generic: drop downstream gpio-cascade driver

The single user of the downstream gpio-cascade driver has been switched
to use the upstream gpio-line-mux driver. Thus, we can drop the former
now.

Signed-off-by: Jonas Jelonek <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/22206
Signed-off-by: Robert Marko <[email protected]>

package/kernel/linux/modules/gpio.mk

@@ -40,22 +40,6 @@ endef
 $(eval $(call KernelPackage,gpio-beeper))
 
 
-define KernelPackage/gpio-cascade
-  SUBMENU:=$(GPIO_MENU)
-  TITLE:=Generic GPIO cascade
-  KCONFIG:=CONFIG_GPIO_CASCADE
-  DEPENDS:=@GPIO_SUPPORT +kmod-mux-core
-  FILES:=$(LINUX_DIR)/drivers/gpio/gpio-cascade.ko
-  AUTOLOAD:=$(call AutoLoad,29,gpio-cascade,1)
-endef
-
-define KernelPackage/gpio-cascade/description
-  Kernel module for Generic GPIO cascade
-endef
-
-$(eval $(call KernelPackage,gpio-cascade))
-
-
 define KernelPackage/gpio-f7188x
   SUBMENU:=$(GPIO_MENU)
   TITLE:=Fintek F718xx/F818xx GPIO Support

target/linux/generic/config-6.12

@@ -2229,7 +2229,6 @@ CONFIG_GPIOLIB_FASTPATH_LIMIT=512
 # CONFIG_GPIO_BRCMSTB is not set
 # CONFIG_GPIO_BT8XX is not set
 # CONFIG_GPIO_CADENCE is not set
-# CONFIG_GPIO_CASCADE is not set
 # CONFIG_GPIO_CDEV is not set
 # CONFIG_GPIO_CDEV_V1 is not set
 # CONFIG_GPIO_CS5535 is not set

target/linux/generic/pending-6.12/801-gpio-gpio-cascade-add-generic-GPIO-cascade.patch

