From: Baolin Wang <baolin.wang@linaro.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
Subject: [PATCH v2 1/3] spi: Introduce one new field to set word delay
Date: Thu, 16 Aug 2018 20:54:49 +0800 [thread overview]
Message-ID: <a77a6bb8b3abf1c127014c78f71533c24afacd93.1534423916.git.baolin.wang@linaro.org> (raw)
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 <baolin.wang@linaro.org>
---
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
next reply other threads:[~2018-08-16 12:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-16 12:54 Baolin Wang [this message]
2018-08-16 12:54 ` [PATCH v2 2/3] dt-bindings: spi: Add Spreadtrum SPI controller documentation Baolin Wang
2018-08-20 19:38 ` Rob Herring
2018-08-16 12:54 ` [PATCH v2 3/3] spi: sprd: Add SPI driver for Spreadtrum SC9860 Baolin Wang
2018-08-28 20:57 ` Applied "spi: sprd: Add SPI driver for Spreadtrum SC9860" to the spi tree Mark Brown
2018-08-29 11:02 ` Applied "spi: Introduce one new field to set word delay" " Mark Brown
2018-08-29 11:33 ` [PATCH v2 1/3] spi: Introduce one new field to set word delay Jan Kundrát
2018-08-29 11:47 ` Mark Brown
2018-08-31 8:38 ` Baolin Wang
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