David Herrmann | cb99221 | 2011-11-17 14:12:01 +0100 | [diff] [blame] | 1 | /* |
| 2 | * HID driver for Nintendo Wiimote extension devices |
| 3 | * Copyright (c) 2011 David Herrmann |
| 4 | */ |
| 5 | |
| 6 | /* |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms of the GNU General Public License as published by the Free |
| 9 | * Software Foundation; either version 2 of the License, or (at your option) |
| 10 | * any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/atomic.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/workqueue.h> |
| 17 | #include "hid-wiimote.h" |
| 18 | |
| 19 | struct wiimote_ext { |
| 20 | struct wiimote_data *wdata; |
| 21 | struct work_struct worker; |
| 22 | |
| 23 | atomic_t opened; |
| 24 | atomic_t mp_opened; |
| 25 | bool plugged; |
| 26 | bool motionp; |
| 27 | __u8 ext_type; |
| 28 | }; |
| 29 | |
| 30 | enum wiiext_type { |
| 31 | WIIEXT_NONE, /* placeholder */ |
| 32 | WIIEXT_CLASSIC, /* Nintendo classic controller */ |
| 33 | WIIEXT_NUNCHUCK, /* Nintendo nunchuck controller */ |
| 34 | }; |
| 35 | |
David Herrmann | 82fb1b3 | 2011-11-17 14:12:02 +0100 | [diff] [blame^] | 36 | /* diable all extensions */ |
| 37 | static void ext_disable(struct wiimote_ext *ext) |
| 38 | { |
| 39 | unsigned long flags; |
| 40 | |
| 41 | spin_lock_irqsave(&ext->wdata->state.lock, flags); |
| 42 | ext->motionp = false; |
| 43 | ext->ext_type = WIIEXT_NONE; |
| 44 | spin_unlock_irqrestore(&ext->wdata->state.lock, flags); |
| 45 | } |
| 46 | |
| 47 | static bool motionp_read(struct wiimote_ext *ext) |
| 48 | { |
| 49 | return false; |
| 50 | } |
| 51 | |
| 52 | static __u8 ext_read(struct wiimote_ext *ext) |
| 53 | { |
| 54 | return WIIEXT_NONE; |
| 55 | } |
| 56 | |
| 57 | static void ext_enable(struct wiimote_ext *ext, bool motionp, __u8 ext_type) |
| 58 | { |
| 59 | unsigned long flags; |
| 60 | |
| 61 | spin_lock_irqsave(&ext->wdata->state.lock, flags); |
| 62 | ext->motionp = motionp; |
| 63 | ext->ext_type = ext_type; |
| 64 | spin_unlock_irqrestore(&ext->wdata->state.lock, flags); |
| 65 | } |
| 66 | |
David Herrmann | cb99221 | 2011-11-17 14:12:01 +0100 | [diff] [blame] | 67 | static void wiiext_worker(struct work_struct *work) |
| 68 | { |
| 69 | struct wiimote_ext *ext = container_of(work, struct wiimote_ext, |
| 70 | worker); |
David Herrmann | 82fb1b3 | 2011-11-17 14:12:02 +0100 | [diff] [blame^] | 71 | bool motionp; |
| 72 | __u8 ext_type; |
| 73 | |
| 74 | ext_disable(ext); |
| 75 | motionp = motionp_read(ext); |
| 76 | ext_type = ext_read(ext); |
| 77 | ext_enable(ext, motionp, ext_type); |
David Herrmann | cb99221 | 2011-11-17 14:12:01 +0100 | [diff] [blame] | 78 | } |
| 79 | |
| 80 | /* schedule work only once, otherwise mark for reschedule */ |
| 81 | static void wiiext_schedule(struct wiimote_ext *ext) |
| 82 | { |
| 83 | queue_work(system_nrt_wq, &ext->worker); |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Reacts on extension port events |
| 88 | * Whenever the driver gets an event from the wiimote that an extension has been |
| 89 | * plugged or unplugged, this funtion shall be called. It checks what extensions |
| 90 | * are connected and initializes and activates them. |
| 91 | * This can be called in atomic context. The initialization is done in a |
| 92 | * separate worker thread. The state.lock spinlock must be held by the caller. |
| 93 | */ |
| 94 | void wiiext_event(struct wiimote_data *wdata, bool plugged) |
| 95 | { |
| 96 | if (!wdata->ext) |
| 97 | return; |
| 98 | |
| 99 | if (wdata->ext->plugged == plugged) |
| 100 | return; |
| 101 | |
| 102 | wdata->ext->plugged = plugged; |
| 103 | /* |
| 104 | * We need to call wiiext_schedule(wdata->ext) here, however, the |
| 105 | * extension initialization logic is not fully understood and so |
| 106 | * automatic initialization is not supported, yet. |
| 107 | */ |
| 108 | } |
| 109 | |
| 110 | /* |
| 111 | * Returns true if the current DRM mode should contain extension data and false |
| 112 | * if there is no interest in extension data. |
| 113 | * All supported extensions send 6 byte extension data so any DRM that contains |
| 114 | * extension bytes is fine. |
| 115 | * The caller must hold the state.lock spinlock. |
| 116 | */ |
| 117 | bool wiiext_active(struct wiimote_data *wdata) |
| 118 | { |
| 119 | if (!wdata->ext) |
| 120 | return false; |
| 121 | |
| 122 | return wdata->ext->motionp || wdata->ext->ext_type; |
| 123 | } |
| 124 | |
| 125 | /* Initializes the extension driver of a wiimote */ |
| 126 | int wiiext_init(struct wiimote_data *wdata) |
| 127 | { |
| 128 | struct wiimote_ext *ext; |
| 129 | unsigned long flags; |
| 130 | |
| 131 | ext = kzalloc(sizeof(*ext), GFP_KERNEL); |
| 132 | if (!ext) |
| 133 | return -ENOMEM; |
| 134 | |
| 135 | ext->wdata = wdata; |
| 136 | INIT_WORK(&ext->worker, wiiext_worker); |
| 137 | |
| 138 | spin_lock_irqsave(&wdata->state.lock, flags); |
| 139 | wdata->ext = ext; |
| 140 | spin_unlock_irqrestore(&wdata->state.lock, flags); |
| 141 | |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | /* Deinitializes the extension driver of a wiimote */ |
| 146 | void wiiext_deinit(struct wiimote_data *wdata) |
| 147 | { |
| 148 | struct wiimote_ext *ext = wdata->ext; |
| 149 | unsigned long flags; |
| 150 | |
| 151 | if (!ext) |
| 152 | return; |
| 153 | |
| 154 | /* |
| 155 | * We first unset wdata->ext to avoid further input from the wiimote |
| 156 | * core. The worker thread does not access this pointer so it is not |
| 157 | * affected by this. |
| 158 | * We kill the worker after this so it does not get respawned during |
| 159 | * deinitialization. |
| 160 | */ |
| 161 | |
| 162 | spin_lock_irqsave(&wdata->state.lock, flags); |
| 163 | wdata->ext = NULL; |
| 164 | spin_unlock_irqrestore(&wdata->state.lock, flags); |
| 165 | |
| 166 | cancel_work_sync(&ext->worker); |
| 167 | kfree(ext); |
| 168 | } |