From: Vignesh Raghavendra vigneshr@ti.com
[ Upstream commit e4e8276a4f652be2c7bb783a0155d4adb85f5d7d ]
On AM654, McSPI can only support 4K - 1 bytes per transfer when DMA is enabled. Therefore populate master->max_transfer_size callback to inform client drivers of this restriction when DMA channels are available.
Signed-off-by: Vignesh Raghavendra vigneshr@ti.com Link: https://lore.kernel.org/r/20200204124816.16735-2-vigneshr@ti.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-omap2-mcspi.c | 26 +++++++++++++++++++ include/linux/platform_data/spi-omap2-mcspi.h | 1 + 2 files changed, 27 insertions(+)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 848e03e5f42d5..8e435da730996 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -130,6 +130,7 @@ struct omap2_mcspi { int fifo_depth; bool slave_aborted; unsigned int pin_dir:1; + size_t max_xfer_len; };
struct omap2_mcspi_cs { @@ -1316,6 +1317,18 @@ static bool omap2_mcspi_can_dma(struct spi_master *master, return (xfer->len >= DMA_MIN_BYTES); }
+static size_t omap2_mcspi_max_xfer_size(struct spi_device *spi) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); + struct omap2_mcspi_dma *mcspi_dma = + &mcspi->dma_channels[spi->chip_select]; + + if (mcspi->max_xfer_len && mcspi_dma->dma_rx) + return mcspi->max_xfer_len; + + return SIZE_MAX; +} + static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi) { struct spi_master *master = mcspi->master; @@ -1384,6 +1397,11 @@ static struct omap2_mcspi_platform_config omap4_pdata = { .regs_offset = OMAP4_MCSPI_REG_OFFSET, };
+static struct omap2_mcspi_platform_config am654_pdata = { + .regs_offset = OMAP4_MCSPI_REG_OFFSET, + .max_xfer_len = SZ_4K - 1, +}; + static const struct of_device_id omap_mcspi_of_match[] = { { .compatible = "ti,omap2-mcspi", @@ -1393,6 +1411,10 @@ static const struct of_device_id omap_mcspi_of_match[] = { .compatible = "ti,omap4-mcspi", .data = &omap4_pdata, }, + { + .compatible = "ti,am654-mcspi", + .data = &am654_pdata, + }, { }, }; MODULE_DEVICE_TABLE(of, omap_mcspi_of_match); @@ -1450,6 +1472,10 @@ static int omap2_mcspi_probe(struct platform_device *pdev) mcspi->pin_dir = pdata->pin_dir; } regs_offset = pdata->regs_offset; + if (pdata->max_xfer_len) { + mcspi->max_xfer_len = pdata->max_xfer_len; + master->max_transfer_size = omap2_mcspi_max_xfer_size; + }
r = platform_get_resource(pdev, IORESOURCE_MEM, 0); mcspi->base = devm_ioremap_resource(&pdev->dev, r); diff --git a/include/linux/platform_data/spi-omap2-mcspi.h b/include/linux/platform_data/spi-omap2-mcspi.h index 0bf9fddb83064..3b400b1919a9b 100644 --- a/include/linux/platform_data/spi-omap2-mcspi.h +++ b/include/linux/platform_data/spi-omap2-mcspi.h @@ -11,6 +11,7 @@ struct omap2_mcspi_platform_config { unsigned short num_cs; unsigned int regs_offset; unsigned int pin_dir:1; + size_t max_xfer_len; };
struct omap2_mcspi_device_config {