Initial commit

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

@@ -0,0 +1,181 @@
+// 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-mikrotik"
+#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 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 = gpiochip_get_data(gc);
+	int ret;
+
+	gpio_latch_lock(glc, false);
+	ret = gpiod_get_raw_value_cansleep(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 = gpiochip_get_data(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_cansleep(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 = gpiochip_get_data(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;
+	int err, i, n;
+
+	glc = devm_kzalloc(dev, sizeof(*glc), GFP_KERNEL);
+	if (!glc)
+		return -ENOMEM;
+
+	err = devm_mutex_init(&pdev->dev, &glc->mutex);
+	if (err)
+		return err;
+
+	err = devm_mutex_init(&pdev->dev, &glc->latch_mutex);
+	if (err)
+		return err;
+
+	n = gpiod_count(dev, NULL);
+	if (n <= 0)
+		return dev_err_probe(dev, n, "failed to get gpios");
+	if (n != GPIO_LATCH_LINES) {
+		dev_err(dev, "expected %d gpios", 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]))
+			return dev_err_probe(dev, PTR_ERR(glc->gpios[i]),
+					     "failed to get gpio %d", 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->parent = dev;
+	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;
+
+	return devm_gpiochip_add_data(dev, gc, glc);
+}
+
+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,
+	.driver = {
+		.name = GPIO_LATCH_DRIVER_NAME,
+		.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 +1,165 @@
+// 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;
+	int err;
+
+	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;
+
+	err = devm_mutex_init(&pdev->dev, &gpio->lock);
+	if (err)
+		return err;
+
+	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 devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
+}
+
+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,
+	.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");

