From e2ecfd5565423701cdff01461a62494e52d1720f Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Thu, 21 Dec 2023 18:18:09 -0500 Subject: [PATCH] serial: sc16is7xx: add check for unsupported SPI modes during probe [ Upstream commit 6d710b769c1f5f0d55c9ad9bb49b7dce009ec103 ] The original comment is confusing because it implies that variants other than the SC16IS762 supports other SPI modes beside SPI_MODE_0. Extract from datasheet: The SC16IS762 differs from the SC16IS752 in that it supports SPI clock speeds up to 15 Mbit/s instead of the 4 Mbit/s supported by the SC16IS752... In all other aspects, the SC16IS762 is functionally and electrically the same as the SC16IS752. The same is also true of the SC16IS760 variant versus the SC16IS740 and SC16IS750 variants. For all variants, only SPI mode 0 is supported. Change comment and abort probing if the specified SPI mode is not SPI_MODE_0. Fixes: 2c837a8a8f9f ("sc16is7xx: spi interface is added") Cc: Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20231221231823.2327894-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/sc16is7xx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index ce0681ba7734..892e27cddb0f 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1413,7 +1413,10 @@ static int sc16is7xx_spi_probe(struct spi_device *spi) /* Setup SPI bus */ spi->bits_per_word = 8; - /* only supports mode 0 on SC16IS762 */ + /* For all variants, only mode 0 is supported */ + if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0) + return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n"); + spi->mode = spi->mode ? : SPI_MODE_0; spi->max_speed_hz = spi->max_speed_hz ? : 4 * HZ_PER_MHZ; ret = spi_setup(spi);