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-rw-r--r--drivers/gpio/gpiolib-of.c90
-rw-r--r--drivers/gpio/gpiolib-of.h2
-rw-r--r--drivers/gpio/gpiolib.c14
-rw-r--r--drivers/gpio/gpiolib.h3
4 files changed, 106 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 2b47f9388607..ccc449df3792 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -628,6 +628,10 @@ static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
ret = gpiod_hog(desc, name, lflags, dflags);
if (ret < 0)
return ret;
+
+#ifdef CONFIG_OF_DYNAMIC
+ desc->hog = hog;
+#endif
}
return 0;
@@ -655,11 +659,97 @@ static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
of_node_put(np);
return ret;
}
+
+ of_node_set_flag(np, OF_POPULATED);
}
return 0;
}
+#ifdef CONFIG_OF_DYNAMIC
+/**
+ * of_gpiochip_remove_hog - Remove all hogs in a hog device node
+ * @chip: gpio chip to act on
+ * @hog: device node describing the hogs
+ */
+static void of_gpiochip_remove_hog(struct gpio_chip *chip,
+ struct device_node *hog)
+{
+ struct gpio_desc *descs = chip->gpiodev->descs;
+ unsigned int i;
+
+ for (i = 0; i < chip->ngpio; i++) {
+ if (test_bit(FLAG_IS_HOGGED, &descs[i].flags) &&
+ descs[i].hog == hog)
+ gpiochip_free_own_desc(&descs[i]);
+ }
+}
+
+static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
+{
+ return chip->gpiodev->dev.of_node == data;
+}
+
+static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
+{
+ return gpiochip_find(np, of_gpiochip_match_node);
+}
+
+static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
+ void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct gpio_chip *chip;
+ int ret;
+
+ /*
+ * This only supports adding and removing complete gpio-hog nodes.
+ * Modifying an existing gpio-hog node is not supported (except for
+ * changing its "status" property, which is treated the same as
+ * addition/removal).
+ */
+ switch (of_reconfig_get_state_change(action, arg)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ if (!of_property_read_bool(rd->dn, "gpio-hog"))
+ return NOTIFY_OK; /* not for us */
+
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ chip = of_find_gpiochip_by_node(rd->dn->parent);
+ if (chip == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ ret = of_gpiochip_add_hog(chip, rd->dn);
+ if (ret < 0) {
+ pr_err("%s: failed to add hogs for %pOF\n", __func__,
+ rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ return notifier_from_errno(ret);
+ }
+ break;
+
+ case OF_RECONFIG_CHANGE_REMOVE:
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK; /* already depopulated */
+
+ chip = of_find_gpiochip_by_node(rd->dn->parent);
+ if (chip == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ of_gpiochip_remove_hog(chip, rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+struct notifier_block gpio_of_notifier = {
+ .notifier_call = of_gpio_notify,
+};
+#endif /* CONFIG_OF_DYNAMIC */
+
/**
* of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
* @gc: pointer to the gpio_chip structure
diff --git a/drivers/gpio/gpiolib-of.h b/drivers/gpio/gpiolib-of.h
index 9768831b1fe2..ed26664f1537 100644
--- a/drivers/gpio/gpiolib-of.h
+++ b/drivers/gpio/gpiolib-of.h
@@ -35,4 +35,6 @@ static inline bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
}
#endif /* CONFIG_OF_GPIO */
+extern struct notifier_block gpio_of_notifier;
+
#endif /* GPIOLIB_OF_H */
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 2c3a9c1c76be..9ad86477af9c 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3103,6 +3103,9 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
clear_bit(FLAG_PULL_DOWN, &desc->flags);
clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
+#ifdef CONFIG_OF_DYNAMIC
+ desc->hog = NULL;
+#endif
ret = true;
}
@@ -5281,10 +5284,15 @@ static int __init gpiolib_dev_init(void)
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
bus_unregister(&gpio_bus_type);
- } else {
- gpiolib_initialized = true;
- gpiochip_setup_devs();
+ return ret;
}
+
+ gpiolib_initialized = true;
+ gpiochip_setup_devs();
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
+
return ret;
}
core_initcall(gpiolib_dev_init);
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 5ab90746b519..853ce681b4a4 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -120,6 +120,9 @@ struct gpio_desc {
const char *label;
/* Name of the GPIO */
const char *name;
+#ifdef CONFIG_OF_DYNAMIC
+ struct device_node *hog;
+#endif
};
int gpiod_request(struct gpio_desc *desc, const char *label);