diff options
Diffstat (limited to 'drivers/spi/spi-bcm2835.c')
| -rw-r--r-- | drivers/spi/spi-bcm2835.c | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 77de5a07639a..d4e267ebd734 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -119,6 +119,7 @@ MODULE_PARM_DESC(polling_limit_us, */ struct bcm2835_spi { void __iomem *regs; + phys_addr_t phys_addr; struct clk *clk; struct gpio_desc *cs_gpio; unsigned long clk_hz; @@ -891,19 +892,8 @@ static int bcm2835_dma_init(struct spi_controller *ctlr, struct device *dev, struct bcm2835_spi *bs) { struct dma_slave_config slave_config; - const __be32 *addr; - dma_addr_t dma_reg_base; int ret; - /* base address in dma-space */ - addr = of_get_address(ctlr->dev.of_node, 0, NULL, NULL); - if (!addr) { - dev_err(dev, "could not get DMA-register address - not using dma mode\n"); - /* Fall back to interrupt mode */ - return 0; - } - dma_reg_base = be32_to_cpup(addr); - /* get tx/rx dma */ ctlr->dma_tx = dma_request_chan(dev, "tx"); if (IS_ERR(ctlr->dma_tx)) { @@ -925,7 +915,7 @@ static int bcm2835_dma_init(struct spi_controller *ctlr, struct device *dev, * or, in case of an RX-only transfer, cyclically copies from the zero * page to the FIFO using a preallocated, reusable descriptor. */ - slave_config.dst_addr = (u32)(dma_reg_base + BCM2835_SPI_FIFO); + slave_config.dst_addr = bs->phys_addr + BCM2835_SPI_FIFO; slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; ret = dmaengine_slave_config(ctlr->dma_tx, &slave_config); @@ -964,9 +954,9 @@ static int bcm2835_dma_init(struct spi_controller *ctlr, struct device *dev, * RX FIFO or, in case of a TX-only transfer, cyclically writes a * precalculated value to the CS register to clear the RX FIFO. */ - slave_config.src_addr = (u32)(dma_reg_base + BCM2835_SPI_FIFO); + slave_config.src_addr = bs->phys_addr + BCM2835_SPI_FIFO; slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - slave_config.dst_addr = (u32)(dma_reg_base + BCM2835_SPI_CS); + slave_config.dst_addr = bs->phys_addr + BCM2835_SPI_CS; slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; ret = dmaengine_slave_config(ctlr->dma_rx, &slave_config); @@ -1059,6 +1049,16 @@ static int bcm2835_spi_transfer_one(struct spi_controller *ctlr, unsigned long hz_per_byte, byte_limit; u32 cs = target->prepare_cs; + if (unlikely(!tfr->len)) { + static int warned; + + if (!warned) + dev_warn(&spi->dev, + "zero-length SPI transfer ignored\n"); + warned = 1; + return 0; + } + /* set clock */ spi_hz = tfr->speed_hz; @@ -1350,6 +1350,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev) { struct spi_controller *ctlr; struct bcm2835_spi *bs; + struct resource *iomem; int err; ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(*bs)); @@ -1373,10 +1374,11 @@ static int bcm2835_spi_probe(struct platform_device *pdev) bs = spi_controller_get_devdata(ctlr); bs->ctlr = ctlr; - bs->regs = devm_platform_ioremap_resource(pdev, 0); + bs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &iomem); if (IS_ERR(bs->regs)) return PTR_ERR(bs->regs); + bs->phys_addr = iomem->start; bs->clk = devm_clk_get_enabled(&pdev->dev, NULL); if (IS_ERR(bs->clk)) return dev_err_probe(&pdev->dev, PTR_ERR(bs->clk), |