[radio] remove OT_RADIO_CHANNEL_PAGE_MAX and address gcc warnings (#6646)

This commit modifies the (<=) usage in two ‘if’ conditions as these
operations as written today (with constants), are resulting in the
compile time warnings (and cmake errors) specifically when working
with proprietary radio configurations and setting Channel Min to 0.

Updated the radio header to get rid of OT_RADIO_CHANNEL_PAGE_MAX. Also
adds a compile-time error, if a user sets the proprietary channel page
to a value greater than 31, as it is currently not supported.

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (115)
+#define OPENTHREAD_API_VERSION (116)
 
 /**
  * @addtogroup api-instance

include/openthread/platform/radio.h

@@ -88,7 +88,6 @@ enum
     OT_RADIO_CHANNEL_PAGE_0_MASK = (1U << OT_RADIO_CHANNEL_PAGE_0), ///< 2.4 GHz IEEE 802.15.4-2006
     OT_RADIO_CHANNEL_PAGE_2      = 2,                               ///< 915 MHz IEEE 802.15.4-2006
     OT_RADIO_CHANNEL_PAGE_2_MASK = (1U << OT_RADIO_CHANNEL_PAGE_2), ///< 915 MHz IEEE 802.15.4-2006
-    OT_RADIO_CHANNEL_PAGE_MAX    = OT_RADIO_CHANNEL_PAGE_2,         ///< Maximum supported channel page value
 };
 
 /**

src/core/config/platform.h

@@ -140,6 +140,10 @@
  OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MASK\
  to be defined by Platform."
 #endif
+
+#if OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_PAGE > 31
+#error "Maximum Proprietary Channel Page value currently supported is 31."
+#endif
 #endif
 
 #endif // CONFIG_PLATFORM_H_

src/core/meshcop/meshcop_tlvs.cpp

@@ -173,7 +173,6 @@ bool ChannelTlv::IsValid(void) const
     bool ret = false;
 
     VerifyOrExit(GetLength() == sizeof(*this) - sizeof(Tlv));
-    VerifyOrExit(mChannelPage <= OT_RADIO_CHANNEL_PAGE_MAX);
     VerifyOrExit((1U << mChannelPage) & Radio::kSupportedChannelPages);
     VerifyOrExit(Radio::kChannelMin <= GetChannel() && GetChannel() <= Radio::kChannelMax);
     ret = true;
@@ -201,8 +200,9 @@ void ChannelTlv::SetChannel(uint16_t aChannel)
 #endif
 
 #if OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_SUPPORT
-    if ((OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MIN <= aChannel) &&
-        (aChannel <= OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MAX))
+    if ((OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MIN == aChannel) ||
+        ((OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MIN < aChannel) &&
+         (aChannel <= OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_MAX)))
     {
         channelPage = OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_PAGE;
     }
@@ -228,7 +228,11 @@ bool ChannelMaskBaseTlv::IsValid(void) const
 
         channelPage = cur->GetChannelPage();
 
+#if OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_SUPPORT
+        if (channelPage == OPENTHREAD_CONFIG_PLATFORM_RADIO_PROPRIETARY_CHANNEL_PAGE)
+#else
         if ((channelPage == OT_RADIO_CHANNEL_PAGE_0) || (channelPage == OT_RADIO_CHANNEL_PAGE_2))
+#endif
         {
             VerifyOrExit(static_cast<const ChannelMaskEntry *>(cur)->IsValid());
         }

src/core/radio/radio.hpp

@@ -635,7 +635,8 @@ public:
      */
     static bool IsCslChannelValid(uint8_t aCslChannel)
     {
-        return (aCslChannel == 0) || ((kChannelMin <= aCslChannel) && (aCslChannel <= kChannelMax));
+        return ((aCslChannel == 0) ||
+                ((kChannelMin == aCslChannel) || ((kChannelMin < aCslChannel) && (aCslChannel <= kChannelMax))));
     }
 
 private: