gpio/omap: don't create an IRQ mapping for every GPIO on DT

When a GPIO is defined as an interrupt line using Device
Tree, a call to irq_create_of_mapping() is made that calls
irq_create_mapping(). So, is not necessary to do the mapping
for all OMAP GPIO lines and explicitly call irq_create_mapping()
on the driver probe() when booting with Device Tree.

Add a custom IRQ domain .map function handler that will be
called by irq_create_mapping() to map the GPIO lines used as IRQ.
This also allows to execute needed setup code such as configuring
a GPIO as input and enabling the GPIO bank.

Changes since v3:
  - Use bank->chip.of_node instead of_have_populated_dt() to check
    DT or legacy boot as suggested by Jean-Christophe PLAGNIOL-VILLARD

Changes since v2:
  - Unconditionally do the IRQ setup in the .map() function and
    only call irq_create_mapping() in the gpio chip init to avoid
    code duplication as suggested by Grant Likely.

Changes since v1:
  - Split the addition of the .map function handler and the
    automatic gpio request in two different patches.
  - Add GPIO IRQ setup logic to the irq domain mapping function.
  - Only call irq_create_mapping for every GPIO on legacy boot.
  - Only setup a GPIO IRQ on the .map function for DeviceTree boot.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 40 insertions, 14 deletions

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index dfeb3a3a8f20..5e667ff91dc3 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1068,24 +1068,50 @@ static void omap_gpio_chip_init(struct gpio_bank *bank)
 
         gpiochip_add(&bank->chip);
 
-        for (j = 0; j < bank->width; j++) {
-                int irq = irq_create_mapping(bank->domain, j);
-                irq_set_lockdep_class(irq, &gpio_lock_class);
-                irq_set_chip_data(irq, bank);
-                if (bank->is_mpuio) {
-                        omap_mpuio_alloc_gc(bank, irq, bank->width);
-                } else {
-                        irq_set_chip_and_handler(irq, &gpio_irq_chip,
-                                                 handle_simple_irq);
-                        set_irq_flags(irq, IRQF_VALID);
-                }
-        }
+        /*
+         * REVISIT these explicit calls to irq_create_mapping()
+         * to do the GPIO to IRQ domain mapping for each GPIO in
+         * the bank can be removed once all OMAP platforms have
+         * been migrated to Device Tree boot only.
+         * Since in DT boot irq_create_mapping() is called from
+         * irq_create_of_mapping() only for the GPIO lines that
+         * are used as interrupts.
+         */
+        if (!bank->chip.of_node)
+                for (j = 0; j < bank->width; j++)
+                        irq_create_mapping(bank->domain, j);
         irq_set_chained_handler(bank->irq, gpio_irq_handler);
         irq_set_handler_data(bank->irq, bank);
 }
 
 static const struct of_device_id omap_gpio_match[];
 
+static int omap_gpio_irq_map(struct irq_domain *d, unsigned int virq,
+                             irq_hw_number_t hwirq)
+{
+        struct gpio_bank *bank = d->host_data;
+
+        if (!bank)
+                return -EINVAL;
+
+        irq_set_lockdep_class(virq, &gpio_lock_class);
+        irq_set_chip_data(virq, bank);
+        if (bank->is_mpuio) {
+                omap_mpuio_alloc_gc(bank, virq, bank->width);
+        } else {
+                irq_set_chip_and_handler(virq, &gpio_irq_chip,
+                                         handle_simple_irq);
+                set_irq_flags(virq, IRQF_VALID);
+        }
+
+        return 0;
+}
+
+static struct irq_domain_ops omap_gpio_irq_ops = {
+        .xlate  = irq_domain_xlate_onetwocell,
+        .map    = omap_gpio_irq_map,
+};
+
 static int omap_gpio_probe(struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
@@ -1151,10 +1177,10 @@ static int omap_gpio_probe(struct platform_device *pdev)
         }
 
         bank->domain = irq_domain_add_legacy(node, bank->width, irq_base,
-                                             0, &irq_domain_simple_ops, NULL);
+                                             0, &omap_gpio_irq_ops, bank);
 #else
         bank->domain = irq_domain_add_linear(node, bank->width,
-                                             &irq_domain_simple_ops, NULL);
+                                             &omap_gpio_irq_ops, bank);
 #endif
         if (!bank->domain) {
                 dev_err(dev, "Couldn't register an IRQ domain\n");