mc68328digi.c

老外写的触摸屏驱动程序

/*
 * Write the SPIM (data and control).
 */
#define SET_SPIMDATA(x) { SPIMDATA = x; }
#define SET_SPIMCONT(x) { SPIMCONT = x; }

/*----------------------------------------------------------------------------*/

#define SPIM_ENABLE  { SET_SPIMCONT(SPIMCONT_ENABLE); }  /* enable SPIM       */
#define SPIM_INIT    { SPIMCONT |= SPIMCONT_INIT; }      /* init SPIM         */
#define SPIM_DISABLE { SET_SPIMCONT(0x0000); }           /* disable SPIM      */

/*----------------------------------------------------------------------------*/
#ifdef CONFIG_XCOPILOT_BUGS
# define CARD_SELECT   
# define CARD_DESELECT 
#else
# define CARD_SELECT   { CS_DATA &= ~CS_MASK; }     /* PB4 active (=low)       */
# define CARD_DESELECT { CS_DATA |=  CS_MASK; }     /* PB4 inactive (=high)    */
#endif
/*----------------------------------------------------------------------------*/

#define ENABLE_PEN_IRQ    { IMR &= ~IMR_MPEN; }
#define ENABLE_SPIM_IRQ   { IMR &= ~IMR_MSPI; SPIMCONT |= SPIMCONT_IRQEN; }

#define DISABLE_PEN_IRQ   { IMR |= IMR_MPEN; }
#define DISABLE_SPIM_IRQ  { SPIMCONT &= ~SPIMCONT_IRQEN; IMR |= IMR_MSPI; }

#define CLEAR_SPIM_IRQ    { SPIMCONT &= ~SPIMCONT_IRQ; }

/*----------------------------------------------------------------------------*/
/* predefinitions ------------------------------------------------------------*/

static void handle_timeout(void);
static void handle_pen_irq(int irq, void *dev_id, struct pt_regs *regs);
static void handle_spi_irq(void);

/*----------------------------------------------------------------------------*/
/* structure -----------------------------------------------------------------*/

struct ts_pen_position { int x,y; };

struct ts_queue {
  unsigned long head;
  unsigned long tail;
  wait_queue_head_t proc_list;
  struct fasync_struct *fasync;
  unsigned char buf[TS_BUF_SIZE];
};

/*----------------------------------------------------------------------------*/
/* Variables -----------------------------------------------------------------*/

/*
 * driver state variable.
 */
static int ts_drv_state;

/*
 * first tick initiated at ts_open.
 */
static struct timeval   first_tick;

/*
 * pen state.
 */
static int new_pen_state;

/*
 * event counter.
 */
static int ev_counter;

/*
 * counter to differentiate a click from a move.
 */
static int state_counter;

static struct timer_list         ts_wake_time;

/*
 * drv parameters.
 */
static struct ts_drv_params      current_params;
static int                       sample_ticks;
/*
 * pen info variables.
 */
static struct ts_pen_info        ts_pen;
static struct ts_pen_info        ts_pen_prev;
static struct ts_pen_position    current_pos;

/*
 * driver management.
 */
static struct ts_queue *queue;
static int    device_open = 0;   /* number of open device to prevent concurrent
                                  * access to the same device
				  */


/*----------------------------------------------------------------------------*/
/* Init & release functions --------------------------------------------------*/

static void init_ts_state(void) {
  DISABLE_SPIM_IRQ;      /* Disable SPIM interrupt */

  ts_drv_state = TS_DRV_IDLE;
  state_counter = 0;

  ENABLE_PEN_IRQ;        /* Enable interrupt IRQ5  */
}

static void init_ts_pen_values(void) {
  ts_pen.x = 0;ts_pen.y = 0;
  ts_pen.dx = 0;ts_pen.dy = 0;
  ts_pen.event = EV_PEN_UP;
  ts_pen.state &= 0;ts_pen.state |= ST_PEN_UP;

  ts_pen_prev.x = 0;ts_pen_prev.y = 0;
  ts_pen_prev.dx = 0;ts_pen_prev.dy = 0;
  ts_pen_prev.event = EV_PEN_UP;
  ts_pen_prev.state &= 0;ts_pen_prev.state |= ST_PEN_UP;
  
  new_pen_state = 0;
  ev_counter = 0;
  do_gettimeofday(&first_tick);
}

static void init_ts_timer(struct timer_list *timer) {
  init_timer(timer);
  timer->function = (void *)handle_timeout;
}

static void release_ts_timer(struct timer_list *timer) {
  del_timer(timer);
}

/*
 * Set default values for the params of the driver.
 */
static void init_ts_settings(void) {
  current_params.version = MC68328DIGI_VERSION;
  current_params.version_req = 0;
  current_params.x_ratio_num = 1;
  current_params.x_ratio_den = 1;
  current_params.y_ratio_num = 1;
  current_params.y_ratio_den = 1;
  current_params.x_offset = 0;
  current_params.y_offset = 0;
  current_params.xy_swap = 1;
  current_params.x_min = 0;
  current_params.x_max = 4095;
  current_params.y_min = 0;
  current_params.y_max = 4095;
  current_params.mv_thrs = 50;
  current_params.follow_thrs = 5;    /* to eliminate the conversion noise */
  current_params.sample_ms = 20;
  current_params.deglitch_on = 1; //added by duwei 07/03/2003
  current_params.deglitch_ms=1;
  current_params.event_queue_on = 1;
  sample_ticks = TICKS(current_params.sample_ms);
}

