| Message ID | 20190412094131.25616-1-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] spi: Add spi_is_bpw_supported() | expand |
On Fri, Apr 12, 2019 at 11:41:30AM +0200, Noralf Trønnes wrote: > 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. The following changes since commit 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b: Linux 5.1-rc1 (2019-03-17 14:22:26 -0700) are available in the Git repository at: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git tags/spi-bpw-is-supported for you to fetch changes up to e6f3f7e4dc76eb8d8a546dc66621a02c5c84f4ac: spi: Add spi_is_bpw_supported() (2019-04-12 11:13:36 +0100) ---------------------------------------------------------------- spi: Add spi_is_bpw_supported() Lets client drivers check and potentially handle issues. ---------------------------------------------------------------- Noralf Trønnes (1): spi: Add spi_is_bpw_supported() 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 662b336aa2e4..b30e3d13a5ac 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 */
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 <noralf@tronnes.org> --- include/linux/spi/spi.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)