// SPDX-License-Identifier: GPL-2.0
/*
* 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:
*
* - /sys/bus/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.
* - move bus probe to a kernel thread
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/sched/signal.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 <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/kthread.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/uaccess.h>
#ifdef CONFIG_PPC
#include <asm/machdep.h>
#endif
EXPORT_SYMBOL(adb_client_list);
extern struct adb_driver via_macii_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 DEFINE_MUTEX(adb_mutex);
static struct adb_driver *adb_driver_list[] = {
#ifdef CONFIG_ADB_MACII
&via_macii_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
};
static const struct class adb_dev_class = {
.name = "adb",
};
static struct adb_driver *adb_controller;
BLOCKING_NOTIFIER_HEAD(adb_client_list);
static int adb_got_sleep;
static int adb_inited;
static DEFINE_SEMAPHORE(adb_probe_mutex, 1);
static int sleepy_trackpad;
static int autopoll_devs;
int __adb_probe_sync;
static int adb_scan_bus(void);
static int do_adb_reset_bus(void);
static void adbdev_init(void);
static int try_handler_change(int, int);
static struct adb_handler {
void (*handler)(unsigned char *, int, int);
int original_address;
int handler_id;
int busy;
} adb_handler[16];
/*
* The adb_handler_mutex mutex protects all accesses to the original_address
* and handler_id fields of adb_handler[i] for all i, and changes to the
* handler field.
* Accesses to the handler field are protected by the adb_handler_lock
* rwlock. It is held across all calls to any handler, so that by the
* time adb_unregister returns, we know that the old handler isn't being
* called.
*/
static DEFINE_MUTEX(adb_handler_mutex);
static DEFINE_RWLOCK(adb_handler_lock);
#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:
*
* https://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. */
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(KERN_DEBUG "adb device [%d]: %d 0x%X\n", i,
adb_handler[i].original_address,
adb_handler[i].handler_id);
devmask |= 1 << i;
}
return devmask;
}
/*
* This kernel task handles ADB probing. It dies once probing is
* completed.
*/
static int
adb_probe_task(void *x)
{
pr_debug("adb: starting probe task...\n");
do_adb_reset_bus();
pr_debug("adb: finished probe task...\n");
up(&adb_probe_mutex);
return 0;
}
static void
__adb_probe_task(struct work_struct *bullshit)
{
kthread_run(adb_probe_task, NULL, "kadbprobe");
}
static DECLARE_WORK(adb_reset_work, __adb_probe_task);
int
adb_reset_bus(void)
{
if (__adb_probe_sync) {
do_adb_reset_bus();
return 0;
}
down(&adb_probe_mutex);
schedule_work(&adb_reset_work);
return 0;
}
#ifdef CONFIG_PM
/*
* notify clients before sleep
*/
static int __adb_suspend(struct platform_device *dev, pm_message_t state)
{
adb_got_sleep = 1;
/* We need to get a lock on the probe thread */
down(&adb_probe_mutex);
/* Stop autopoll */
if (adb_controller->autopoll)
adb_controller->autopoll(0);
blocking_notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
return 0;
}
static int adb_suspend(struct device *dev)
{
return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND);
}
static int adb_freeze(struct device *dev)
{
return __adb_suspend(to_platform_device(dev), PMSG_FREEZE);
}
static int adb_poweroff(struct device *dev)
{
return __adb_suspend(to_platform_device(dev), PMSG_HIBERNATE);
}
/*
* reset bus after sleep
*/
static int __adb_resume(struct platform_device *dev)
{
adb_got_sleep = 0;
up(&adb_probe_mutex);
adb_reset_bus();
return 0;
}
static int adb_resume(struct device *dev)
{
return __adb_resume(to_platform_device(dev));
}
#endif /* CONFIG_PM */
static int __init adb_init(void)
{
struct adb_driver *driver;
int i;
#ifdef CONFIG_PPC32
if (!machine_is(chrp) && !machine_is(powermac))