static void init_ts_hardware(void) {
  /* Set bit 2 of port F for interrupt (IRQ5 for pen_irq)                 */
#if 0
  PENIRQ_PUEN |= PEN_MASK;     /* Port F as pull-up			*/
#endif
  PENIRQ_DIR &= ~PEN_MASK;    /* PF1 as input                                 */
  PENIRQ_SEL &= ~PEN_MASK;    /* PF1 internal chip function is connected
			       */
#if 0
  /* Set polarity of IRQ5 as low (interrupt occure when signal is low)    */
  ICR &= ~ICR_PENPOL;
#endif

  /* Init stuff for port E. The 3 LSB are multiplexed with the SPIM       */
  PESEL &= ~PESEL_MASK;
  
  /* Set bit 4 of port B for the CARD_SELECT signal of ADS7843 as output. */
#ifndef CONFIG_XCOPILOT_BUGS
  CS_PUEN |= CS_MASK;       /* Port B as pull-up                           */
  CS_DIR  |= CS_MASK;       /* PB4 as output                               */
  CS_DATA |= CS_MASK;       /* PB4 inactive (=high)                        */
  CS_SEL  |= CS_MASK;       /* PB4 as I/O not dedicated                    */
#endif
  
  /* Set bit 5 of port F for the BUSY signal of ADS7843 as input          */
 // PFPUEN |= BUSY_MASK;     /* Port F as pull-up                           */
 //PFDIR  &= ~BUSY_MASK;    /* PF5 as input                                */
 // PFSEL  |= BUSY_MASK;     /* PF5 I/O port function pin is connected      */
//changed by duwei 03/21/2003

  PBPUEN |= BUSY_MASK;     /* Port F as pull-up                           */
  PBDIR  &= ~BUSY_MASK;    /* PF5 as input                                */
  PBSEL  |= BUSY_MASK;     /* PF5 I/O port function pin is connected      */

#ifdef USE_PENIRQ_PULLUP
  /* Set bit 4 of port D for the pen irq pull-up of ADS7843 as output.    */
  PDDIR  |= PEN_MASK_2;    /* PD4 as output                               */
  PDDATA |= PEN_MASK_2;    /* PD4 up (pull-up)                            */
  PDPUEN |= PEN_MASK_2;    /* PD4 as pull-up                              */
#ifndef CONFIG_XCOPILOT_BUGS
  PDSEL  |= PEN_MASK_2;    /* PD4 I/O port function pin is connected      */
#endif
#endif
}


/*
 * Reset bits used in each register to their default value.
 */
static void release_ts_hardware(void) {
                          /* Register   default value */
#ifndef CONFIG_XCOPILOT_BUGS
  PESEL  |= PESEL_MASK;   /* PESEL      0xFF          */
  CS_DIR  &= ~CS_MASK;    /* PBDIR      0x00          */
  //CS_DIR |= CS_MASK;  //changed by duwei  05/29/2003
  CS_DATA &= ~CS_MASK;    /* PBDATA     0x00          */
  CS_PUEN |= CS_MASK;     /* PBPUEN     0xFF          */
  CS_SEL  |= CS_MASK;     /* PBSEL      0xFF          */
#ifdef USE_PENIRQ_PULLUP
  PDDIR  |= PEN_MASK_2;   /* PDDIR      0xFF          */
  PDDATA |= PEN_MASK_2;   /* PDDATA     0xF0          */
  PDPUEN |= PEN_MASK_2;   /* PDPUEN     0xFF          */
  PDSEL  |= PEN_MASK_2;   /* PDSEL      0xF0          */
#endif
  PENIRQ_PUEN |= PEN_MASK;     /* PFPUEN     0xFF          */
  PENIRQ_DIR  &= ~PEN_MASK;    /* PFDIR      0x00          */
  PENIRQ_SEL  |= PEN_MASK;     /* PFSEL      0xFF          */
#endif
  IMR    |= IMR_MPEN;     /* IMR        0xFFFFFFFF    */
                          /* I release it anyway!     */ 
}

static void init_ts_drv(void) {
  printk("a\n");
  init_ts_state();
  printk("b\n");
  init_ts_pen_values();
  printk("c\n");
  init_ts_timer(&ts_wake_time);
  printk("d\n");
  init_ts_hardware();
  printk("e\n");
}

static void release_ts_drv(void) {
  release_ts_timer(&ts_wake_time);
  release_ts_hardware();
}


/*----------------------------------------------------------------------------*/
/* scaling functions ---------------------------------------------------------*/

static inline void rescale_xpos(int *x) {
  *x &= CONV_MASK;

