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Message-Id: <20171013154913.29448-12-thierry.reding@gmail.com>
Date: Fri, 13 Oct 2017 17:49:11 +0200
From: Thierry Reding <thierry.reding@...il.com>
To: Linus Walleij <linus.walleij@...aro.org>
Cc: Jonathan Hunter <jonathanh@...dia.com>,
Grygorii Strashko <grygorii.strashko@...com>,
linux-gpio@...r.kernel.org, linux-tegra@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v5 11/13] gpio: Implement tighter IRQ chip integration
From: Thierry Reding <treding@...dia.com>
Currently GPIO drivers are required to add the GPIO chip and its
corresponding IRQ chip separately, which can result in a lot of
boilerplate. Use the newly introduced struct gpio_irq_chip, embedded in
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@...dia.com>
---
drivers/gpio/gpiolib.c | 125 +++++++++++++++++++++++++++++++++++++++++++-
include/linux/gpio/driver.h | 7 +++
2 files changed, 130 insertions(+), 2 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index eb487af120d9..672b61024413 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);
@@ -1260,6 +1261,10 @@ 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;
@@ -1701,9 +1706,120 @@ static void gpiochip_irq_relres(struct irq_data *d)
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
{
+ unsigned int irq;
+ int err;
+
if (!gpiochip_irqchip_irq_valid(chip, offset))
return -ENXIO;
- return irq_create_mapping(chip->irq.domain, offset);
+
+ irq = irq_create_mapping(chip->irq.domain, offset);
+ if (!irq)
+ return 0;
+
+ if (chip->irq.map) {
+ err = irq_set_parent(irq, chip->irq.map[offset]);
+ if (err < 0)
+ return err;
+ }
+
+ return irq;
+}
+
+/**
+ * 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->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->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
+ gpiochip->irq.first,
+ ops, gpiochip);
+ if (!gpiochip->irq.domain)
+ 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;
+ }
+
+ acpi_gpiochip_request_interrupts(gpiochip);
+
+ return 0;
}
/**
@@ -1718,7 +1834,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
acpi_gpiochip_free_interrupts(gpiochip);
- if (gpiochip->irq.num_parents > 0) {
+ if (gpiochip->irq.chip) {
struct gpio_irq_chip *irq = &gpiochip->irq;
unsigned int i;
@@ -1852,6 +1968,11 @@ 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 4ae8dd945617..6e344ddd4df5 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -108,6 +108,13 @@ struct gpio_irq_chip {
*/
unsigned int *parents;
+ /**
+ * @map:
+ *
+ * A list of interrupt parents for each line of a GPIO chip.
+ */
+ unsigned int *map;
+
/**
* @nested:
*
--
2.14.1
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