grcan.h

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/*
 *  COPYRIGHT (c) 2007.
 *  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 __GRCAN_H__
#define __GRCAN_H__

#ifdef __cplusplus
extern "C" {
#endif

struct grcan_regs {
    volatile unsigned int conf;          /* 0x00 */
    volatile unsigned int stat;          /* 0x04 */
    volatile unsigned int ctrl;          /* 0x08 */
    volatile unsigned int dummy0[3];     /* 0x0C-0x014 */
    volatile unsigned int smask;         /* 0x18 */
    volatile unsigned int scode;         /* 0x1C */

    volatile unsigned int dummy1[56];    /* 0x20-0xFC */

    volatile unsigned int pimsr;         /* 0x100 */
    volatile unsigned int pimr;          /* 0x104 */
    volatile unsigned int pisr;          /* 0x108 */
    volatile unsigned int pir;           /* 0x10C */
    volatile unsigned int imr;           /* 0x110 */
    volatile unsigned int picr;          /* 0x114 */

    volatile unsigned int dummy2[58];    /* 0x118-0x1FC */

    volatile unsigned int tx0ctrl;       /* 0x200 */
    volatile unsigned int tx0addr;       /* 0x204 */
    volatile unsigned int tx0size;       /* 0x208 */
    volatile unsigned int tx0wr;         /* 0x20C */
    volatile unsigned int tx0rd;         /* 0x210 */
    volatile unsigned int tx0irq;        /* 0x214 */

    volatile unsigned int dummy3[58];    /* 0x218-0x2FC */

    volatile unsigned int rx0ctrl;       /* 0x300 */
    volatile unsigned int rx0addr;       /* 0x304 */
    volatile unsigned int rx0size;       /* 0x308 */
    volatile unsigned int rx0wr;         /* 0x30C */
    volatile unsigned int rx0rd;         /* 0x310 */
    volatile unsigned int rx0irq;        /* 0x314 */
    volatile unsigned int rx0mask;       /* 0x318 */
    volatile unsigned int rx0code;       /* 0x31C */
};

struct grcan_stats {
    unsigned int passive_cnt;
    unsigned int overrun_cnt;
    unsigned int rxsync_cnt;
    unsigned int txsync_cnt;
    unsigned int txloss_cnt;
    unsigned int ahberr_cnt;
    unsigned int ints;
    unsigned int busoff_cnt;
};

struct grcan_timing {
    unsigned char scaler;
    unsigned char ps1;
    unsigned char ps2;
    unsigned int  rsj;
    unsigned char bpr;
};

struct grcan_selection {
    int selection;
    int enable0;
    int enable1;
};

struct grcan_filter {
    unsigned long long mask;
    unsigned long long code;
};

/* CAN MESSAGE */
typedef struct {
    char extended; /* 1= Extended Frame (29-bit id), 0= STD Frame (11-bit id) */
    char rtr; /* RTR - Remote Transmission Request */
    char unused; /* unused */
    unsigned char len;
    unsigned char data[8];
    unsigned int id;
} CANMsg;

enum {
    GRCAN_RET_OK            =  0,
    GRCAN_RET_INVARG        = -1,
    GRCAN_RET_NOTSTARTED    = -2,
    GRCAN_RET_TIMEOUT       = -3,
    /* Bus-off condition detected (request aborted by driver) */
    GRCAN_RET_BUSOFF        = -4,
    /* AHB error condition detected (request aborted by driver) */
    GRCAN_RET_AHBERR        = -5,
};

/*
 * User functions can cause these transitions:
 *   STATE_STOPPED -> STATE_STARTED
 *   STATE_STARTED -> STATE_STOPPED
 *   STATE_BUSOFF  -> STATE_STOPPED
 *   STATE_AHBERR  -> STATE_STOPPED
 *
 * ISR can cause these transition
 *   STATE_STARTED -> STATE_BUSOFF
 *   STATE_STARTED -> STATE_AHBERR
 *
 * STATE_BUSOFF is entered from ISR on bus-off condition. STATE_AHBERR is
 * entered from ISR on AHB DMA errors on RX/TX operations. At transition the ISR
 * disables DMA, masks all interrupts and releases semaphores.
 */
enum grcan_state {
    STATE_STOPPED       = 0,
    STATE_STARTED       = 1,
    STATE_BUSOFF        = 2,
    STATE_AHBERR        = 3,
};

