4.19-stable review patch. If anyone has any objections, please let me know.
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From: Hugo Villeneuve hvilleneuve@dimonoff.com
[ 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: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com Link: https://lore.kernel.org/r/20231221231823.2327894-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 07898a46fd96..800cb94e4b91 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1407,7 +1407,10 @@ 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);