[PATCH 2/7] HID: uclogic: Refactor UGEE v2 string descriptor parsing
From: José Expósito
Date: Sun Jul 10 2022 - 13:51:29 EST
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: Jouke Witteveen <j.witteveen@xxxxxxxxx>
Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
---
drivers/hid/Makefile | 1 +
drivers/hid/hid-uclogic-params-test.c | 159 ++++++++++++++++++++++++++
drivers/hid/hid-uclogic-params.c | 86 ++++++++++----
3 files changed, 226 insertions(+), 20 deletions(-)
create mode 100644 drivers/hid/hid-uclogic-params-test.c
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 82d8fd97d96c..fe69dece2a46 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -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
diff --git a/drivers/hid/hid-uclogic-params-test.c b/drivers/hid/hid-uclogic-params-test.c
new file mode 100644
index 000000000000..9f043f2ab387
--- /dev/null
+++ b/drivers/hid/hid-uclogic-params-test.c
@@ -0,0 +1,159 @@
+// 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@xxxxxxxxx>
+ */
+
+#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@xxxxxxxxx>");
diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
index f24a4aca7920..ab54f0125e05 100644
--- a/drivers/hid/hid-uclogic-params.c
+++ b/drivers/hid/hid-uclogic-params.c
@@ -1052,6 +1052,62 @@ 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.
@@ -1082,7 +1138,6 @@ 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
};
@@ -1124,25 +1179,12 @@ 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;
@@ -1513,3 +1555,7 @@ 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
--
2.25.1