diff options
Diffstat (limited to 'arch/m68k/mach-mcfv4e/fecbd.c')
| -rw-r--r-- | arch/m68k/mach-mcfv4e/fecbd.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/arch/m68k/mach-mcfv4e/fecbd.c b/arch/m68k/mach-mcfv4e/fecbd.c new file mode 100644 index 0000000000..26fb16d98d --- /dev/null +++ b/arch/m68k/mach-mcfv4e/fecbd.c @@ -0,0 +1,232 @@ +/* + * File: fecbd.c + * Purpose: Provide a simple buffer management driver + * + * Notes: + */ +#include <common.h> +#include <linux/types.h> + +#include <asm/arch/mcf54xx-regs.h> +#include <asm/proc/mcdapi/MCD_dma.h> +#include <asm/proc/net/net.h> +#include <asm/proc/fecbd.h> +#include <asm/proc/fec.h> +#include <asm/proc/dma_utils.h> + +#define ASSERT(x) if (!(x)) hang(); + +/* + * This implements a simple static buffer descriptor + * ring for each channel and each direction + * + * FEC Buffer Descriptors need to be aligned to a 4-byte boundary. + * In order to accomplish this, data is over-allocated and manually + * aligned at runtime + * + * Enough space is allocated for each of the two FEC channels to have + * NRXBD Rx BDs and NTXBD Tx BDs + * + */ +FECBD unaligned_bds[(2 * NRXBD) + (2 * NTXBD) + 1]; + +/* + * These pointers are used to reference into the chunck of data set + * aside for buffer descriptors + */ +FECBD *RxBD; +FECBD *TxBD; + +/* + * Macros to easier access to the BD ring + */ +#define RxBD(ch,i) RxBD[(ch * NRXBD) + i] +#define TxBD(ch,i) TxBD[(ch * NTXBD) + i] + +/* + * Buffer descriptor indexes + */ +static int iTxbd_new; +static int iTxbd_old; +static int iRxbd; + +/* + * Initialize the FEC Buffer Descriptor ring + * Buffer Descriptor format is defined by the MCDAPI + * + * Parameters: + * ch FEC channel + */ +void +fecbd_init(uint8_t ch) +{ + NBUF *nbuf; + int i; + + /* + * Align Buffer Descriptors to 4-byte boundary + */ + RxBD = (FECBD *)(((int)unaligned_bds + 3) & 0xFFFFFFFC); + TxBD = (FECBD *)((int)RxBD + (sizeof(FECBD) * 2 * NRXBD)); + + /* + * Initialize the Rx Buffer Descriptor ring + */ + for (i = 0; i < NRXBD; ++i) + { + /* Grab a network buffer from the free list */ + nbuf = nbuf_alloc(); + ASSERT(nbuf); + + /* Initialize the BD */ + RxBD(ch,i).status = RX_BD_E | RX_BD_INTERRUPT; + RxBD(ch,i).length = RX_BUF_SZ; + RxBD(ch,i).data = nbuf->data; + + /* Add the network buffer to the Rx queue */ + nbuf_add(NBUF_RX_RING, nbuf); + } + + /* + * Set the WRAP bit on the last one + */ + RxBD(ch,i-1).status |= RX_BD_W; + + /* + * Initialize the Tx Buffer Descriptor ring + */ + for (i = 0; i < NTXBD; ++i) + { + TxBD(ch,i).status = TX_BD_INTERRUPT; + TxBD(ch,i).length = 0; + TxBD(ch,i).data = NULL; + } + + /* + * Set the WRAP bit on the last one + */ + TxBD(ch,i-1).status |= TX_BD_W; + + /* + * Initialize the buffer descriptor indexes + */ + iTxbd_new = iTxbd_old = iRxbd = 0; +} + +void +fecbd_dump(uint8_t ch) +{ + #ifdef CONFIG_DRIVER_NET_MCF54XX_DEBUG + int i; + + printf("\n------------ FEC%d BDs -----------\n",ch); + printf("RxBD Ring\n"); + for (i=0; i<NRXBD; i++) + { + printf("%02d: BD Addr=0x%08x, Ctrl=0x%04x, Lgth=%04d, DataPtr=0x%08x\n", + i, &RxBD(ch,i), + RxBD(ch,i).status, + RxBD(ch,i).length, + RxBD(ch,i).data); + } + printf("TxBD Ring\n"); + for (i=0; i<NTXBD; i++) + { + printf("%02d: BD Addr=0x%08x, Ctrl=0x%04x, Lgth=%04d, DataPtr=0x%08x\n", + i, &TxBD(ch,i), + TxBD(ch,i).status, + TxBD(ch,i).length, + TxBD(ch,i).data); + } + printf("--------------------------------\n\n"); + #endif +} + +/* + * Return the address of the first buffer descriptor in the ring. + * + * Parameters: + * ch FEC channel + * direction Rx or Tx Macro + * + * Return Value: + * The start address of the selected Buffer Descriptor ring + */ +uint32_t +fecbd_get_start(uint8_t ch, uint8_t direction) +{ + switch (direction) + { + case Rx: + return (uint32_t)((int)RxBD + (ch * sizeof(FECBD) * NRXBD)); + case Tx: + default: + return (uint32_t)((int)TxBD + (ch * sizeof(FECBD) * NTXBD)); + } +} + +FECBD * +fecbd_rx_alloc(uint8_t ch) +{ + int i = iRxbd; + + /* Check to see if the ring of BDs is full */ + if (RxBD(ch,i).status & RX_BD_E) + return NULL; + + /* Increment the circular index */ + iRxbd = (uint8_t)((iRxbd + 1) % NRXBD); + + return &RxBD(ch,i); +} + +/* + * This function keeps track of the next available Tx BD in the ring + * + * Parameters: + * ch FEC channel + * + * Return Value: + * Pointer to next available buffer descriptor. + * NULL if the BD ring is full + */ +FECBD * +fecbd_tx_alloc(uint8_t ch) +{ + int i = iTxbd_new; + + /* Check to see if the ring of BDs is full */ + if (TxBD(ch,i).status & TX_BD_R) + return NULL; + + /* Increment the circular index */ + iTxbd_new = (uint8_t)((iTxbd_new + 1) % NTXBD); + + return &TxBD(ch,i); +} + +/* + * This function keeps track of the Tx BDs that have already been + * processed by the FEC + * + * Parameters: + * ch FEC channel + * + * Return Value: + * Pointer to the oldest buffer descriptor that has already been sent + * by the FEC, NULL if the BD ring is empty + */ +FECBD * +fecbd_tx_free(uint8_t ch) +{ + int i = iTxbd_old; + + /* Check to see if the ring of BDs is empty */ + if ((TxBD(ch,i).data == NULL) || (TxBD(ch,i).status & TX_BD_R)) + return NULL; + + /* Increment the circular index */ + iTxbd_old = (uint8_t)((iTxbd_old + 1) % NTXBD); + + return &TxBD(ch,i); +} |