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 &&
adb_controller->init())
adb_controller = NULL;
if (adb_controller == NULL) {
pr_warn("Warning: no ADB interface detected\n");
} else {
#ifdef CONFIG_PPC
if (of_machine_is_compatible("AAPL,PowerBook1998") ||
of_machine_is_compatible("PowerBook1,1"))
sleepy_trackpad = 1;
#endif /* CONFIG_PPC */
adbdev_init();
adb_reset_bus();
}
return 0;
}
device_initcall(adb_init);
static int
do_adb_reset_bus(void)
{
int ret;
if (adb_controller == NULL)
return -ENXIO;
if (adb_controller->autopoll)
adb_controller->autopoll(0);
blocking_notifier_call_chain(&adb_client_list,
ADB_MSG_PRE_RESET, NULL);
if (sleepy_trackpad) {
/* Let the trackpad settle down */
msleep(500);
}
mutex_lock(&adb_handler_mutex);
write_lock_irq(&adb_handler_lock);
memset(adb_handler, 0, sizeof(adb_handler));
write_unlock_irq(&adb_handler_lock);
/* That one is still a bit synchronous, oh well... */
if (adb_controller->reset_bus)
ret = adb_controller->reset_bus();
else
ret = 0;
if (sleepy_trackpad) {
/* Let the trackpad settle down */
msleep(1500);
}
if (!ret) {
autopoll_devs = adb_scan_bus();
if (adb_controller->autopoll)
adb_controller->autopoll(autopoll_devs);
}
mutex_unlock(&adb_handler_mutex);
blocking_notifier_call_chain(&adb_client_list,
ADB_MSG_POST_RESET, NULL);
return ret;
}
void
adb_poll(void)
{
if ((adb_controller == NULL)||(adb_controller->poll == NULL))
return;
adb_controller->poll();
}
EXPORT_SYMBOL(adb_poll);
static void adb_sync_req_done(struct adb_request *req)
{
struct completion *comp = req->arg;
complete(comp);
}
int
adb_request(struct adb_request *req, void (*done)(struct adb_request *),
int flags, int nbytes, ...)
{
va_list list;
int i;
int rc;
struct completion comp;
if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
return -ENXIO;
if (nbytes < 1)
return -EINVAL;
req->nbytes = nbytes+1;
req->done = done;
req->reply_expected = flags & ADBREQ_REPLY;
req->data[0] = ADB_PACKET;
va_start(list, nbytes);
for (i = 0; i < nbytes; ++i)
req->data[i+1] = va_arg(list, int);
va_end(list);
if (flags & ADBREQ_NOSEND)
return 0;
/* Synchronous requests block using an on-stack completion */
if (flags & ADBREQ_SYNC) {
WARN_ON(done);
req->done = adb_sync_req_done;
req->arg = ∁
init_completion(&comp);
}
rc = adb_controller->send_request(req, 0);
if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
wait_for_completion(&comp);
return rc;
}
EXPORT_SYMBOL(adb_request);
/* Ultimately this should return the number of devices with
the given default id.
And it does it now ! Note: changed behaviour: This function
will now register if default_id _and_ handler_id both match
but handler_id can be left to 0 to match with default_id only.
When handler_id is set, this function will try to adjust
the handler_id id it doesn't match. */
int
adb_register(int default_id, int handler_id, struct adb_ids *ids,
void (*handler)(unsigned char *, int, int))
{
int i;
mutex_lock(&adb_handler_mutex);
ids->nids = 0;
for (i = 1; i < 16; i++) {
if ((adb_handler[i].original_address == default_id) &&
(!handler_id || (handler_id == adb_handler[i].handler_id) ||
try_handler_change(i, handler_id))) {
if (adb_handler[i].handler) {
pr_err("Two handlers for ADB device %d\n",
default_id);
continue;
}
write_lock_irq(&adb_handler_lock);
adb_handler[i].handler = handler;
write_unlock_irq(&adb_handler_lock);
ids->id[ids->nids++] = i;
}
}
mutex_unlock(&adb_handler_mutex);
return ids->nids;
}
EXPORT_SYMBOL(adb_register);
int
adb_unregister(int index)
{
int ret = -ENODEV;
mutex_lock(&adb_handler_mutex);
write_lock_irq(&adb_handler_lock);
if (adb_handler[index].handler) {
while(adb_handler[index].busy) {
write_unlock_irq(&adb_handler_lock);
yield();
write_lock_irq(&adb_handler_lock);
}
ret = 0;
adb_handler[index].handler = NULL;
}
write_unlock_irq(&adb_handler_lock);
mutex_unlock(&adb_handler_mutex);
return ret;
}
EXPORT_SYMBOL(adb_unregister);
