[PATCH 1/2] HID: hid-logitech: Simplify wheel detection scheme

From: Simon Wood
Date: Mon Nov 02 2015 - 09:57:20 EST


Simplfy how hid-logitech driver detects the native mode of the wheel,
done by looking at the USB-ID revision and comparing bit mask.

Signed-off-by: Simon Wood <simon@xxxxxxxxxxxxx>
---
drivers/hid/hid-lg4ff.c | 70 ++++++++++++++++++++-----------------------------
1 file changed, 28 insertions(+), 42 deletions(-)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 02cec83..b363d88 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -114,16 +114,12 @@ struct lg4ff_compat_mode_switch {
};

struct lg4ff_wheel_ident_info {
+ const u32 modes;
const u16 mask;
const u16 result;
const u16 real_product_id;
};

-struct lg4ff_wheel_ident_checklist {
- const u32 count;
- const struct lg4ff_wheel_ident_info *models[];
-};
-
struct lg4ff_multimode_wheel {
const u16 product_id;
const u32 alternate_modes;
@@ -174,36 +170,39 @@ static const struct lg4ff_alternate_mode lg4ff_alternate_modes[] = {

/* Multimode wheel identificators */
static const struct lg4ff_wheel_ident_info lg4ff_dfp_ident_info = {
+ LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
0xf000,
0x1000,
USB_DEVICE_ID_LOGITECH_DFP_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g25_ident_info = {
+ LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
0xff00,
0x1200,
USB_DEVICE_ID_LOGITECH_G25_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g27_ident_info = {
+ LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
0xfff0,
0x1230,
USB_DEVICE_ID_LOGITECH_G27_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_dfgt_ident_info = {
+ LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
0xff00,
0x1300,
USB_DEVICE_ID_LOGITECH_DFGT_WHEEL
};

/* Multimode wheel identification checklists */
-static const struct lg4ff_wheel_ident_checklist lg4ff_main_checklist = {
- 4,
- {&lg4ff_dfgt_ident_info,
- &lg4ff_g27_ident_info,
- &lg4ff_g25_ident_info,
- &lg4ff_dfp_ident_info}
+static const struct lg4ff_wheel_ident_info *lg4ff_main_checklist[] = {
+ &lg4ff_dfgt_ident_info,
+ &lg4ff_g27_ident_info,
+ &lg4ff_g25_ident_info,
+ &lg4ff_dfp_ident_info
};

/* Compatibility mode switching commands */
@@ -1037,41 +1036,28 @@ static enum led_brightness lg4ff_led_get_brightness(struct led_classdev *led_cde

static u16 lg4ff_identify_multimode_wheel(struct hid_device *hid, const u16 reported_product_id, const u16 bcdDevice)
{
- const struct lg4ff_wheel_ident_checklist *checklist;
- int i, from_idx, to_idx;
+ u32 current_mode;
+ int i;

- switch (reported_product_id) {
- case USB_DEVICE_ID_LOGITECH_WHEEL:
- case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
- checklist = &lg4ff_main_checklist;
- from_idx = 0;
- to_idx = checklist->count - 1;
- break;
- case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
- checklist = &lg4ff_main_checklist;
- from_idx = 0;
- to_idx = checklist->count - 2; /* End identity check at G25 */
- break;
- case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
- checklist = &lg4ff_main_checklist;
- from_idx = 1; /* Start identity check at G27 */
- to_idx = checklist->count - 3; /* End identity check at G27 */
- break;
- case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
- checklist = &lg4ff_main_checklist;
- from_idx = 0;
- to_idx = checklist->count - 4; /* End identity check at DFGT */
- break;
- default:
- return 0;
+ /* identify current mode from USB PID */
+ for (i = 1; i < ARRAY_SIZE(lg4ff_alternate_modes); i++) {
+ dbg_hid("Testing whether PID is %X\n", lg4ff_alternate_modes[i].product_id);
+ if (reported_product_id == lg4ff_alternate_modes[i].product_id)
+ break;
}

- for (i = from_idx; i <= to_idx; i++) {
- const u16 mask = checklist->models[i]->mask;
- const u16 result = checklist->models[i]->result;
- const u16 real_product_id = checklist->models[i]->real_product_id;
+ if (i == ARRAY_SIZE(lg4ff_alternate_modes))
+ return 0;
+
+ current_mode = BIT(i);
+
+ for (i = 0; i < ARRAY_SIZE(lg4ff_main_checklist); i++) {
+ const u16 mask = lg4ff_main_checklist[i]->mask;
+ const u16 result = lg4ff_main_checklist[i]->result;
+ const u16 real_product_id = lg4ff_main_checklist[i]->real_product_id;

- if ((bcdDevice & mask) == result) {
+ if ((current_mode & lg4ff_main_checklist[i]->modes) && \
+ (bcdDevice & mask) == result) {
dbg_hid("Found wheel with real PID %X whose reported PID is %X\n", real_product_id, reported_product_id);
return real_product_id;
}
--
2.1.4

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