[PATCH v3 2/4] HID: hid-lg4ff: Display the real wheel model and supported alternate modes through sysfs. This applies only to multimode wheels.

From: Michal MalÃ
Date: Wed Feb 18 2015 - 12:00:00 EST


Display the real wheel model and supported alternate modes through sysfs. This
applies only to multimode wheels.

Signed-off-by: Michal Malà <madcatxster@xxxxxxxxxxxxxxxxxx>
---
v2: Document the sysfs interface

.../ABI/testing/sysfs-driver-hid-logitech-lg4ff | 20 ++
drivers/hid/hid-lg4ff.c | 205 ++++++++++++++++++++-
2 files changed, 218 insertions(+), 7 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff b/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
index 167d903..60f24a1 100644
--- a/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
+++ b/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
@@ -5,3 +5,23 @@ Contact: Michal Malà <madcatxster@xxxxxxxxx>
Description: Display minimum, maximum and current range of the steering
wheel. Writing a value within min and max boundaries sets the
range of the wheel.
+
+What: /sys/bus/hid/drivers/logitech/<dev>/alternate_modes
+Date: Feb 2015
+KernelVersion: 4.1
+Contact: Michal Malà <madcatxster@xxxxxxxxx>
+Description: Displays a set of alternate modes supported by a wheel. Each
+ mode is listed as follows:
+ Tag: Mode Name
+ Currently active mode is marked with an asterisk. List also
+ contains an abstract item "native" which always denotes the
+ native mode of the wheel.
+
+What: /sys/bus/hid/drivers/logitech/<dev>/real_id
+Date: Feb 2015
+KernelVersion: 4.1
+Contact: Michal Malà <madcatxster@xxxxxxxxx>
+Description: Displays the real model of the wheel regardless of any
+ alternate mode the wheel might be switched to.
+ It is a read-only value.
+ This entry is not created for devices that have only one mode.
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 190c5e3..a64a35e 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -34,10 +34,36 @@

#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)

-#define LG4FF_MMODE_DONE 0
+#define LG4FF_MMODE_IS_MULTIMODE 0
#define LG4FF_MMODE_SWITCHED 1
#define LG4FF_MMODE_NOT_MULTIMODE 2

+#define LG4FF_MODE_NATIVE_IDX 0
+#define LG4FF_MODE_DFEX_IDX 1
+#define LG4FF_MODE_DFP_IDX 2
+#define LG4FF_MODE_G25_IDX 3
+#define LG4FF_MODE_DFGT_IDX 4
+#define LG4FF_MODE_G27_IDX 5
+#define LG4FF_MODE_MAX_IDX 6
+
+#define LG4FF_MODE_NATIVE BIT(LG4FF_MODE_NATIVE_IDX)
+#define LG4FF_MODE_DFEX BIT(LG4FF_MODE_DFEX_IDX)
+#define LG4FF_MODE_DFP BIT(LG4FF_MODE_DFP_IDX)
+#define LG4FF_MODE_G25 BIT(LG4FF_MODE_G25_IDX)
+#define LG4FF_MODE_DFGT BIT(LG4FF_MODE_DFGT_IDX)
+#define LG4FF_MODE_G27 BIT(LG4FF_MODE_G27_IDX)
+
+#define LG4FF_DFEX_TAG "DF-EX"
+#define LG4FF_DFEX_NAME "Driving Force / Formula EX"
+#define LG4FF_DFP_TAG "DFP"
+#define LG4FF_DFP_NAME "Driving Force Pro"
+#define LG4FF_G25_TAG "G25"
+#define LG4FF_G25_NAME "G25 Racing Wheel"
+#define LG4FF_G27_TAG "G27"
+#define LG4FF_G27_NAME "G27 Racing Wheel"
+#define LG4FF_DFGT_TAG "DFGT"
+#define LG4FF_DFGT_NAME "Driving Force GT"
+
#define LG4FF_FFEX_REV_MAJ 0x21
#define LG4FF_FFEX_REV_MIN 0x00

@@ -53,6 +79,10 @@ struct lg4ff_device_entry {
__u8 led_state;
struct led_classdev *led[5];
#endif
+ u32 alternate_modes;
+ const char *real_tag;
+ const char *real_name;
+ u16 real_product_id;
struct list_head list;
void (*set_range)(struct hid_device *hid, u16 range);
};
@@ -87,6 +117,19 @@ struct lg4ff_wheel_ident_checklist {
const struct lg4ff_wheel_ident_info *models[];
};

+struct lg4ff_multimode_wheel {
+ const u16 product_id;
+ const u32 alternate_modes;
+ const char *real_tag;
+ const char *real_name;
+};
+
+struct lg4ff_alternate_mode {
+ const u16 product_id;
+ const char *tag;
+ const char *name;
+};
+
static const struct lg4ff_wheel lg4ff_devices[] = {
{USB_DEVICE_ID_LOGITECH_WHEEL, lg4ff_wheel_effects, 40, 270, NULL},
{USB_DEVICE_ID_LOGITECH_MOMO_WHEEL, lg4ff_wheel_effects, 40, 270, NULL},
@@ -98,6 +141,30 @@ static const struct lg4ff_wheel lg4ff_devices[] = {
{USB_DEVICE_ID_LOGITECH_WII_WHEEL, lg4ff_wheel_effects, 40, 270, NULL}
};

