From 63ab645f4d8b2dc1351c41751e7ebb1b3f1c99d3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stefan=20Br=C3=BCns?= Date: Sun, 23 Aug 2015 16:06:30 +0200 Subject: spi: check bits_per_word in spi_setup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows drivers for devices connected via SPI to check if the controller supports a given bits_per_word value during setup. Currently any BPW value is accepted durings setup, and transfers are rejected later. Signed-off-by: Stefan Brüns Signed-off-by: Mark Brown --- drivers/spi/spi.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 637d892..829323ce 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1740,6 +1740,20 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master); * other core methods are currently defined as inline functions. */ +static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word) +{ + if (master->bits_per_word_mask) { + /* Only 32 bits fit in the mask */ + if (bits_per_word > 32) + return -EINVAL; + if (!(master->bits_per_word_mask & + SPI_BPW_MASK(bits_per_word))) + return -EINVAL; + } + + return 0; +} + /** * spi_setup - setup SPI mode and clock rate * @spi: the device whose settings are being modified @@ -1798,6 +1812,9 @@ int spi_setup(struct spi_device *spi) if (!spi->bits_per_word) spi->bits_per_word = 8; + if (__spi_validate_bits_per_word(spi->master, spi->bits_per_word)) + return -EINVAL; + if (!spi->max_speed_hz) spi->max_speed_hz = spi->master->max_speed_hz; @@ -1867,14 +1884,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) xfer->speed_hz > master->max_speed_hz) xfer->speed_hz = master->max_speed_hz; - if (master->bits_per_word_mask) { - /* Only 32 bits fit in the mask */ - if (xfer->bits_per_word > 32) - return -EINVAL; - if (!(master->bits_per_word_mask & - BIT(xfer->bits_per_word - 1))) - return -EINVAL; - } + if (__spi_validate_bits_per_word(master, xfer->bits_per_word)) + return -EINVAL; /* * SPI transfer length should be multiple of SPI word size -- cgit v1.1