static void bcm2835_dma_release(struct spi_master *master)
{
if (master->dma_tx) {
dmaengine_terminate_sync(master->dma_tx);
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
}
if (master->dma_rx) {
dmaengine_terminate_sync(master->dma_rx);
dma_release_channel(master->dma_rx);
master->dma_rx = NULL;
}
}
static void bcm2835_spi_handle_err(struct spi_master *master,
struct spi_message *msg)
{
struct bcm2835_spi *bs = spi_master_get_devdata(master);
/* if an error occurred and we have an active dma, then terminate */
if (cmpxchg(&bs->dma_pending, true, false)) {
dmaengine_terminate_sync(master->dma_tx);
dmaengine_terminate_sync(master->dma_rx);
bcm2835_spi_undo_prologue(bs);
}
/* and reset */
bcm2835_spi_reset_hw(master);
}
void pxa2xx_spi_dma_release(struct driver_data *drv_data)
{
struct spi_master *master = drv_data->master;
if (master->dma_rx) {
dmaengine_terminate_sync(master->dma_rx);
dma_release_channel(master->dma_rx);
master->dma_rx = NULL;
}
if (master->dma_tx) {
dmaengine_terminate_sync(master->dma_tx);
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
}
}
static int bcm2835_spi_transfer_one_dma(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *tfr,
u32 cs)
{
struct bcm2835_spi *bs = spi_master_get_devdata(master);
int ret;
/*
* Transfer first few bytes without DMA if length of first TX or RX
* sglist entry is not a multiple of 4 bytes (hardware limitation).
*/
bcm2835_spi_transfer_prologue(master, tfr, bs, cs);
/* setup tx-DMA */
ret = bcm2835_spi_prepare_sg(master, tfr, true);
if (ret)
goto err_reset_hw;
/* start TX early */
dma_async_issue_pending(master->dma_tx);
/* mark as dma pending */
bs->dma_pending = 1;
/* set the DMA length */
bcm2835_wr(bs, BCM2835_SPI_DLEN, bs->tx_len);
/* start the HW */
bcm2835_wr(bs, BCM2835_SPI_CS,
cs | BCM2835_SPI_CS_TA | BCM2835_SPI_CS_DMAEN);
/* setup rx-DMA late - to run transfers while
* mapping of the rx buffers still takes place
* this saves 10us or more.
*/
ret = bcm2835_spi_prepare_sg(master, tfr, false);
if (ret) {
/* need to reset on errors */
dmaengine_terminate_sync(master->dma_tx);
bs->dma_pending = false;
goto err_reset_hw;
}
/* start rx dma late */
dma_async_issue_pending(master->dma_rx);
/* wait for wakeup in framework */
return 1;
err_reset_hw:
bcm2835_spi_reset_hw(master);
bcm2835_spi_undo_prologue(bs);
return ret;
}
void serial8250_release_dma(struct uart_8250_port *p)
{
struct uart_8250_dma *dma = p->dma;
if (!dma)
return;
/* Release RX resources */
dmaengine_terminate_sync(dma->rxchan);
dma_free_coherent(dma->rxchan->device->dev, dma->rx_size, dma->rx_buf,
dma->rx_addr);
dma_release_channel(dma->rxchan);
dma->rxchan = NULL;
/* Release TX resources */
dmaengine_terminate_sync(dma->txchan);
dma_unmap_single(dma->txchan->device->dev, dma->tx_addr,
UART_XMIT_SIZE, DMA_TO_DEVICE);
dma_release_channel(dma->txchan);
dma->txchan = NULL;
dma->tx_running = 0;
dev_dbg_ratelimited(p->port.dev, "dma channels released\n");
}
static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
{
unsigned long flags;
struct dma_slave_config rxconf, txconf;
struct dma_async_tx_descriptor *rxdesc, *txdesc;
spin_lock_irqsave(&rs->lock, flags);
rs->state &= ~RXBUSY;
rs->state &= ~TXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
rxdesc = NULL;
if (rs->rx) {
rxconf.direction = rs->dma_rx.direction;
rxconf.src_addr = rs->dma_rx.addr;
rxconf.src_addr_width = rs->n_bytes;
if (rs->dma_caps.max_burst > 4)
rxconf.src_maxburst = 4;
else
rxconf.src_maxburst = 1;
dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
rxdesc = dmaengine_prep_slave_sg(
rs->dma_rx.ch,
rs->rx_sg.sgl, rs->rx_sg.nents,
rs->dma_rx.direction, DMA_PREP_INTERRUPT);
if (!rxdesc)
return -EINVAL;
rxdesc->callback = rockchip_spi_dma_rxcb;
rxdesc->callback_param = rs;
}
txdesc = NULL;
if (rs->tx) {
txconf.direction = rs->dma_tx.direction;
txconf.dst_addr = rs->dma_tx.addr;
txconf.dst_addr_width = rs->n_bytes;
if (rs->dma_caps.max_burst > 4)
txconf.dst_maxburst = 4;
else
txconf.dst_maxburst = 1;
dmaengine_slave_config(rs->dma_tx.ch, &txconf);
txdesc = dmaengine_prep_slave_sg(
rs->dma_tx.ch,
rs->tx_sg.sgl, rs->tx_sg.nents,
rs->dma_tx.direction, DMA_PREP_INTERRUPT);
if (!txdesc) {
if (rxdesc)
dmaengine_terminate_sync(rs->dma_rx.ch);
return -EINVAL;
}
txdesc->callback = rockchip_spi_dma_txcb;
txdesc->callback_param = rs;
}
/* rx must be started before tx due to spi instinct */
if (rxdesc) {
spin_lock_irqsave(&rs->lock, flags);
rs->state |= RXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
dmaengine_submit(rxdesc);
dma_async_issue_pending(rs->dma_rx.ch);
}
if (txdesc) {
spin_lock_irqsave(&rs->lock, flags);
rs->state |= TXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
dmaengine_submit(txdesc);
dma_async_issue_pending(rs->dma_tx.ch);
}
return 0;
}
