From 509ca1a9383601fdc5612d3d3ba5b981f6eb6c8b Mon Sep 17 00:00:00 2001 From: Anssi Hannula Date: Wed, 19 Jul 2006 01:40:22 -0400 Subject: [PATCH] Input: implement new force feedback interface Implement a new force feedback interface, in which all non-driver-specific operations are separated to a common module. This includes handling effect type validations, locking, etc. The effects are now file descriptor specific instead of the previous strange half-process half-fd specific behaviour. The effect memory of devices is not emptied if the root user opens and closes the device while another user is using effects. This is a minor change and most likely no force feedback aware programs are affected by this negatively. Otherwise the userspace interface is left unaltered. Signed-off-by: Anssi Hannula Signed-off-by: Dmitry Torokhov --- drivers/input/Makefile | 2 +- drivers/input/evdev.c | 32 ++-- drivers/input/ff-core.c | 367 ++++++++++++++++++++++++++++++++++++++++ drivers/input/input.c | 6 + include/linux/input.h | 61 +++++++ 5 files changed, 450 insertions(+), 18 deletions(-) create mode 100644 drivers/input/ff-core.c diff --git a/drivers/input/Makefile b/drivers/input/Makefile index e539a309df..abdc9d4357 100644 --- a/drivers/input/Makefile +++ b/drivers/input/Makefile @@ -5,7 +5,7 @@ # Each configuration option enables a list of files. obj-$(CONFIG_INPUT) += input-core.o -input-core-objs := input.o +input-core-objs := input.o ff-core.o obj-$(CONFIG_INPUT_MOUSEDEV) += mousedev.o obj-$(CONFIG_INPUT_JOYDEV) += joydev.o diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 4bf48188cc..12c7ab876c 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -391,8 +391,10 @@ static long evdev_ioctl_handler(struct file *file, unsigned int cmd, struct evdev *evdev = list->evdev; struct input_dev *dev = evdev->handle.dev; struct input_absinfo abs; + struct ff_effect effect; int __user *ip = (int __user *)p; int i, t, u, v; + int error; if (!evdev->exist) return -ENODEV; @@ -460,27 +462,22 @@ static long evdev_ioctl_handler(struct file *file, unsigned int cmd, return 0; case EVIOCSFF: - if (dev->upload_effect) { - struct ff_effect effect; - int err; - - if (copy_from_user(&effect, p, sizeof(effect))) - return -EFAULT; - err = dev->upload_effect(dev, &effect); - if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) - return -EFAULT; - return err; - } else - return -ENOSYS; + if (copy_from_user(&effect, p, sizeof(effect))) + return -EFAULT; - case EVIOCRMFF: - if (!dev->erase_effect) - return -ENOSYS; + error = input_ff_upload(dev, &effect, file); - return dev->erase_effect(dev, (int)(unsigned long) p); + if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) + return -EFAULT; + + return error; + + case EVIOCRMFF: + return input_ff_erase(dev, (int)(unsigned long) p, file); case EVIOCGEFFECTS: - if (put_user(dev->ff_effects_max, ip)) + i = test_bit(EV_FF, dev->evbit) ? dev->ff->max_effects : 0; + if (put_user(i, ip)) return -EFAULT; return 0; @@ -669,6 +666,7 @@ static void evdev_disconnect(struct input_handle *handle) evdev->exist = 0; if (evdev->open) { + input_flush_device(handle, NULL); input_close_device(handle); wake_up_interruptible(&evdev->wait); list_for_each_entry(list, &evdev->list, node) diff --git a/drivers/input/ff-core.c b/drivers/input/ff-core.c new file mode 100644 index 0000000000..35656cadc9 --- /dev/null +++ b/drivers/input/ff-core.c @@ -0,0 +1,367 @@ +/* + * Force feedback support for Linux input subsystem + * + * Copyright (c) 2006 Anssi Hannula + * Copyright (c) 2006 Dmitry Torokhov + */ + +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* #define DEBUG */ + +#define debug(format, arg...) pr_debug("ff-core: " format "\n", ## arg) + +#include +#include +#include + +/* + * Check