Merge tag 'spi-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The diffstat for this release is dominated by the new Airoha driver,
  mainly as a result of this being a generally quite quiet release.
  There were a couple of cleanups in the core but nothing substantial,
  the updates here are almost all driver specific ones.

   - Support for multi-word mode in the OMAP2 McSPI driver

   - Overhaul of the PXA2xx driver, mostly API updates

   - A number of DT binding conversions

   - Support for Airoha NAND controllers, Cirrus Logic CS35L56, Mobileye
     EYEQ5 and Renesas R8A779H0"

* tag 'spi-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (87 commits)
  spi: dw: Bail out early on unsupported target mode
  spi: Remove unneded check for orig_nents
  MAINTAINERS: repair file entry in AIROHA SPI SNFI DRIVER
  spi: pxa2xx: Drop the stale entry in documentation TOC
  spi: pxa2xx: Don't provide struct chip_data for others
  spi: pxa2xx: Remove timeout field from struct chip_data
  spi: pxa2xx: Remove DMA parameters from struct chip_data
  spi: pxa2xx: Drop struct pxa2xx_spi_chip
  spi: pxa2xx: Don't use "proxy" headers
  spi: pxa2xx: Remove outdated documentation
  spi: pxa2xx: Move contents of linux/spi/pxa2xx_spi.h to a local one
  spi: pxa2xx: Provide num-cs for Sharp PDAs via device properties
  spi: pxa2xx: Allow number of chip select pins to be read from property
  spi: dt-bindings: ti,qspi: convert to dtschema
  spi: bitbang: Add missing MODULE_DESCRIPTION()
  spi: bitbang: Use NSEC_PER_*SEC rather than hard coding
  spi: dw: Drop default number of CS setting
  spi: dw: Convert dw_spi::num_cs to u32
  spi: dw: Add a number of native CS auto-detection
  spi: dw: Convert to using BITS_TO_BYTES() macro
  ...

2 files changed, 53 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b50d0b470849..00b5c007a2bb 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -103,6 +103,15 @@ config GPIO_REGMAP
 	select REGMAP
 	tristate
 
+config GPIO_SWNODE_UNDEFINED
+	bool
+	help
+	  This adds a special place holder for software nodes to contain an
+	  undefined GPIO reference, this is primarily used by SPI to allow a
+	  list of GPIO chip selects to mark a certain chip select as being
+	  controlled the SPI device's internal chip select mechanism and not
+	  a GPIO.
+
 # put drivers in the right section, in alphabetical order
 
 # This symbol is selected by both I2C and SPI expanders
diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c
index fa52bdb1a29a..cec1ab878af8 100644
--- a/drivers/gpio/gpiolib-swnode.c
+++ b/drivers/gpio/gpiolib-swnode.c
@@ -4,8 +4,13 @@
  *
  * Copyright 2022 Google LLC
  */
+
+#define pr_fmt(fmt) "gpiolib: swnode: " fmt
+
 #include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/printk.h>
 #include <linux/property.h>
@@ -17,6 +22,8 @@
 #include "gpiolib.h"
 #include "gpiolib-swnode.h"
 
+#define GPIOLIB_SWNODE_UNDEFINED_NAME "swnode-gpio-undefined"
+
 static void swnode_format_propname(const char *con_id, char *propname,
 				   size_t max_size)
 {
@@ -40,6 +47,14 @@ static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
 	if (!gdev_node || !gdev_node->name)
 		return ERR_PTR(-EINVAL);
 
+	/*
+	 * Check for a special node that identifies undefined GPIOs, this is
+	 * primarily used as a key for internal chip selects in SPI bindings.
+	 */
+	if (IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) &&
+	    !strcmp(gdev_node->name, GPIOLIB_SWNODE_UNDEFINED_NAME))
+		return ERR_PTR(-ENOENT);
+
 	gdev = gpio_device_find_by_label(gdev_node->name);
 	return gdev ?: ERR_PTR(-EPROBE_DEFER);
 }
@@ -121,3 +136,32 @@ int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
 
 	return count ?: -ENOENT;
 }
+
+#if IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED)
+/*
+ * A special node that identifies undefined GPIOs, this is primarily used as
+ * a key for internal chip selects in SPI bindings.
+ */
+const struct software_node swnode_gpio_undefined = {
+	.name = GPIOLIB_SWNODE_UNDEFINED_NAME,
+};
+EXPORT_SYMBOL_NS_GPL(swnode_gpio_undefined, GPIO_SWNODE);
+
+static int __init swnode_gpio_init(void)
+{
+	int ret;
+
+	ret = software_node_register(&swnode_gpio_undefined);
+	if (ret < 0)
+		pr_err("failed to register swnode: %d\n", ret);
+
+	return ret;
+}
+subsys_initcall(swnode_gpio_init);
+
+static void __exit swnode_gpio_cleanup(void)
+{
+	software_node_unregister(&swnode_gpio_undefined);
+}
+__exitcall(swnode_gpio_cleanup);
+#endif