packages: kernel: add gpio-nxp-74hc153

NXP 74HC153 is a GPIO expander. Its original source cide sits in ar71xx
architecture tree. It has been slightly modified to get GPIO pin
configuration from the device tree rather than a MACH file.

 Changes to the source file:
  - Remove struct nxp_74hc153_config
  - in nxp_74hc153_probe(), fetch GPIO configuration from device tree
  - allow GPIO framework decide the base number by passing -1 to it
  - remove support for kernel versions below 4.5.0
  - add OF device compatibility string

 Create a package for inclusion in image.

References: https://lore.kernel.org/linux-gpio/545111184.50061.1615922388276@ichabod.co-bxl/
Signed-off-by: Mauri Sandberg <sandberg@mailfence.com>
[added link to driver usptreaming work in progress]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

3 files changed, 327 insertions, 0 deletions

diff --git a/package/kernel/gpio-nxp-74hc153/Makefile b/package/kernel/gpio-nxp-74hc153/Makefile
new file mode 100644
index 0000000000..e275a9a856
--- /dev/null
+++ b/package/kernel/gpio-nxp-74hc153/Makefile
@@ -0,0 +1,35 @@
+#
+# Copyright (C) 2020 Mauri Sandberg <sandberg@mailfence.com>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=gpio-nxp-74hc153
+PKG_RELEASE:=1
+PKG_LICENSE:=GPL-2.0
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/gpio-nxp-74hc153
+  SUBMENU:=Other modules
+  TITLE:= NXP 74HC153 GPIO expander
+  FILES:=$(PKG_BUILD_DIR)/gpio-nxp-74hc153.ko
+  AUTOLOAD:=$(call AutoLoad,30,gpio-nxp-74hc153,1)
+  KCONFIG:=
+  DEPENDS:= @GPIO_SUPPORT @TARGET_ath79
+endef
+
+define KernelPackage/gpio-nxp-74hc153/description
+  Platform driver for NXP 74HC153 Dual 4-input Multiplexer.
+  This provides a GPIO interface supporting input mode only.
+endef
+
+define Build/Compile
+	$(KERNEL_MAKE) M=$(PKG_BUILD_DIR) modules
+endef
+
+$(eval $(call KernelPackage,gpio-nxp-74hc153))
diff --git a/package/kernel/gpio-nxp-74hc153/src/Makefile b/package/kernel/gpio-nxp-74hc153/src/Makefile
new file mode 100644
index 0000000000..0a5cc2fdda
--- /dev/null
+++ b/package/kernel/gpio-nxp-74hc153/src/Makefile
@@ -0,0 +1 @@
+obj-m += gpio-nxp-74hc153.o
diff --git a/package/kernel/gpio-nxp-74hc153/src/gpio-nxp-74hc153.c b/package/kernel/gpio-nxp-74hc153/src/gpio-nxp-74hc153.c
new file mode 100644
index 0000000000..f683547cfd
--- /dev/null
+++ b/package/kernel/gpio-nxp-74hc153/src/gpio-nxp-74hc153.c
@@ -0,0 +1,291 @@
+/*
+ *  NXP 74HC153 - Dual 4-input multiplexer GPIO driver
+ *
+ *  Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2020 Mauri Sandberg <sandberg@mailfence.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  Example device tree definition:
+ *
+ *  gpio-extender {
+ *    compatible = "nxp,74hc153-gpio";
+ *    gpio-controller;
+ *    #gpio-cells = <2>;
+ *
+ *    // GPIOs used by this node
+ *    gpio-s0 = <&gpio 9 GPIO_ACTIVE_HIGH>;
+ *    gpio-s1 = <&gpio 11 GPIO_ACTIVE_HIGH>;
+ *    gpio-1y = <&gpio 12 GPIO_ACTIVE_HIGH>;
+ *    gpio-2y = <&gpio 14 GPIO_ACTIVE_HIGH>;
+ *  };
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of_gpio.h>
+
+#define NXP_74HC153_NUM_GPIOS   8
+#define NXP_74HC153_S0_MASK     0x1
+#define NXP_74HC153_S1_MASK     0x2
