From e6f3f7e4dc76eb8d8a546dc66621a02c5c84f4ac Mon Sep 17 00:00:00 2001 From: =?utf8?q?Noralf=20Tr=C3=B8nnes?= Date: Fri, 12 Apr 2019 11:41:30 +0200 Subject: [PATCH] spi: Add spi_is_bpw_supported() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This let SPI clients check if the controller supports a particular word width. drivers/gpu/drm/tinydrm/mipi-dbi.c will use this to determine if the controller supports 16-bit for RGB565 pixels. If it doesn't it will swap the bytes before transfer on little endian machines. Signed-off-by: Noralf Trønnes Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 662b336..b30e3d1 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -983,6 +983,26 @@ spi_max_transfer_size(struct spi_device *spi) return min(tr_max, msg_max); } +/** + * spi_is_bpw_supported - Check if bits per word is supported + * @spi: SPI device + * @bpw: Bits per word + * + * This function checks to see if the SPI controller supports @bpw. + * + * Returns: + * True if @bpw is supported, false otherwise. + */ +static inline bool spi_is_bpw_supported(struct spi_device *spi, u32 bpw) +{ + u32 bpw_mask = spi->master->bits_per_word_mask; + + if (bpw == 8 || (bpw <= 32 && bpw_mask & SPI_BPW_MASK(bpw))) + return true; + + return false; +} + /*---------------------------------------------------------------------------*/ /* SPI transfer replacement methods which make use of spi_res */ -- 2.7.4