Initial commit

target/linux/ath79/files/drivers/gpio/gpio-latch.c

@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  GPIO latch driver
+ *
+ *  Copyright (C) 2014 Gabor Juhos <juhosg@openwrt.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+
+#define GPIO_LATCH_DRIVER_NAME  "gpio-latch"
+#define GPIO_LATCH_LINES 9
+
+struct gpio_latch_chip {
+	struct gpio_chip gc;
+	struct mutex mutex;
+	struct mutex latch_mutex;
+	bool latch_enabled;
+	int le_gpio;
+	bool le_active_low;
+	struct gpio_desc *gpios[GPIO_LATCH_LINES];
+};
+
+static inline struct gpio_latch_chip *to_gpio_latch_chip(struct gpio_chip *gc)
+{
+	return container_of(gc, struct gpio_latch_chip, gc);
+}
+
+static void gpio_latch_lock(struct gpio_latch_chip *glc, bool enable)
+{
+	mutex_lock(&glc->mutex);
+
+	if (enable)
+		glc->latch_enabled = true;
+
+	if (glc->latch_enabled)
+		mutex_lock(&glc->latch_mutex);
+}
+
+static void gpio_latch_unlock(struct gpio_latch_chip *glc, bool disable)
+{
+	if (glc->latch_enabled)
+		mutex_unlock(&glc->latch_mutex);
+
+	if (disable)
+		glc->latch_enabled = true;
+
+	mutex_unlock(&glc->mutex);
+}
+
+static int
+gpio_latch_get(struct gpio_chip *gc, unsigned offset)
+{
+	struct gpio_latch_chip *glc = to_gpio_latch_chip(gc);
+	int ret;
+
+	gpio_latch_lock(glc, false);
+	ret = gpiod_get_value(glc->gpios[offset]);
+	gpio_latch_unlock(glc, false);
+
+	return ret;
+}
+
+static void
+gpio_latch_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+	struct gpio_latch_chip *glc = to_gpio_latch_chip(gc);
+	bool enable_latch = false;
+	bool disable_latch = false;
+
+	if (offset == glc->le_gpio) {
+		enable_latch = value ^ glc->le_active_low;
+		disable_latch = !enable_latch;
+	}
+
+	gpio_latch_lock(glc, enable_latch);
+	gpiod_set_raw_value(glc->gpios[offset], value);
+	gpio_latch_unlock(glc, disable_latch);
+}
+
+static int
+gpio_latch_direction_output(struct gpio_chip *gc, unsigned offset, int value)
+{
+	struct gpio_latch_chip *glc = to_gpio_latch_chip(gc);
+	bool enable_latch = false;
+	bool disable_latch = false;
+	int ret;
+
+	if (offset == glc->le_gpio) {
+		enable_latch = value ^ glc->le_active_low;
+		disable_latch = !enable_latch;
+	}
+
+	gpio_latch_lock(glc, enable_latch);
+	ret = gpiod_direction_output_raw(glc->gpios[offset], value);
+	gpio_latch_unlock(glc, disable_latch);
+
+	return ret;
+}
+
+static int gpio_latch_probe(struct platform_device *pdev)
+{
+	struct gpio_latch_chip *glc;
+	struct gpio_chip *gc;
+	struct device *dev = &pdev->dev;
+	struct device_node *of_node = dev->of_node;
+	int i, n;
+
+	glc = devm_kzalloc(dev, sizeof(*glc), GFP_KERNEL);
+	if (!glc)
+		return -ENOMEM;
+
+	mutex_init(&glc->mutex);
+	mutex_init(&glc->latch_mutex);
+
+	n = gpiod_count(dev, NULL);
+	if (n <= 0) {
+		dev_err(dev, "failed to get gpios: %d\n", n);
+		return n;
+	} else if (n != GPIO_LATCH_LINES) {
+		dev_err(dev, "expected %d gpios\n", GPIO_LATCH_LINES);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < n; i++) {
+		glc->gpios[i] = devm_gpiod_get_index_optional(dev, NULL, i,
+			GPIOD_OUT_LOW);
+		if (IS_ERR(glc->gpios[i])) {
+			dev_err(dev, "failed to get gpio %d: %d\n", i,
+				PTR_ERR(glc->gpios[i]));
+			return PTR_ERR(glc->gpios[i]);
+		}
+	}
+
+	glc->le_gpio = 8;
+	glc->le_active_low = gpiod_is_active_low(glc->gpios[glc->le_gpio]);
+
+	if (!glc->gpios[glc->le_gpio]) {
+		dev_err(dev, "missing required latch-enable gpio %d\n",
+			glc->le_gpio);
+		return -EINVAL;
+	}
+
+	gc = &glc->gc;
+	gc->label = GPIO_LATCH_DRIVER_NAME;
+	gc->can_sleep = true;
+	gc->base = -1;
+	gc->ngpio = GPIO_LATCH_LINES;
+	gc->get = gpio_latch_get;
+	gc->set = gpio_latch_set;
+	gc->direction_output = gpio_latch_direction_output;
+	gc->of_node = of_node;
+
+	platform_set_drvdata(pdev, glc);
+
+	i = gpiochip_add(&glc->gc);
+	if (i) {
+		dev_err(dev, "gpiochip_add() failed: %d\n", i);
+		return i;
+	}
+
+	return 0;
+}
+
+static int gpio_latch_remove(struct platform_device *pdev)
+{
+	struct gpio_latch_chip *glc = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&glc->gc);
+	return 0;
+}
+
+static const struct of_device_id gpio_latch_match[] = {
+	{ .compatible = GPIO_LATCH_DRIVER_NAME },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, gpio_latch_match);
+
+static struct platform_driver gpio_latch_driver = {
+	.probe = gpio_latch_probe,
+	.remove = gpio_latch_remove,
+	.driver = {
+		.name = GPIO_LATCH_DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = gpio_latch_match,
+	},
+};
+
+module_platform_driver(gpio_latch_driver);
+
+MODULE_DESCRIPTION("GPIO latch driver");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_AUTHOR("Denis Kalashnikov <denis281089@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" GPIO_LATCH_DRIVER_NAME);

