summaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/adb.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/macintosh/adb.c
downloadop-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/macintosh/adb.c')
-rw-r--r--drivers/macintosh/adb.c910
1 files changed, 910 insertions, 0 deletions
diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
new file mode 100644
index 0000000..7297c77
--- /dev/null
+++ b/drivers/macintosh/adb.c
@@ -0,0 +1,910 @@
+/*
+ * 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/config.h>
+#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.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 <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/devfs_fs_kernel.h>
+
+#include <asm/uaccess.h>
+#include <asm/semaphore.h>
+#ifdef CONFIG_PPC
+#include <asm/prom.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
+#if defined(CONFIG_ADB_PMU) || defined(CONFIG_ADB_PMU68K)
+ &via_pmu_driver,
+#endif
+#ifdef CONFIG_ADB_MACIO
+ &macio_adb_driver,
+#endif
+ NULL
+};
+
+static struct class_simple *adb_dev_class;
+
+struct adb_driver *adb_controller;
+struct notifier_block *adb_client_list = NULL;
+static int adb_got_sleep;
+static int adb_inited;
+static pid_t adb_probe_task_pid;
+static DECLARE_MUTEX(adb_probe_mutex);
+static struct completion adb_probe_task_comp;
+static int sleepy_trackpad;
+static int autopoll_devs;
+int __adb_probe_sync;
+
+#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 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, struct pt_regs *, int);
+ int original_address;
+ int handler_id;
+ int busy;
+} adb_handler[16];
+
+/*
+ * The adb_handler_sem 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 DECLARE_MUTEX(adb_handler_sem);
+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 __inline__ void adb_wait_ms(unsigned int ms)
+{
+ if (current->pid && adb_probe_task_pid &&
+ adb_probe_task_pid == current->pid)
+ msleep(ms);
+ else
+ mdelay(ms);
+}
+
+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;
+}
+
+/*
+ * This kernel task handles ADB probing. It dies once probing is
+ * completed.
+ */
+static int
+adb_probe_task(void *x)
+{
+ sigset_t blocked;
+
+ strcpy(current->comm, "kadbprobe");
+
+ sigfillset(&blocked);
+ sigprocmask(SIG_BLOCK, &blocked, NULL);
+ flush_signals(current);
+
+ printk(KERN_INFO "adb: starting probe task...\n");
+ do_adb_reset_bus();
+ printk(KERN_INFO "adb: finished probe task...\n");
+
+ adb_probe_task_pid = 0;
+ up(&adb_probe_mutex);
+
+ return 0;
+}
+
+static void
+__adb_probe_task(void *data)
+{
+ adb_probe_task_pid = kernel_thread(adb_probe_task, NULL, SIGCHLD | CLONE_KERNEL);
+}
+
+static DECLARE_WORK(adb_reset_work, __adb_probe_task, NULL);
+
+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;
+}
+
+int __init adb_init(void)
+{
+ struct adb_driver *driver;
+ int i;
+
+#ifdef CONFIG_PPC32
+ 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");
+ adb_controller = NULL;
+ } else {
+#ifdef CONFIG_PMAC_PBOOK
+ pmu_register_sleep_notifier(&adb_sleep_notifier);
+#endif /* CONFIG_PMAC_PBOOK */
+#ifdef CONFIG_PPC
+ if (machine_is_compatible("AAPL,PowerBook1998") ||
+ machine_is_compatible("PowerBook1,1"))
+ sleepy_trackpad = 1;
+#endif /* CONFIG_PPC */
+ init_completion(&adb_probe_task_comp);
+ adbdev_init();
+ 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;
+ /* We need to get a lock on the probe thread */
+ down(&adb_probe_mutex);
+ /* Stop autopoll */
+ if (adb_controller->autopoll)
+ adb_controller->autopoll(0);
+ ret = notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
+ if (ret & NOTIFY_STOP_MASK) {
+ up(&adb_probe_mutex);
+ return PBOOK_SLEEP_REFUSE;
+ }
+ break;
+ case PBOOK_SLEEP_REJECT:
+ if (adb_got_sleep) {
+ adb_got_sleep = 0;
+ up(&adb_probe_mutex);
+ adb_reset_bus();
+ }
+ break;
+
+ case PBOOK_SLEEP_NOW:
+ break;
+ case PBOOK_WAKE:
+ adb_got_sleep = 0;
+ up(&adb_probe_mutex);
+ adb_reset_bus();
+ break;
+ }
+ return PBOOK_SLEEP_OK;
+}
+#endif /* CONFIG_PMAC_PBOOK */
+
+static int
+do_adb_reset_bus(void)
+{
+ int ret, nret;
+
+ 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(autopoll_devs);
+ return -EBUSY;
+ }
+
+ if (sleepy_trackpad) {
+ /* Let the trackpad settle down */
+ adb_wait_ms(500);
+ }
+
+ down(&adb_handler_sem);
+ 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 */
+ adb_wait_ms(1500);
+ }
+
+ if (!ret) {
+ autopoll_devs = adb_scan_bus();
+ if (adb_controller->autopoll)
+ adb_controller->autopoll(autopoll_devs);
+ }
+ up(&adb_handler_sem);
+
+ 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();
+}
+
+static void
+adb_probe_wakeup(struct adb_request *req)
+{
+ complete(&adb_probe_task_comp);
+}
+
+/* Static request used during probe */
+static struct adb_request adb_sreq;
+static unsigned long adb_sreq_lock; // Use semaphore ! */
+
+int
+adb_request(struct adb_request *req, void (*done)(struct adb_request *),
+ int flags, int nbytes, ...)
