diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c index 27667c17ce90789759679556b006ecb190fa607c..9578af782a7732e3c9d4e4242c780f0bb7a21d01 100644 --- a/drivers/spi/spi-bcm63xx.c +++ b/drivers/spi/spi-bcm63xx.c @@ -37,6 +37,8 @@ #define PFX KBUILD_MODNAME +#define BCM63XX_SPI_MAX_PREPEND 15 + struct bcm63xx_spi { struct completion done; @@ -169,13 +171,17 @@ static int bcm63xx_spi_setup(struct spi_device *spi) return 0; } -static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) +static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first, + unsigned int num_transfers) { struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); u16 msg_ctl; u16 cmd; u8 rx_tail; - unsigned int timeout = 0; + unsigned int i, timeout = 0, prepend_len = 0, len = 0; + struct spi_transfer *t = first; + bool do_rx = false; + bool do_tx = false; /* Disable the CMD_DONE interrupt */ bcm_spi_writeb(bs, 0, SPI_INT_MASK); @@ -183,19 +189,45 @@ static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", t->tx_buf, t->rx_buf, t->len); - if (t->tx_buf) - memcpy_toio(bs->tx_io, t->tx_buf, t->len); + if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND) + prepend_len = t->len; + + /* prepare the buffer */ + for (i = 0; i < num_transfers; i++) { + if (t->tx_buf) { + do_tx = true; + memcpy_toio(bs->tx_io + len, t->tx_buf, t->len); + + /* don't prepend more than one tx */ + if (t != first) + prepend_len = 0; + } + + if (t->rx_buf) { + do_rx = true; + /* prepend is half-duplex write only */ + if (t == first) + prepend_len = 0; + } + + len += t->len; + + t = list_entry(t->transfer_list.next, struct spi_transfer, + transfer_list); + } + + len -= prepend_len; init_completion(&bs->done); /* Fill in the Message control register */ - msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT); + msg_ctl = (len << SPI_BYTE_CNT_SHIFT); - if (t->rx_buf && t->tx_buf) + if (do_rx && do_tx && prepend_len == 0) msg_ctl |= (SPI_FD_RW << bs->msg_type_shift); - else if (t->rx_buf) + else if (do_rx) msg_ctl |= (SPI_HD_R << bs->msg_type_shift); - else if (t->tx_buf) + else if (do_tx) msg_ctl |= (SPI_HD_W << bs->msg_type_shift); switch (bs->msg_ctl_width) { @@ -209,7 +241,7 @@ static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) /* Issue the transfer */ cmd = SPI_CMD_START_IMMEDIATE; - cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); + cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT); bcm_spi_writew(bs, cmd, SPI_CMD); @@ -223,9 +255,25 @@ static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) /* read out all data */ rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL); + if (do_rx && rx_tail != len) + return -EIO; + + if (!rx_tail) + return 0; + + len = 0; + t = first; /* Read out all the data */ - if (rx_tail) - memcpy_fromio(t->rx_ptr, bs->rx_io, rx_tail); + for (i = 0; i < num_transfers; i++) { + if (t->rx_buf) + memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len); + + if (t != first || prepend_len == 0) + len += t->len; + + t = list_entry(t->transfer_list.next, struct spi_transfer, + transfer_list); + } return 0; } @@ -252,46 +300,76 @@ static int bcm63xx_spi_transfer_one(struct spi_master *master, struct spi_message *m) { struct bcm63xx_spi *bs = spi_master_get_devdata(master); - struct spi_transfer *t; + struct spi_transfer *t, *first = NULL; struct spi_device *spi = m->spi; int status = 0; - + unsigned int n_transfers = 0, total_len = 0; + bool can_use_prepend = false; + + /* + * This SPI controller does not support keeping CS active after a + * transfer. + * Work around this by merging as many transfers we can into one big + * full-duplex transfers. + */ list_for_each_entry(t, &m->transfers, transfer_list) { status = bcm63xx_spi_check_transfer(spi, t); if (status < 0) goto exit; + if (!first) + first = t; + + n_transfers++; + total_len += t->len; + + if (n_transfers == 2 && !first->rx_buf && !t->tx_buf && + first->len <= BCM63XX_SPI_MAX_PREPEND) + can_use_prepend = true; + else if (can_use_prepend && t->tx_buf) + can_use_prepend = false; + /* we can only transfer one fifo worth of data */ - if (t->len > bs->fifo_size) { + if ((can_use_prepend && + total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) || + (!can_use_prepend && total_len > bs->fifo_size)) { dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n", - t->len, bs->fifo_size); + total_len, bs->fifo_size); status = -EINVAL; goto exit; } - /* CS will be deasserted directly after transfer */ - if (t->delay_usecs) { - dev_err(&spi->dev, "unable to keep CS asserted after transfer\n"); + /* all combined transfers have to have the same speed */ + if (t->speed_hz != first->speed_hz) { + dev_err(&spi->dev, "unable to change speed between transfers\n"); status = -EINVAL; goto exit; } - if (!t->cs_change && - !list_is_last(&t->transfer_list, &m->transfers)) { - dev_err(&spi->dev, "unable to keep CS asserted between transfers\n"); + /* CS will be deasserted directly after transfer */ + if (t->delay_usecs) { + dev_err(&spi->dev, "unable to keep CS asserted after transfer\n"); status = -EINVAL; goto exit; } - /* configure adapter for a new transfer */ - bcm63xx_spi_setup_transfer(spi, t); + if (t->cs_change || + list_is_last(&t->transfer_list, &m->transfers)) { + /* configure adapter for a new transfer */ + bcm63xx_spi_setup_transfer(spi, first); - /* send the data */ - status = bcm63xx_txrx_bufs(spi, t); - if (status) - goto exit; + /* send the data */ + status = bcm63xx_txrx_bufs(spi, first, n_transfers); + if (status) + goto exit; + + m->actual_length += total_len; - m->actual_length += t->len; + first = NULL; + n_transfers = 0; + total_len = 0; + can_use_prepend = false; + } } exit: m->status = status;