  *x *= current_params.x_ratio_num;
  *x /= current_params.x_ratio_den;
  *x += current_params.x_offset;
  *x = (*x > current_params.x_max ? current_params.x_max :
	(*x < current_params.x_min ? current_params.x_min :
	 *x));
}

static inline void rescale_ypos(int *y) {
  *y &= CONV_MASK;

  *y *= current_params.y_ratio_num;
  *y /= current_params.y_ratio_den;
  *y += current_params.y_offset;
  *y = (*y > current_params.y_max ? current_params.y_max :
	(*y < current_params.y_min ? current_params.y_min :
	 *y));
}

static inline void swap_xy(int *x, int *y)
{
  if(current_params.xy_swap) {
    int t = *x;
    *x = *y;
    *y = t;
  }
}

/*----------------------------------------------------------------------------*/
/* xcopilot compatibility hacks ----------------------------------------------*/
#ifdef CONFIG_XCOPILOT_BUGS

/* xcopilot has the following bugs:
 *
 * - Disabling the penirq has no effect; we keep on getting irqs even when
 *   penirq is disabled; this is not too annoying: we just trash pen irq events
 *   that come when disabled.
 *
 * - SPIM interrupt is not simulated; this is not too annoying: we just read
 *   SPI data immediately and bypass a couple of states related to SPI irq.
 *
 * - We do not get mouse drag events; this is a known xcopilot bug.
 *   This is annoying: we miss all moves ! You should patch and recompile
 *   your xcopilot.
 *
 *   This has been reported as Debian bug #64367, and there is a patch there:
 *     http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=64367&repeatmerged=yes
 *   which is:
 *   +-----------------------------------------------------------------------+
 *   | --- display.c   Tue Aug 25 14:56:02 1998
 *   | +++ display2.c  Fri May 19 16:07:52 2000
 *   | @@ -439,7 +439,7 @@
 *   | static void HandleDigitizer(Widget w, XtPointer client_data, XEvent\
 *   | *event, Boolean *continue_to_dispatch)
 *   | {
 *   | -  Time start;
 *   | +  static Time start;
 *   | 
 *   | *continue_to_dispatch = True;
 *   +-----------------------------------------------------------------------+
 *   In short, add 'static' to the declaration of 'start' in HandleDigitizer()
 *   in display.c
 *
 *   With this patch, all works perfectly !
 *
 * - The pen state can be read only in IPR, not in port D; again, we're doing
 *   the workaround.
 *
 * With all these workarounds in this file, and with the patch on xcopilot,
 * things go perfectly smoothly.
 *
 */

/*
 * Ugly stuff to read the mouse position on xcopilot
 *
 * We get the position of the last mouse up/down only, we get no moves !!! :-(
 */
static void xcopilot_read_now(void) {
    PFDATA &= ~0xf; PFDATA |= 6;
    SPIMCONT |= SPIMCONT_XCH | SPIMCONT_IRQEN;
    current_pos.x = SPIMDATA;
    rescale_xpos(&current_pos.x);

    PFDATA &= ~0xf; PFDATA |= 9;
    SPIMCONT |= SPIMCONT_XCH | SPIMCONT_IRQEN;
    current_pos.y = SPIMDATA;
    rescale_ypos(&current_pos.y);

    swap_xy(&current_pos.x, &current_pos.y);
}


#endif
/*----------------------------------------------------------------------------*/
/* flow functions ------------------------------------------------------------*/

/*
 * Set timer irq to now + delay ticks.
 */
static void set_timer_irq(struct timer_list *timer,int delay) {
  del_timer(timer);
  timer->expires = jiffies + delay;
  add_timer(timer);
}

/*
 * Set ADS7843 and SPIM parameters for transfer.
 */
static void set_SPIM_transfert(void) {
  /* DragonBall drive I/O 1 and I/O 2 LOW to reverse bias the PENIRQ diode
   * of the ADS7843
   */
#ifdef USE_PENIRQ_PULLUP
  PDDATA &= ~PEN_MASK_2;        /* Pull down I/0 2 of PENIRQ */
#endif
  PENIRQ_DIR  |= PEN_MASK;      /* I/O 1 of PENIRQ as output */
  PENIRQ_DATA &= ~PEN_MASK;     /* Pull down I/O 2 of PENIRQ */

  /* Initiate selection and parameters for using the Burr-Brown ADS7843
   * and the DragonBall SPIM.
   */
  CARD_SELECT;          /* Select ADS7843.     */
//  printk("Now the ADS7843 is selected!\n");
  SPIM_ENABLE;          /* Enable SPIM         */
  SPIM_INIT;            /* Set SPIM parameters */
}

/*
 * Clock the Burr-Brown to fall the AD_BUSY. 
 * With a 'start' bit and PD1,PD0 = 00 to enable PENIRQ.
 * Used for the first pen irq after booting. And when error occures during
 * conversion that need an initialisation.
 */
static void fall_BUSY_enable_PENIRQ(void) {
  SET_SPIMDATA(SPIMDATA_NOP);
  SPIMCONT |= SPIMCONT_XCH;     /* initiate exchange */
}

/*
 * Release transfer settings.
 */
static void release_SPIM_transfert(void) {
  SPIM_DISABLE;
  CARD_DESELECT;