+#define NXP_74HC153_BANK_MASK   0x4
+
+#define NXP_74HC153_DRIVER_NAME "nxp-74hc153"
+
+struct nxp_74hc153_config {
+	unsigned gpio_pin_s0;
+	unsigned gpio_pin_s1;
+	unsigned gpio_pin_1y;
+	unsigned gpio_pin_2y;
+};
+
+struct nxp_74hc153_chip {
+	struct device             *parent;
+	struct gpio_chip          gpio_chip;
+	struct mutex              lock;
+	struct nxp_74hc153_config config;
+};
+
+static struct nxp_74hc153_chip *gpio_to_nxp(struct gpio_chip *gc)
+{
+	return container_of(gc, struct nxp_74hc153_chip, gpio_chip);
+}
+
+static int nxp_74hc153_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	return 0;
+}
+
+static int nxp_74hc153_direction_output(struct gpio_chip *gc,
+					unsigned offset, int val)
+{
+	return -EINVAL;
+}
+
+static int nxp_74hc153_get_value(struct gpio_chip *gc, unsigned offset)
+{
+	struct nxp_74hc153_chip *nxp;
+	struct nxp_74hc153_platform_data *pdata;
+	unsigned s0;
+	unsigned s1;
+	unsigned pin;
+	int ret;
+
+	nxp = gpio_to_nxp(gc);
+	pdata = nxp->parent->platform_data;
+
+	s0 = !!(offset & NXP_74HC153_S0_MASK);
+	s1 = !!(offset & NXP_74HC153_S1_MASK);
+	pin = (offset & NXP_74HC153_BANK_MASK) ? nxp->config.gpio_pin_2y
+	                                       : nxp->config.gpio_pin_1y;
+
+	mutex_lock(&nxp->lock);
+	gpio_set_value(nxp->config.gpio_pin_s0, s0);
+	gpio_set_value(nxp->config.gpio_pin_s1, s1);
+	ret = gpio_get_value(pin);
+	mutex_unlock(&nxp->lock);
+
+	return ret;
+}
+
+static void nxp_74hc153_set_value(struct gpio_chip *gc,
+	unsigned offset, int val)
+{
+	/* not supported */
+}
+
+static int nxp_74hc153_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct nxp_74hc153_chip *nxp;
+	struct gpio_chip *gc;
+	int err;
+	unsigned gpio_s0;
+	unsigned gpio_s1;
+	unsigned gpio_1y;
+        unsigned gpio_2y;
+
+	nxp = kzalloc(sizeof(struct nxp_74hc153_chip), GFP_KERNEL);
+	if (nxp == NULL) {
+		dev_err(&pdev->dev, "no memory for private data\n");
+		return -ENOMEM;
+	}
+
+	gpio_s0 = of_get_named_gpio(np, "gpio-s0", 0);
+	gpio_s1 = of_get_named_gpio(np, "gpio-s1", 0);
+	gpio_1y = of_get_named_gpio(np, "gpio-1y", 0);
+	gpio_2y = of_get_named_gpio(np, "gpio-2y", 0);
+
+	if (!gpio_is_valid(gpio_s0) || !gpio_is_valid(gpio_s1) ||
+  	    !gpio_is_valid(gpio_1y) || !gpio_is_valid(gpio_2y)) {
+
+		dev_err(&pdev->dev, "control GPIO(s) are missing\n");
+		err = -EINVAL;
+		goto err_free_nxp;
+	} else {
+		nxp->config.gpio_pin_s0 = gpio_s0;
+		nxp->config.gpio_pin_s1 = gpio_s1;
+		nxp->config.gpio_pin_1y = gpio_1y;
+		nxp->config.gpio_pin_2y = gpio_2y;
+	}
+
+	// apply pin configuration
+	err = gpio_request(nxp->config.gpio_pin_s0, dev_name(&pdev->dev));
+	if (err) {
+		dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
+			nxp->config.gpio_pin_s0, err);
+		goto err_free_nxp;
+	}
+
+	err = gpio_request(nxp->config.gpio_pin_s1, dev_name(&pdev->dev));
+	if (err) {
+		dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
+			nxp->config.gpio_pin_s1, err);
+		goto err_free_s0;
+	}
+
+	err = gpio_request(nxp->config.gpio_pin_1y, dev_name(&pdev->dev));
+	if (err) {
+		dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
+			nxp->config.gpio_pin_1y, err);
+		goto err_free_s1;
+	}
+
