capture:add CAPIOC_ALL for ioctl.

When monitoring multiple capture channels, the `ioctl` function
is called three times, leading to significant overhead mainly due
to VFS and `nxmutex_lock/unlock`. Adding a new interface can save
the overhead of two `ioctl` calls.

Signed-off-by: yangguangcai <yangguangcai@xiaomi.com>

drivers/timers/capture.c

@@ -316,6 +316,39 @@ static int cap_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         }
         break;
 
+      /* CAPIOC_ALL - Get the pwm duty, pulse frequence, pwm edges, from
+       * the capture.
+       * Argument: A reference to struct cap_all_s.
+       */
+
+      case CAPIOC_ALL:
+        {
+          FAR struct cap_all_s *ptr =
+                     (FAR struct cap_all_s *)((uintptr_t)arg);
+          DEBUGASSERT(lower->ops->getduty != NULL && ptr);
+          DEBUGASSERT(lower->ops->getedges != NULL && ptr);
+          DEBUGASSERT(lower->ops->getfreq != NULL && ptr);
+
+          ret = lower->ops->getduty(lower, &ptr->duty);
+          if (ret < 0)
+            {
+              break;
+            }
+
+          ret = lower->ops->getfreq(lower, &ptr->freq);
+          if (ret < 0)
+            {
+              break;
+            }
+
+          ret = lower->ops->getedges(lower, &ptr->edges);
+          if (ret < 0)
+            {
+              break;
+            }
+        }
+        break;
+
       /* Any unrecognized IOCTL commands might be platform-specific ioctl
        * commands
        */

include/nuttx/timers/capture.h

@@ -37,11 +37,19 @@
 #define CAPIOC_DUTYCYCLE _CAPIOC(1)
 #define CAPIOC_FREQUENCE _CAPIOC(2)
 #define CAPIOC_EDGES     _CAPIOC(3)
+#define CAPIOC_ALL       _CAPIOC(4)
 
 /****************************************************************************
  * Public Types
  ****************************************************************************/
 
+struct cap_all_s
+{
+  uint32_t freq;
+  uint32_t edges;
+  uint8_t  duty;
+};
+
 /* This structure provides the "lower-half" driver operations available to
  * the "upper-half" driver.
  */