Commit 945d5dd5 authored by Nikolai Kondrashov's avatar Nikolai Kondrashov Committed by Jiri Kosina
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HID: uclogic: Return raw parameters from v2 pen init 



Return the raw parameters buffer from uclogic_params_pen_init_v2(), if
requested, as a way to identify the tablet.

Signed-off-by: default avatarNikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent a228809f

drivers/hid/hid-uclogic-params.c

+58 −34
Original line number Diff line number Diff line
@@ -339,27 +339,44 @@ static s32 uclogic_params_get_le24(const void *p) 
 * input and retrieve its parameters from the device, using v2 protocol.

 *

 * @pen:		Pointer to the pen parameters to initialize (to be

 *		cleaned up with uclogic_params_pen_cleanup()). Not modified in

 *		case of error, or if parameters are not found. Cannot be NULL.

 * @pfound:	Location for a flag which is set to true if the parameters

 *		were found, and to false if not (e.g. device was

 *		incompatible). Not modified in case of error. Cannot be NULL.

 * @hdev:	The HID device of the tablet interface to initialize and get

 *		parameters from. Cannot be NULL.

 *			cleaned up with uclogic_params_pen_cleanup()). Not

 *			modified in case of error, or if parameters are not

 *			found. Cannot be NULL.

 * @pfound:		Location for a flag which is set to true if the

 *			parameters were found, and to false if not (e.g.

 *			device was incompatible). Not modified in case of

 *			error. Cannot be NULL.

 * @pparams_ptr:	Location for a kmalloc'ed pointer to the retrieved raw

 *			parameters, which could be used to identify the tablet

 *			to some extent. Should be freed with kfree after use.

 *			NULL, if not needed. Not modified in case of error.

 *			Only set if *pfound is set to true.

 * @pparams_len:	Location for the length of the retrieved raw

 *			parameters. NULL, if not needed. Not modified in case

 *			of error. Only set if *pfound is set to true.

 * @hdev:		The HID device of the tablet interface to initialize

 *			and get parameters from. Cannot be NULL.

 *

 * Returns:

 *	Zero, if successful. A negative errno code on error.

 */

static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen,

					bool *pfound,

					__u8 **pparams_ptr,

					size_t *pparams_len,

					struct hid_device *hdev)

{

	int rc;

	bool found = false;

	/* Buffer for (part of) the string descriptor */

	/* Buffer for (part of) the parameter string descriptor */

	__u8 *buf = NULL;

	/* Descriptor length required */

	const int len = 18;

	/* Parameter string descriptor required length */

	const int params_len_min = 18;

	/* Parameter string descriptor accepted length */

	const int params_len_max = 32;

	/* Parameter string descriptor received length */

	int params_len;

	size_t i;

	s32 resolution;

	/* Pen report descriptor template parameters */

	s32 desc_params[UCLOGIC_RDESC_PEN_PH_ID_NUM];
@@ -377,7 +394,7 @@ static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen, 
	 * the Windows driver traffic.

	 * NOTE: This enables fully-functional tablet mode.

	 */

	rc = uclogic_params_get_str_desc(&buf, hdev, 200, len);

	rc = uclogic_params_get_str_desc(&buf, hdev, 200, params_len_max);

	if (rc == -EPIPE) {

		hid_dbg(hdev,

			"string descriptor with pen parameters not found, assuming not compatible\n");
@@ -385,28 +402,29 @@ static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen, 
	} else if (rc < 0) {

		hid_err(hdev, "failed retrieving pen parameters: %d\n", rc);

		goto cleanup;

	} else if (rc != len) {

	} else if (rc < params_len_min) {

		hid_dbg(hdev,

			"string descriptor with pen parameters has invalid length (got %d, expected %d), assuming not compatible\n",

			rc, len);

			"string descriptor with pen parameters is too short (got %d, expected at least %d), assuming not compatible\n",

			rc, params_len_min);

		goto finish;

	} else {

		size_t i;

	}



	params_len = rc;



	/*

	 * Check it's not just a catch-all UTF-16LE-encoded ASCII

	 * string (such as the model name) some tablets put into all

	 * unknown string descriptors.

	 */

	for (i = 2;

		     i < len &&

	     i < params_len &&

		(buf[i] >= 0x20 && buf[i] < 0x7f && buf[i + 1] == 0);

	     i += 2);

		if (i >= len) {

	if (i >= params_len) {

		hid_dbg(hdev,

			"string descriptor with pen parameters seems to contain only text, assuming not compatible\n");

		goto finish;

	}

	}



	/*

	 * Fill report descriptor parameters from the string descriptor
@@ -429,8 +447,6 @@ static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen, 
			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] * 1000 /

			resolution;

	}

	kfree(buf);

	buf = NULL;



	/*

	 * Generate pen report descriptor
@@ -456,6 +472,13 @@ static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen, 
	pen->fragmented_hires = true;

	pen->tilt_y_flipped = true;

	found = true;

	if (pparams_ptr != NULL) {

		*pparams_ptr = buf;

		buf = NULL;

	}

	if (pparams_len != NULL)

		*pparams_len = params_len;



finish:

	*pfound = found;

	rc = 0;
@@ -828,7 +851,8 @@ static int uclogic_params_huion_init(struct uclogic_params *params, 
			"transition firmware detected, not probing pen v2 parameters\n");

	} else {

		/* Try to probe v2 pen parameters */

		rc = uclogic_params_pen_init_v2(&p.pen, &found, hdev);

		rc = uclogic_params_pen_init_v2(&p.pen, &found,

						NULL, NULL, hdev);

		if (rc != 0) {

			hid_err(hdev,

				"failed probing pen v2 parameters: %d\n", rc);