target/linux/ath79/files/drivers/gpio/gpio-rb91x-key.c

@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for reset key gpio line on MikroTik RB91x board series.
+ * This line is shared between NAND ALE (goes through a latch),
+ * NAND IO7 and reset key. We make 3 virtual gpio lines from the
+ * single physical one:
+ *   1) Capable output one for NAND,
+ *   2) Capable input one for reset key,
+ *   3) And capable output one, aka "key-poll-disable",
+ *      for NAND -- to syncronise NAND operation and key polling.
+ *
+ * Copyright (C) 2021 Denis Kalashnikov <denis281089@gmail.com>
+ */
+
+#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>
+#include <linux/delay.h>
+
+#define GPIO_RB91X_KEY_DRIVER_NAME  "gpio-rb91x-key"
+
+enum gpio_rb91x_key_gpios {
+	GPIO_RB91X_KEY_NAND,
+	GPIO_RB91X_KEY_POLL,
+	GPIO_RB91X_KEY_PDIS,
+
+	GPIO_RB91X_KEY_NGPIOS,
+};
+
+struct gpio_rb91x_key {
+	struct gpio_chip gc;
+	struct mutex mutex;
+	struct mutex poll_mutex;
+	int polling_disabled;
+	struct gpio_desc *gpio;
+};
+
+static int gpio_rb91x_key_get(struct gpio_chip *gc, unsigned offset)
+{
+	struct gpio_rb91x_key *drvdata = gpiochip_get_data(gc);
+	struct gpio_desc *gpio = drvdata->gpio;
+	int val, bak_val;
+
+	switch (offset) {
+	case GPIO_RB91X_KEY_NAND:
+		mutex_lock(&drvdata->mutex);
+		val = gpiod_get_value_cansleep(gpio);
+		mutex_unlock(&drvdata->mutex);
+		break;
+	case GPIO_RB91X_KEY_PDIS:
+		mutex_lock(&drvdata->mutex);
+		val = drvdata->polling_disabled;
+		mutex_unlock(&drvdata->mutex);
+		break;
+	case GPIO_RB91X_KEY_POLL:
+		mutex_lock(&drvdata->poll_mutex);
+		mutex_lock(&drvdata->mutex);
+		bak_val = gpiod_get_raw_value_cansleep(gpio);
+		gpiod_direction_input(gpio);
+		/*
+		 * Without this delay nothing works. Get it
+		 * from mikrotik RouterOS linux kernel patches.
+		 */
+		udelay(200);
+		val = gpiod_get_raw_value_cansleep(gpio);
+		gpiod_direction_output_raw(gpio, bak_val);
+		mutex_unlock(&drvdata->mutex);
+		mutex_unlock(&drvdata->poll_mutex);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return val;
+}
+
+static int gpio_rb91x_key_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	switch (offset) {
+	case GPIO_RB91X_KEY_POLL:
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static void gpio_rb91x_key_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+	struct gpio_rb91x_key *drvdata = gpiochip_get_data(gc);
+	struct gpio_desc *gpio = drvdata->gpio;
+
+	mutex_lock(&drvdata->mutex);
+
+	switch (offset) {
+	case GPIO_RB91X_KEY_NAND:
+		gpiod_set_raw_value_cansleep(gpio, value);
+		break;
+	case GPIO_RB91X_KEY_PDIS:
+		if (value) {
+			if (!drvdata->polling_disabled) {
+				mutex_lock(&drvdata->poll_mutex);
+				drvdata->polling_disabled = 1;
+			}
+		} else {
+			if (drvdata->polling_disabled) {
+				mutex_unlock(&drvdata->poll_mutex);
+				drvdata->polling_disabled = 0;
+			}
+		}
+		break;
+	default:
+		break;
+	}
+
+	mutex_unlock(&drvdata->mutex);
+}
+
+static int gpio_rb91x_key_direction_output(struct gpio_chip *gc, unsigned offset,
+					   int value)
+{
+	switch (offset) {
+	case GPIO_RB91X_KEY_NAND:
+	case GPIO_RB91X_KEY_PDIS:
+		gpio_rb91x_key_set(gc, offset, value);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int gpio_rb91x_key_probe(struct platform_device *pdev)
+{
+	struct gpio_rb91x_key *drvdata;
+	struct gpio_chip *gc;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	err = devm_mutex_init(dev, &drvdata->mutex);
+	if (err)
+		return err;
+
+	err = devm_mutex_init(dev, &drvdata->poll_mutex);
+	if (err)
+		return err;
+
+	drvdata->gpio = devm_gpiod_get(dev, NULL, GPIOD_OUT_LOW);
+	if (IS_ERR(drvdata->gpio))
+		return dev_err_probe(dev, PTR_ERR(drvdata->gpio), "failed to get gpio");
+
+	gc = &drvdata->gc;
+	gc->label = GPIO_RB91X_KEY_DRIVER_NAME;
+	gc->parent = dev;
+	gc->can_sleep = 1;
+	gc->base = -1;
+	gc->ngpio = GPIO_RB91X_KEY_NGPIOS;
+	gc->get = gpio_rb91x_key_get;
+	gc->set = gpio_rb91x_key_set;
+	gc->direction_output = gpio_rb91x_key_direction_output;
+	gc->direction_input = gpio_rb91x_key_direction_input;
+
+	return devm_gpiochip_add_data(dev, gc, drvdata);
+}
+
+static const struct of_device_id gpio_rb91x_key_match[] = {
+	{ .compatible = "mikrotik,"GPIO_RB91X_KEY_DRIVER_NAME },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, gpio_rb91x_key_match);
+
+static struct platform_driver gpio_rb91x_key_driver = {
+	.probe = gpio_rb91x_key_probe,
+	.driver = {
+		.name = GPIO_RB91X_KEY_DRIVER_NAME,
+		.of_match_table = gpio_rb91x_key_match,
+	},
+};
+
+module_platform_driver(gpio_rb91x_key_driver);
+
+MODULE_DESCRIPTION("Driver for reset key gpio line shared with NAND for MikroTik RB91x board series.");
+MODULE_AUTHOR("Denis Kalashnikov <denis281089@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" GPIO_RB91X_KEY_DRIVER_NAME);