From: Thierry Reding <treding@xxxxxxxxxx>
Currently GPIO drivers are required to a GPIO chip and the corresponding
IRQ chip separately, which can result in a lot of boilerplate. Introduce
a new struct gpio_irq_chip, embedded in a struct gpio_chip, that drivers
can fill in if they want the GPIO core to automatically register the IRQ
chip associated with a GPIO chip.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 157 ++++++++++++++++++++++++++++++++++++++++++--
include/linux/gpio/driver.h | 39 +++++++++++
2 files changed, 192 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7a0df48e09da..d403a0572d4b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -72,6 +72,7 @@ static LIST_HEAD(gpio_lookup_list);
LIST_HEAD(gpio_devices);
static void gpiochip_free_hogs(struct gpio_chip *chip);
+static int gpiochip_add_irqchip(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
@@ -1240,6 +1241,10 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
if (status)
goto err_remove_from_list;
+ status = gpiochip_add_irqchip(chip);
+ if (status)
+ goto err_remove_chip;
+
status = of_gpiochip_add(chip);
if (status)
goto err_remove_chip;
@@ -1602,10 +1607,16 @@ EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
* stored inside the gpiochip.
*/
-static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
- irq_hw_number_t hwirq)
+int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
{
struct gpio_chip *chip = d->host_data;
+ struct irq_chip *irqchip;
+
+ if (chip->irq.chip)
+ irqchip = chip->irq.chip;
+ else
+ irqchip = chip->irqchip;
irq_set_chip_data(irq, chip);
/*
@@ -1613,7 +1624,7 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
* category than their parents, so it won't report false recursion.
*/
irq_set_lockdep_class(irq, chip->lock_key);
- irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
+ irq_set_chip_and_handler(irq, irqchip, chip->irq_handler);
/* Chips that use nested thread handlers have them marked */
if (chip->irq_nested)
irq_set_nested_thread(irq, 1);
@@ -1628,8 +1639,9 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
return 0;
}
+EXPORT_SYMBOL_GPL(gpiochip_irq_map);
-static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
+void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *chip = d->host_data;
@@ -1638,6 +1650,7 @@ static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
+EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
static const struct irq_domain_ops gpiochip_domain_ops = {
.map = gpiochip_irq_map,
@@ -1677,6 +1690,127 @@ static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
}
/**
+ * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
+ * @gpiochip: the GPIO chip to add the IRQ chip to
+ */
+static int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
+{
+ struct irq_chip *irqchip = gpiochip->irq.chip;
+ const struct irq_domain_ops *ops;
+ struct device_node *np;
+ unsigned int type;
+ unsigned int i;
+
+ if (!irqchip)
+ return 0;
+
+ if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
+ chip_err(gpiochip, "you cannot have chained interrupts on a "
+ "chip that may sleep\n");
+ return -EINVAL;
+ }
+
+ type = gpiochip->irq.default_type;
+ np = gpiochip->parent->of_node;
+
+#ifdef CONFIG_OF_GPIO
+ /*
+ * If the gpiochip has an assigned OF node this takes precedence
+ * FIXME: get rid of this and use gpiochip->parent->of_node
+ * everywhere
+ */
+ if (gpiochip->of_node)
+ np = gpiochip->of_node;
+#endif
+
+ /*
+ * Specifying a default trigger is a terrible idea if DT or ACPI is
+ * used to configure the interrupts, as you may end up with
+ * conflicting triggers. Tell the user, and reset to NONE.
+ */
+ if (WARN(np && type != IRQ_TYPE_NONE,
+ "%s: Ignoring %u default trigger\n", np->full_name, type))
+ type = IRQ_TYPE_NONE;
+
+ if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
+ acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
+ "Ignoring %u default trigger\n", type);
+ type = IRQ_TYPE_NONE;
+ }
+
+ gpiochip->irq_handler = gpiochip->irq.handler;
+ gpiochip->lock_key = gpiochip->irq.lock_key;
+
+ gpiochip->to_irq = gpiochip_to_irq;
+ gpiochip->irq_default_type = type;
+
+ if (gpiochip->irq.domain_ops)
+ ops = gpiochip->irq.domain_ops;
+ else
+ ops = &gpiochip_domain_ops;
+
+ gpiochip->irqdomain = irq_domain_add_simple(np, gpiochip->ngpio,
+ gpiochip->irq.first,
+ ops, gpiochip);
+ if (!gpiochip->irqdomain)
+ return -EINVAL;
+
+ /*
+ * It is possible for a driver to override this, but only if the
+ * alternative functions are both implemented.