void
adb_input(unsigned char *buf, int nb, int autopoll)
{
int i, id;
static int dump_adb_input;
unsigned long flags;
void (*handler)(unsigned char *, int, int);
/* We skip keystrokes and mouse moves when the sleep process
* has been started. We stop autopoll, but this is another security
*/
if (adb_got_sleep)
return;
id = buf[0] >> 4;
if (dump_adb_input) {
pr_info("adb packet: ");
for (i = 0; i < nb; ++i)
pr_cont(" %x", buf[i]);
pr_cont(", id = %d\n", id);
}
write_lock_irqsave(&adb_handler_lock, flags);
handler = adb_handler[id].handler;
if (handler != NULL)
adb_handler[id].busy = 1;
write_unlock_irqrestore(&adb_handler_lock, flags);
if (handler != NULL) {
(*handler)(buf, nb, autopoll);
wmb();
adb_handler[id].busy = 0;
}
}
/* Try to change handler to new_id. Will return 1 if successful. */
static int try_handler_change(int address, int new_id)
{
struct adb_request req;
if (adb_handler[address].handler_id == new_id)
return 1;
adb_request(&req, NULL, ADBREQ_SYNC, 3,
ADB_WRITEREG(address, 3), address | 0x20, new_id);
adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
ADB_READREG(address, 3));
if (req.reply_len < 2)
return 0;
if (req.reply[2] != new_id)
return 0;
adb_handler[address].handler_id = req.reply[2];
return 1;
}
int
adb_try_handler_change(int address, int new_id)
{
int ret;
mutex_lock(&adb_handler_mutex);
ret = try_handler_change(address, new_id);
mutex_unlock(&adb_handler_mutex);
if (ret)
pr_debug("adb handler change: [%d] 0x%X\n", address, new_id);
return ret;
}
EXPORT_SYMBOL(adb_try_handler_change);
int
adb_get_infos(int address, int *original_address, int *handler_id)
{
mutex_lock(&adb_handler_mutex);
*original_address = adb_handler[address].original_address;
*handler_id = adb_handler[address].handler_id;
mutex_unlock(&adb_handler_mutex);
return (*original_address != 0);
}
/*
* /dev/adb device driver.
*/
#define ADB_MAJOR 56 /* major number for /dev/adb */
struct adbdev_state {
spinlock_t lock;
atomic_t n_pending;
struct adb_request *completed;
wait_queue_head_t wait_queue;
int inuse;
};
static void adb_write_done(struct adb_request *req)
{
struct adbdev_state *state = (struct adbdev_state *) req->arg;
unsigned long flags;
if (!req->complete) {
req->reply_len = 0;
req->complete = 1;
}
spin_lock_irqsave(&state->lock, flags);
atomic_dec(&state->n_pending);
if (!state->inuse) {
kfree(req);
if (atomic_read(&state->n_pending) == 0) {
spin_unlock_irqrestore(&state->lock, flags);
kfree(state);
return;
}
} else {
struct adb_request **ap = &state->completed;
while (*ap != NULL)
ap = &(*ap)->next;
req->next = NULL;
*ap = req;
wake_up_interruptible(&state->wait_queue);
}
spin_unlock_irqrestore(&state->lock, flags);
}
static int
do_adb_query(struct adb_request *req)
{
int ret = -EINVAL;
switch(req->data[1]) {
case ADB_QUERY_GETDEVINFO:
if (req->nbytes < 3 || req->data[2] >= 16)
break;
mutex_lock(&adb_handler_mutex);
req->reply[0] = adb_handler[req->data[2]].original_address;
req->reply[1] = adb_handler[req->data[2]].handler_id;
mutex_unlock(&adb_handler_mutex);
req->complete = 1;
req->reply_len = 2;
adb_write_done(req);
ret = 0;
break;
}
return ret;
}
static int adb_open(struct inode *inode, struct file *file)
{
struct adbdev_state *state;
int ret = 0;
mutex_lock(&adb_mutex);
if (iminor(inode) > 0 || adb_controller == NULL) {
ret = -ENXIO;
goto out;
}
state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
if (!state) {
ret = -ENOMEM;
goto out;
}
file->private_data = state;
spin_lock_init(&state->lock);
atomic_set(&state->n_pending, 0);
state->completed = NULL;
init_waitqueue_head(&state->wait_queue);
state->inuse = 1;
out:
mutex_unlock(&adb_mutex);
return ret;
}
static int adb_release(struct inode *inode, struct file *file)
{
struct adbdev_state *state = file->private_data;
unsigned long flags;
mutex_lock(&adb_mutex);
if (state) {
file->private_data = NULL;
spin_lock_irqsave(&state->lock, flags);
