Infinite reads handling

[openparking.git] / firmware / modbus.h

diff --git a/firmware/modbus.h b/firmware/modbus.h
old mode 100755 (executable)
new mode 100644 (file)
index 4218317..3a3fcdf
--- a/firmware/modbus.h
+++ b/firmware/modbus.h
@@ -8,7 +8,31 @@
  * All bugs by Jan "Yenya" Kasprzak <kas@fi.muni.cz> :-)
  */
 
  * All bugs by Jan "Yenya" Kasprzak <kas@fi.muni.cz> :-)
  */
 

-void modbus_init();
-void modbus_poll();
+/*
+ * Call this at the beginning of the program.
+ */
+void modbus_init(uint8_t unit_id);
+
+/*
+ * Call this frequently. Returns 0 when no data was received
+ * and the processing went on quickly. Returns 1 after potentially lengthy
+ * packet processing.
+ */
+uint8_t modbus_poll();
+
+typedef enum {
+       MB_OK = 0,
+       MB_ILLEGAL_FUNC = 1,
+       MB_ILLEGAL_ADDR = 2,
+       MB_ILLEGAL_VAL  = 3,
+} mb_exception;
+
+#define MB_HOLD_REGS_BASE      0       // first register
+#define MB_N_HOLD_REGS         80      // total # of registers
+#define MB_N_HOLD_REGS_EEPROM  20      // the first N registers eeprom-backed
+extern uint16_t hold_regs[MB_N_HOLD_REGS];
+#define mb_unit_id     (hold_regs[0])  // MODBUS id in the first register
+
+uint8_t hold_reg_is_valid(uint16_t reg, uint16_t val);

 
 #endif /* MODBUS_H__ */
 
 #endif /* MODBUS_H__ */