+ */
+ if (!irqchip->irq_request_resources &&
+ !irqchip->irq_release_resources) {
+ irqchip->irq_request_resources = gpiochip_irq_reqres;
+ irqchip->irq_release_resources = gpiochip_irq_relres;
+ }
+
+ if (gpiochip->irq.parent_handler) {
+ void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
+
+ for (i = 0; i < gpiochip->irq.num_parents; i++) {
+ /*
+ * The parent IRQ chip is already using the chip_data
+ * for this IRQ chip, so our callbacks simply use the
+ * handler_data.
+ */
+ irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
+ gpiochip->irq.parent_handler,
+ data);
+ }
+
+ gpiochip->irq_nested = false;
+ } else {
+ gpiochip->irq_nested = true;
+ }
+
+ /*
+ * Prepare the mapping since the IRQ chip shall be orthogonal to any
+ * GPIO chip calls.
+ */
+ for (i = 0; i < gpiochip->ngpio; i++) {
+ unsigned int irq;
+
+ if (!gpiochip_irqchip_irq_valid(gpiochip, i))
+ continue;
+
+ irq = irq_create_mapping(gpiochip->irqdomain, i);
+ if (!irq) {
+ chip_err(gpiochip,
+ "failed to create IRQ mapping for GPIO#%u\n",
+ i);
+ continue;
+ }
+
+ irq_set_parent(irq, gpiochip->irq.map[i]);
+ }
+
+ acpi_gpiochip_request_interrupts(gpiochip);
+
+ return 0;
+}
+
+/**
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
* @gpiochip: the gpiochip to remove the irqchip from
*
@@ -1693,6 +1827,16 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
}
+ if (gpiochip->irq.chip) {
+ struct gpio_irq_chip *irq = &gpiochip->irq;
+ unsigned int i;
+
+ for (i = 0; i < irq->num_parents; i++) {
+ irq_set_chained_handler(irq->parents[i], NULL);
+ irq_set_handler_data(irq->parents[i], NULL);
+ }
+ }
+
/* Remove all IRQ mappings and delete the domain */
if (gpiochip->irqdomain) {
for (offset = 0; offset < gpiochip->ngpio; offset++) {
@@ -1835,6 +1979,11 @@ EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
#else /* CONFIG_GPIOLIB_IRQCHIP */
+static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
+{
+ return 0;
+}
+
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 393582867afd..223645a1d80f 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -19,6 +19,39 @@ struct module;
#ifdef CONFIG_GPIOLIB
+#ifdef CONFIG_GPIOLIB_IRQCHIP
+/**
+ * struct gpio_irq_chip - GPIO interrupt controller
+ * @chip: GPIO IRQ chip implementation, provided by GPIO driver
+ * @first: if not dynamically assigned, the base (first) IRQ to allocate GPIO
+ * chip IRQs from
+ * @domain_ops: table of interrupt domain operations for this IRQ chip
+ * @handler: the interrupt handler for the GPIO chip's parent interrupts
+ * @lock_key: per GPIO IRQ chip lockdep class
+ * @default_type: default IRQ triggering type applied during GPIO driver
+ * initialization, provided by GPIO driver
+ * @parent_handler: the interrupt handler for the GPIO chip's parent
+ * interrupts, may be NULL if the parent interrupts are
+ * nested rather than cascaded
+ * @num_parents: the number of interrupt parents of a GPIO chip
+ * @parents: a list of interrupt parents of a GPIO chip
+ * @map: a list of interrupt parents for each line of a GPIO chip
+ */
+struct gpio_irq_chip {
+ struct irq_chip *chip;
+ unsigned int first;
+ const struct irq_domain_ops *domain_ops;
+ irq_flow_handler_t handler;
+ struct lock_class_key *lock_key;
+ unsigned int default_type;
+ irq_flow_handler_t parent_handler;
+ void *parent_handler_data;
+ unsigned int num_parents;
+ unsigned int *parents;
+ unsigned int *map;
+};
+#endif
+
/**
* struct gpio_chip - abstract a GPIO controller
* @label: a functional name for the GPIO device, such as a part
@@ -173,6 +206,8 @@ struct gpio_chip {
bool irq_need_valid_mask;
unsigned long *irq_valid_mask;
struct lock_class_key *lock_key;
+
+ struct gpio_irq_chip irq;
#endif
#if defined(CONFIG_OF_GPIO)
@@ -242,6 +277,10 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
#ifdef CONFIG_GPIOLIB_IRQCHIP
+int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq);
+void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
+
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int parent_irq,
--
2.12.0
--
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