grcan_internal.h

/*
 *  GRCAN driver
 *
 *  COPYRIGHT (c) 2007-2019.
 *  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_DEFAULT_BAUD
 /* default to 500kbits/s */
 #define GRCAN_DEFAULT_BAUD 500000
#endif
 
#ifndef GRCAN_SAMPLING_POINT
 #define GRCAN_SAMPLING_POINT 80
#endif
 
#define WRAP_AROUND_TX_MSGS 1
#define WRAP_AROUND_RX_MSGS 2
#define GRCAN_MSG_SIZE sizeof(struct grcan_msg)
 
struct grcan_msg {
    unsigned int head[2];
    unsigned char data[8];
};
 
struct grcan_config {
    struct grcan_timing timing;
    struct grcanfd_timing timing_fd;
    struct grcan_selection selection;
    int abort;
    int silent;
};
 
struct grcan_priv {
    struct drvmgr_dev *dev; /* Driver manager device */
    char devName[32];   /* Device Name */
    unsigned int baseaddr, ram_base;
    struct grcan_regs *regs;
    int irq;
    int minor;
    int open;
    int started;
    unsigned int channel;
    int flushing;
    unsigned int corefreq_hz;
    int fd_capable;
 
    /* Circular DMA buffers */
    void *_rx, *_rx_hw;
    void *_tx, *_tx_hw;
    void *txbuf_adr;
    void *rxbuf_adr;
    struct grcan_msg *rx;
    struct grcan_msg *tx;
    unsigned int rxbuf_size;    /* requested RX buf size in bytes */
    unsigned int txbuf_size;    /* requested TX buf size in bytes */
 
    int txblock, rxblock;
    int txcomplete, rxcomplete;
 
    struct grcan_filter sfilter;
    struct grcan_filter afilter;
    int config_changed; /* 0=no changes, 1=changes ==> a Core reset is needed */
    struct grcan_config config;
    struct grcan_stats stats;
 
    rtems_id rx_sem, tx_sem, txempty_sem, dev_sem;
    SPIN_DECLARE(devlock);
};
 
#ifdef GRCAN_REG_BYPASS_CACHE
#define READ_REG(address) grlib_read_uncached32((unsigned int)(address))
#else
#define READ_REG(address) (*(volatile unsigned int *)(address))
#endif
 
#ifdef GRCAN_DMA_BYPASS_CACHE
#define READ_DMA_DOUBLE(address) grlib_read_uncached64((uint64_t *)(address))
#define READ_DMA_WORD(address) grlib_read_uncached32((unsigned int)(address))
#define READ_DMA_BYTE(address) grlib_read_uncached8((unsigned int)(address))
#else
#define READ_DMA_DOUBLE(address) (*(volatile uint64_t *)(address))
#define READ_DMA_WORD(address) (*(volatile unsigned int *)(address))
#define READ_DMA_BYTE(address) (*(volatile unsigned char *)(address))
#endif
 
extern int state2err[4];
extern struct grlib_canbtrs_ranges grcan_btrs_ranges;
extern struct grlib_canbtrs_ranges grcanfd_nom_btrs_ranges;
extern struct grlib_canbtrs_ranges grcanfd_fd_btrs_ranges;
 
int grcan_wait_rxdata(struct grcan_priv *pDev, int min);
int grcan_wait_txspace(struct grcan_priv *pDev, int min);
 
static inline unsigned int grcan_hw_rxavail(
    unsigned int rp,
    unsigned int wp,
    unsigned int size)
{
    if (rp == wp) {
        /* read pointer and write pointer is equal only
         * when RX buffer is empty.
         */
        return 0;
    }
 
    if (wp > rp) {
        return (wp - rp) / GRCAN_MSG_SIZE;
    } else {
        return (size - (rp - wp)) / GRCAN_MSG_SIZE;
    }
}
 
static inline unsigned int grcan_hw_txspace(
    unsigned int rp,
    unsigned int wp,
    unsigned int size)
{
    unsigned int left;
 
    if (rp == wp) {
        /* read pointer and write pointer is equal only
         * when TX buffer is empty.
         */
        return size / GRCAN_MSG_SIZE - WRAP_AROUND_TX_MSGS;
    }
 
    /* size - 4 - abs(read-write) */
    if (wp > rp) {
        left = size - (wp - rp);
    } else {
        left = rp - wp;
    }
 
    return left / GRCAN_MSG_SIZE - WRAP_AROUND_TX_MSGS;
}