target/linux/ath79/files/drivers/gpio/gpio-rb4xx.c

@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO driver for the MikroTik RouterBoard 4xx series
+ *
+ * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ * Copyright (C) 2015 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2020 Christopher Hill <ch6574@gmail.com>
+ *
+ * This file was based on the driver for Linux 2.6.22 published by
+ * MikroTik for their RouterBoard 4xx series devices.
+ *
+ * N.B. driver probe reports "DMA mask not set" warnings which are
+ * an artifact of using a platform_driver as an MFD device child.
+ * See conversation here https://lkml.org/lkml/2020/4/28/675
+ */
+#include <linux/platform_device.h>
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#include <mfd/rb4xx-cpld.h>
+
+struct rb4xx_gpio {
+	struct rb4xx_cpld *cpld;
+	struct device *dev;
+
+	struct gpio_chip chip;
+	struct mutex lock;
+	u16 values;		/* bitfield of GPIO 0-8 current values */
+};
+
+static int rb4xx_gpio_cpld_set(struct rb4xx_gpio *gpio, unsigned int offset,
+			       int value)
+{
+	struct rb4xx_cpld *cpld = gpio->cpld;
+	u16 values;
+	int ret;
+
+	mutex_lock(&gpio->lock);
+	values = gpio->values;
+
+	if (value)
+		values |= BIT(offset);
+	else
+		values &= ~(BIT(offset));
+
+	if (values == gpio->values) {
+		ret = 0;
+		goto unlock;
+	}
+
+	if (offset < 8) {
+		ret = cpld->gpio_set_0_7(cpld, values & 0xff);
+	} else if (offset == 8) {
+		ret = cpld->gpio_set_8(cpld, values >> 8);
+	}
+
+	if(likely(!ret))
+		gpio->values = values;
+
+unlock:
+	mutex_unlock(&gpio->lock);
+	return ret;
+}
+
+static int rb4xx_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+	return 0; /* All 9 GPIOs are out */
+}
+
+static int rb4xx_gpio_direction_input(struct gpio_chip *chip,
+				      unsigned int offset)
+{
+	return -EOPNOTSUPP;
+}
+
+static int rb4xx_gpio_direction_output(struct gpio_chip *chip,
+				       unsigned int offset, int value)
+{
+	return rb4xx_gpio_cpld_set(gpiochip_get_data(chip), offset, value);
+}
+
+static int rb4xx_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct rb4xx_gpio *gpio = gpiochip_get_data(chip);
+	int ret;
+
+	mutex_lock(&gpio->lock);
+	ret = (gpio->values >> offset) & 0x1;
+	mutex_unlock(&gpio->lock);
+
+	return ret;
+}
+
+static void rb4xx_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			   int value)
+{
+	rb4xx_gpio_cpld_set(gpiochip_get_data(chip), offset, value);
+}
+
+static int rb4xx_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *parent = dev->parent;
+	struct rb4xx_gpio *gpio;
+	u32 val;
+
+	if (!parent)
+		return -ENODEV;
+
+	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
+	if (!gpio)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, gpio);
+	gpio->cpld	= dev_get_drvdata(parent);
+	gpio->dev	= dev;
+	gpio->values	= 0;
+	mutex_init(&gpio->lock);
+
+	gpio->chip.label		= "rb4xx-gpio";
+	gpio->chip.parent		= dev;
+	gpio->chip.owner		= THIS_MODULE;
+	gpio->chip.get_direction	= rb4xx_gpio_get_direction;
+	gpio->chip.direction_input	= rb4xx_gpio_direction_input;
+	gpio->chip.direction_output	= rb4xx_gpio_direction_output;
+	gpio->chip.get			= rb4xx_gpio_get;
+	gpio->chip.set			= rb4xx_gpio_set;
+	gpio->chip.ngpio		= 9;
+	gpio->chip.base			= -1;
+	gpio->chip.can_sleep		= 1;
+
+	if (!of_property_read_u32(dev->of_node, "base", &val))
+		gpio->chip.base = val;
+
+	return gpiochip_add_data(&gpio->chip, gpio);
+}
+
+static int rb4xx_gpio_remove(struct platform_device *pdev)
+{
+	struct rb4xx_gpio *gpio = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&gpio->chip);
+	mutex_destroy(&gpio->lock);
+
+	return 0;
+}
+
+static const struct platform_device_id rb4xx_gpio_id_table[] = {
+	{ "mikrotik,rb4xx-gpio", },
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, rb4xx_gpio_id_table);
+
+static struct platform_driver rb4xx_gpio_driver = {
+	.probe = rb4xx_gpio_probe,
+	.remove = rb4xx_gpio_remove,
+	.id_table = rb4xx_gpio_id_table,
+	.driver = {
+		.name = "rb4xx-gpio",
+	},
+};
+
+module_platform_driver(rb4xx_gpio_driver);
+
+MODULE_DESCRIPTION("Mikrotik RB4xx GPIO driver");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
+MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
+MODULE_AUTHOR("Christopher Hill <ch6574@gmail.com");
+MODULE_LICENSE("GPL v2");