[openwrt/openwrt] ath79: add gpio-latch driver for MikroTik RouterBOARDs
LEDE Commits
lede-commits at lists.infradead.org
Fri Jul 9 08:14:32 PDT 2021
xback pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/43723e6db9a5fca33ccdc1f9344cc6f7cf04e7df
commit 43723e6db9a5fca33ccdc1f9344cc6f7cf04e7df
Author: Denis Kalashnikov <denis281089 at gmail.com>
AuthorDate: Thu May 27 11:16:44 2021 +0300
ath79: add gpio-latch driver for MikroTik RouterBOARDs
This is a slighty modified version of ar71xx gpio-latch driver
written by Gabor Juhos <juhosg at openwrt.org>.
Changes:
* DTS support,
* New gpio API (gpiod_*).
Reviewed-by: Sergey Ryazanov <ryazanov.s.a at gmail.com>
Signed-off-by: Denis Kalashnikov <denis281089 at gmail.com>
(cherry-picked from commit 7b8931678c36c8d8c333b446258a653b1358bf70)
---
target/linux/ath79/files/drivers/gpio/gpio-latch.c | 203 +++++++++++++++++++++
.../ath79/patches-5.4/939-mikrotik-rb91x.patch | 23 +++
2 files changed, 226 insertions(+)
diff --git a/target/linux/ath79/files/drivers/gpio/gpio-latch.c b/target/linux/ath79/files/drivers/gpio/gpio-latch.c
new file mode 100644
index 0000000000..f3545a663e
--- /dev/null
+++ b/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 at 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 at openwrt.org>");
+MODULE_AUTHOR("Denis Kalashnikov <denis281089 at gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" GPIO_LATCH_DRIVER_NAME);
diff --git a/target/linux/ath79/patches-5.4/939-mikrotik-rb91x.patch b/target/linux/ath79/patches-5.4/939-mikrotik-rb91x.patch
new file mode 100644
index 0000000000..baeaab4611
--- /dev/null
+++ b/target/linux/ath79/patches-5.4/939-mikrotik-rb91x.patch
@@ -0,0 +1,23 @@
+--- a/drivers/gpio/Kconfig
++++ b/drivers/gpio/Kconfig
+@@ -130,6 +130,10 @@ config GPIO_ATH79
+ Select this option to enable GPIO driver for
+ Atheros AR71XX/AR724X/AR913X SoC devices.
+
++config GPIO_LATCH
++ tristate "MikroTik RouterBOARD GPIO latch support"
++ depends on ATH79
++
+ config GPIO_RASPBERRYPI_EXP
+ tristate "Raspberry Pi 3 GPIO Expander"
+ default RASPBERRYPI_FIRMWARE
+--- a/drivers/gpio/Makefile
++++ b/drivers/gpio/Makefile
+@@ -67,6 +67,7 @@ obj-$(CONFIG_GPIO_IT87) += gpio-it87.o
+ obj-$(CONFIG_GPIO_IXP4XX) += gpio-ixp4xx.o
+ obj-$(CONFIG_GPIO_JANZ_TTL) += gpio-janz-ttl.o
+ obj-$(CONFIG_GPIO_KEMPLD) += gpio-kempld.o
++obj-$(CONFIG_GPIO_LATCH) += gpio-latch.o
+ obj-$(CONFIG_GPIO_LOONGSON1) += gpio-loongson1.o
+ obj-$(CONFIG_GPIO_LOONGSON) += gpio-loongson.o
+ obj-$(CONFIG_GPIO_LP3943) += gpio-lp3943.o
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