![Arjan van de Ven](/assets/img/avatar_default.png)
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. [akpm@sdl.org: dvb fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
910 lines
20 KiB
C
910 lines
20 KiB
C
/*
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* Device driver for the Apple Desktop Bus
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* and the /dev/adb device on macintoshes.
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*
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* Copyright (C) 1996 Paul Mackerras.
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*
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* Modified to declare controllers as structures, added
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* client notification of bus reset and handles PowerBook
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* sleep, by Benjamin Herrenschmidt.
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*
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* To do:
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*
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* - /sys/bus/adb to list the devices and infos
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* - more /dev/adb to allow userland to receive the
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* flow of auto-polling datas from a given device.
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* - move bus probe to a kernel thread
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*/
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/smp_lock.h>
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#include <linux/adb.h>
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#include <linux/cuda.h>
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#include <linux/pmu.h>
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#include <linux/notifier.h>
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#include <linux/wait.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/spinlock.h>
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#include <linux/completion.h>
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#include <linux/device.h>
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#include <asm/uaccess.h>
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#include <asm/semaphore.h>
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#ifdef CONFIG_PPC
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#include <asm/prom.h>
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#include <asm/machdep.h>
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#endif
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EXPORT_SYMBOL(adb_controller);
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EXPORT_SYMBOL(adb_client_list);
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extern struct adb_driver via_macii_driver;
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extern struct adb_driver via_maciisi_driver;
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extern struct adb_driver via_cuda_driver;
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extern struct adb_driver adb_iop_driver;
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extern struct adb_driver via_pmu_driver;
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extern struct adb_driver macio_adb_driver;
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static struct adb_driver *adb_driver_list[] = {
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#ifdef CONFIG_ADB_MACII
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&via_macii_driver,
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#endif
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#ifdef CONFIG_ADB_MACIISI
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&via_maciisi_driver,
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#endif
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#ifdef CONFIG_ADB_CUDA
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&via_cuda_driver,
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#endif
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#ifdef CONFIG_ADB_IOP
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&adb_iop_driver,
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#endif
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#if defined(CONFIG_ADB_PMU) || defined(CONFIG_ADB_PMU68K)
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&via_pmu_driver,
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#endif
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#ifdef CONFIG_ADB_MACIO
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&macio_adb_driver,
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#endif
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NULL
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};
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static struct class *adb_dev_class;
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struct adb_driver *adb_controller;
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BLOCKING_NOTIFIER_HEAD(adb_client_list);
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static int adb_got_sleep;
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static int adb_inited;
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static pid_t adb_probe_task_pid;
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static DECLARE_MUTEX(adb_probe_mutex);
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static struct completion adb_probe_task_comp;
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static int sleepy_trackpad;
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static int autopoll_devs;
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int __adb_probe_sync;
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#ifdef CONFIG_PM
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static int adb_notify_sleep(struct pmu_sleep_notifier *self, int when);
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static struct pmu_sleep_notifier adb_sleep_notifier = {
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adb_notify_sleep,
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SLEEP_LEVEL_ADB,
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};
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#endif
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static int adb_scan_bus(void);
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static int do_adb_reset_bus(void);
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static void adbdev_init(void);
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static int try_handler_change(int, int);
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static struct adb_handler {
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void (*handler)(unsigned char *, int, int);
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int original_address;
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int handler_id;
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int busy;
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} adb_handler[16];
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/*
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* The adb_handler_sem mutex protects all accesses to the original_address
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* and handler_id fields of adb_handler[i] for all i, and changes to the
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* handler field.
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* Accesses to the handler field are protected by the adb_handler_lock
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* rwlock. It is held across all calls to any handler, so that by the
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* time adb_unregister returns, we know that the old handler isn't being
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* called.