if (atomic_read(&state->n_pending) == 0
&& state->completed == NULL) {
spin_unlock_irqrestore(&state->lock, flags);
kfree(state);
} else {
state->inuse = 0;
spin_unlock_irqrestore(&state->lock, flags);
}
}
mutex_unlock(&adb_mutex);
return 0;
}
static ssize_t adb_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int ret = 0;
struct adbdev_state *state = file->private_data;
struct adb_request *req;
DECLARE_WAITQUEUE(wait, current);
unsigned long flags;
if (count < 2)
return -EINVAL;
if (count > sizeof(req->reply))
count = sizeof(req->reply);
req = NULL;
spin_lock_irqsave(&state->lock, flags);
add_wait_queue(&state->wait_queue, &wait);
set_current_state(TASK_INTERRUPTIBLE);
for (;;) {
req = state->completed;
if (req != NULL)
state->completed = req->next;
else if (atomic_read(&state->n_pending) == 0)
ret = -EIO;
if (req != NULL || ret != 0)
break;
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
spin_unlock_irqrestore(&state->lock, flags);
schedule();
spin_lock_irqsave(&state->lock, flags);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&state->wait_queue, &wait);
spin_unlock_irqrestore(&state->lock, flags);
if (ret)
return ret;
ret = req->reply_len;
if (ret > count)
ret = count;
if (ret > 0 && copy_to_user(buf, req->reply, ret))
ret = -EFAULT;
kfree(req);
return ret;
}
static ssize_t adb_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int ret/*, i*/;
struct adbdev_state *state = file->private_data;
struct adb_request *req;
if (count < 2 || count > sizeof(req->data))
return -EINVAL;
if (adb_controller == NULL)
return -ENXIO;
req = kmalloc(sizeof(struct adb_request),
GFP_KERNEL);
if (req == NULL)
return -ENOMEM;
req->nbytes = count;
req->done = adb_write_done;
req->arg = (void *) state;
req->complete = 0;
ret = -EFAULT;
if (copy_from_user(req->data, buf, count))
goto out;
atomic_inc(&state->n_pending);
/* If a probe is in progress or we are sleeping, wait for it to complete */
down(&adb_probe_mutex);
/* Queries are special requests sent to the ADB driver itself */
if (req->data[0] == ADB_QUERY) {
if (count > 1)
ret = do_adb_query(req);
else
ret = -EINVAL;
up(&adb_probe_mutex);
}
/* Special case for ADB_BUSRESET request, all others are sent to
the controller */
else if ((req->data[0] == ADB_PACKET) && (count > 1)
&& (req->data[1] == ADB_BUSRESET)) {
ret = do_adb_reset_bus();
up(&adb_probe_mutex);
atomic_dec(&state->n_pending);
if (ret == 0)
ret = count;
goto out;
} else {
req->reply_expected = ((req->data[1] & 0xc) == 0xc);
if (adb_controller && adb_controller->send_request)
ret = adb_controller->send_request(req, 0);
else
ret = -ENXIO;
up(&adb_probe_mutex);
}
if (ret != 0) {
atomic_dec(&state->n_pending);
goto out;
}
return count;
out:
kfree(req);
return ret;
}
static const struct file_operations adb_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = adb_read,
.write = adb_write,
.open = adb_open,
.release = adb_release,
};
#ifdef CONFIG_PM
static const struct dev_pm_ops adb_dev_pm_ops = {
.suspend = adb_suspend,
.resume = adb_resume,
/* Hibernate hooks */
.freeze = adb_freeze,
.thaw = adb_resume,
.poweroff = adb_poweroff,
.restore = adb_resume,
};
#endif
static struct platform_driver adb_pfdrv = {
.driver = {
.name = "adb",
#ifdef CONFIG_PM
.pm = &adb_dev_pm_ops,
#endif
},
};
static struct platform_device adb_pfdev = {
.name = "adb",
};
static int __init
adb_dummy_probe(struct platform_device *dev)
{
if (dev == &adb_pfdev)
return 0;
return -ENODEV;
}
static void __init
adbdev_init(void)
{
if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
pr_err("adb: unable to get major %d\n", ADB_MAJOR);
return;
}
if (class_register(&adb_dev_class))
return;
device_create(&adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
platform_device_register(&adb_pfdev);
platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
}
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