The added API is aligned with the API in Linux, but has the caveat that
barebox has no set_multiple callbacks implemented in the GPIO drivers,
so switching may result in a bad intermediate state. We add a note about
that and implement the API in the easiest possible way.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 123 ++++++++++++++++++++++++++++++++++
include/linux/gpio/consumer.h | 31 +++++++++
2 files changed, 154 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 3e57cf6239c3..40010262bd81 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -8,6 +8,7 @@
#include <gpio.h>
#include <of_gpio.h>
#include <linux/gpio/consumer.h>
+#include <linux/overflow.h>
#include <errno.h>
#include <malloc.h>
@@ -207,6 +208,21 @@ void gpiod_put(struct gpio_desc *desc)
}
EXPORT_SYMBOL(gpiod_put);
+/**
+ * gpiod_put_array - dispose of multiple GPIO descriptors
+ * @descs: struct gpio_descs containing an array of descriptors
+ */
+void gpiod_put_array(struct gpio_descs *descs)
+{
+ unsigned int i;
+
+ for (i = 0; i < descs->ndescs; i++)
+ gpiod_put(descs->desc[i]);
+
+ kfree(descs);
+}
+EXPORT_SYMBOL_GPL(gpiod_put_array);
+
/**
* gpiod_set_raw_value() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
@@ -865,8 +881,115 @@ struct gpio_desc *dev_gpiod_get_index(struct device *dev,
return ret ? ERR_PTR(ret): desc;
}
+
+/**
+ * gpiod_count - return the number of GPIOs associated with a device / function
+ * or -ENOENT if no GPIO has been assigned to the requested function
+ * @dev: GPIO consumer, can be NULL for system-global GPIOs
+ * @_con_id: function within the GPIO consumer
+ */
+int gpiod_count(struct device *dev, const char *con_id)
+{
+ struct device_node *np = dev_of_node(dev);
+ struct property *pp;
+
+ if (!np)
+ return -ENODEV;
+
+ pp = of_find_gpio_property(np, con_id);
+ if (!pp)
+ return -ENOENT;
+
+ return of_gpio_named_count(np, pp->name);
+}
+EXPORT_SYMBOL_GPL(gpiod_count);
+
+/**
+ * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
+ * @dev: GPIO consumer, can be NULL for system-global GPIOs
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * This function acquires all the GPIOs defined under a given function.
+ *
+ * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
+ * no GPIO has been assigned to the requested function, or another IS_ERR()
+ * code if an error occurred while trying to acquire the GPIOs.
+ */
+struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+{
+ struct gpio_desc *desc;
+ struct gpio_descs *descs;
+ int count;
+
+ count = gpiod_count(dev, con_id);
+ if (count < 0)
+ return ERR_PTR(count);
+
+ descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
+ if (!descs)
+ return ERR_PTR(-ENOMEM);
+
+ for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
+ desc = dev_gpiod_get_index(dev, dev_of_node(dev), con_id,
+ descs->ndescs, flags, NULL);
+ if (IS_ERR(desc)) {
+ gpiod_put_array(descs);
+ return ERR_CAST(desc);
+ }
+
+ descs->desc[descs->ndescs] = desc;
+ }
+
+ return descs;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_array);
+
#endif
+static int gpiod_set_array_value_complex(bool raw,
+ unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
+{
+ int i;
+
+ BUG_ON(array_info != NULL);
+
+ for (i = 0; i < array_size; i++)
+ gpiod_set_value(desc_array[i], test_bit(i, value_bitmap));
+
+ return 0;
+}
+
+/**
+ * gpiod_set_array_value() - assign values to an array of GPIOs
+ * @array_size: number of elements in the descriptor array / value bitmap
+ * @desc_array: array of GPIO descriptors whose values will be assigned
+ * @array_info: information on applicability of fast bitmap processing path
+ * @value_bitmap: bitmap of values to assign
+ *
+ * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
+ * into account. NOTE: This function has no special handling for GPIOs
+ * in the same bank that could've been set atomically: GPIO sequencing
+ * is not guaranteed to always remain in the same order.
+ */
+int gpiod_set_array_value(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap)
+{
+ if (!desc_array)
+ return -EINVAL;
+ return gpiod_set_array_value_complex(false, array_size,
+ desc_array, array_info,
+ value_bitmap);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_array_value);
+
int gpiochip_add(struct gpio_chip *chip)
{
int i;
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index c89b0c48ee2b..6ad3b265c835 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -25,6 +25,24 @@ enum gpiod_flags {
#define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
struct gpio_desc;
+struct gpio_array;
+
+/**
+ * struct gpio_descs - Struct containing an array of descriptors that can be
+ * obtained using gpiod_get_array()
+ *
+ * @info: Pointer to the opaque gpio_array structure
+ * @ndescs: Number of held descriptors
+ * @desc: Array of pointers to GPIO descriptors
+ */
+struct gpio_descs {
+ unsigned int ndescs;
+ /* info is used for fastpath, which we don't have in barebox.
+ * We define the member anyway, as not to change API
+ */
+ struct gpio_array *info;
+ DECLARE_FLEX_ARRAY(struct gpio_desc *, desc);
+};
#ifdef CONFIG_OFDEVICE
@@ -103,4 +121,17 @@ int gpiod_get_value(const struct gpio_desc *desc);
__state == (active), timeout_us); \
})
+int gpiod_count(struct device *dev, const char *con_id);
+
+struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+
+void gpiod_put_array(struct gpio_descs *descs);
+
+int gpiod_set_array_value(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
+ unsigned long *value_bitmap);
+
#endif
--
2.39.2
