openwrt/target/linux/bcm27xx/patches-6.6/950-0821-spi-bcm2835-Support-spi0-0cs-and-SPI_NO_CS-mode.patch
Álvaro Fernández Rojas 8c405cdccc bcm27xx: add 6.6 kernel patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.34..rpi-6.1.y

Some patches needed rebasing and, as usual, the applied and reverted, wireless
drivers, Github workflows, READMEs and defconfigs patches were removed.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-06-18 18:52:49 +02:00

43 lines
1.4 KiB
Diff

From a70302cd341cb331bbed1b5fa3d1ec5af1105676 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Mon, 8 Jan 2024 11:42:57 +0000
Subject: [PATCH 0821/1085] spi: bcm2835: Support spi0-0cs and SPI_NO_CS mode
The forced conversion of native CS lines into software CS lines is done
whether or not the controller has been given any CS lines to use. This
breaks the use of the spi0-0cs overlay to prevent SPI from claiming any
CS lines, particularly with spidev which doesn't pass in the SPI_NO_CS
flag at creation.
Use the presence of an empty cs-gpios property as an indication that no
CS lines should be used, bypassing the native CS conversion code.
See: https://github.com/raspberrypi/linux/issues/5835
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
drivers/spi/spi-bcm2835.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -1222,6 +1222,7 @@ static int bcm2835_spi_setup(struct spi_
struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
struct bcm2835_spidev *target = spi_get_ctldata(spi);
struct gpio_chip *chip;
+ int len;
int ret;
u32 cs;
@@ -1287,6 +1288,10 @@ static int bcm2835_spi_setup(struct spi_
goto err_cleanup;
}
+ /* Skip forced CS conversion if controller has an empty cs-gpios property */
+ if (of_find_property(ctlr->dev.of_node, "cs-gpios", &len) && len == 0)
+ return 0;
+
/*
* Translate native CS to GPIO
*