+static const struct lg4ff_multimode_wheel lg4ff_multimode_wheels[] = {
+ {USB_DEVICE_ID_LOGITECH_DFP_WHEEL,
+ LG4FF_MODE_NATIVE | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
+ LG4FF_DFP_TAG, LG4FF_DFP_NAME},
+ {USB_DEVICE_ID_LOGITECH_G25_WHEEL,
+ LG4FF_MODE_NATIVE | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
+ LG4FF_G25_TAG, LG4FF_G25_NAME},
+ {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,
+ LG4FF_MODE_NATIVE | LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
+ LG4FF_DFGT_TAG, LG4FF_DFGT_NAME},
+ {USB_DEVICE_ID_LOGITECH_G27_WHEEL,
+ LG4FF_MODE_NATIVE | LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
+ LG4FF_G27_TAG, LG4FF_G27_NAME},
+};
+
+static const struct lg4ff_alternate_mode lg4ff_alternate_modes[] = {
+ [LG4FF_MODE_NATIVE_IDX] = {0, "native", ""},
+ [LG4FF_MODE_DFEX_IDX] = {USB_DEVICE_ID_LOGITECH_WHEEL, LG4FF_DFEX_TAG, LG4FF_DFEX_NAME},
+ [LG4FF_MODE_DFP_IDX] = {USB_DEVICE_ID_LOGITECH_DFP_WHEEL, LG4FF_DFP_TAG, LG4FF_DFP_NAME},
+ [LG4FF_MODE_G25_IDX] = {USB_DEVICE_ID_LOGITECH_G25_WHEEL, LG4FF_G25_TAG, LG4FF_G25_NAME},
+ [LG4FF_MODE_DFGT_IDX] = {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL, LG4FF_DFGT_TAG, LG4FF_DFGT_NAME},
+ [LG4FF_MODE_G27_IDX] = {USB_DEVICE_ID_LOGITECH_G27_WHEEL, LG4FF_G27_TAG, LG4FF_G27_NAME}
+};
+
/* Multimode wheel identificators */
static const struct lg4ff_wheel_ident_info lg4ff_dfp_ident_info = {
0xf000,
@@ -439,6 +506,61 @@ static int lg4ff_switch_compatibility_mode(struct hid_device *hid, const struct
return 0;
}

+static ssize_t lg4ff_alternate_modes_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct lg4ff_device_entry *entry;
+ struct lg_drv_data *drv_data;
+ ssize_t count = 0;
+ int i;
+
+ drv_data = hid_get_drvdata(hid);
+ if (!drv_data) {
+ hid_err(hid, "Private driver data not found!\n");
+ return 0;
+ }
+
+ entry = drv_data->device_props;
+ if (!entry) {
+ hid_err(hid, "Device properties not found!\n");
+ return 0;
+ }
+
+ if (!entry->real_name) {
+ hid_err(hid, "NULL pointer to string\n");
+ return 0;
+ }
+
+ for (i = 0; i < LG4FF_MODE_MAX_IDX; i++) {
+ if (entry->alternate_modes & BIT(i)) {
+ /* Print tag and full name */
+ count += scnprintf(buf + count, PAGE_SIZE - count, "%s: %s",
+ lg4ff_alternate_modes[i].tag,
+ !lg4ff_alternate_modes[i].product_id ? entry->real_name : lg4ff_alternate_modes[i].name);
+ if (count >= PAGE_SIZE - 1)
+ return count;
+
+ /* Mark the currently active mode with an asterisk */
+ if (lg4ff_alternate_modes[i].product_id == entry->product_id ||
+ (lg4ff_alternate_modes[i].product_id == 0 && entry->product_id == entry->real_product_id))
+ count += scnprintf(buf + count, PAGE_SIZE - count, " *\n");
+ else
+ count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
+
+ if (count >= PAGE_SIZE - 1)
+ return count;
+ }
+ }
+
+ return count;
+}
+
+static ssize_t lg4ff_alternate_modes_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+ return -ENOSYS;
+}
+static DEVICE_ATTR(alternate_modes, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, lg4ff_alternate_modes_show, lg4ff_alternate_modes_store);
+
/* Read current range and display it in terminal */
static ssize_t range_show(struct device *dev, struct device_attribute *attr,
char *buf)
@@ -500,6 +622,41 @@ static ssize_t range_store(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RW(range);

