From: Denis Kalashnikov
This is a slighty modified version of ar71xx gpio-latch driver
written by Gabor Juhos .
Changes:
* DTS support,
* New gpio API (gpiod_*).
Signed-off-by: Denis Kalashnikov
---
Changelog:
RFC v1 --> RFC v2
- Don't use MFD driver API anymore,
- Use the new gpio API (gpiod_*),
- Add support of kernel 5.10.
RFC v2 --> v1
- Change DTS node params -- remove redundant latch-enable-gpios param,
- Delete unneeded direction input callback (latch is output-only),
- Add support of pin holes (unconnected lines of the latch).
---
.../ath79/files/drivers/gpio/gpio-latch.c | 203 ++
.../patches-5.10/939-mikrotik-rb91x.patch | 26 +++
.../patches-5.4/939-mikrotik-rb91x.patch | 23 ++
3 files changed, 252 insertions(+)
create mode 100644 target/linux/ath79/files/drivers/gpio/gpio-latch.c
create mode 100644 target/linux/ath79/patches-5.10/939-mikrotik-rb91x.patch
create mode 100644 target/linux/ath79/patches-5.4/939-mikrotik-rb91x.patch
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 00..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
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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(>mutex);
+
+ if (enable)
+ glc->latch_enabled = true;
+
+ if (glc->latch_enabled)
+ mutex_lock(>latch_mutex);
+}
+
+static void gpio_latch_unlock(struct gpio_latch_chip *glc, bool disable)
+{
+ if (glc->latch_enabled)
+ mutex_unlock(>latch_mutex);
+
+ if (disable)
+ glc->latch_enabled = true;
+
+ mutex_unlock(>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 = >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(>mutex);
+ mutex_init(>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]);
+ }
+
