dm: Add GPIO support and tests
Add driver model support for GPIOs. Since existing GPIO drivers do not use
driver model, this feature must be enabled by CONFIG_DM_GPIO. After all
GPO drivers are converted over we can perhaps remove this config.
Tests are provided for the sandbox implementation, and are a sufficient
sanity check for basic operation.
The GPIO uclass understands the concept of named banks of GPIOs, with each
GPIO device providing a single bank. Within each bank the GPIOs are numbered
using an offset from 0 to n-1. For example a bank named 'b' with 20
offsets will provide GPIOs named b0 to b19.
Anonymous GPIO banks are also supported, and are just numbered without any
prefix.
Each time a GPIO driver is added to the uclass, the GPIOs are renumbered
accordinging, so there is always a global GPIO numbering order.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: Viktor Křivák <viktor.krivak@gmail.com>
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
new file mode 100644
index 0000000..56bfd11
--- /dev/null
+++ b/drivers/gpio/gpio-uclass.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/gpio.h>
+
+/**
+ * gpio_to_device() - Convert global GPIO number to device, number
+ * gpio: The numeric representation of the GPIO
+ *
+ * Convert the GPIO number to an entry in the list of GPIOs
+ * or GPIO blocks registered with the GPIO controller. Returns
+ * entry on success, NULL on error.
+ */
+static int gpio_to_device(unsigned int gpio, struct device **devp,
+ unsigned int *offset)
+{
+ struct gpio_dev_priv *uc_priv;
+ struct device *dev;
+ int ret;
+
+ for (ret = uclass_first_device(UCLASS_GPIO, &dev);
+ dev;
+ ret = uclass_next_device(&dev)) {
+ uc_priv = dev->uclass_priv;
+ if (gpio >= uc_priv->gpio_base &&
+ gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
+ *devp = dev;
+ *offset = gpio - uc_priv->gpio_base;
+ return 0;
+ }
+ }
+
+ /* No such GPIO */
+ return ret ? ret : -EINVAL;
+}
+
+int gpio_lookup_name(const char *name, struct device **devp,
+ unsigned int *offsetp, unsigned int *gpiop)
+{
+ struct gpio_dev_priv *uc_priv;
+ struct device *dev;
+ int ret;
+
+ if (devp)
+ *devp = NULL;
+ for (ret = uclass_first_device(UCLASS_GPIO, &dev);
+ dev;
+ ret = uclass_next_device(&dev)) {
+ ulong offset;
+ int len;
+
+ uc_priv = dev->uclass_priv;
+ len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;
+
+ if (!strncmp(name, uc_priv->bank_name, len)) {
+ if (strict_strtoul(name + len, 10, &offset))
+ continue;
+ if (devp)
+ *devp = dev;
+ if (offsetp)
+ *offsetp = offset;
+ if (gpiop)
+ *gpiop = uc_priv->gpio_base + offset;
+ return 0;
+ }
+ }
+
+ return ret ? ret : -EINVAL;
+}
+
+/**
+ * gpio_request() - [COMPAT] Request GPIO
+ * gpio: GPIO number
+ * label: Name for the requested GPIO
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns 0 on success, negative value on error.
+ */
+int gpio_request(unsigned gpio, const char *label)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ if (!gpio_get_ops(dev)->request)
+ return 0;
+
+ return gpio_get_ops(dev)->request(dev, offset, label);
+}
+
+/**
+ * gpio_free() - [COMPAT] Relinquish GPIO
+ * gpio: GPIO number
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns 0 on success, negative value on error.
+ */
+int gpio_free(unsigned gpio)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ if (!gpio_get_ops(dev)->free)
+ return 0;
+ return gpio_get_ops(dev)->free(dev, offset);
+}
+
+/**
+ * gpio_direction_input() - [COMPAT] Set GPIO direction to input
+ * gpio: GPIO number
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns 0 on success, negative value on error.
+ */
+int gpio_direction_input(unsigned gpio)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ return gpio_get_ops(dev)->direction_input(dev, offset);
+}
+
+/**
+ * gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
+ * gpio: GPIO number
+ * value: Logical value to be set on the GPIO pin
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns 0 on success, negative value on error.
+ */
+int gpio_direction_output(unsigned gpio, int value)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ return gpio_get_ops(dev)->direction_output(dev, offset, value);
+}
+
+/**
+ * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
+ * gpio: GPIO number
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns the value of the GPIO pin, or negative value
+ * on error.
+ */
+int gpio_get_value(unsigned gpio)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ return gpio_get_ops(dev)->get_value(dev, offset);
+}
+
+/**
+ * gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
+ * gpio: GPIO number
+ * value: Logical value to be set on the GPIO pin.
+ *
+ * This function implements the API that's compatible with current
+ * GPIO API used in U-Boot. The request is forwarded to particular
+ * GPIO driver. Returns 0 on success, negative value on error.
+ */
+int gpio_set_value(unsigned gpio, int value)
+{
+ unsigned int offset;
+ struct device *dev;
+ int ret;
+
+ ret = gpio_to_device(gpio, &dev, &offset);
+ if (ret)
+ return ret;
+
+ return gpio_get_ops(dev)->set_value(dev, offset, value);
+}
+
+const char *gpio_get_bank_info(struct device *dev, int *bit_count)
+{
+ struct gpio_dev_priv *priv;
+
+ /* Must be called on an active device */
+ priv = dev->uclass_priv;
+ assert(priv);
+
+ *bit_count = priv->gpio_count;
+ return priv->bank_name;
+}
+
+/* We need to renumber the GPIOs when any driver is probed/removed */
+static int gpio_renumber(void)
+{
+ struct gpio_dev_priv *uc_priv;
+ struct device *dev;
+ struct uclass *uc;
+ unsigned base;
+ int ret;
+
+ ret = uclass_get(UCLASS_GPIO, &uc);
+ if (ret)
+ return ret;
+
+ /* Ensure that we have a base for each bank */
+ base = 0;
+ uclass_foreach_dev(dev, uc) {
+ if (device_active(dev)) {
+ uc_priv = dev->uclass_priv;
+ uc_priv->gpio_base = base;
+ base += uc_priv->gpio_count;
+ }
+ }
+
+ return 0;
+}
+
+static int gpio_post_probe(struct device *dev)
+{
+ return gpio_renumber();
+}
+
+static int gpio_pre_remove(struct device *dev)
+{
+ return gpio_renumber();
+}
+
+UCLASS_DRIVER(gpio) = {
+ .id = UCLASS_GPIO,
+ .name = "gpio",
+ .post_probe = gpio_post_probe,
+ .pre_remove = gpio_pre_remove,
+ .per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
+};