Re: [PATCH 1/2] HID: hid-lg4ff: Add support for G27 LEDs

From: Jiri Kosina
Date: Wed Apr 18 2012 - 07:24:50 EST


On Wed, 18 Apr 2012, Simon Wood wrote:

> This patch adds supports for controlling the LED 'tachometer' on
> the G27 wheel, via the LED subsystem.
>
> The 5 LEDs are arranged from right (1=grn, 2=grn, 3=yel, 4=yel, 5=red)
> and 'mirrored' to the left (10 LEDs in total).
>
> Signed-off-by: Simon Wood <simon@xxxxxxxxxxxxx>
> ---
> drivers/hid/hid-lg4ff.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 154 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
> index 32c173f..ab5232e 100644
> --- a/drivers/hid/hid-lg4ff.c
> +++ b/drivers/hid/hid-lg4ff.c
> @@ -55,7 +55,8 @@ struct lg4ff_device_entry {
> __u16 range;
> __u16 min_range;
> __u16 max_range;
> - __u8 leds;
> + __u8 led_state;
> + struct led_classdev *led[5];

Why not put this under the CONFIG_LEDS_CLASS condition as well?

> struct list_head list;
> void (*set_range)(struct hid_device *hid, u16 range);
> };
> @@ -335,6 +336,88 @@ static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *at
> return count;
> }
>
> +#ifdef CONFIG_LEDS_CLASS
> +static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
> +{
> + struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
> + struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
> +
> + report->field[0]->value[0] = 0xf8;
> + report->field[0]->value[1] = 0x12;
> + report->field[0]->value[2] = leds;
> + report->field[0]->value[3] = 0x00;
> + report->field[0]->value[4] = 0x00;
> + report->field[0]->value[5] = 0x00;
> + report->field[0]->value[6] = 0x00;
> + usbhid_submit_report(hid, report, USB_DIR_OUT);
> +}
> +
> +static void lg4ff_led_set_brightness(struct led_classdev *led_cdev,
> + enum led_brightness value)
> +{
> + struct device *dev = led_cdev->dev->parent;
> + struct hid_device *hid = container_of(dev, struct hid_device, dev);
> + struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
> + struct lg4ff_device_entry *entry;
> + int i, state = 0;
> +
> + if (!drv_data) {
> + hid_err(hid, "Device data not found.");
> + return;
> + }
> +
> + entry = (struct lg4ff_device_entry *)drv_data->device_props;
> +
> + if (!entry) {
> + hid_err(hid, "Device properties not found.");
> + return;
> + }
> +
> + for (i = 0; i < 5; i++) {
> + if (led_cdev != entry->led[i])
> + continue;
> + state = (entry->led_state >> i) & 1;
> + if (value == LED_OFF && state) {
> + entry->led_state &= ~(1 << i);
> + lg4ff_set_leds(hid, entry->led_state);
> + } else if (value != LED_OFF && !state) {
> + entry->led_state |= 1 << i;
> + lg4ff_set_leds(hid, entry->led_state);
> + }
> + break;
> + }
> +}
> +
> +static enum led_brightness lg4ff_led_get_brightness(struct led_classdev *led_cdev)
> +{
> + struct device *dev = led_cdev->dev->parent;
> + struct hid_device *hid = container_of(dev, struct hid_device, dev);
> + struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
> + struct lg4ff_device_entry *entry;
> + int i, value = 0;
> +
> + if (!drv_data) {
> + hid_err(hid, "Device data not found.");
> + return LED_OFF;
> + }
> +
> + entry = (struct lg4ff_device_entry *)drv_data->device_props;
> +
> + if (!entry) {
> + hid_err(hid, "Device properties not found.");
> + return LED_OFF;
> + }
> +
> + for (i = 0; i < 5; i++)
> + if (led_cdev == entry->led[i]) {
> + value = (entry->led_state >> i) & 1;
> + break;
> + }
> +
> + return value ? LED_FULL : LED_OFF;
> +}
> +#endif
> +
> int lg4ff_init(struct hid_device *hid)
> {
> struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
> @@ -453,6 +536,57 @@ int lg4ff_init(struct hid_device *hid)
> if (entry->set_range != NULL)
> entry->set_range(hid, entry->range);
>
> + /* register led subsystem - G27 only */
> + entry->led_state = 0;
> + for (j = 0; j < 5; j++)
> + entry->led[j] = NULL;
> +

The same here.

> +#ifdef CONFIG_LEDS_CLASS
> + if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G27_WHEEL) {
> + struct led_classdev *led;
> + size_t name_sz;
> + char *name;
> +
> + lg4ff_set_leds(hid, 0);
> +
> + name_sz = strlen(dev_name(&hid->dev)) + 8;
> +
> + for (j = 0; j < 5; j++) {
> + led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
> + if (!led) {
> + hid_err(hid, "can't allocate memory for LED %d\n", j);
> + goto err;
> + }
> +
> + name = (void *)(&led[1]);
> + snprintf(name, name_sz, "%s::RPM%d", dev_name(&hid->dev), j+1);
> + led->name = name;
> + led->brightness = 0;
> + led->max_brightness = 1;
> + led->brightness_get = lg4ff_led_get_brightness;
> + led->brightness_set = lg4ff_led_set_brightness;
> +
> + entry->led[j] = led;
> + error = led_classdev_register(&hid->dev, led);
> +
> + if (error) {
> + hid_err(hid, "failed to register LED %d. Aborting.\n", j);
> +err:
> + /* Deregister LEDs (if any) but let the driver continue */
> + for (j = 0; j < 5; j++) {
> + led = entry->led[j];
> + entry->led[j] = NULL;
> + if (!led)
> + continue;
> + led_classdev_unregister(led);
> + kfree(led);

Indentation seems to be wrong here.

> + }
> + break; /* Don't create any more LEDs */

Putting the whole err: label outside the outer for cycle would make the
whole thing much more readable (and would save you the break). Could you
please redo this?

> + }
> + }
> + }
> +#endif
> +
> hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@xxxxxxxxxxxxx>\n");
> return 0;
> }
> @@ -474,6 +608,25 @@ int lg4ff_deinit(struct hid_device *hid)
> hid_err(hid, "Error while deinitializing device, no device properties data.\n");
> return -1;
> }
> +
> +#ifdef CONFIG_LEDS_CLASS
> + {
> + int j;
> + struct led_classdev *led;
> +
> + /* Deregister LEDs (if any) */
> + for (j = 0; j < 5; j++) {
> +
> + led = entry->led[j];
> + entry->led[j] = NULL;
> + if (!led)
> + continue;
> + led_classdev_unregister(led);
> + kfree(led);
> + }
> + }
> +#endif
> +
> /* Deallocate memory */
> kfree(entry);
>

Thanks,

--
Jiri Kosina
SUSE Labs
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