|  | /* | 
|  | *  PID Force feedback support for hid devices. | 
|  | * | 
|  | *  Copyright (c) 2002 Rodrigo Damazio. | 
|  | *  Portions by Johann Deneux and Bjorn Augustson | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * 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 | 
|  | * | 
|  | * Should you need to contact me, the author, you can do so by | 
|  | * e-mail - mail your message to <rdamazio@lsi.usp.br> | 
|  | */ | 
|  |  | 
|  | #include <linux/config.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/smp_lock.h> | 
|  | #include <linux/spinlock.h> | 
|  | #include <linux/input.h> | 
|  | #include <linux/usb.h> | 
|  | #include "hid.h" | 
|  | #include "pid.h" | 
|  |  | 
|  | #define DEBUG | 
|  |  | 
|  | #define CHECK_OWNERSHIP(i, hid_pid)	\ | 
|  | ((i) < FF_EFFECTS_MAX && i >= 0 && \ | 
|  | test_bit(FF_PID_FLAGS_USED, &hid_pid->effects[(i)].flags) && \ | 
|  | (current->pid == 0 || \ | 
|  | (hid_pid)->effects[(i)].owner == current->pid)) | 
|  |  | 
|  | /* Called when a transfer is completed */ | 
|  | static void hid_pid_ctrl_out(struct urb *u, struct pt_regs *regs) | 
|  | { | 
|  | dev_dbg(&u->dev->dev, "hid_pid_ctrl_out - Transfer Completed\n"); | 
|  | } | 
|  |  | 
|  | static void hid_pid_exit(struct hid_device *hid) | 
|  | { | 
|  | struct hid_ff_pid *private = hid->ff_private; | 
|  |  | 
|  | if (private->urbffout) { | 
|  | usb_kill_urb(private->urbffout); | 
|  | usb_free_urb(private->urbffout); | 
|  | } | 
|  | } | 
|  |  | 
|  | static int pid_upload_periodic(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) | 
|  | { | 
|  | dev_info(&pid->hid->dev->dev, "requested periodic force upload\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int pid_upload_constant(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) | 
|  | { | 
|  | dev_info(&pid->hid->dev->dev, "requested constant force upload\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int pid_upload_condition(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) | 
|  | { | 
|  | dev_info(&pid->hid->dev->dev, "requested Condition force upload\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int pid_upload_ramp(struct hid_ff_pid *pid, struct ff_effect *effect, int is_update) | 
|  | { | 
|  | dev_info(&pid->hid->dev->dev, "request ramp force upload\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int hid_pid_event(struct hid_device *hid, struct input_dev *input, | 
|  | unsigned int type, unsigned int code, int value) | 
|  | { | 
|  | dev_dbg(&hid->dev->dev, "PID event received: type=%d,code=%d,value=%d.\n", type, code, value); | 
|  |  | 
|  | if (type != EV_FF) | 
|  | return -1; | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* Lock must be held by caller */ | 
|  | static void hid_pid_ctrl_playback(struct hid_device *hid, struct hid_pid_effect *effect, int play) | 
|  | { | 
|  | if (play) | 
|  | set_bit(FF_PID_FLAGS_PLAYING, &effect->flags); | 
|  | else | 
|  | clear_bit(FF_PID_FLAGS_PLAYING, &effect->flags); | 
|  | } | 
|  |  | 
|  | static int hid_pid_erase(struct input_dev *dev, int id) | 
|  | { | 
|  | struct hid_device *hid = dev->private; | 
|  | struct hid_ff_pid *pid = hid->ff_private; | 
|  | struct hid_field *field; | 
|  | unsigned long flags; | 
|  | int ret; | 
|  |  | 
|  | if (!CHECK_OWNERSHIP(id, pid)) | 
|  | return -EACCES; | 
|  |  | 
|  | /* Find report */ | 
|  | field = hid_find_field_by_usage(hid, HID_UP_PID | FF_PID_USAGE_BLOCK_FREE, | 
|  | HID_OUTPUT_REPORT); | 
|  | if (!field) { | 
|  | dev_err(&hid->dev->dev, "couldn't find report\n"); | 
|  | return -EIO; | 
|  | } | 
|  |  | 
|  | ret = hid_set_field(field, 0, pid->effects[id].device_id); | 
|  | if (ret) { | 
|  | dev_err(&hid->dev->dev, "couldn't set field\n"); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | hid_submit_report(hid, field->report, USB_DIR_OUT); | 
|  |  | 
|  | spin_lock_irqsave(&pid->lock, flags); | 
|  | hid_pid_ctrl_playback(hid, pid->effects + id, 0); | 
|  | pid->effects[id].flags = 0; | 
|  | spin_unlock_irqrestore(&pid->lock, flags); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* Erase all effects this process owns */ | 
|  | static int hid_pid_flush(struct input_dev *dev, struct file *file) | 
|  | { | 
|  | struct hid_device *hid = dev->private; | 
|  | struct hid_ff_pid *pid = hid->ff_private; | 
|  | int i; | 
|  |  | 
|  | /*NOTE: no need to lock here. The only times EFFECT_USED is | 
|  | modified is when effects are uploaded or when an effect is | 
|  | erased. But a process cannot close its dev/input/eventX fd | 
|  | and perform ioctls on the same fd all at the same time */ | 
|  | /*FIXME: multiple threads, anyone? */ | 
|  | for (i = 0; i < dev->ff_effects_max; ++i) | 
|  | if (current->pid == pid->effects[i].owner | 
