samples: hid-mouse: protect report buffer

Use the message queue to pass the new report from the input callback,
and use a semaphore to protect the report buffer until it is transferred
to the host.

(cherry picked from commit 67a31ef)

Original-Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>
GitOrigin-RevId: 67a31ef
Change-Id: I1cd577c19818038ad57b0a96a3cfd95cfe8f8bfa
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5688009
Tested-by: Yuval Peress <peress@google.com>
Reviewed-by: Yuval Peress <peress@google.com>
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Commit-Queue: Yuval Peress <peress@google.com>

samples/subsys/usb/hid-mouse/prj.conf

@@ -10,3 +10,4 @@ CONFIG_USB_DEVICE_LOG_LEVEL_ERR=y
 
 CONFIG_GPIO=y
 CONFIG_INPUT=y
+CONFIG_INPUT_MODE_SYNCHRONOUS=y

samples/subsys/usb/hid-mouse/src/main.c

@@ -37,8 +37,8 @@ enum mouse_report_idx {
  MOUSE_REPORT_COUNT = 4,
 };
 
-static uint8_t __aligned(sizeof(void *)) report[MOUSE_REPORT_COUNT];
-static K_SEM_DEFINE(report_sem, 0, 1);
+K_MSGQ_DEFINE(mouse_msgq, MOUSE_REPORT_COUNT, 2, 1);
+static K_SEM_DEFINE(ep_write_sem, 0, 1);
 
 static inline void status_cb(enum usb_dc_status_code status, const uint8_t *param)
 {
@@ -57,9 +57,7 @@ static ALWAYS_INLINE void rwup_if_suspended(void)
 
 static void input_cb(struct input_event *evt)
 {
- uint8_t tmp[MOUSE_REPORT_COUNT];
-
- (void)memcpy(tmp, report, sizeof(tmp));
+ static uint8_t tmp[MOUSE_REPORT_COUNT];
 
  switch (evt->code) {
  case INPUT_KEY_0:
@@ -88,10 +86,13 @@ static void input_cb(struct input_event *evt)
  return;
  }
 
- if (memcmp(tmp, report, sizeof(tmp))) {
- memcpy(report, tmp, sizeof(report));
- k_sem_give(&report_sem);
+ if (k_msgq_put(&mouse_msgq, tmp, K_NO_WAIT) != 0) {
+ LOG_ERR("Failed to put new input event");
  }
+
+ tmp[MOUSE_X_REPORT_IDX] = 0U;
+ tmp[MOUSE_Y_REPORT_IDX] = 0U;
+
 }
 
 INPUT_CALLBACK_DEFINE(NULL, input_cb);
@@ -120,6 +121,16 @@ static int enable_usb_device_next(void)
 }
 #endif /* defined(CONFIG_USB_DEVICE_STACK_NEXT) */
 
+static void int_in_ready_cb(const struct device *dev)
+{
+ ARG_UNUSED(dev);
+ k_sem_give(&ep_write_sem);
+}
+
+static const struct hid_ops ops = {
+ .int_in_ready = int_in_ready_cb,
+};
+
 int main(void)
 {
  const struct device *hid_dev;
@@ -148,7 +159,7 @@ int main(void)
 
  usb_hid_register_device(hid_dev,
  hid_report_desc, sizeof(hid_report_desc),
- NULL);
+ &ops);
 
  usb_hid_init(hid_dev);
 
@@ -163,19 +174,17 @@ int main(void)
  }
 
  while (true) {
- k_sem_take(&report_sem, K_FOREVER);
+ uint8_t __aligned(sizeof(void *)) report[MOUSE_REPORT_COUNT];
+
+ k_msgq_get(&mouse_msgq, &report, K_FOREVER);
 
  ret = hid_int_ep_write(hid_dev, report, sizeof(report), NULL);
- report[MOUSE_X_REPORT_IDX] = 0U;
- report[MOUSE_Y_REPORT_IDX] = 0U;
  if (ret) {
  LOG_ERR("HID write error, %d", ret);
- }
-
- /* Toggle LED on sent report */
- ret = gpio_pin_toggle(led0.port, led0.pin);
- if (ret < 0) {
- LOG_ERR("Failed to toggle the LED pin, error: %d", ret);
+ } else {
+ k_sem_take(&ep_write_sem, K_FOREVER);
+ /* Toggle LED on sent report */
+ (void)gpio_pin_toggle(led0.port, led0.pin);
  }
  }
  return 0;