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*/
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static DECLARE_MUTEX(adb_handler_sem);
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static DEFINE_RWLOCK(adb_handler_lock);
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#if 0
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static void printADBreply(struct adb_request *req)
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{
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int i;
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printk("adb reply (%d)", req->reply_len);
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for(i = 0; i < req->reply_len; i++)
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printk(" %x", req->reply[i]);
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printk("\n");
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}
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#endif
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static __inline__ void adb_wait_ms(unsigned int ms)
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{
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if (current->pid && adb_probe_task_pid &&
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adb_probe_task_pid == current->pid)
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msleep(ms);
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else
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mdelay(ms);
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}
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static int adb_scan_bus(void)
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{
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int i, highFree=0, noMovement;
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int devmask = 0;
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struct adb_request req;
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/* assumes adb_handler[] is all zeroes at this point */
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for (i = 1; i < 16; i++) {
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/* see if there is anything at address i */
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adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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(i << 4) | 0xf);
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if (req.reply_len > 1)
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/* one or more devices at this address */
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adb_handler[i].original_address = i;
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else if (i > highFree)
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highFree = i;
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}
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/* Note we reset noMovement to 0 each time we move a device */
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for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
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for (i = 1; i < 16; i++) {
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if (adb_handler[i].original_address == 0)
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continue;
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/*
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* Send a "talk register 3" command to address i
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* to provoke a collision if there is more than
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* one device at this address.
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*/
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adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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(i << 4) | 0xf);
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/*
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* Move the device(s) which didn't detect a
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* collision to address `highFree'. Hopefully
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* this only moves one device.
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*/
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adb_request(&req, NULL, ADBREQ_SYNC, 3,
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(i<< 4) | 0xb, (highFree | 0x60), 0xfe);
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/*
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* See if anybody actually moved. This is suggested
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* by HW TechNote 01:
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*
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* http://developer.apple.com/technotes/hw/hw_01.html
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*/
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adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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(highFree << 4) | 0xf);
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if (req.reply_len <= 1) continue;
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/*
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* Test whether there are any device(s) left
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* at address i.
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*/
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adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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(i << 4) | 0xf);
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if (req.reply_len > 1) {
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/*
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* There are still one or more devices
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* left at address i. Register the one(s)
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* we moved to `highFree', and find a new
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* value for highFree.
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*/
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adb_handler[highFree].original_address =
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adb_handler[i].original_address;
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while (highFree > 0 &&
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adb_handler[highFree].original_address)
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highFree--;
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if (highFree <= 0)
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break;
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noMovement = 0;
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}
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else {
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/*
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* No devices left at address i; move the
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* one(s) we moved to `highFree' back to i.
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*/
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adb_request(&req, NULL, ADBREQ_SYNC, 3,
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(highFree << 4) | 0xb,
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(i | 0x60), 0xfe);
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}
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}
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}
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/* Now fill in the handler_id field of the adb_handler entries. */
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printk(KERN_DEBUG "adb devices:");
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for (i = 1; i < 16; i++) {
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if (adb_handler[i].original_address == 0)
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continue;
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adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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(i << 4) | 0xf);
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adb_handler[i].handler_id = req.reply[2];
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printk(" [%d]: %d %x", i, adb_handler[i].original_address,
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adb_handler[i].handler_id);
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devmask |= 1 << i;
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}
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printk("\n");
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return devmask;
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}
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/*
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* This kernel task handles ADB probing. It dies once probing is
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* completed.