@@ -1,217 +0,0 @@
-From fc23ea48ba52c24f201fe5ca0132ee1a3de5a70a Mon Sep 17 00:00:00 2001
-From: Mauri Sandberg <[email protected]>
-Date: Thu, 25 Mar 2021 11:48:05 +0200
-Subject: [PATCH 2/2] gpio: gpio-cascade: add generic GPIO cascade
-
-Adds support for building cascades of GPIO lines. That is, it allows
-setups when there is one upstream line and multiple cascaded lines, out
-of which one can be chosen at a time. The status of the upstream line
-can be conveyed to the selected cascaded line or, vice versa, the status
-of the cascaded line can be conveyed to the upstream line.
-
-A multiplexer is being used to select, which cascaded GPIO line is being
-used at any given time.
-
-At the moment only input direction is supported. In future it should be
-possible to add support for output direction, too.
-
-Signed-off-by: Mauri Sandberg <[email protected]>
-Reviewed-by: Linus Walleij <[email protected]>
-Reviewed-by: Andy Shevchenko <[email protected]>
----
-v7 -> v8:
- - rearrange members in struct gpio_cascade
- - cosmetic changes in file header and in one function declaration
- - added Reviewed-by tags by Linus and Andy
-v6 -> v7:
- - In Kconfig add info about module name
- - adhere to new convention that allows lines longer than 80 chars
- - use dev_probe_err with upstream gpio line too
- - refactor for cleaner exit of probe function.
-v5 -> v6:
- - In Kconfig, remove dependency to OF_GPIO and select only MULTIPLEXER
- - refactor code preferring one-liners
- - clean up prints, removing them from success-path.
- - don't explicitly set gpio_chip.of_node as it's done in the GPIO library
- - use devm_gpiochip_add_data instead of gpiochip_add
-v4 -> v5:
- - renamed gpio-mux-input -> gpio-cascade. refactored code accordingly
-   here and there and changed to use new bindings and compatible string
-   - ambigious and vague 'pin' was rename to 'upstream_line'
- - dropped Tested-by and Reviewed-by due to changes in bindings
- - dropped Reported-by suggested by an automatic bot as it was not really
-   appropriate to begin with
- - functionally it's the same as v4
-v3 -> v4:
- - Changed author email
- - Included Tested-by and Reviewed-by from Drew
-v2 -> v3:
- - use managed device resources
- - update Kconfig description
-v1 -> v2:
- - removed .owner from platform_driver as per test bot's instruction
- - added MODULE_AUTHOR, MODULE_DESCRIPTION, MODULE_LICENSE
- - added gpio_mux_input_get_direction as it's recommended for all chips
- - removed because this is input only chip: gpio_mux_input_set_value
- - removed because they are not needed for input/output only chips:
-     gpio_mux_input_direction_input
-     gpio_mux_input_direction_output
- - fixed typo in an error message
- - added info message about successful registration
- - removed can_sleep flag as this does not sleep while getting GPIO value
-   like I2C or SPI do
- - Updated description in Kconfig
----
- drivers/gpio/Kconfig        |  15 +++++
- drivers/gpio/Makefile       |   1 +
- drivers/gpio/gpio-cascade.c | 117 ++++++++++++++++++++++++++++++++++++
- 3 files changed, 133 insertions(+)
- create mode 100644 drivers/gpio/gpio-cascade.c
-
---- a/drivers/gpio/Kconfig
-+++ b/drivers/gpio/Kconfig
-@@ -1929,4 +1929,19 @@ config GPIO_VIRTUSER
- 
- endmenu
- 
-+comment "Other GPIO expanders"
-+
-+config GPIO_CASCADE
-+	tristate "General GPIO cascade"
-+	select MULTIPLEXER
-+	help
-+	  Say yes here to enable support for generic GPIO cascade.
-+
-+	  This allows building one-to-many cascades of GPIO lines using
-+	  different types of multiplexers readily available. At the
-+	  moment only input lines are supported.
-+
-+	  To build the driver as a module choose 'm' and the resulting module
-+	  will be called 'gpio-cascade'.
-+
- endif
---- a/drivers/gpio/Makefile
-+++ b/drivers/gpio/Makefile
-@@ -46,6 +46,7 @@ obj-$(CONFIG_GPIO_BD9571MWV)		+= gpio-bd
- obj-$(CONFIG_GPIO_BRCMSTB)		+= gpio-brcmstb.o
- obj-$(CONFIG_GPIO_BT8XX)		+= gpio-bt8xx.o
- obj-$(CONFIG_GPIO_CADENCE)		+= gpio-cadence.o
-+obj-$(CONFIG_GPIO_CASCADE)		+= gpio-cascade.o
- obj-$(CONFIG_GPIO_CLPS711X)		+= gpio-clps711x.o
- obj-$(CONFIG_GPIO_SNPS_CREG)		+= gpio-creg-snps.o
- obj-$(CONFIG_GPIO_CROS_EC)		+= gpio-cros-ec.o
---- /dev/null
-+++ b/drivers/gpio/gpio-cascade.c
-@@ -0,0 +1,112 @@
-+// SPDX-License-Identifier: GPL-2.0-only
-+/*
-+ *  A generic GPIO cascade driver
-+ *
-+ *  Copyright (C) 2021 Mauri Sandberg <[email protected]>
-+ *
-+ * This allows building cascades of GPIO lines in a manner illustrated
-+ * below:
-+ *
-+ *                 /|---- Cascaded GPIO line 0
-+ *  Upstream      | |---- Cascaded GPIO line 1
-+ *  GPIO line ----+ | .
-+ *                | | .
-+ *                 \|---- Cascaded GPIO line n
-+ *
-+ * A multiplexer is being used to select, which cascaded line is being
-+ * addressed at any given time.
-+ *
-+ * At the moment only input mode is supported due to lack of means for
-+ * testing output functionality. At least theoretically output should be
-+ * possible with open drain constructions.
-+ */
-+
-+#include <linux/module.h>
-+#include <linux/slab.h>
-+#include <linux/platform_device.h>
-+#include <linux/mux/consumer.h>
-+
-+#include <linux/gpio/consumer.h>
-+#include <linux/gpio/driver.h>
-+
-+struct gpio_cascade {
-+	struct gpio_chip	gpio_chip;
-+	struct device		*parent;
-+	struct mux_control	*mux_control;
-+	struct gpio_desc	*upstream_line;
-+};
-+
-+static int gpio_cascade_get_direction(struct gpio_chip *gc, unsigned int offset)
-+{
-+	return GPIO_LINE_DIRECTION_IN;
-+}
-+
-+static int gpio_cascade_get_value(struct gpio_chip *gc, unsigned int offset)
-+{
-+	struct gpio_cascade *cas = gpiochip_get_data(gc);
-+	int ret;
-+
-+	ret = mux_control_select(cas->mux_control, offset);
-+	if (ret)
-+		return ret;
-+
-+	ret = gpiod_get_value(cas->upstream_line);
-+	mux_control_deselect(cas->mux_control);
-+	return ret;
-+}
-+
-+static int gpio_cascade_probe(struct platform_device *pdev)
-+{
-+	struct device *dev = &pdev->dev;
-+	struct gpio_cascade *cas;
-+	struct mux_control *mc;
-+	struct gpio_desc *upstream;
-+	struct gpio_chip *gc;
-+
-+	cas = devm_kzalloc(dev, sizeof(*cas), GFP_KERNEL);
-+	if (!cas)
-+		return -ENOMEM;
-+
-+	mc = devm_mux_control_get(dev, NULL);
-+	if (IS_ERR(mc))
-+		return dev_err_probe(dev, PTR_ERR(mc), "unable to get mux-control\n");
-+
-+	cas->mux_control = mc;
-+	upstream = devm_gpiod_get(dev, "upstream",  GPIOD_IN);
-+	if (IS_ERR(upstream))
-+		return dev_err_probe(dev, PTR_ERR(upstream), "unable to claim upstream GPIO line\n");
-+
-+	cas->upstream_line = upstream;
-+	cas->parent = dev;
-+
-+	gc = &cas->gpio_chip;
-+	gc->get = gpio_cascade_get_value;
-+	gc->get_direction = gpio_cascade_get_direction;
-+	gc->base = -1;
-+	gc->ngpio = mux_control_states(mc);
-+	gc->label = dev_name(cas->parent);
-+	gc->parent = cas->parent;
-+	gc->owner = THIS_MODULE;
-+
-+	platform_set_drvdata(pdev, cas);
-+	return devm_gpiochip_add_data(dev, &cas->gpio_chip, cas);
-+}
-+
-+static const struct of_device_id gpio_cascade_id[] = {
-+	{ .compatible = "gpio-cascade" },
-+	{ /* sentinel */ }
-+};
-+MODULE_DEVICE_TABLE(of, gpio_cascade_id);
-+
-+static struct platform_driver gpio_cascade_driver = {
-+	.driver	= {
-+		.name		= "gpio-cascade",
-+		.of_match_table = gpio_cascade_id,
-+	},
-+	.probe	= gpio_cascade_probe,
-+};
-+module_platform_driver(gpio_cascade_driver);
-+
-+MODULE_AUTHOR("Mauri Sandberg <[email protected]>");
-+MODULE_DESCRIPTION("Generic GPIO cascade");
-+MODULE_LICENSE("GPL");