diff options
Diffstat (limited to 'drivers/spi/spi-dw-dma.c')
| -rw-r--r-- | drivers/spi/spi-dw-dma.c | 76 |
1 files changed, 58 insertions, 18 deletions
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c index ababb910b391..df819652901a 100644 --- a/drivers/spi/spi-dw-dma.c +++ b/drivers/spi/spi-dw-dma.c @@ -72,12 +72,22 @@ static void dw_spi_dma_maxburst_init(struct dw_spi *dws) dw_writel(dws, DW_SPI_DMATDLR, dws->txburst); } -static void dw_spi_dma_sg_burst_init(struct dw_spi *dws) +static int dw_spi_dma_caps_init(struct dw_spi *dws) { - struct dma_slave_caps tx = {0}, rx = {0}; + struct dma_slave_caps tx, rx; + int ret; + + ret = dma_get_slave_caps(dws->txchan, &tx); + if (ret) + return ret; - dma_get_slave_caps(dws->txchan, &tx); - dma_get_slave_caps(dws->rxchan, &rx); + ret = dma_get_slave_caps(dws->rxchan, &rx); + if (ret) + return ret; + + if (!(tx.directions & BIT(DMA_MEM_TO_DEV) && + rx.directions & BIT(DMA_DEV_TO_MEM))) + return -ENXIO; if (tx.max_sg_burst > 0 && rx.max_sg_burst > 0) dws->dma_sg_burst = min(tx.max_sg_burst, rx.max_sg_burst); @@ -87,6 +97,15 @@ static void dw_spi_dma_sg_burst_init(struct dw_spi *dws) dws->dma_sg_burst = rx.max_sg_burst; else dws->dma_sg_burst = 0; + + /* + * Assuming both channels belong to the same DMA controller hence the + * peripheral side address width capabilities most likely would be + * the same. + */ + dws->dma_addr_widths = tx.dst_addr_widths & rx.src_addr_widths; + + return 0; } static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws) @@ -95,6 +114,7 @@ static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws) struct dw_dma_slave dma_rx = { .src_id = 0 }, *rx = &dma_rx; struct pci_dev *dma_dev; dma_cap_mask_t mask; + int ret = -EBUSY; /* * Get pci device for DMA controller, currently it could only @@ -124,20 +144,25 @@ static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws) init_completion(&dws->dma_completion); - dw_spi_dma_maxburst_init(dws); + ret = dw_spi_dma_caps_init(dws); + if (ret) + goto free_txchan; - dw_spi_dma_sg_burst_init(dws); + dw_spi_dma_maxburst_init(dws); pci_dev_put(dma_dev); return 0; +free_txchan: + dma_release_channel(dws->txchan); + dws->txchan = NULL; free_rxchan: dma_release_channel(dws->rxchan); dws->rxchan = NULL; err_exit: pci_dev_put(dma_dev); - return -EBUSY; + return ret; } static int dw_spi_dma_init_generic(struct device *dev, struct dw_spi *dws) @@ -163,12 +188,17 @@ static int dw_spi_dma_init_generic(struct device *dev, struct dw_spi *dws) init_completion(&dws->dma_completion); - dw_spi_dma_maxburst_init(dws); + ret = dw_spi_dma_caps_init(dws); + if (ret) + goto free_txchan; - dw_spi_dma_sg_burst_init(dws); + dw_spi_dma_maxburst_init(dws); return 0; +free_txchan: + dma_release_channel(dws->txchan); + dws->txchan = NULL; free_rxchan: dma_release_channel(dws->rxchan); dws->rxchan = NULL; @@ -198,22 +228,32 @@ static irqreturn_t dw_spi_dma_transfer_handler(struct dw_spi *dws) return IRQ_HANDLED; } +static enum dma_slave_buswidth dw_spi_dma_convert_width(u8 n_bytes) +{ + switch (n_bytes) { + case 1: + return DMA_SLAVE_BUSWIDTH_1_BYTE; + case 2: + return DMA_SLAVE_BUSWIDTH_2_BYTES; + case 4: + return DMA_SLAVE_BUSWIDTH_4_BYTES; + default: + return DMA_SLAVE_BUSWIDTH_UNDEFINED; + } +} + static bool dw_spi_can_dma(struct spi_controller *master, struct spi_device *spi, struct spi_transfer *xfer) { struct dw_spi *dws = spi_controller_get_devdata(master); + enum dma_slave_buswidth dma_bus_width; - return xfer->len > dws->fifo_len; -} + if (xfer->len <= dws->fifo_len) + return false; -static enum dma_slave_buswidth dw_spi_dma_convert_width(u8 n_bytes) -{ - if (n_bytes == 1) - return DMA_SLAVE_BUSWIDTH_1_BYTE; - else if (n_bytes == 2) - return DMA_SLAVE_BUSWIDTH_2_BYTES; + dma_bus_width = dw_spi_dma_convert_width(dws->n_bytes); - return DMA_SLAVE_BUSWIDTH_UNDEFINED; + return dws->dma_addr_widths & BIT(dma_bus_width); } static int dw_spi_dma_wait(struct dw_spi *dws, unsigned int len, u32 speed) |