From 281a1b6569b97d1de5b2c6a295f75b3f5aec1e41 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 21 Jun 2018 13:08:58 +1000
Subject: [PATCH] AP_HAL: added I2C bus mask functions and macros

---
 libraries/AP_HAL/I2CDevice.h   | 22 ++++++++++++++++++++++
 libraries/AP_HAL/board/linux.h | 13 +++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/libraries/AP_HAL/I2CDevice.h b/libraries/AP_HAL/I2CDevice.h
index 28dca3e59d..55a58bff39 100644
--- a/libraries/AP_HAL/I2CDevice.h
+++ b/libraries/AP_HAL/I2CDevice.h
@@ -89,6 +89,28 @@ public:
         // Not implemented
         return nullptr;
     }
+
+    /*
+      get mask of bus numbers for all configured I2C buses
+     */
+    virtual uint32_t get_bus_mask(void) const { return 0x0F; }
+
+    /*
+      get mask of bus numbers for all configured external I2C buses
+     */
+    virtual uint32_t get_bus_mask_external(void) const { return 0x0F; }
+
+    /*
+      get mask of bus numbers for all configured internal I2C buses
+     */
+    virtual uint32_t get_bus_mask_internal(void) const { return 0x01; }
 };
 
+/*
+  convenient macros for iterating over I2C bus numbers
+ */
+#define FOREACH_I2C_EXTERNAL(i) for (uint32_t _bmask=hal.i2c_mgr->get_bus_mask_external(), i=0; i<32; i++) if ((1U<<i)&_bmask)
+#define FOREACH_I2C_INTERNAL(i) for (uint32_t _bmask=hal.i2c_mgr->get_bus_mask_internal(), i=0; i<32; i++) if ((1U<<i)&_bmask)
+#define FOREACH_I2C(i) for (uint32_t _bmask=hal.i2c_mgr->get_bus_mask(), i=0; i<32; i++) if ((1U<<i)&_bmask)
+    
 }
diff --git a/libraries/AP_HAL/board/linux.h b/libraries/AP_HAL/board/linux.h
index 3b002ecbd8..be4fefad5b 100644
--- a/libraries/AP_HAL/board/linux.h
+++ b/libraries/AP_HAL/board/linux.h
@@ -382,3 +382,16 @@
 #ifndef HAL_BOARD_CAN_IFACE_NAME
 #define HAL_BOARD_CAN_IFACE_NAME "can0"
 #endif
+
+// if bus masks are not setup above then use these defaults
+#ifndef HAL_LINUX_I2C_BUS_MASK
+#define HAL_LINUX_I2C_BUS_MASK 0x1f
+#endif
+
+#ifndef HAL_LINUX_I2C_INTERNAL_BUS_MASK
+#define HAL_LINUX_I2C_INTERNAL_BUS_MASK 0x01
+#endif
+
+#ifndef HAL_LINUX_I2C_EXTERNAL_BUS_MASK
+#define HAL_LINUX_I2C_EXTERNAL_BUS_MASK 0x1E
+#endif