From 7dc9fbc342deb2e2658ebdecb5ffd7ff57945a66 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 20 Aug 2015 11:52:18 -0700 Subject: [PATCH 1/2] spi: Fall back to master maximum speed if no slave speed specified If a slave appears with no maximum transfer speed specified fall back to using the maximum for the master instead. It's questionable if we should let slaves do this but let's be defensive. Signed-off-by: Mark Brown --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index cf8b91b23a76..637d892b316d 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1860,6 +1860,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) if (!xfer->speed_hz) xfer->speed_hz = spi->max_speed_hz; + if (!xfer->speed_hz) + xfer->speed_hz = master->max_speed_hz; if (master->max_speed_hz && xfer->speed_hz > master->max_speed_hz) 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: [PATCH 2/2] 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(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 637d892b316d..829323ce7cdf 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