that the effect_id is a valid effect and whether the user + * is the owner + */ +static int check_effect_access(struct ff_device *ff, int effect_id, + struct file *file) +{ + if (effect_id < 0 || effect_id >= ff->max_effects || + !ff->effect_owners[effect_id]) + return -EINVAL; + + if (file && ff->effect_owners[effect_id] != file) + return -EACCES; + + return 0; +} + +/* + * Checks whether 2 effects can be combined together + */ +static inline int check_effects_compatible(struct ff_effect *e1, + struct ff_effect *e2) +{ + return e1->type == e2->type && + (e1->type != FF_PERIODIC || + e1->u.periodic.waveform == e2->u.periodic.waveform); +} + +/* + * Convert an effect into compatible one + */ +static int compat_effect(struct ff_device *ff, struct ff_effect *effect) +{ + int magnitude; + + switch (effect->type) { + case FF_RUMBLE: + if (!test_bit(FF_PERIODIC, ff->ffbit)) + return -EINVAL; + + /* + * calculate manginude of sine wave as average of rumble's + * 2/3 of strong magnitude and 1/3 of weak magnitude + */ + magnitude = effect->u.rumble.strong_magnitude / 3 + + effect->u.rumble.weak_magnitude / 6; + + effect->type = FF_PERIODIC; + effect->u.periodic.waveform = FF_SINE; + effect->u.periodic.period = 50; + effect->u.periodic.magnitude = max(magnitude, 0x7fff); + effect->u.periodic.offset = 0; + effect->u.periodic.phase = 0; + effect->u.periodic.envelope.attack_length = 0; + effect->u.periodic.envelope.attack_level = 0; + effect->u.periodic.envelope.fade_length = 0; + effect->u.periodic.envelope.fade_level = 0; + + return 0; + + default: + /* Let driver handle conversion */ + return 0; + } +} + +/** + * input_ff_upload() - upload effect into force-feedback device + * @dev: input device + * @effect: effect to be uploaded + * @file: owner of the effect + */ +int input_ff_upload(struct input_dev *dev, struct ff_effect *effect, + struct file *file) +{ + struct ff_device *ff = dev->ff; + struct ff_effect *old; + int ret = 0; + int id; + + if (!test_bit(EV_FF, dev->evbit)) + return -ENOSYS; + + if (effect->type < FF_EFFECT_MIN || effect->type > FF_EFFECT_MAX || + !test_bit(effect->type, dev->ffbit)) { + debug("invalid or not supported effect type in upload"); + return -EINVAL; + } + + if (effect->type == FF_PERIODIC && + (effect->u.periodic.waveform < FF_WAVEFORM_MIN || + effect->u.periodic.waveform > FF_WAVEFORM_MAX || + !test_bit(effect->u.periodic.waveform, dev->ffbit))) { + debug("invalid or not supported wave form in upload"); + return -EINVAL; + } + + if (!test_bit(effect->type, ff->ffbit)) { + ret = compat_effect(ff, effect); + if (ret) + return ret; + } + + mutex_lock(&ff->mutex); + + if (effect->id == -1) { + for (id = 0; id < ff->max_effects; id++) + if (!ff->effect_owners[id]) + break; + + if (id >= ff->max_effects) { + ret = -ENOSPC; + goto out; + } + + effect->id = id; + old = NULL; + + } else { + id = effect->id; + + ret = check_effect_access(ff, id, file); + if (ret) + goto out; + + old = &ff->effects[id]; + + if (!check_effects_compatible(effect, old)) { + ret = -EINVAL; + goto out; + } + } + + ret = ff->upload(dev, effect, old); + if (ret) + goto out; + + ff->effects[id] = *effect; + ff->effect_owners[id] = file; + + out: + mutex_unlock(&ff->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(input_ff_upload); + +/* + * Erases the effect if the requester is also the effect owner. The mutex + * should already be locked before calling this function. + */ +static int erase_effect(struct input_dev *dev, int effect_id, + struct file *file) +{ + struct ff_device *ff = dev->ff; + int error; + + error = check_effect_access(ff, effect_id, file); + if (error) + return error; + + ff->playback(dev, effect_id, 0); + + if (ff->erase) { + error = ff->erase(dev, effect_id); + if (error) + return error; + } + + ff->effect_owners[effect_id] = NULL; + + return 0; +} + +/** + * input_ff_erase - erase an effect from device + * @dev: input device to erase effect from + * @effect_id: id of the ffect to be erased + * @file: purported owner of the request + * + * This function erases a force-feedback effect from specified device. + * The effect will only be erased if it was uploaded through the same + * file handle that is requesting erase. + */ +int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file) +{ + struct ff_device *ff = dev->ff; + int ret; + + if (!test_bit(EV_FF, dev->evbit)) + return -ENOSYS; + + mutex_lock(&ff->mutex); + ret = erase_effect(dev, effect_id, file); + mutex_unlock(&ff->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(input_ff_erase); + +/* + * flush_effects - erase all effects owned by a file handle + */ +static int flush_effects(struct input_dev *dev, struct file *file) +{ + struct ff_device *ff = dev->ff; + int i; + + debug("flushing now"); + + mutex_lock(&ff->mutex); + + for (i = 0; i < ff->max_effects; i++) + erase_effect(dev, i, file); + + mutex_unlock(&ff->mutex); + + return 0; +} + +/** + * input_ff_event() - generic handler for force-feedback events + * @dev: input device to send the effect to + * @type: event type (anything but EV_FF is ignored) + * @code: event code + * @value: event value + */ +int input_ff_event(struct input_dev *dev, unsigned int type, + unsigned int code, int value) +{ + struct ff_device *ff = dev->ff; + + if (type != EV_FF) + return 0; + + mutex_lock(&ff->mutex); + + switch (code) { + case FF_GAIN: + if (!test_bit(FF_GAIN, dev->ffbit) || value > 0xffff) + break; + + ff->set_gain(dev, value); + break; + + case FF_AUTOCENTER: + if (!test_bit(FF_AUTOCENTER, dev->ffbit) || value > 0xffff) + break; + + ff->set_autocenter(dev, value); + break; + + default: + ff->playback(dev, code, value); + break; + } + + mutex_unlock(&ff->mutex); + return 0; +} +EXPORT_SYMBOL_GPL(input_ff_event); + +/** + * input_ff_create() - create force-feedback device + * @dev: input device supporting force-feedback + * @max_effects: maximum number of effects supported by the device + * + * This function allocates all necessary memory for a force feedback + * portion of an input device and installs all default handlers. + * @dev->ffbit should be already set up before calling this function. + * Once ff device is created you need to setup its upload, erase, + * playback and other handlers before registering input device + */ +int input_ff_create(struct input_dev *dev, int max_effects) +{ + struct ff_device *ff; + int i; + + if (!max_effects) { + printk(KERN_ERR + "ff-core: cannot allocate device without any effects\n"); + return -EINVAL; + } + + ff = kzalloc(sizeof(struct ff_device) + + max_effects * sizeof(struct file *), GFP_KERNEL); + if (!ff) + return -ENOMEM; + + ff->effects = kcalloc(max_effects, sizeof(struct ff_effect), + GFP_KERNEL); + if (!ff->effects) { + kfree(ff); + return -ENOMEM; + } + + ff->max_effects = max_effects; + mutex_init(&ff->mutex); + + dev->ff = ff; + dev->flush = flush_effects; + dev->event = input_ff_event; + set_bit(EV_FF, dev->evbit); + + /* Copy "true" bits into ff device bitmap */ + for (i = 0; i <= FF_MAX; i++) + if (test_bit(i, dev->ffbit)) + set_bit(i, ff->ffbit); + + /* we can emulate RUMBLE with periodic effects */ + if (test_bit(FF_PERIODIC, ff->ffbit)) + set_bit(FF_RUMBLE, dev->ffbit); + + return 0; +} +EXPORT_SYMBOL_GPL(input_ff_create); + +/** + * input_ff_free() - frees force feedback portion of input device + * @dev: input device supporintg force feedback + * + * This function is only needed in error path as input core will + * automatically free force feedback structures when device is + * destroyed. + */ +void input_ff_destroy(struct input_dev *dev) +{ + clear_bit(EV_FF, dev->evbit); + if (dev->ff) { + if (dev->ff->destroy) + dev->ff->destroy(dev->ff); + kfree(dev->ff->private); + kfree(dev->ff); + dev->ff = NULL; + } +} +EXPORT_SYMBOL_GPL(input_ff_destroy); diff --git a/drivers/input/input.c b/drivers/input/input.c index 9cb4b9a54f..1fc0517e94 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -176,6 +176,10 @@ void input_event(struct input_dev *dev, unsigned int type, unsigned int code, in break; case EV_FF: + + if (value < 0) + return; + if (dev->event) dev->event(dev, type, code, value); break; @@ -762,7 +766,9 @@ static void input_dev_release(struct class_device *class_dev) { struct input_dev *dev = to_input_dev(class_dev); + input_ff_destroy(dev); kfree(dev); + module_put(THIS_MODULE); } diff --git a/include/linux/input.h b/include/linux/input.h index b3253ab72f..81c6ea5afe 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -784,6 +784,9 @@ struct ff_effect { #define FF_INERTIA 0x56 #define FF_RAMP 0x57 +#define FF_EFFECT_MIN FF_RUMBLE +#define FF_EFFECT_MAX FF_RAMP + /* * Force feedback periodic effect types */ @@ -795,6 +798,9 @@ struct ff_effect { #define FF_SAW_DOWN 0x5c #define FF_CUSTOM 0x5d +#define FF_WAVEFORM_MIN FF_SQUARE +#define FF_WAVEFORM_MAX FF_CUSTOM + /* * Set ff device properties */ @@ -870,6 +876,8 @@ struct input_dev { unsigned int keycodesize; void *keycode; + struct ff_device *ff; + unsigned int repeat_key; struct timer_list timer; @@ -1108,5 +1116,58 @@ static inline void input_set_abs_params(struct input_dev *dev, int axis, int min extern struct class input_class; +/** + * struct ff_device - force-feedback part of an input device + * @upload: Called to upload an new effect into device + * @erase: Called to erase an effect from device + * @playback: Called to request device to start playing specified effect + * @set_gain: Called to set specified gain + * @set_autocenter: Called to auto-center device + * @destroy: called by input core when parent input device is being + * destroyed + * @private: driver-specific data, will be freed automatically + * @ffbit: bitmap of force feedback capabilities truly supported by + * device (not emulated like ones in input_dev->ffbit) + * @mutex: mutex for serializing access to the device + * @max_effects: maximum number of effects supported by device + * @effects: pointer to an array of effects currently loaded into device + * @effect_owners: array of effect owners; when file handle owning + * an effect gets closed the effcet is automatically erased + * + * Every force-feedback device must implement upload() and playback() + * methods; erase() is optional. set_gain() and set_autocenter() need + * only be implemented if driver sets up FF_GAIN and FF_AUTOCENTER + * bits. + */ +struct ff_device { + int (*upload)(struct input_dev *dev, struct ff_effect *effect, + struct ff_effect *old); + int (*erase)(struct input_dev *dev, int effect_id); + + int (*playback)(struct input_dev *dev, int effect_id, int value); + void (*set_gain)(struct input_dev *dev, u16 gain); + void (*set_autocenter)(struct input_dev *dev, u16 magnitude); + + void (*destroy)(struct ff_device *); + + void *private; + + unsigned long ffbit[NBITS(FF_MAX)]; + + struct mutex mutex; + + int max_effects; + struct ff_effect *effects; + struct file *effect_owners[]; +}; + +int input_ff_create(struct input_dev *dev, int max_effects); +void input_ff_destroy(struct input_dev *dev); + +int input_ff_event(struct input_dev *dev, unsigned int type, unsigned int code, int value); + +int input_ff_upload(struct input_dev *dev, struct ff_effect *effect, struct file *file); +int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file); + #endif #endif -- 2.39.5