diff options
Diffstat (limited to 'nixos/modules/kernel-patches/0077-gpio-gpio-cascade-add-generic-GPIO-cascade.patch')
| -rw-r--r-- | nixos/modules/kernel-patches/0077-gpio-gpio-cascade-add-generic-GPIO-cascade.patch | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/nixos/modules/kernel-patches/0077-gpio-gpio-cascade-add-generic-GPIO-cascade.patch b/nixos/modules/kernel-patches/0077-gpio-gpio-cascade-add-generic-GPIO-cascade.patch deleted file mode 100644 index 98dfc24..0000000 --- a/nixos/modules/kernel-patches/0077-gpio-gpio-cascade-add-generic-GPIO-cascade.patch +++ /dev/null @@ -1,189 +0,0 @@ -From f5105edd6729159f332579da5416aa3a26c84ad6 Mon Sep 17 00:00:00 2001 -From: Mauri Sandberg <maukka@ext.kapsi.fi> -Date: Thu, 25 Mar 2021 11:48:05 +0200 -Subject: [PATCH 77/96] 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 <maukka@ext.kapsi.fi> -Reviewed-by: Linus Walleij <linus.walleij@linaro.org> -Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> ---- - 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 - -diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig -index b01961999ced..b88980948950 100644 ---- a/drivers/gpio/Kconfig -+++ b/drivers/gpio/Kconfig -@@ -1710,4 +1710,19 @@ config GPIO_SIM - - 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 -diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile -index 14352f6dfe8e..561c060b0d9f 100644 ---- a/drivers/gpio/Makefile -+++ b/drivers/gpio/Makefile -@@ -44,6 +44,7 @@ obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o - obj-$(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_CRYSTAL_COVE) += gpio-crystalcove.o -diff --git a/drivers/gpio/gpio-cascade.c b/drivers/gpio/gpio-cascade.c -new file mode 100644 -index 000000000000..5cbda882d79a ---- /dev/null -+++ b/drivers/gpio/gpio-cascade.c -@@ -0,0 +1,117 @@ -+// SPDX-License-Identifier: GPL-2.0-only -+/* -+ * A generic GPIO cascade driver -+ * -+ * Copyright (C) 2021 Mauri Sandberg <maukka@ext.kapsi.fi> -+ * -+ * 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 struct gpio_cascade *chip_to_cascade(struct gpio_chip *gc) -+{ -+ return container_of(gc, struct gpio_cascade, gpio_chip); -+} -+ -+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 = chip_to_cascade(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, NULL); -+} -+ -+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 <maukka@ext.kapsi.fi>"); -+MODULE_DESCRIPTION("Generic GPIO cascade"); -+MODULE_LICENSE("GPL"); --- -2.37.2 - |