From d6e7ffd4820f8894eb865890c96852085d3640e1 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 8 May 2024 12:20:27 +0200 Subject: [PATCH] spi: dw: Bail out early on unsupported target mode Currently, the DesignWare SPI controller driver supports only host mode. However, spi2 on the Kendryte K210 SoC supports only target mode, triggering an error message on e.g. SiPEED MAiXBiT since commit 98d75b9ef282f6b9 ("spi: dw: Drop default number of CS setting"): dw_spi_mmio 50240000.spi: error -22: problem registering spi host dw_spi_mmio 50240000.spi: probe with driver dw_spi_mmio failed with error -22 As spi2 rightfully has no "num-cs" property, num_chipselect is now zero, causing spi_alloc_host() to fail to register the controller. Before, the driver silently registered an SPI host controller with 4 chip selects. Reject target mode early on and warn the user, getting rid of the error message. Signed-off-by: Geert Uytterhoeven Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/7ae28d83bff7351f34782658ae1bb69cc731693e.1715163113.git.geert+renesas@glider.be Signed-off-by: Mark Brown --- drivers/spi/spi-dw-mmio.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index c56de35eca98..819907e332c4 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -321,6 +321,11 @@ static int dw_spi_mmio_probe(struct platform_device *pdev) struct dw_spi *dws; int ret; + if (device_property_read_bool(&pdev->dev, "spi-slave")) { + dev_warn(&pdev->dev, "spi-slave is not yet supported\n"); + return -ENODEV; + } + dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), GFP_KERNEL); if (!dwsmmio)