From e4be7053b9d3aa0a97b311ad77528d8b32236590 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sun, 2 Oct 2016 14:22:35 +0200 Subject: [PATCH] spi: fsl-espi: reject MSB-first transfers with word sizes other than 8 or 16 According to the ESPI spec MSB-first transfers are supported for word size 8 and 16 only. Check for this and reject MSB-first transfers with other word sizes. Signed-off-by: Heiner Kallweit Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-espi.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c index 1f97cce615d3..65bb70d3bfc4 100644 --- a/drivers/spi/spi-fsl-espi.c +++ b/drivers/spi/spi-fsl-espi.c @@ -153,6 +153,7 @@ static int fsl_espi_check_message(struct spi_message *m) first = list_first_entry(&m->transfers, struct spi_transfer, transfer_list); + list_for_each_entry(t, &m->transfers, transfer_list) { if (first->bits_per_word != t->bits_per_word || first->speed_hz != t->speed_hz) { @@ -161,6 +162,15 @@ static int fsl_espi_check_message(struct spi_message *m) } } + /* ESPI supports MSB-first transfers for word size 8 / 16 only */ + if (!(m->spi->mode & SPI_LSB_FIRST) && first->bits_per_word != 8 && + first->bits_per_word != 16) { + dev_err(mspi->dev, + "MSB-first transfer not supported for wordsize %u\n", + first->bits_per_word); + return -EINVAL; + } + return 0; } -- 2.39.5