#define GRCAN_CFG_ABORT      0x00000001
#define GRCAN_CFG_ENABLE0    0x00000002
#define GRCAN_CFG_ENABLE1    0x00000004
#define GRCAN_CFG_SELECTION  0x00000008
#define GRCAN_CFG_SILENT     0x00000010
#define GRCAN_CFG_BPR        0x00000300
#define GRCAN_CFG_RSJ        0x00007000
#define GRCAN_CFG_PS1        0x00f00000
#define GRCAN_CFG_PS2        0x000f0000
#define GRCAN_CFG_SCALER     0xff000000

#define GRCAN_CFG_BPR_BIT    8
#define GRCAN_CFG_RSJ_BIT    12
#define GRCAN_CFG_PS1_BIT    20
#define GRCAN_CFG_PS2_BIT    16
#define GRCAN_CFG_SCALER_BIT 24

#define GRCAN_CTRL_RESET  0x2
#define GRCAN_CTRL_ENABLE 0x1

#define GRCAN_TXCTRL_ENABLE 1
#define GRCAN_TXCTRL_ONGOING 1

#define GRCAN_RXCTRL_ENABLE 1
#define GRCAN_RXCTRL_ONGOING 1

/* Relative offset of IRQ sources to AMBA Plug&Play */
#define GRCAN_IRQ_IRQ 0
#define GRCAN_IRQ_TXSYNC 1
#define GRCAN_IRQ_RXSYNC 2

#define GRCAN_ERR_IRQ        0x1
#define GRCAN_OFF_IRQ        0x2
#define GRCAN_OR_IRQ         0x4
#define GRCAN_RXAHBERR_IRQ   0x8
#define GRCAN_TXAHBERR_IRQ   0x10
#define GRCAN_RXIRQ_IRQ      0x20
#define GRCAN_TXIRQ_IRQ      0x40
#define GRCAN_RXFULL_IRQ     0x80
#define GRCAN_TXEMPTY_IRQ    0x100
#define GRCAN_RX_IRQ         0x200
#define GRCAN_TX_IRQ         0x400
#define GRCAN_RXSYNC_IRQ     0x800
#define GRCAN_TXSYNC_IRQ     0x1000
#define GRCAN_RXERR_IRQ      0x2000
#define GRCAN_TXERR_IRQ      0x4000
#define GRCAN_RXMISS_IRQ     0x8000
#define GRCAN_TXLOSS_IRQ     0x10000

#define GRCAN_STAT_PASS      0x1
#define GRCAN_STAT_OFF       0x2
#define GRCAN_STAT_OR        0x4
#define GRCAN_STAT_AHBERR    0x8
#define GRCAN_STAT_ACTIVE    0x10
#define GRCAN_STAT_RXERRCNT  0xff00
#define GRCAN_STAT_TXERRCNT  0xff0000

/*
 * Return number of GRCAN devices available to driver
 */
extern int grcan_dev_count(void);

/*
 * Open a GRCAN device
 *
 * dev_no:  Device number to open
 * return:  Device handle to use with all other grcan_ API functions. The
 *      function returns NULL if device can not be opened.
 */
extern void *grcan_open(int dev_no);

/*
 * Open a GRCAN device by name. Finds device index then calls
 * grcan_open(index).
 *
 * name:    Device name to open
 * dev_no:  Device number matching name. Will be set if device found.
 * return:  Device handle to use with all other grcan_ API functions. The
 *      function returns NULL if device can not be opened or not found.
 */
extern void *grcan_open_by_name(char *name, int *dev_no);

/*
 * Close a GRCAN device
 *
 * return: This function always returns 0 (success)
 */
extern int grcan_close(void *d);

