1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/usb/input/pid.c b/drivers/usb/input/pid.c
new file mode 100644
index 0000000..2569638
--- /dev/null
+++ b/drivers/usb/input/pid.c
@@ -0,0 +1,295 @@
+/*
+ *  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;
+}