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Commit 63ab645f authored by Stefan Brüns's avatar Stefan Brüns Committed by Mark Brown
Browse files

spi: check bits_per_word in spi_setup 



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: default avatarStefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 7dc9fbc3

drivers/spi/spi.c

+19 −8
Original line number Diff line number Diff line
@@ -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)))

		if (__spi_validate_bits_per_word(master, xfer->bits_per_word))

			return -EINVAL;

		}



		/*

		 * SPI transfer length should be multiple of SPI word size