/* Port I/O abstraction macros - by Tom Torfs, 2006
 * MSP430 implementation
 * Donated to the public domain. No warranties whatsoever.
 *
 * These macros allow you to make easy abstraction of I/O port & pin numbers.
 * You simply define your signal location like:
 *	 #define LED P1,0
 * and then use them like:
 *	 SETDIR(LED);
 *	 CLR(LED);
 *	 TOGGLE(LED);
 *	...
 *
 * The obvious advantage, besides readability, is that in the next
 * hardware design or layout iteration - when most of the signals have
 * shifted to different pins on different ports - all you need to change 
 * is one simple and readable #define in a central location
 *
 * In addition, nothing stops you from porting this header to other
 * microcontroller families. The specifics such as direction and interrupt
 * registers may be different but the basic concepts hold.
 *
 * Overview of user macros:
 * - Reading from port registers: (these are meant to be used in expressions)
 *   x = IN(signal), OUTBUF(signal), DIR(signal), SEL(signal), IE(signal), IES(signal), IFG(signal)
 * - Writing to port registers: (these are meant to be used as statements)
 *   output bit manipulation: SET(signal); CLR(signal); TOGGLE(signal);
 *   direction bit manipulation: SETDIR(signal); CLRDIR(signal);
 *   special function bit manipulation: SETSEL(signal); CLRSEL(signal);
 *   interrupt bits manipulation: SETIE(signal); CLRIE(signal); SETIES(signal); CLRIES(signal);
 *   interrupt flag manipulation: SETIFG(signal); CLRIFG(signal);
 *   copy 1 or 0 into output bit: CPYBIT(signal,bitvalue)
 * - Getting the port name (string) or bit number (integer literal) corresponding to a signal:
 *   const char s[] = PORTNAME(name); 
 *   x = BITNUM(name);
 * - Interrupt vector for port corresponding to a signal: (requires compiler-specific mapping)
 *   INTVECTOR(name)
 */

/********** HELPER MACROS **********/

#define POUT_(Pn) Pn##OUT
#define PIN_(Pn)  Pn##IN
#define PDIR_(Pn) Pn##DIR
#define PSEL_(Pn) Pn##SEL
#define PIE_(Pn)  Pn##IE
#define PIES_(Pn) Pn##IES
#define PIFG_(Pn) Pn##IFG

#define IN_(p,b)  (PIN_(p)&(1<<b))
#define OUTBUF_(p,b) (POUT_(p)&(1<<b))
#define DIR_(p,b) (PDIR_(p)&(1<<b))
#define SEL_(p,b) (PSEL_(p)&(1<<b))
#define IE_(p,b)  (PIE_(p)&(1<<b))
#define IES_(p,b) (PIES_(p)&(1<<b))
#define IFG_(p,b) (PIFG_(p)&(1<<b))

#define SET_(p,b) POUT_(p)|=(1<<(b))
#define CLR_(p,b) POUT_(p)&=~(1<<(b))
#define TOGGLE_(p,b) POUT_(p)^=(1<<(b))
#define SETDIR_(p,b) PDIR_(p)|=(1<<(b))
#define SETSEL_(p,b) PSEL_(p)|=(1<<(b))
#define SETIE_(p,b)  PIE_(p)|=(1<<(b))
#define SETIES_(p,b) PIES_(p)|=(1<<(b))
#define SETIFG_(p,b) PIFG_(p)|=(1<<(b))
#define CLRDIR_(p,b) PDIR_(p)&=~(1<<(b))
#define CLRSEL_(p,b) PSEL_(p)&=~(1<<(b))
#define CLRIE_(p,b)  PIE_(p)&=~(1<<(b))
#define CLRIES_(p,b) PIES_(p)&=~(1<<(b))
#define CLRIFG_(p,b) PIFG_(p)&=~(1<<(b))

#define PORTNAME_(p,b) #p
#define BITNUM_(p,b) b

#define INTVECTOR_(p,b) INTVECTOR_##p

/********** USER MACROS **********/

/* for reading from port registers 
   note: these return 0 or nonzero, not 0 or 1
         if necessary, use as: x = IN(signal) ? 1 : 0; 
		 not necessary for normal use in if() etc. */
#define IN(name)  IN_(name)
#define OUTBUF(name) OUTBUF_(name)
#define DIR(name) DIR_(name)
#define SEL(name) SEL_(name)
#define IE(name)  IE_(name)
#define IES(name) IES_(name)
#define IFG(name) IFG_(name)

/* for writing to port registers */
#define SET(name) SET_(name)
#define CLR(name) CLR_(name)
#define TOGGLE(name) TOGGLE_(name)
#define SETDIR(name) SETDIR_(name)
#define SETSEL(name) SETSEL_(name)
#define SETIE(name)  SETIE_(name)
#define SETIES(name) SETIES_(name)
#define SETIFG(name) SETIFG_(name)
#define CLRDIR(name) CLRDIR_(name)
#define CLRSEL(name) CLRSEL_(name)
#define CLRIE(name)  CLRIE_(name)
#define CLRIES(name) CLRIES_(name)
#define CLRIFG(name) CLRIFG_(name)

#define CPYBIT(name,bit) ((bit) ? (SET_(name)) : (CLR_(name)))

/* if you want to know the port (string) or the bit number (integer literal) */
#define PORTNAME(name) PORTNAME_(name)
#define BITNUM(name)   BITNUM_(name)

/* interrupt vector for port */
#define INTVECTOR(name) INTVECTOR_(name)

/* mapping to compiler-specific interrupt vector names/numbers
   (this is for mspgcc, adapt for your compiler) */
#define INTVECTOR_P1 PORT1_VECTOR
#define INTVECTOR_P2 PORT2_VECTOR

/* USAGE EXAMPLE:

   - define your port I/O's as follows: (note you MUST use a #define, not an enum)
	#define LED P1,0
	#define INPUTSIGNAL P2,1
	#define ANALOGSIGNAL P6,3
	#define INTSIGNAL P2,2
	#define SIGBIT0 P3,7
	#define SIGBIT1 P3,6
	#define SIGBIT2 P3,5
	#define UNUSED1 P1,5
	#define UNUSED2 P1,6
	#define UNUSED3 P1,7

   - examples of usage:
	SETDIR(LED); CLR(LED); TOGGLE(LED);
	CLRDIR(INPUTSIGNAL); x = IN(INPUTSIGNAL);
	SETSEL(ANALOGSIGNAL);
	SETIE(INTSIGNAL); CLRIE(INTSIGNAL);
	CPYBIT(SIGBIT0,x&1); CPYBIT(SIGBIT1,x&2); CPYBIT(SIGBIT2,x&4);
	SETDIR(UNUSED1); SETDIR(UNUSED2); SETDIR(UNUSED3); // set to output to save power
	printf("The LED is on port %s, bit %d.\n", PORTNAME(LED), BITNUM(LED));
    ADC12MCTL0 = SREF_0 | BITNUM(ANALOGSIGNAL);

   - example interrupt routine (compiler-specific syntax)
	interrupt(INTVECTOR(INTSIGNAL)) int_func(void)
	{
		if (IFG(INTSIGNAL))
		{
			// do something...
			CLRIFG(INTSIGNAL);	// clear interrupt flag
		}
	}
*/