+{
+ va_list list;
+ int i, use_sreq;
+ int rc;
+
+ if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
+ return -ENXIO;
+ if (nbytes < 1)
+ return -EINVAL;
+ if (req == NULL && (flags & ADBREQ_NOSEND))
+ return -EINVAL;
+
+ if (req == NULL) {
+ if (test_and_set_bit(0,&adb_sreq_lock)) {
+ printk("adb.c: Warning: contention on static request !\n");
+ return -EPERM;
+ }
+ req = &adb_sreq;
+ flags |= ADBREQ_SYNC;
+ use_sreq = 1;
+ } else
+ use_sreq = 0;
+ 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 send from the probe thread cause it to
+ * block. Beware that the "done" callback will be overriden !
+ */
+ if ((flags & ADBREQ_SYNC) &&
+ (current->pid && adb_probe_task_pid &&
+ adb_probe_task_pid == current->pid)) {
+ req->done = adb_probe_wakeup;
+ rc = adb_controller->send_request(req, 0);
+ if (rc || req->complete)
+ goto bail;
+ wait_for_completion(&adb_probe_task_comp);
+ rc = 0;
+ goto bail;
+ }
+
+ rc = adb_controller->send_request(req, flags & ADBREQ_SYNC);
+bail:
+ if (use_sreq)
+ clear_bit(0, &adb_sreq_lock);
+
+ return rc;
+}
+
+ /* 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, struct pt_regs *, int))
+{
+ int i;
+
+ down(&adb_handler_sem);
+ 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 != 0) {
+ printk(KERN_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;
+ }
+ }
+ up(&adb_handler_sem);
+ return ids->nids;
+}
+
+int
+adb_unregister(int index)
+{
+ int ret = -ENODEV;
+
+ down(&adb_handler_sem);
+ 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);
+ up(&adb_handler_sem);
+ return ret;
+}
+
+void
+adb_input(unsigned char *buf, int nb, struct pt_regs *regs, int autopoll)
+{
+ int i, id;
+ static int dump_adb_input = 0;
+ unsigned long flags;
+
+ void (*handler)(unsigned char *, int, struct pt_regs *, 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) {
+ printk(KERN_INFO "adb packet: ");
+ for (i = 0; i < nb; ++i)
+ printk(" %x", buf[i]);
+ printk(", 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, regs, 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;
+
+ down(&adb_handler_sem);
+ ret = try_handler_change(address, new_id);
+ up(&adb_handler_sem);
+ return ret;
+}
+
+int
+adb_get_infos(int address, int *original_address, int *handler_id)
+{
+ down(&adb_handler_sem);
+ *original_address = adb_handler[address].original_address;
+ *handler_id = adb_handler[address].handler_id;
+ up(&adb_handler_sem);
+
+ 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)
+ break;
+ down(&adb_handler_sem);
+ req->reply[0] = adb_handler[req->data[2]].original_address;
+ req->reply[1] = adb_handler[req->data[2]].handler_id;
+ up(&adb_handler_sem);
+ 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;
+
+ if (iminor(inode) > 0 || adb_controller == NULL)
+ return -ENXIO;
+ state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
+ if (state == 0)
+ return -ENOMEM;
+ 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;
+
+ return 0;
+}
+
+static int adb_release(struct inode *inode, struct file *file)
+{
+ struct adbdev_state *state = file->private_data;
+ unsigned long flags;
+
+ lock_kernel();
+ 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);
+ }
+ }
+ unlock_kernel();
+ 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;
+ wait_queue_t wait = __WAITQUEUE_INITIALIZER(wait,current);
+ unsigned long flags;
+
+ if (count < 2)
+ return -EINVAL;
+ if (count > sizeof(req->reply))
+ count = sizeof(req->reply);
+ if (!access_ok(VERIFY_WRITE, buf, count))
+ return -EFAULT;
+
+ req = NULL;
+ spin_lock_irqsave(&state->lock, flags);
+ add_wait_queue(&state->wait_queue, &wait);
+ 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);
+ }
+
+ 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;
+ if (!access_ok(VERIFY_READ, buf, count))
+ return -EFAULT;
+
+ req = (struct adb_request *) 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 struct file_operations adb_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .read = adb_read,
+ .write = adb_write,
+ .open = adb_open,
+ .release = adb_release,
+};
+
+static void
+adbdev_init(void)
+{
+ if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
+ printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
+ return;
+ }
+
+ devfs_mk_cdev(MKDEV(ADB_MAJOR, 0), S_IFCHR | S_IRUSR | S_IWUSR, "adb");
+
+ adb_dev_class = class_simple_create(THIS_MODULE, "adb");
+ if (IS_ERR(adb_dev_class)) {
+ return;
+ }
+ class_simple_device_add(adb_dev_class, MKDEV(ADB_MAJOR, 0), NULL, "adb");
+}
OpenPOWER on IntegriCloud