From: Boerge Struempfel <boerge.struempfel@gmail.com>
To: unlisted-recipients:; (no To-header on input)
Cc: boerge.struempfel@gmail.com, bstruempfel@ultratronik.de,
andy.shevchenko@gmail.com, festevam@gmail.com,
amit.kumar-mahapatra@amd.com, broonie@kernel.org,
Shawn Guo <shawnguo@kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
NXP Linux Team <linux-imx@nxp.com>,
linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v6 1/5] spi: add SPI_MOSI_IDLE_LOW mode bit
Date: Wed, 24 May 2023 11:19:44 +0200 [thread overview]
Message-ID: <20230524091948.41779-2-boerge.struempfel@gmail.com> (raw)
In-Reply-To: <20230524091948.41779-1-boerge.struempfel@gmail.com>
Some spi controller switch the mosi line to high, whenever they are
idle. This may not be desired in all use cases. For example neopixel
leds can get confused and flicker due to misinterpreting the idle state.
Therefore, we introduce a new spi-mode bit, with which the idle behaviour
can be overwritten on a per device basis.
Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
---
include/uapi/linux/spi/spi.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
index 9d5f58059703..ca56e477d161 100644
--- a/include/uapi/linux/spi/spi.h
+++ b/include/uapi/linux/spi/spi.h
@@ -28,6 +28,7 @@
#define SPI_RX_OCTAL _BITUL(14) /* receive with 8 wires */
#define SPI_3WIRE_HIZ _BITUL(15) /* high impedance turnaround */
#define SPI_RX_CPHA_FLIP _BITUL(16) /* flip CPHA on Rx only xfer */
+#define SPI_MOSI_IDLE_LOW _BITUL(17) /* leave mosi line low when idle */
/*
* All the bits defined above should be covered by SPI_MODE_USER_MASK.
@@ -37,6 +38,6 @@
* These bits must not overlap. A static assert check should make sure of that.
* If adding extra bits, make sure to increase the bit index below as well.
*/
-#define SPI_MODE_USER_MASK (_BITUL(17) - 1)
+#define SPI_MODE_USER_MASK (_BITUL(18) - 1)
#endif /* _UAPI_SPI_H */
--
2.40.1
next prev parent reply other threads:[~2023-05-24 9:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-24 9:19 [PATCH v6 0/5] spi: add SPI_MOSI_IDLE_LOW mode bit Boerge Struempfel
2023-05-24 9:19 ` Boerge Struempfel [this message]
2023-05-24 9:19 ` [PATCH v6 2/5] spi: spi-imx: add support for " Boerge Struempfel
2023-05-24 9:47 ` Frieder Schrempf
2023-05-24 11:42 ` Börge Strümpfel
2023-05-30 12:46 ` Mark Brown
2023-05-30 13:27 ` Börge Strümpfel
2023-05-24 9:19 ` [PATCH v6 3/5] spi: spidev: add two new spi mode bits Boerge Struempfel
2023-05-24 9:19 ` [PATCH v6 4/5] spi: spidev_test: Sorted the options into logical groups Boerge Struempfel
2023-05-24 9:19 ` [PATCH v6 5/5] spi: spidev_test Add three missing spi mode bits Boerge Struempfel
2023-05-30 17:40 ` [PATCH v6 0/5] spi: add SPI_MOSI_IDLE_LOW mode bit Mark Brown
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