+static ssize_t lg4ff_real_id_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct lg4ff_device_entry *entry;
+ struct lg_drv_data *drv_data;
+ size_t count;
+
+ drv_data = hid_get_drvdata(hid);
+ if (!drv_data) {
+ hid_err(hid, "Private driver data not found!\n");
+ return 0;
+ }
+
+ entry = drv_data->device_props;
+ if (!entry) {
+ hid_err(hid, "Device properties not found!\n");
+ return 0;
+ }
+
+ if (!entry->real_tag || !entry->real_name) {
+ hid_err(hid, "NULL pointer to string\n");
+ return 0;
+ }
+
+ count = scnprintf(buf, PAGE_SIZE, "%s: %s\n", entry->real_tag, entry->real_name);
+ return count;
+}
+
+static ssize_t lg4ff_real_id_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+ /* Real ID is a read-only value */
+ return -EPERM;
+}
+static DEVICE_ATTR(real_id, S_IRUGO, lg4ff_real_id_show, lg4ff_real_id_store);
+
#ifdef CONFIG_LEDS_CLASS
static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
{
@@ -664,7 +821,7 @@ static int lg4ff_handle_multimode_wheel(struct hid_device *hid, u16 *real_produc
break;
default:
hid_err(hid, "Invalid product id %X\n", *real_product_id);
- return LG4FF_MMODE_DONE;
+ return LG4FF_MMODE_NOT_MULTIMODE;
}

ret = lg4ff_switch_compatibility_mode(hid, s);
@@ -672,12 +829,12 @@ static int lg4ff_handle_multimode_wheel(struct hid_device *hid, u16 *real_produc
/* Wheel could not have been switched to native mode,
* leave it in "Driving Force" mode and continue */
hid_err(hid, "Unable to switch wheel mode, errno %d\n", ret);
- return LG4FF_MMODE_DONE;
+ return LG4FF_MMODE_IS_MULTIMODE;
}
return LG4FF_MMODE_SWITCHED;
}

- return LG4FF_MMODE_DONE;
+ return LG4FF_MMODE_IS_MULTIMODE;
}


@@ -689,7 +846,8 @@ int lg4ff_init(struct hid_device *hid)
const u16 bcdDevice = le16_to_cpu(udesc->bcdDevice);
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
- int error, i, j, ret;
+ int error, i, j;
+ int mmode_ret, mmode_idx = -1;
u16 real_product_id;

/* Check that the report looks ok */
@@ -698,12 +856,12 @@ int lg4ff_init(struct hid_device *hid)

/* Check if a multimode wheel has been connected and
* handle it appropriately */
- ret = lg4ff_handle_multimode_wheel(hid, &real_product_id, bcdDevice);
+ mmode_ret = lg4ff_handle_multimode_wheel(hid, &real_product_id, bcdDevice);

/* Wheel has been told to switch to native mode. There is no point in going on
* with the initialization as the wheel will do a USB reset when it switches mode
*/
- if (ret == LG4FF_MMODE_SWITCHED)
+ if (mmode_ret == LG4FF_MMODE_SWITCHED)
return 0;

/* Check what wheel has been connected */
@@ -720,6 +878,18 @@ int lg4ff_init(struct hid_device *hid)
return -1;
}

+ if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
+ for (mmode_idx = 0; mmode_idx < ARRAY_SIZE(lg4ff_multimode_wheels); mmode_idx++) {
+ if (real_product_id == lg4ff_multimode_wheels[mmode_idx].product_id)
+ break;
+ }
+
+ if (mmode_idx == ARRAY_SIZE(lg4ff_multimode_wheels)) {
+ hid_err(hid, "Device product ID %X is not listed as a multimode wheel", real_product_id);
+ return -1;
+ }
+ }
+
/* Set supported force feedback capabilities */
for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);
@@ -745,9 +915,16 @@ int lg4ff_init(struct hid_device *hid)
drv_data->device_props = entry;

entry->product_id = lg4ff_devices[i].product_id;
+ entry->real_product_id = real_product_id;
entry->min_range = lg4ff_devices[i].min_range;
entry->max_range = lg4ff_devices[i].max_range;
entry->set_range = lg4ff_devices[i].set_range;
+ if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
+ BUG_ON(mmode_idx == -1);
+ entry->alternate_modes = lg4ff_multimode_wheels[mmode_idx].alternate_modes;
+ entry->real_tag = lg4ff_multimode_wheels[mmode_idx].real_tag;
+ entry->real_name = lg4ff_multimode_wheels[mmode_idx].real_name;
+ }

/* Check if autocentering is available and
* set the centering force to zero by default */
@@ -766,6 +943,14 @@ int lg4ff_init(struct hid_device *hid)
error = device_create_file(&hid->dev, &dev_attr_range);
if (error)
return error;
+ if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
+ error = device_create_file(&hid->dev, &dev_attr_real_id);
+ if (error)
+ return error;
+ error = device_create_file(&hid->dev, &dev_attr_alternate_modes);
+ if (error)
+ return error;
+ }
dbg_hid("sysfs interface created\n");

/* Set the maximum range to start with */
@@ -844,6 +1029,12 @@ int lg4ff_deinit(struct hid_device *hid)

device_remove_file(&hid->dev, &dev_attr_range);

+ /* Multimode devices will have at least the "MODE_NATIVE" bit set */
+ if (entry->alternate_modes) {
+ device_remove_file(&hid->dev, &dev_attr_real_id);
+ device_remove_file(&hid->dev, &dev_attr_alternate_modes);
+ }
+
#ifdef CONFIG_LEDS_CLASS
{
int j;
--
2.3.0

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