/*
 * Receive CAN messages
 *
 * Multiple CAN messages can be received in one call.
 *
 * d: Device handle
 * msg: Pointer to receive messages
 * count: Number of CAN messages to receive
 *
 * return:
 *   >=0:                       Number of CAN messages received. This can be
 *                              less than the count parameter.
 *   GRCAN_RET_INVARG:          count parameter less than one or NULL msg.
 *   GRCAN_RET_NOTSTARTED:      Device not in started mode
 *   GRCAN_RET_TIMEOUT:         Timeout in non-blocking mode
 *   GRCAN_RET_BUSOFF:          A read was interrupted by a bus-off error.
 *                              Device has left started mode.
 *   GRCAN_RET_AHBERR:          Similar to BUSOFF, but was caused by AHB Error.
 */
extern int grcan_read(
    void *d,
    CANMsg *msg,
    size_t count
);

/*
 * Transmit CAN messages
 *
 * Multiple CAN messages can be transmit in one call.
 *
 * d: Device handle
 * msg: Pointer to messages to transmit
 * count: Number of CAN messages to transmit
 *
 * return:
 *   >=0:                       Number of CAN messages transmitted. This can be
 *                              less than the count parameter.
 *   GRCAN_RET_INVARG:          count parameter less than one.
 *   GRCAN_RET_NOTSTARTED:      Device not in started mode
 *   GRCAN_RET_TIMEOUT:         Timeout in non-blocking mode
 *   GRCAN_RET_BUSOFF:          A write was interrupted by a Bus-off error.
 *                              Device has left started mode
 *   GRCAN_RET_AHBERR:          Similar to BUSOFF, but was caused by AHB Error.
 */
extern int grcan_write(
    void *d,
    CANMsg *msg,
    size_t count
);

/*
 * Returns current GRCAN software state
 *
 * If STATE_BUSOFF or STATE_AHBERR is returned then the function grcan_stop()
 * shall be called before continue using the driver.
 *
 * d: Device handle
 * return:
 *   STATE_STOPPED              Stopped
 *   STATE_STARTED              Started
 *   STATE_BUSOFF               Bus-off has been detected
 *   STATE_AHBERR               AHB error has been detected
 */
extern int grcan_get_state(void *d);

/* The remaining functions return 0 on success and non-zero on failure. */

/* Functions controlling operational
 * mode
 */
/* Bring the link up after open or bus-off */
extern int grcan_start(void *d);
/* stop to change baud rate/config or closing down */
extern int grcan_stop(void *d);
/* Wait until all TX messages have been sent */
extern int grcan_flush(void *d);

/* Functions that require connection
 * to be stopped
 */
/* enable silent mode read only state */
extern int grcan_set_silent(void *d, int silent);
/* enable/disable stopping link on AHB Error */
extern int grcan_set_abort(void *d, int abort);
/* Set Enable0,Enable1,Selection */
extern int grcan_set_selection(void *d, const struct grcan_selection *selection);
/* Set baudrate by using driver's baud rate timing calculation routines */
extern int grcan_set_speed(void *d, unsigned int hz);
/* Set baudrate by specifying the timing registers manually */
extern int grcan_set_btrs(void *d, const struct grcan_timing *timing);

/* Functions can be called whenever */
/* Enable/disable Blocking on reception (until at least one message has been received) */
int grcan_set_rxblock(void* d, int block);
/* Enable/disable Blocking on transmission (until at least one message has been transmitted) */
int grcan_set_txblock(void* d, int block);
/* Enable/disable Blocking until all requested messages has been sent */
int grcan_set_txcomplete(void* d, int complete);
/* Enable/disable Blocking until all requested has been received */
int grcan_set_rxcomplete(void* d, int complete);
/* Get statistics */
extern int grcan_get_stats(void *d, struct grcan_stats *stats);
/* Clear statistics */
extern int grcan_clr_stats(void *d);
/* Set Acceptance filters, provide pointer to "struct grcan_filter" or NULL to disable filtering (let all messages pass) */
extern int grcan_set_afilter(void *d, const struct grcan_filter *filter);
/* Set Sync Messages RX/TX filters, NULL disables the IRQ completely */
extern int grcan_set_sfilter(void *d, const struct grcan_filter *filter);
/* Get status register of GRCAN core */
extern int grcan_get_status(void *d, unsigned int *status);

void grcan_register_drv(void);

#ifdef __cplusplus
}
#endif

#endif