spictrl.h

/*
 *  SPICTRL SPI Driver interface.
 *
 *  COPYRIGHT (c) 2009.
 *  Cobham Gaisler AB.
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#ifndef __SPICTRL_H__
#define __SPICTRL_H__

#ifdef __cplusplus
extern "C" {
#endif

extern void spictrl_register_drv (void);

/*** REGISTER LAYOUT ***/
struct spictrl_regs {
    volatile unsigned int capability;   /* 0x00 */
    volatile unsigned int resv[7];      /* 0x04 */
    volatile unsigned int mode;     /* 0x20 */
    volatile unsigned int event;        /* 0x24 */
    volatile unsigned int mask;     /* 0x28 */
    volatile unsigned int command;      /* 0x2c */
    volatile unsigned int tx;       /* 0x30 */
    volatile unsigned int rx;       /* 0x34 */
    volatile unsigned int slvsel;       /* 0x38 */
    volatile unsigned int am_slvsel;    /* 0x3c */
    volatile unsigned int am_cfg;       /* 0x40 */
    volatile unsigned int am_period;    /* 0x44 */
    int reserved0[2];
    volatile unsigned int am_mask[4];   /* 0x50-0x5C */
    int reserved1[(0x200-0x60)/4];
    volatile unsigned int am_tx[128];   /* 0x200-0x3FC */
    volatile unsigned int am_rx[128];   /* 0x400-0x5FC */
};

/* -- About automated periodic transfer mode --
 *
 * Core must support this feature.
 *
 * The SPI core must be configured in periodic mode before
 * writing the data into the transfer FIFO which will be used
 * mutiple times in different transfers, it will also make
 * the receive FIFO to be updated.
 *
 * In periodic mode the following sequence is performed,
 *   1. start()
 *   2. ioctl(CONFIG, &config)    - Enable periodic mode
 *   3. set_address()
 *   4. write()                   - Fills TX FIFO, this has some constraints
 *   5. ioctl(START)              - Starts the periodic transmission of the TX FIFO
 *   6. read()                    - Read one response of the tranistted data. It will 
 *                                  hang until data is available. If hanging is not an
 *                                  options use ioctl(STATUS)
 *   7. go back to 6.
 *
 *   8. ioctl(STOP)               - Stop to set up a new periodic or normal transfer
 *   9. stop()
 *
 * Note that the the read length must equal the total write length.
 */

/* Custom SPICTRL driver ioctl commands */
#define SPICTRL_IOCTL_PERIOD_START  5000    /* Start automated periodic transfer mode */
#define SPICTRL_IOCTL_PERIOD_STOP   5001    /* Stop to SPI core from doing periodic transfers */
#define SPICTRL_IOCTL_CONFIG        5002    /* Configure Periodic transfer mode (before calling write() and START) */
#define SPICTRL_IOCTL_STATUS        5003    /* Get status */

#define SPICTRL_IOCTL_PERIOD_READ   5005    /* Write transmit registers and mask register 
                         * (only in automatic periodic mode) 
                         * Note that it is probably prefferred to read
                         * the received words using the read() using
                         * operations instead.
                         */
#define SPICTRL_IOCTL_PERIOD_WRITE  5006    /* Read receive registers and mask register 
                         * (only in automatic periodic mode) */
#define SPICTRL_IOCTL_REGS      5007    /* Get SPICTRL Register */

/* SPICTRL_IOCTL_CONFIG argument */
struct spictrl_ioctl_config {
    int     clock_gap;  /* Clock GAP between */
    unsigned int    flags;      /* Normal mode flags */
    int     periodic_mode;  /* 1=Enables Automated periodic transfers if supported by hardware */
    unsigned int    period;     /* Number of clocks between automated transfers are started */
    unsigned int    period_flags;   /* Options */
    unsigned int    period_slvsel;  /* Slave Select when transfer is not active, default is 0xffffffff */
};
#define SPICTRL_FLAGS_TAC       0x10

#define SPICTRL_PERIOD_FLAGS_ERPT   0x80    /* Trigger start-period from external signal */
#define SPICTRL_PERIOD_FLAGS_SEQ    0x40
#define SPICTRL_PERIOD_FLAGS_STRICT 0x20
#define SPICTRL_PERIOD_FLAGS_OVTB   0x10
#define SPICTRL_PERIOD_FLAGS_OVDB   0x08
#define SPICTRL_PERIOD_FLAGS_ASEL   0x04
#define SPICTRL_PERIOD_FLAGS_EACT   0x01

/* SPICTRL_IOCTL_PERIOD_READ and SPICTRL_IOCTL_PERIOD_WRITE Argument data structure 
 *
 * Note that the order of reading the mask registers are different for read/write
 *      operation. See options notes.
 */
struct spictrl_period_io {
    int options;    /* READ: bit0=Read Mask Registers into masks[].
             *       bit1=Read Receive registers according to masks[]
             *            (after reading masks).
             *
             * WRITE: bit0=Update Mask accoring to masks[].
             *        bit1=Update Transmit registers according to masks[].
             *             (before reading masks)
             */
    unsigned int masks[4];

    void *data; /* Data read sequentially according to masks[] bit. */
};

#ifdef __cplusplus
}
#endif

#endif