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*/
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static int
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adb_probe_task(void *x)
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{
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sigset_t blocked;
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strcpy(current->comm, "kadbprobe");
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sigfillset(&blocked);
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sigprocmask(SIG_BLOCK, &blocked, NULL);
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flush_signals(current);
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printk(KERN_INFO "adb: starting probe task...\n");
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do_adb_reset_bus();
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printk(KERN_INFO "adb: finished probe task...\n");
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adb_probe_task_pid = 0;
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up(&adb_probe_mutex);
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return 0;
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}
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static void
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__adb_probe_task(struct work_struct *bullshit)
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{
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adb_probe_task_pid = kernel_thread(adb_probe_task, NULL, SIGCHLD | CLONE_KERNEL);
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}
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static DECLARE_WORK(adb_reset_work, __adb_probe_task);
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int
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adb_reset_bus(void)
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{
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if (__adb_probe_sync) {
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do_adb_reset_bus();
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return 0;
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}
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down(&adb_probe_mutex);
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schedule_work(&adb_reset_work);
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return 0;
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}
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int __init adb_init(void)
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{
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struct adb_driver *driver;
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int i;
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#ifdef CONFIG_PPC32
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if (!machine_is(chrp) && !machine_is(powermac))
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return 0;
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#endif
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#ifdef CONFIG_MAC
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if (!MACH_IS_MAC)
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return 0;
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#endif
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/* xmon may do early-init */
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if (adb_inited)
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return 0;
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adb_inited = 1;
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adb_controller = NULL;
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i = 0;
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while ((driver = adb_driver_list[i++]) != NULL) {
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if (!driver->probe()) {
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adb_controller = driver;
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break;
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}
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}
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if ((adb_controller == NULL) || adb_controller->init()) {
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printk(KERN_WARNING "Warning: no ADB interface detected\n");
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adb_controller = NULL;
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} else {
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#ifdef CONFIG_PM
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pmu_register_sleep_notifier(&adb_sleep_notifier);
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#endif /* CONFIG_PM */
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#ifdef CONFIG_PPC
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if (machine_is_compatible("AAPL,PowerBook1998") ||
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machine_is_compatible("PowerBook1,1"))
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sleepy_trackpad = 1;
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#endif /* CONFIG_PPC */
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init_completion(&adb_probe_task_comp);
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adbdev_init();
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adb_reset_bus();
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}
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return 0;
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}
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__initcall(adb_init);
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#ifdef CONFIG_PM
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/*
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* notify clients before sleep and reset bus afterwards
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*/
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int
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adb_notify_sleep(struct pmu_sleep_notifier *self, int when)
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{
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int ret;
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switch (when) {
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case PBOOK_SLEEP_REQUEST:
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adb_got_sleep = 1;
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/* We need to get a lock on the probe thread */
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down(&adb_probe_mutex);
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/* Stop autopoll */
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if (adb_controller->autopoll)
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adb_controller->autopoll(0);
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ret = blocking_notifier_call_chain(&adb_client_list,
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ADB_MSG_POWERDOWN, NULL);
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if (ret & NOTIFY_STOP_MASK) {
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up(&adb_probe_mutex);
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return PBOOK_SLEEP_REFUSE;
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}
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break;
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case PBOOK_SLEEP_REJECT:
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if (adb_got_sleep) {
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adb_got_sleep = 0;
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up(&adb_probe_mutex);
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adb_reset_bus();
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}
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break;
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case PBOOK_SLEEP_NOW:
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break;
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case PBOOK_WAKE:
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adb_got_sleep = 0;
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up(&adb_probe_mutex);
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adb_reset_bus();
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break;
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}
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return PBOOK_SLEEP_OK;
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}
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#endif /* CONFIG_PM */
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static int
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do_adb_reset_bus(void)
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{
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int ret, nret;
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if (adb_controller == NULL)
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return -ENXIO;
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if (adb_controller->autopoll)
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adb_controller->autopoll(0);
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nret = blocking_notifier_call_chain(&adb_client_list,
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ADB_MSG_PRE_RESET, NULL);