+	err = gpio_request(nxp->config.gpio_pin_2y, dev_name(&pdev->dev));
+	if (err) {
+		dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
+			nxp->config.gpio_pin_2y, err);
+		goto err_free_1y;
+	}
+
+	err = gpio_direction_output(nxp->config.gpio_pin_s0, 0);
+	if (err) {
+		dev_err(&pdev->dev,
+			"unable to set direction of gpio %u, err=%d\n",
+			nxp->config.gpio_pin_s0, err);
+		goto err_free_2y;
+	}
+
+	err = gpio_direction_output(nxp->config.gpio_pin_s1, 0);
+	if (err) {
+		dev_err(&pdev->dev,
+			"unable to set direction of gpio %u, err=%d\n",
+			nxp->config.gpio_pin_s1, err);
+		goto err_free_2y;
+	}
+
+	err = gpio_direction_input(nxp->config.gpio_pin_1y);
+	if (err) {
+		dev_err(&pdev->dev,
+			"unable to set direction of gpio %u, err=%d\n",
+			nxp->config.gpio_pin_1y, err);
+		goto err_free_2y;
+	}
+
+	err = gpio_direction_input(nxp->config.gpio_pin_2y);
+	if (err) {
+		dev_err(&pdev->dev,
+			"unable to set direction of gpio %u, err=%d\n",
+			nxp->config.gpio_pin_2y, err);
+		goto err_free_2y;
+	}
+
+	nxp->parent = &pdev->dev;
+	mutex_init(&nxp->lock);
+
+	gc = &nxp->gpio_chip;
+
+	gc->direction_input  = nxp_74hc153_direction_input;
+	gc->direction_output = nxp_74hc153_direction_output;
+	gc->get = nxp_74hc153_get_value;
+	gc->set = nxp_74hc153_set_value;
+	gc->can_sleep = 1;
+
+	gc->base = -1;
+	gc->ngpio = NXP_74HC153_NUM_GPIOS;
+	gc->label = dev_name(nxp->parent);
+	gc->parent = nxp->parent;
+	gc->owner = THIS_MODULE;
+	gc->of_node = np;
+
+	err = gpiochip_add(&nxp->gpio_chip);
+	if (err) {
+		dev_err(&pdev->dev, "unable to add gpio chip, err=%d\n", err);
+		goto err_free_2y;
+	}
+
+	platform_set_drvdata(pdev, nxp);
+	return 0;
+
+err_free_2y:
+	gpio_free(nxp->config.gpio_pin_2y);
+err_free_1y:
+	gpio_free(nxp->config.gpio_pin_1y);
+err_free_s1:
+	gpio_free(nxp->config.gpio_pin_s1);
+err_free_s0:
+	gpio_free(nxp->config.gpio_pin_s0);
+err_free_nxp:
+	kfree(nxp);
+	return err;
+}
+
+static int nxp_74hc153_remove(struct platform_device *pdev)
+{
+	struct nxp_74hc153_chip *nxp = platform_get_drvdata(pdev);
+
+	if (nxp) {
+		gpiochip_remove(&nxp->gpio_chip);
+		gpio_free(nxp->config.gpio_pin_2y);
+		gpio_free(nxp->config.gpio_pin_1y);
+		gpio_free(nxp->config.gpio_pin_s1);
+		gpio_free(nxp->config.gpio_pin_s0);
+
+		kfree(nxp);
+		platform_set_drvdata(pdev, NULL);
+	}
+
+	return 0;
+}
+
+static struct of_device_id nxp_74hc153_id[] = {
+	{
+		.compatible = "nxp,74hc153-gpio",
+		.data = NULL,
+	}, { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, nxp_74hc153_id);
+
+static struct platform_driver nxp_74hc153_driver = {
+	.probe          = nxp_74hc153_probe,
+	.remove         = nxp_74hc153_remove,
+	.driver = {
+		.name   = NXP_74HC153_DRIVER_NAME,
+		.owner  = THIS_MODULE,
+		.of_match_table = nxp_74hc153_id,
+	},
+};
+
+static int __init nxp_74hc153_init(void)
+{
+	return platform_driver_register(&nxp_74hc153_driver);
+}
+subsys_initcall(nxp_74hc153_init);
+
+static void __exit nxp_74hc153_exit(void)
+{
+	platform_driver_unregister(&nxp_74hc153_driver);
+}
+module_exit(nxp_74hc153_exit);
+
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC153");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" NXP_74HC153_DRIVER_NAME);