Commit a64cbf3c authored by José Expósito's avatar José Expósito Committed by Jiri Kosina
Browse files

HID: uclogic: Refactor UGEE v2 string descriptor parsing 



The UGEE v2 tablets expose a string descriptor with their capabilities.

Move the code used to parse the descriptors and generate a parameter
list from it to its own function and add KUnit tests to validate the
parser.

Tested-by: default avatarJouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 08809e48

drivers/hid/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ obj-$(CONFIG_HID_SENSOR_HUB) += hid-sensor-hub.o 
obj-$(CONFIG_HID_SENSOR_CUSTOM_SENSOR)	+= hid-sensor-custom.o



hid-uclogic-test-objs		:= hid-uclogic-rdesc.o \

				   hid-uclogic-params.o \

				   hid-uclogic-rdesc-test.o

obj-$(CONFIG_HID_KUNIT_TEST)	+= hid-uclogic-test.o

drivers/hid/hid-uclogic-params-test.c

0 → 100644
+159 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+



/*

 *  HID driver for UC-Logic devices not fully compliant with HID standard

 *

 *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>

 */



#include <kunit/test.h>

#include "./hid-uclogic-rdesc.h"



#define MAX_STR_DESC_SIZE 14



struct uclogic_parse_ugee_v2_desc_case {

	const char *name;

	int res;

	const __u8 str_desc[MAX_STR_DESC_SIZE];

	size_t str_desc_size;

	const s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];

};



static struct uclogic_parse_ugee_v2_desc_case uclogic_parse_ugee_v2_desc_cases[] = {

	{

		.name = "invalid_str_desc",

		.res = -EINVAL,

		.str_desc = {},

		.str_desc_size = 0,

		.desc_params = {},

	},

	{

		.name = "resolution_with_value_0",

		.res = 0,

		.str_desc = {

			0x0E, 0x03,

			0x70, 0xB2,

			0x10, 0x77,

			0x08,

			0x00,

			0xFF, 0x1F,

			0x00, 0x00,

		},

		.str_desc_size = 12,

		.desc_params = {

			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,

			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0,

			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,

			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,

		},

	},

	/* XP-PEN Deco L str_desc: Frame with 8 buttons */

	{

		.name = "frame_type_buttons",

		.res = 0,

		.str_desc = {

			0x0E, 0x03,

			0x70, 0xB2,

			0x10, 0x77,

			0x08,

			0x00,

			0xFF, 0x1F,

			0xD8, 0x13,

		},

		.str_desc_size = 12,

		.desc_params = {

			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,

			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2320,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1770,

			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,

			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,

		},

	},

	/* PARBLO A610 PRO str_desc: Frame with 9 buttons and dial */

	{

		.name = "frame_type_dial",

		.res = 0,

		.str_desc = {

			0x0E, 0x03,

			0x96, 0xC7,

			0xF9, 0x7C,

			0x09,

			0x01,

			0xFF, 0x1F,

			0xD8, 0x13,

		},

		.str_desc_size = 12,

		.desc_params = {

			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xC796,

			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2749,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7CF9,

			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1899,

			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,

			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x09,

		},

	},

};



static void uclogic_parse_ugee_v2_desc_case_desc(struct uclogic_parse_ugee_v2_desc_case *t,

						 char *desc)

{

	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);

}



KUNIT_ARRAY_PARAM(uclogic_parse_ugee_v2_desc, uclogic_parse_ugee_v2_desc_cases,

		  uclogic_parse_ugee_v2_desc_case_desc);



static void uclogic_parse_ugee_v2_desc_test(struct kunit *test)

{

	int res;

	s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];

	const struct uclogic_parse_ugee_v2_desc_case *params = test->param_value;



	res = uclogic_params_parse_ugee_v2_desc(params->str_desc,

						params->str_desc_size,

						desc_params,

						ARRAY_SIZE(desc_params));

	KUNIT_ASSERT_EQ(test, res, params->res);



	if (res)

		return;



	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM],

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM]);

	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM],

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM]);

	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM],

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM]);

	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM],

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM]);

	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM],

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM]);

	KUNIT_EXPECT_EQ(test,

			params->desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM],

			desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM]);

