ads7843.h

触摸屏驱动芯片ADS7843在LINUX2.6内核下的驱动程序

#ifndef _ADS_7843_H_
#define _ADS_7843_H_

// ADS7843 Control Byte bit defines
#define ADS7843_CMD_START	0x0080
#define ADS7843_ADDR_BIT	4
#define ADS7843_ADDR_MASK 	(0x7<<ADS7843_ADDR_BIT)
#define ADS7843_MEASURE_X  	(0x5<<ADS7843_ADDR_BIT)
#define ADS7843_MEASURE_Y  	(0x1<<ADS7843_ADDR_BIT)
#define ADS7843_MEASURE_Z1 	(0x3<<ADS7843_ADDR_BIT)
#define ADS7843_MEASURE_Z2 	(0x4<<ADS7843_ADDR_BIT)
#define ADS7843_8BITS     	(1<<3)
#define ADS7843_12BITS    	0
#define ADS7843_SER       	(1<<2)
#define ADS7843_DFR       	0
#define ADS7843_PWR_BIT   	0
#define ADS7843_PD      	0
#define ADS7843_ADC_ON  	(0x1<<ADS7843_PWR_BIT)
#define ADS7843_REF_ON  	(0x2<<ADS7843_PWR_BIT)
#define ADS7843_REF_ADC_ON 	(0x3<<ADS7843_PWR_BIT)

#define MEASURE_8BIT_X\
    (unsigned short)(ADS7843_CMD_START | ADS7843_MEASURE_X | ADS7843_8BITS | ADS7843_DFR | ADS7843_PD)
#define MEASURE_8BIT_Y\
    (unsigned short)(ADS7843_CMD_START | ADS7843_MEASURE_Y | ADS7843_8BITS | ADS7843_DFR | ADS7843_PD)

#define MEASURE_12BIT_X \
    (unsigned short)(ADS7843_CMD_START | ADS7843_MEASURE_X | ADS7843_12BITS | ADS7843_DFR | ADS7843_PD)
#define MEASURE_12BIT_Y \
    (unsigned short)(ADS7843_CMD_START | ADS7843_MEASURE_Y | ADS7843_12BITS | ADS7843_DFR | ADS7843_PD)
#define MEASURE_12BIT_Z1 \
    (unsigned char)(ADS7843_MEASURE_Z1 | ADS7843_12BITS | ADS7843_DFR | ADS7843_PD)
#define MEASURE_12BIT_Z2 \
    (unsigned char)(ADS7843_MEASURE_Z2 | ADS7843_12BITS | ADS7843_DFR | ADS7843_PD)
/*
 *  Hardware Pins
 */
#define TS_CLK	AT91_PIN_PD1
#define TS_CS	   	AT91_PIN_PD5
#define TS_DIN	AT91_PIN_PD2
#define TS_DOUT	AT91_PIN_PD3
/*
 * This structure is nonsense - millisecs is not very useful
 * since the field size is too small.  Also, we SHOULD NOT
 * be exposing jiffies to user space directly.
 */
struct ts_event {
	unsigned short		pressure;
	unsigned short		x;
	unsigned short		y;
	unsigned short		pad;
	struct timeval	stamp;
};

#define NR_EVENTS	16
struct ads7843_dev{
	struct semaphore	sem;
	struct cdev cdev;
	int			use_count;
	
	u8			evt_head;
	u8			evt_tail;
	struct ts_event	events[NR_EVENTS];
	struct timer_list	timer;	
};
#define ads7843_ts_evt_pending(ts)	((volatile u8)(ts)->evt_head != (ts)->evt_tail)
#define ads7843_ts_evt_get(ts)		((ts)->events + (ts)->evt_tail)
#define ads7843_ts_evt_pull(ts)		((ts)->evt_tail = ((ts)->evt_tail + 1) & (NR_EVENTS - 1))
#define ads7843_ts_evt_clear(ts)	((ts)->evt_head = (ts)->evt_tail = 0)

#endif /* _ADS_7843_H_ */