From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baolin Wang Subject: [PATCH v2 1/3] spi: Introduce one new field to set word delay Date: Thu, 16 Aug 2018 20:54:49 +0800 Message-ID: Return-path: Sender: linux-kernel-owner@vger.kernel.org To: broonie@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com Cc: orsonzhai@gmail.com, zhang.lyra@gmail.com, lanqing.liu@spreadtrum.com, baolin.wang@linaro.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org For some SPI controllers, after each word size (specified by bits_per_word) transimission, the hardware need some delay to make sure the slave has enough time to receive the whole data. So introducing one new 'word_delay' field of struct spi_tansfer for slave devices to set this inter word delay time. Signed-off-by: Baolin Wang --- Changes from v1: - New patch in v2. --- include/linux/spi/spi.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a64235e..d698f9d 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -711,6 +711,8 @@ extern void spi_res_release(struct spi_controller *ctlr, * @delay_usecs: microseconds to delay after this transfer before * (optionally) changing the chipselect status, then starting * the next transfer or completing this @spi_message. + * @word_delay: clock cycles to inter word delay after each word size + * (set by bits_per_word) transmission. * @transfer_list: transfers are sequenced through @spi_message.transfers * @tx_sg: Scatterlist for transmit, currently not for client use * @rx_sg: Scatterlist for receive, currently not for client use @@ -793,6 +795,7 @@ struct spi_transfer { u8 bits_per_word; u16 delay_usecs; u32 speed_hz; + u16 word_delay; struct list_head transfer_list; }; -- 1.7.9.5