|  | && test_bit(FF_PID_FLAGS_USED, &pid->effects[i].flags)) | 
|  | if (hid_pid_erase(dev, i)) | 
|  | dev_warn(&hid->dev->dev, "erase effect %d failed", i); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int hid_pid_upload_effect(struct input_dev *dev, | 
|  | struct ff_effect *effect) | 
|  | { | 
|  | struct hid_ff_pid *pid_private = (struct hid_ff_pid *)(dev->private); | 
|  | int ret; | 
|  | int is_update; | 
|  | unsigned long flags; | 
|  |  | 
|  | dev_dbg(&pid_private->hid->dev->dev, "upload effect called: effect_type=%x\n", effect->type); | 
|  | /* Check this effect type is supported by this device */ | 
|  | if (!test_bit(effect->type, dev->ffbit)) { | 
|  | dev_dbg(&pid_private->hid->dev->dev, | 
|  | "invalid kind of effect requested.\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * If we want to create a new effect, get a free id | 
|  | */ | 
|  | if (effect->id == -1) { | 
|  | int id = 0; | 
|  |  | 
|  | // Spinlock so we don`t get a race condition when choosing IDs | 
|  | spin_lock_irqsave(&pid_private->lock, flags); | 
|  |  | 
|  | while (id < FF_EFFECTS_MAX) | 
|  | if (!test_and_set_bit(FF_PID_FLAGS_USED, &pid_private->effects[id++].flags)) | 
|  | break; | 
|  |  | 
|  | if (id == FF_EFFECTS_MAX) { | 
|  | spin_unlock_irqrestore(&pid_private->lock, flags); | 
|  | // TEMP - We need to get ff_effects_max correctly first:  || id >= dev->ff_effects_max) { | 
|  | dev_dbg(&pid_private->hid->dev->dev, "Not enough device memory\n"); | 
|  | return -ENOMEM; | 
|  | } | 
|  |  | 
|  | effect->id = id; | 
|  | dev_dbg(&pid_private->hid->dev->dev, "effect ID is %d\n.", id); | 
|  | pid_private->effects[id].owner = current->pid; | 
|  | pid_private->effects[id].flags = (1 << FF_PID_FLAGS_USED); | 
|  | spin_unlock_irqrestore(&pid_private->lock, flags); | 
|  |  | 
|  | is_update = FF_PID_FALSE; | 
|  | } else { | 
|  | /* We want to update an effect */ | 
|  | if (!CHECK_OWNERSHIP(effect->id, pid_private)) | 
|  | return -EACCES; | 
|  |  | 
|  | /* Parameter type cannot be updated */ | 
|  | if (effect->type != pid_private->effects[effect->id].effect.type) | 
|  | return -EINVAL; | 
|  |  | 
|  | /* Check the effect is not already being updated */ | 
|  | if (test_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags)) | 
|  | return -EAGAIN; | 
|  |  | 
|  | is_update = FF_PID_TRUE; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Upload the effect | 
|  | */ | 
|  | switch (effect->type) { | 
|  | case FF_PERIODIC: | 
|  | ret = pid_upload_periodic(pid_private, effect, is_update); | 
|  | break; | 
|  |  | 
|  | case FF_CONSTANT: | 
|  | ret = pid_upload_constant(pid_private, effect, is_update); | 
|  | break; | 
|  |  | 
|  | case FF_SPRING: | 
|  | case FF_FRICTION: | 
|  | case FF_DAMPER: | 
|  | case FF_INERTIA: | 
|  | ret = pid_upload_condition(pid_private, effect, is_update); | 
|  | break; | 
|  |  | 
|  | case FF_RAMP: | 
|  | ret = pid_upload_ramp(pid_private, effect, is_update); | 
|  | break; | 
|  |  | 
|  | default: | 
|  | dev_dbg(&pid_private->hid->dev->dev, | 
|  | "invalid type of effect requested - %x.\n", | 
|  | effect->type); | 
|  | return -EINVAL; | 
|  | } | 
|  | /* If a packet was sent, forbid new updates until we are notified | 
|  | * that the packet was updated | 
|  | */ | 
|  | if (ret == 0) | 
|  | set_bit(FF_PID_FLAGS_UPDATING, &pid_private->effects[effect->id].flags); | 
|  | pid_private->effects[effect->id].effect = *effect; | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | int hid_pid_init(struct hid_device *hid) | 
|  | { | 
|  | struct hid_ff_pid *private; | 
|  | struct hid_input *hidinput = list_entry(&hid->inputs, struct hid_input, list); | 
|  |  | 
|  | private = hid->ff_private = kcalloc(1, sizeof(struct hid_ff_pid), GFP_KERNEL); | 
|  | if (!private) | 
|  | return -ENOMEM; | 
|  |  | 
|  | private->hid = hid; | 
|  |  | 
|  | hid->ff_exit = hid_pid_exit; | 
|  | hid->ff_event = hid_pid_event; | 
|  |  | 
|  | /* Open output URB */ | 
|  | if (!(private->urbffout = usb_alloc_urb(0, GFP_KERNEL))) { | 
|  | kfree(private); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | usb_fill_control_urb(private->urbffout, hid->dev, 0, | 
|  | (void *)&private->ffcr, private->ctrl_buffer, 8, | 
|  | hid_pid_ctrl_out, hid); | 
|  | hidinput->input.upload_effect = hid_pid_upload_effect; | 
|  | hidinput->input.flush = hid_pid_flush; | 
|  | hidinput->input.ff_effects_max = 8;	// A random default | 
|  | set_bit(EV_FF, hidinput->input.evbit); | 
|  | set_bit(EV_FF_STATUS, hidinput->input.evbit); | 
|  |  | 
|  | spin_lock_init(&private->lock); | 
|  |  | 
|  | printk(KERN_INFO "Force feedback driver for PID devices by Rodrigo Damazio <rdamazio@lsi.usp.br>.\n"); | 
|  |  | 
|  | return 0; | 
|  | } |