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if (nret & NOTIFY_STOP_MASK) {
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if (adb_controller->autopoll)
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adb_controller->autopoll(autopoll_devs);
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return -EBUSY;
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}
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if (sleepy_trackpad) {
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/* Let the trackpad settle down */
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adb_wait_ms(500);
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}
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down(&adb_handler_sem);
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write_lock_irq(&adb_handler_lock);
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memset(adb_handler, 0, sizeof(adb_handler));
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write_unlock_irq(&adb_handler_lock);
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/* That one is still a bit synchronous, oh well... */
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if (adb_controller->reset_bus)
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ret = adb_controller->reset_bus();
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else
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ret = 0;
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if (sleepy_trackpad) {
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/* Let the trackpad settle down */
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adb_wait_ms(1500);
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}
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if (!ret) {
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autopoll_devs = adb_scan_bus();
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if (adb_controller->autopoll)
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adb_controller->autopoll(autopoll_devs);
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}
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up(&adb_handler_sem);
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nret = blocking_notifier_call_chain(&adb_client_list,
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ADB_MSG_POST_RESET, NULL);
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if (nret & NOTIFY_STOP_MASK)
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return -EBUSY;
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return ret;
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}
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void
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adb_poll(void)
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{
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if ((adb_controller == NULL)||(adb_controller->poll == NULL))
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return;
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adb_controller->poll();
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}
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static void
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adb_probe_wakeup(struct adb_request *req)
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{
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complete(&adb_probe_task_comp);
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}
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/* Static request used during probe */
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static struct adb_request adb_sreq;
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static unsigned long adb_sreq_lock; // Use semaphore ! */
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int
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adb_request(struct adb_request *req, void (*done)(struct adb_request *),
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int flags, int nbytes, ...)
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{
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va_list list;
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int i, use_sreq;
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int rc;
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if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
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return -ENXIO;
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if (nbytes < 1)
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return -EINVAL;
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if (req == NULL && (flags & ADBREQ_NOSEND))
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return -EINVAL;
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if (req == NULL) {
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if (test_and_set_bit(0,&adb_sreq_lock)) {
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printk("adb.c: Warning: contention on static request !\n");
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return -EPERM;
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}
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req = &adb_sreq;
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flags |= ADBREQ_SYNC;
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use_sreq = 1;
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} else
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use_sreq = 0;
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req->nbytes = nbytes+1;
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req->done = done;
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req->reply_expected = flags & ADBREQ_REPLY;
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req->data[0] = ADB_PACKET;
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va_start(list, nbytes);
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for (i = 0; i < nbytes; ++i)
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req->data[i+1] = va_arg(list, int);
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va_end(list);
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if (flags & ADBREQ_NOSEND)
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return 0;
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/* Synchronous requests send from the probe thread cause it to
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* block. Beware that the "done" callback will be overriden !
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*/
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if ((flags & ADBREQ_SYNC) &&
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(current->pid && adb_probe_task_pid &&
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adb_probe_task_pid == current->pid)) {
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req->done = adb_probe_wakeup;
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rc = adb_controller->send_request(req, 0);
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if (rc || req->complete)
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goto bail;
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wait_for_completion(&adb_probe_task_comp);
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rc = 0;
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goto bail;
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}
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rc = adb_controller->send_request(req, flags & ADBREQ_SYNC);
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bail:
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if (use_sreq)
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clear_bit(0, &adb_sreq_lock);
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return rc;
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}
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/* Ultimately this should return the number of devices with
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the given default id.
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And it does it now ! Note: changed behaviour: This function
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will now register if default_id _and_ handler_id both match
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but handler_id can be left to 0 to match with default_id only.
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When handler_id is set, this function will try to adjust
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the handler_id id it doesn't match. */
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int
|
|
adb_register(int default_id, int handler_id, struct adb_ids *ids,
|
|
void (*handler)(unsigned char *, int, 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, int autopoll)
|
|
{
|
|
int i, id;
|
|
static int dump_adb_input = 0;
|
|
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) {
|
|
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, 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 = 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,
|
|
};
|
|
|
|
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;
|
|
}
|
|
|
|
adb_dev_class = class_create(THIS_MODULE, "adb");
|
|
if (IS_ERR(adb_dev_class))
|
|
return;
|
|
class_device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
|
|
}
|