nuclear@6: #ifndef MEGADRIVE_IO_H_
nuclear@6: #define MEGADRIVE_IO_H_
nuclear@6: 
nuclear@7: #include <stdint.h>
nuclear@7: 
nuclear@7: #define IO_REG_VER		*((volatile uint8_t*)0xa10001)
nuclear@7: #define IO_REG_DATA1	*((volatile uint8_t*)0xa10003)
nuclear@7: #define IO_REG_DATA2	*((volatile uint8_t*)0xa10005)
nuclear@7: #define IO_REG_DATA3	*((volatile uint8_t*)0xa10007)
nuclear@7: #define IO_REG_CTRL1	*((volatile uint8_t*)0xa10009)
nuclear@7: #define IO_REG_CTRL2	*((volatile uint8_t*)0xa1000b)
nuclear@7: #define IO_REG_CTRL3	*((volatile uint8_t*)0xa1000d)
nuclear@7: #define IO_REG_TXDATA1	*((volatile uint8_t*)0xa1000f)
nuclear@7: #define IO_REG_RXDATA1	*((volatile uint8_t*)0xa10011)
nuclear@7: #define IO_REG_S_CTRL1	*((volatile uint8_t*)0xa10013)
nuclear@7: #define IO_REG_TXDATA2	*((volatile uint8_t*)0xa10015)
nuclear@7: #define IO_REG_RXDATA2	*((volatile uint8_t*)0xa10017)
nuclear@7: #define IO_REG_S_CTRL2	*((volatile uint8_t*)0xa10013)
nuclear@7: #define IO_REG_TXDATA3	*((volatile uint8_t*)0xa1001b)
nuclear@7: #define IO_REG_RXDATA3	*((volatile uint8_t*)0xa1001d)
nuclear@7: #define IO_REG_S_CTRL3	*((volatile uint8_t*)0xa1001f)
nuclear@7: #define IO_REG_LOCK		*((volatile uint8_t*)0xa14000)
nuclear@7: #define IO_REG_TMSS		*((volatile uint8_t*)0xa14101)
nuclear@7: 
nuclear@8: #define IO_REG_DATA(x)	*((volatile uint8_t*)0xa10003 + ((x) << 1))
nuclear@8: #define IO_REG_CTRL(x)	*((volatile uint8_t*)0xa10009 + ((x) << 1))
nuclear@8: 
nuclear@6: 
nuclear@6: enum {
nuclear@6: 	IO_VER_VERSION_MASK = 0x0f,
nuclear@6: 	IO_VER_EXP		= 0x20,
nuclear@6: 	IO_VER_PAL		= 0x40,
nuclear@6: 	IO_VER_NONJP	= 0x80
nuclear@6: };
nuclear@6: 
nuclear@8: enum {
nuclear@11: 	IO_PAD_UP		= 0x001,
nuclear@11: 	IO_PAD_DOWN		= 0x002,
nuclear@11: 	IO_PAD_LEFT		= 0x004,
nuclear@11: 	IO_PAD_RIGHT	= 0x008,
nuclear@11: 	IO_PAD_B		= 0x010,
nuclear@11: 	IO_PAD_C		= 0x020,
nuclear@11: 	IO_PAD_A		= 0x040,
nuclear@11: 	IO_PAD_START	= 0x080,
nuclear@11: 
nuclear@11: 	IO_PAD_Z		= 0x100,
nuclear@11: 	IO_PAD_Y		= 0x200,
nuclear@11: 	IO_PAD_X		= 0x400
nuclear@8: };
nuclear@10: #define IO_PAD_LOW_MASK		0x3f
nuclear@10: #define IO_PAD_HIGH_MASK	(IO_PAD_A | IO_PAD_START)
nuclear@8: 
nuclear@8: static inline void io_setdir(int port, uint8_t dir)
nuclear@8: {
nuclear@8: 	IO_REG_CTRL(port) = dir;
nuclear@8: }
nuclear@8: 
nuclear@8: static inline uint16_t io_readpad(int port)
nuclear@8: {
nuclear@8: 	uint16_t bnstate;
nuclear@8: 
nuclear@10: 	bnstate = ~(IO_REG_DATA(port) << 2) & IO_PAD_HIGH_MASK;
nuclear@10: 
nuclear@8: 	IO_REG_DATA(port) = 0x40;	/* select mode 1 */
nuclear@10: 	asm volatile("nop");
nuclear@10: 	asm volatile("nop");
nuclear@10: 	bnstate |= ~IO_REG_DATA(port) & IO_PAD_LOW_MASK;
nuclear@10: 
nuclear@8: 	IO_REG_DATA(port) = 0;		/* select mode 0 */
nuclear@10: 	return bnstate;
nuclear@8: }
nuclear@8: 
nuclear@11: static inline uint16_t io_readpad6(int port)
nuclear@11: {
nuclear@11: 	uint16_t bnstate;
nuclear@11: 
nuclear@11: 	IO_REG_DATA(port) = 0x40;	/* start with mode 1 */
nuclear@11: 	asm volatile("nop");
nuclear@11: 	asm volatile("nop");
nuclear@11: 	bnstate = ~IO_REG_DATA(port) & IO_PAD_LOW_MASK;
nuclear@11: 
nuclear@11: 	IO_REG_DATA(port) = 0;		/* select mode 0 */
nuclear@11: 	asm volatile("nop");
nuclear@11: 	asm volatile("nop");
nuclear@11: 	bnstate |= ~(IO_REG_DATA(port) << 2) & IO_PAD_HIGH_MASK;
nuclear@11: 
nuclear@11: 	/* then introduce two more rising edges to trigger extended mode */
nuclear@11: 	IO_REG_DATA(port) = 0x40;
nuclear@11: 	asm volatile("nop");
nuclear@11: 	asm volatile("nop");
nuclear@11: 	IO_REG_DATA(port) = 0;
nuclear@11: 	asm volatile("nop");
nuclear@11: 	asm volatile("nop");
nuclear@11: 	IO_REG_DATA(port) = 0x40;
nuclear@11: 	asm volatile("nop");
nuclear@11: 	asm volatile("nop");
nuclear@11: 
nuclear@11: 	bnstate |= (uint16_t)(~IO_REG_DATA(port) & 0x7) << 8;
nuclear@11: 	IO_REG_DATA(port) = 0;		/* return mode to 0 */
nuclear@11: 	return bnstate;
nuclear@11: }
nuclear@11: 
nuclear@10: void io_init(void);
nuclear@10: /*uint16_t io_readpad(int port);*/
nuclear@10: 
nuclear@6: #endif	/* MEGADRIVE_IO_H_ */