb_controller->init()) {
		printk(KERN_WARNING "Warning: no ADB interface detected\n");
	} else {
#ifdef CONFIG_PMAC_PBOOK
		pmu_register_sleep_notifier(&adb_sleep_notifier);
#endif /* CONFIG_PMAC_PBOOK */

		adb_reset_bus();
	}
	return 0;
}

__initcall(adb_init);

#ifdef CONFIG_PMAC_PBOOK
/*
 * notify clients before sleep and reset bus afterwards
 */
int
adb_notify_sleep(struct pmu_sleep_notifier *self, int when)
{
	int ret;
	
	switch (when) {
	case PBOOK_SLEEP_REQUEST:
		adb_got_sleep = 1;
		if (adb_controller->autopoll)
			adb_controller->autopoll(0);
		ret = notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
		if (ret & NOTIFY_STOP_MASK)
			return PBOOK_SLEEP_REFUSE;
		break;
	case PBOOK_SLEEP_REJECT:
		if (adb_got_sleep) {
			adb_got_sleep = 0;
			adb_reset_bus();
		}
		break;
		
	case PBOOK_SLEEP_NOW:
		break;
	case PBOOK_WAKE:
		adb_reset_bus();
		adb_got_sleep = 0;
		break;
	}
	return PBOOK_SLEEP_OK;
}
#endif /* CONFIG_PMAC_PBOOK */

int
adb_reset_bus(void)
{
	int ret, nret, devs;
	unsigned long flags;
	
	if (adb_controller == NULL)
		return -ENXIO;
		
	if (adb_controller->autopoll)
		adb_controller->autopoll(0);

	nret = notifier_call_chain(&adb_client_list, ADB_MSG_PRE_RESET, NULL);
	if (nret & NOTIFY_STOP_MASK) {
		if (adb_controller->autopoll)
			adb_controller->autopoll(devs);
		return -EBUSY;
	}

	save_flags(flags);
	cli();
	memset(adb_handler, 0, sizeof(adb_handler));
	restore_flags(flags);
	
	if (adb_controller->reset_bus)
		ret = adb_controller->reset_bus();
	else
		ret = 0;

	if (!ret) {
		devs = adb_scan_bus();
		if (adb_controller->autopoll)
			adb_controller->autopoll(devs);
	}

	nret = notifier_call_chain(&adb_client_list, ADB_MSG_POST_RESET, NULL);
	if (nret & NOTIFY_STOP_MASK)
		return -EBUSY;
	
	return ret;
}

void
adb_poll(void)
{
	if ((adb_controller == NULL)||(adb_controller->poll == NULL))
		return;
	adb_controller->poll();
}


int
adb_request(struct adb_request *req, void (*done)(struct adb_request *),
	    int flags, int nbytes, ...)
{
	va_list list;
	int i;
	struct adb_request sreq;

	if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
		return -ENXIO;
	if (nbytes < 1)
		return -EINVAL;
	
	if (req == NULL) {
		req = &sreq;