gpio: Use separate bitfield array to indicate GPIO is claimed
The current gpio-uclass design uses name field in struct gpio_dev_priv as
an indicator that GPIO is claimed by consumer. This overloads the function
of name field and does not work well for named pins not configured as GPIO
pins.
Introduce separate bitfield array as the claim indicator.
This unbreaks dual-purpose AF and GPIO operation on STM32MP since commit
2c38f7c31806 ("pinctrl: pinctrl_stm32: Populate uc_priv->name[] with pinmux node's name")
where any pin which has already been configured as AF could no longer be
claimed as dual-purpose GPIO. This is important for pins like STM32 MMCI
st,cmd-gpios .
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 31027f3..fc395c9 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -28,6 +28,8 @@
DECLARE_GLOBAL_DATA_PTR;
+#define GPIO_ALLOC_BITS 32
+
/**
* gpio_desc_init() - Initialize the GPIO descriptor
*
@@ -75,6 +77,46 @@
return -ENOENT;
}
+/**
+ * gpio_is_claimed() - Test whether GPIO is claimed by consumer
+ *
+ * Test whether GPIO is claimed by consumer already.
+ *
+ * @uc_priv: gpio_dev_priv pointer.
+ * @offset: gpio offset within the device
+ * @return: true if claimed, false if not claimed
+ */
+static bool gpio_is_claimed(struct gpio_dev_priv *uc_priv, unsigned int offset)
+{
+ return !!(uc_priv->claimed[offset / GPIO_ALLOC_BITS] & BIT(offset % GPIO_ALLOC_BITS));
+}
+
+/**
+ * gpio_set_claim() - Set GPIO claimed by consumer
+ *
+ * Set a bit which indicate the GPIO is claimed by consumer
+ *
+ * @uc_priv: gpio_dev_priv pointer.
+ * @offset: gpio offset within the device
+ */
+static void gpio_set_claim(struct gpio_dev_priv *uc_priv, unsigned int offset)
+{
+ uc_priv->claimed[offset / GPIO_ALLOC_BITS] |= BIT(offset % GPIO_ALLOC_BITS);
+}
+
+/**
+ * gpio_clear_claim() - Clear GPIO claimed by consumer
+ *
+ * Clear a bit which indicate the GPIO is claimed by consumer
+ *
+ * @uc_priv: gpio_dev_priv pointer.
+ * @offset: gpio offset within the device
+ */
+static void gpio_clear_claim(struct gpio_dev_priv *uc_priv, unsigned int offset)
+{
+ uc_priv->claimed[offset / GPIO_ALLOC_BITS] &= ~BIT(offset % GPIO_ALLOC_BITS);
+}
+
#if CONFIG_IS_ENABLED(DM_GPIO_LOOKUP_LABEL)
/**
* dm_gpio_lookup_label() - look for name in gpio device
@@ -94,7 +136,7 @@
*offset = -1;
for (i = 0; i < uc_priv->gpio_count; i++) {
- if (!uc_priv->name[i])
+ if (!gpio_is_claimed(uc_priv, i))
continue;
if (!strcmp(name, uc_priv->name[i])) {
*offset = i;
@@ -350,7 +392,7 @@
int ret;
uc_priv = dev_get_uclass_priv(dev);
- if (uc_priv->name[desc->offset])
+ if (gpio_is_claimed(uc_priv, desc->offset))
return -EBUSY;
str = strdup(label);
if (!str)
@@ -362,6 +404,8 @@
return ret;
}
}
+
+ gpio_set_claim(uc_priv, desc->offset);
uc_priv->name[desc->offset] = str;
return 0;
@@ -438,7 +482,7 @@
int ret;
uc_priv = dev_get_uclass_priv(dev);
- if (!uc_priv->name[offset])
+ if (!gpio_is_claimed(uc_priv, offset))
return -ENXIO;
if (ops->rfree) {
ret = ops->rfree(dev, offset);
@@ -446,6 +490,7 @@
return ret;
}
+ gpio_clear_claim(uc_priv, offset);
free(uc_priv->name[offset]);
uc_priv->name[offset] = NULL;
@@ -480,7 +525,7 @@
return -ENOENT;
uc_priv = dev_get_uclass_priv(desc->dev);
- if (!uc_priv->name[desc->offset]) {
+ if (!gpio_is_claimed(uc_priv, desc->offset)) {
printf("%s: %s: error: gpio %s%d not reserved\n",
desc->dev->name, func,
uc_priv->bank_name ? uc_priv->bank_name : "",
@@ -826,7 +871,7 @@
return -EINVAL;
if (namep)
*namep = uc_priv->name[offset];
- if (skip_unused && !uc_priv->name[offset])
+ if (skip_unused && !gpio_is_claimed(uc_priv, offset))
return GPIOF_UNUSED;
if (ops->get_function) {
int ret;
@@ -1340,6 +1385,14 @@
uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
if (!uc_priv->name)
return -ENOMEM;
+
+ uc_priv->claimed = calloc(DIV_ROUND_UP(uc_priv->gpio_count,
+ GPIO_ALLOC_BITS),
+ GPIO_ALLOC_BITS / 8);
+ if (!uc_priv->claimed) {
+ free(uc_priv->name);
+ return -ENOMEM;
+ }
return gpio_renumber(NULL);
}
@@ -1353,6 +1406,7 @@
if (uc_priv->name[i])
free(uc_priv->name[i]);
}
+ free(uc_priv->claimed);
free(uc_priv->name);
return gpio_renumber(dev);
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index c4a7fd2..a21c606 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -414,6 +414,7 @@
* @gpio_base: Base GPIO number for this device. For the first active device
* this will be 0; the numbering for others will follow sequentially so that
* @gpio_base for device 1 will equal the number of GPIOs in device 0.
+ * @claimed: Array of bits indicating which GPIOs in the bank are claimed.
* @name: Array of pointers to the name for each GPIO in this bank. The
* value of the pointer will be NULL if the GPIO has not been claimed.
*/
@@ -421,6 +422,7 @@
const char *bank_name;
unsigned gpio_count;
unsigned gpio_base;
+ u32 *claimed;
char **name;
};