}



static struct kunit_case hid_uclogic_params_test_cases[] = {

	KUNIT_CASE_PARAM(uclogic_parse_ugee_v2_desc_test,

			 uclogic_parse_ugee_v2_desc_gen_params),

	{}

};



static struct kunit_suite hid_uclogic_params_test_suite = {

	.name = "hid_uclogic_params_test",

	.test_cases = hid_uclogic_params_test_cases,

};



kunit_test_suite(hid_uclogic_params_test_suite);



MODULE_DESCRIPTION("KUnit tests for the UC-Logic driver");

MODULE_LICENSE("GPL");

MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");

drivers/hid/hid-uclogic-params.c

+66 −20
Original line number Diff line number Diff line
@@ -1056,6 +1056,62 @@ static int uclogic_probe_interface(struct hid_device *hdev, u8 *magic_arr, 
	return rc;

}



/**

 * uclogic_params_parse_ugee_v2_desc - parse the string descriptor containing

 * pen and frame parameters returned by UGEE v2 devices.

 *

 * @str_desc:		String descriptor, cannot be NULL.

 * @str_desc_size:	Size of the string descriptor.

 * @desc_params:	Output description params list.

 * @desc_params_size:	Size of the output description params list.

 *

 * Returns:

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

 */

static int uclogic_params_parse_ugee_v2_desc(const __u8 *str_desc,

					     size_t str_desc_size,

					     s32 *desc_params,

					     size_t desc_params_size)

{

	s32 pen_x_lm, pen_y_lm;

	s32 pen_x_pm, pen_y_pm;

	s32 pen_pressure_lm;

	s32 frame_num_buttons;

	s32 resolution;



	/* Minimum descriptor length required, maximum seen so far is 14 */

	const int min_str_desc_size = 12;



	if (!str_desc || str_desc_size < min_str_desc_size)

		return -EINVAL;



	if (desc_params_size != UCLOGIC_RDESC_PH_ID_NUM)

		return -EINVAL;



	pen_x_lm = get_unaligned_le16(str_desc + 2);

	pen_y_lm = get_unaligned_le16(str_desc + 4);

	frame_num_buttons = str_desc[6];

	pen_pressure_lm = get_unaligned_le16(str_desc + 8);



	resolution = get_unaligned_le16(str_desc + 10);

	if (resolution == 0) {

		pen_x_pm = 0;

		pen_y_pm = 0;

	} else {

		pen_x_pm = pen_x_lm * 1000 / resolution;

		pen_y_pm = pen_y_lm * 1000 / resolution;

	}



	desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = pen_x_lm;

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = pen_x_pm;

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = pen_y_lm;

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = pen_y_pm;

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = pen_pressure_lm;

	desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM] = frame_num_buttons;



	return 0;

}



/**

 * uclogic_params_ugee_v2_init() - initialize a UGEE graphics tablets by

 * discovering their parameters.
@@ -1086,7 +1142,6 @@ static int uclogic_params_ugee_v2_init(struct uclogic_params *params, 
	__u8 *rdesc_pen = NULL;

	__u8 *rdesc_frame = NULL;

	s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];

	s32 resolution;

	__u8 magic_arr[] = {

		0x02, 0xb0, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00

	};
@@ -1128,25 +1183,12 @@ static int uclogic_params_ugee_v2_init(struct uclogic_params *params, 
		goto output;

	}



	desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] =

		get_unaligned_le16(str_desc + 2);

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] =

		get_unaligned_le16(str_desc + 4);

	desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM] = str_desc[6];

	desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] =

		get_unaligned_le16(str_desc + 8);

	resolution = get_unaligned_le16(str_desc + 10);

	if (resolution == 0) {

		desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0;

		desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0;

	} else {

		desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] =

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] * 1000 /

			resolution;

		desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] =

			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] * 1000 /

			resolution;

	}

	rc = uclogic_params_parse_ugee_v2_desc(str_desc, str_desc_len,

					       desc_params,

					       ARRAY_SIZE(desc_params));

	if (rc)

		goto cleanup;



	kfree(str_desc);

	str_desc = NULL;
@@ -1517,3 +1559,7 @@ int uclogic_params_init(struct uclogic_params *params, 
	uclogic_params_cleanup(&p);

	return rc;

}



#ifdef CONFIG_HID_KUNIT_TEST

#include "hid-uclogic-params-test.c"

#endif