dm: gpio: Implement GPIO reservation in the uclass
We have several GPIO drivers now and all are doing similar things to record
which GPIOs are reserved.
Move this logic into the uclass to make the drivers similar.
We retain the request()/free() methods since currently one driver does use
these for setting up the pin.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index a5ffd85..e11c5a6 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -7,6 +7,7 @@
#include <common.h>
#include <dm.h>
#include <errno.h>
+#include <malloc.h>
#include <asm/gpio.h>
#include <linux/ctype.h>
@@ -92,24 +93,41 @@
* gpio: GPIO number
* label: Name for the requested GPIO
*
+ * The label is copied and allocated so the caller does not need to keep
+ * the pointer around.
+ *
* 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)
{
+ struct gpio_dev_priv *uc_priv;
unsigned int offset;
struct udevice *dev;
+ char *str;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
- if (!gpio_get_ops(dev)->request)
- return 0;
+ uc_priv = dev->uclass_priv;
+ if (uc_priv->name[offset])
+ return -EBUSY;
+ str = strdup(label);
+ if (!str)
+ return -ENOMEM;
+ if (gpio_get_ops(dev)->request) {
+ ret = gpio_get_ops(dev)->request(dev, offset, label);
+ if (ret) {
+ free(str);
+ return ret;
+ }
+ }
+ uc_priv->name[offset] = str;
- return gpio_get_ops(dev)->request(dev, offset, label);
+ return 0;
}
/**
@@ -122,6 +140,7 @@
*/
int gpio_free(unsigned gpio)
{
+ struct gpio_dev_priv *uc_priv;
unsigned int offset;
struct udevice *dev;
int ret;
@@ -130,9 +149,34 @@
if (ret)
return ret;
+ uc_priv = dev->uclass_priv;
+ if (!uc_priv->name[offset])
+ return -ENXIO;
+ if (gpio_get_ops(dev)->free) {
+ ret = gpio_get_ops(dev)->free(dev, offset);
+ if (ret)
+ return ret;
+ }
+
+ free(uc_priv->name[offset]);
+ uc_priv->name[offset] = NULL;
+
+ return 0;
+}
+
+static int check_reserved(struct udevice *dev, unsigned offset,
+ const char *func)
+{
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
- if (!gpio_get_ops(dev)->free)
- return 0;
- return gpio_get_ops(dev)->free(dev, offset);
+ if (!uc_priv->name[offset]) {
+ printf("%s: %s: error: gpio %s%d not reserved\n",
+ dev->name, func,
+ uc_priv->bank_name ? uc_priv->bank_name : "", offset);
+ return -EBUSY;
+ }
+
+ return 0;
}
/**
@@ -152,8 +196,9 @@
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
+ ret = check_reserved(dev, offset, "dir_input");
- return gpio_get_ops(dev)->direction_input(dev, offset);
+ return ret ? ret : gpio_get_ops(dev)->direction_input(dev, offset);
}
/**
@@ -174,8 +219,10 @@
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
+ ret = check_reserved(dev, offset, "dir_output");
- return gpio_get_ops(dev)->direction_output(dev, offset, value);
+ return ret ? ret :
+ gpio_get_ops(dev)->direction_output(dev, offset, value);
}
/**
@@ -196,8 +243,9 @@
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
+ ret = check_reserved(dev, offset, "get_value");
- return gpio_get_ops(dev)->get_value(dev, offset);
+ return ret ? ret : gpio_get_ops(dev)->get_value(dev, offset);
}
/**
@@ -218,8 +266,9 @@
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
+ ret = check_reserved(dev, offset, "set_value");
- return gpio_get_ops(dev)->set_value(dev, offset, value);
+ return ret ? ret : gpio_get_ops(dev)->set_value(dev, offset, value);
}
const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
@@ -235,7 +284,7 @@
}
/* We need to renumber the GPIOs when any driver is probed/removed */
-static int gpio_renumber(void)
+static int gpio_renumber(struct udevice *removed_dev)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
@@ -250,7 +299,7 @@
/* Ensure that we have a base for each bank */
base = 0;
uclass_foreach_dev(dev, uc) {
- if (device_active(dev)) {
+ if (device_active(dev) && dev != removed_dev) {
uc_priv = dev->uclass_priv;
uc_priv->gpio_base = base;
base += uc_priv->gpio_count;
@@ -262,12 +311,27 @@
static int gpio_post_probe(struct udevice *dev)
{
- return gpio_renumber();
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
+ uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
+ if (!uc_priv->name)
+ return -ENOMEM;
+
+ return gpio_renumber(NULL);
}
static int gpio_pre_remove(struct udevice *dev)
{
- return gpio_renumber();
+ struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+ int i;
+
+ for (i = 0; i < uc_priv->gpio_count; i++) {
+ if (uc_priv->name[i])
+ free(uc_priv->name[i]);
+ }
+ free(uc_priv->name);
+
+ return gpio_renumber(dev);
}
UCLASS_DRIVER(gpio) = {