Commit b4dbde9d authored by Alan Ott's avatar Alan Ott Committed by Jiri Kosina
Browse files

HID: Add Support for Setting and Getting Feature Reports from hidraw 



Per the HID Specification, Feature reports must be sent and received on
the Configuration endpoint (EP 0) through the Set_Report/Get_Report
interfaces.  This patch adds two ioctls to hidraw to set and get feature
reports to and from the device.  Modifications were made to hidraw and
usbhid.

New hidraw ioctls:
  HIDIOCSFEATURE - Perform a Set_Report transfer of a Feature report.
  HIDIOCGFEATURE - Perform a Get_Report transfer of a Feature report.

Signed-off-by: default avatarAlan Ott <alan@signal11.us>
Signed-off-by: default avatarAntonio Ospite <ospite@studenti.unina.it>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 0825411a

drivers/hid/hidraw.c

+100 −6
Original line number Diff line number Diff line
@@ -102,15 +102,14 @@ out: 
}



/* the first byte is expected to be a report number */

static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)

/* This function is to be called with the minors_lock mutex held */

static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)

{

	unsigned int minor = iminor(file->f_path.dentry->d_inode);

	struct hid_device *dev;

	__u8 *buf;

	int ret = 0;



	mutex_lock(&minors_lock);



	if (!hidraw_table[minor]) {

		ret = -ENODEV;

		goto out;
@@ -148,14 +147,92 @@ static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t 
		goto out_free;

	}



	ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT);

	ret = dev->hid_output_raw_report(dev, buf, count, report_type);

out_free:

	kfree(buf);

out:

	return ret;

}



/* the first byte is expected to be a report number */

static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)

{

	ssize_t ret;

	mutex_lock(&minors_lock);

	ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);

	mutex_unlock(&minors_lock);

	return ret;

}





/* This function performs a Get_Report transfer over the control endpoint

   per section 7.2.1 of the HID specification, version 1.1.  The first byte

   of buffer is the report number to request, or 0x0 if the defice does not

   use numbered reports. The report_type parameter can be HID_FEATURE_REPORT

   or HID_INPUT_REPORT.  This function is to be called with the minors_lock

   mutex held.  */

static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)

{

	unsigned int minor = iminor(file->f_path.dentry->d_inode);

	struct hid_device *dev;

	__u8 *buf;

	int ret = 0, len;

	unsigned char report_number;



	dev = hidraw_table[minor]->hid;



	if (!dev->hid_get_raw_report) {

		ret = -ENODEV;

		goto out;

	}



	if (count > HID_MAX_BUFFER_SIZE) {

		printk(KERN_WARNING "hidraw: pid %d passed too large report\n",

				task_pid_nr(current));

		ret = -EINVAL;

		goto out;

	}



	if (count < 2) {

		printk(KERN_WARNING "hidraw: pid %d passed too short report\n",

				task_pid_nr(current));

		ret = -EINVAL;

		goto out;

	}



	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);

	if (!buf) {

		ret = -ENOMEM;

		goto out;

	}



	/* Read the first byte from the user. This is the report number,

	   which is passed to dev->hid_get_raw_report(). */

	if (copy_from_user(&report_number, buffer, 1)) {

		ret = -EFAULT;

		goto out_free;

	}



	ret = dev->hid_get_raw_report(dev, report_number, buf, count, report_type);



	if (ret < 0)

		goto out_free;



	len = (ret < count) ? ret : count;



	if (copy_to_user(buffer, buf, len)) {

		ret = -EFAULT;

		goto out_free;

	}



	ret = len;



out_free:

	kfree(buf);

out:

	return ret;

}



static unsigned int hidraw_poll(struct file *file, poll_table *wait)

{

	struct hidraw_list *list = file->private_data;
@@ -295,7 +372,24 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, 
		default:

			{

				struct hid_device *hid = dev->hid;

				if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) {

				if (_IOC_TYPE(cmd) != 'H') {

					ret = -EINVAL;

					break;

				}



				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {

					int len = _IOC_SIZE(cmd);

					ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);

					break;

				}

				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {

					int len = _IOC_SIZE(cmd);

					ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);

					break;

				}



				/* Begin Read-only ioctls. */

				if (_IOC_DIR(cmd) != _IOC_READ) {

					ret = -EINVAL;

					break;

				}

drivers/hid/usbhid/hid-core.c

+35 −0
Original line number Diff line number Diff line
@@ -799,6 +799,40 @@ static int hid_alloc_buffers(struct usb_device *dev, struct hid_device *hid) 
	return 0;

}



static int usbhid_get_raw_report(struct hid_device *hid,

		unsigned char report_number, __u8 *buf, size_t count,

		unsigned char report_type)

{

	struct usbhid_device *usbhid = hid->driver_data;

	struct usb_device *dev = hid_to_usb_dev(hid);

	struct usb_interface *intf = usbhid->intf;

	struct usb_host_interface *interface = intf->cur_altsetting;

	int skipped_report_id = 0;

	int ret;



	/* Byte 0 is the report number. Report data starts at byte 1.*/

	buf[0] = report_number;

	if (report_number == 0x0) {

		/* Offset the return buffer by 1, so that the report ID

		   will remain in byte 0. */

		buf++;

		count--;

		skipped_report_id = 1;

	}

	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),

		HID_REQ_GET_REPORT,

		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,

		((report_type + 1) << 8) | report_number,

		interface->desc.bInterfaceNumber, buf, count,

		USB_CTRL_SET_TIMEOUT);



	/* count also the report id */

	if (ret > 0 && skipped_report_id)

		ret++;



	return ret;

}



static int usbhid_output_raw_report(struct hid_device *hid, __u8 *buf, size_t count,

		unsigned char report_type)

{
@@ -1139,6 +1173,7 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id * 


	usb_set_intfdata(intf, hid);

	hid->ll_driver = &usb_hid_driver;

	hid->hid_get_raw_report = usbhid_get_raw_report;

	hid->hid_output_raw_report = usbhid_output_raw_report;

	hid->ff_init = hid_pidff_init;

#ifdef CONFIG_USB_HIDDEV

include/linux/hid.h

+3 −0
Original line number Diff line number Diff line
@@ -504,6 +504,9 @@ struct hid_device { /* device report descriptor */ 
				  struct hid_usage *, __s32);

	void (*hiddev_report_event) (struct hid_device *, struct hid_report *);



	/* handler for raw input (Get_Report) data, used by hidraw */

	int (*hid_get_raw_report) (struct hid_device *, unsigned char, __u8 *, size_t, unsigned char);



	/* handler for raw output data, used by hidraw */

	int (*hid_output_raw_report) (struct hid_device *, __u8 *, size_t, unsigned char);

include/linux/hidraw.h

+3 −0
Original line number Diff line number Diff line
@@ -35,6 +35,9 @@ struct hidraw_devinfo { 
#define HIDIOCGRAWINFO		_IOR('H', 0x03, struct hidraw_devinfo)

#define HIDIOCGRAWNAME(len)     _IOC(_IOC_READ, 'H', 0x04, len)

#define HIDIOCGRAWPHYS(len)     _IOC(_IOC_READ, 'H', 0x05, len)

/* The first byte of SFEATURE and GFEATURE is the report number */

#define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)

#define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)



#define HIDRAW_FIRST_MINOR 0

#define HIDRAW_MAX_DEVICES 64

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