gpio: mockup: add a dummy irqchip

Setup a dummy irqchip that will allow us to inject line events for
testing purposes.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d4cec615a71ec4450dd34b284e92436567d838d8..05043071fc9805e1b9595090450f405ab28c22db 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -298,6 +298,8 @@ config GPIO_MOCKUP
        tristate "GPIO Testing Driver"
        depends on GPIOLIB && SYSFS
        select GPIO_SYSFS
+       select GPIOLIB_IRQCHIP
+       select IRQ_WORK
        help
          This enables GPIO Testing driver, which provides a way to test GPIO
          subsystem through sysfs(or char device) and debugfs. GPIO_SYSFS

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 0ce9acc3550e6eff663c4cd1644b272ebecd9b39..03beadb20dee0761be0ba45ec0bbf99090b69d96 100644 (file)
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -16,6 +16,9 @@
 #include <linux/gpio/driver.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irq_work.h>
 
 #define GPIO_MOCKUP_NAME       "gpio-mockup"
 #define        GPIO_MOCKUP_MAX_GC      10
@@ -35,9 +38,15 @@ struct gpio_mockup_line_status {
        bool value;
 };
 
+struct gpio_mockup_irq_context {
+       struct irq_work work;
+       int irq;
+};
+
 struct gpio_mockup_chip {
        struct gpio_chip gc;
        struct gpio_mockup_line_status *lines;
+       struct gpio_mockup_irq_context irq_ctx;
 };
 
 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
@@ -115,6 +124,57 @@ static int gpio_mockup_name_lines(struct device *dev,
        return 0;
 }
 
+static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset)
+{
+       return chip->irq_base + offset;
+}
+
+/*
+ * While we should generally support irqmask and irqunmask, this driver is
+ * for testing purposes only so we don't care.
+ */
+static void gpio_mockup_irqmask(struct irq_data *d) { }
+static void gpio_mockup_irqunmask(struct irq_data *d) { }
+
+static struct irq_chip gpio_mockup_irqchip = {
+       .name           = GPIO_MOCKUP_NAME,
+       .irq_mask       = gpio_mockup_irqmask,
+       .irq_unmask     = gpio_mockup_irqunmask,
+};
+
+static void gpio_mockup_handle_irq(struct irq_work *work)
+{
+       struct gpio_mockup_irq_context *irq_ctx;
+
+       irq_ctx = container_of(work, struct gpio_mockup_irq_context, work);
+       handle_simple_irq(irq_to_desc(irq_ctx->irq));
+}
+
+static int gpio_mockup_irqchip_setup(struct device *dev,
+                                    struct gpio_mockup_chip *chip)
+{
+       struct gpio_chip *gc = &chip->gc;
+       int irq_base, i;
+
+       irq_base = irq_alloc_descs(-1, 0, gc->ngpio, 0);
+       if (irq_base < 0)
+               return irq_base;
+
+       gc->irq_base = irq_base;
+       gc->irqchip = &gpio_mockup_irqchip;
+
+       for (i = 0; i < gc->ngpio; i++) {
+               irq_set_chip(irq_base + i, gc->irqchip);
+               irq_set_handler(irq_base + i, &handle_simple_irq);
+               irq_modify_status(irq_base + i,
+                                 IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
+       }
+
+       init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq);
+
+       return 0;
+}
+
 static int gpio_mockup_add(struct device *dev,
                           struct gpio_mockup_chip *chip,
                           const char *name, int base, int ngpio)
@@ -132,6 +192,7 @@ static int gpio_mockup_add(struct device *dev,
        gc->direction_output = gpio_mockup_dirout;
        gc->direction_input = gpio_mockup_dirin;
        gc->get_direction = gpio_mockup_get_direction;
+       gc->to_irq = gpio_mockup_to_irq;
 
        chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
                                   GFP_KERNEL);
@@ -144,6 +205,10 @@ static int gpio_mockup_add(struct device *dev,
                        return ret;
        }
 
+       ret = gpio_mockup_irqchip_setup(dev, chip);
+       if (ret)
+               return ret;
+
        return devm_gpiochip_add_data(dev, &chip->gc, chip);
 }
 
@@ -200,11 +265,25 @@ static int gpio_mockup_probe(struct platform_device *pdev)
        return 0;
 }
 
+static int gpio_mockup_remove(struct platform_device *pdev)
+{
+       struct gpio_mockup_chip *chips;
+       int i;
+
+       chips = platform_get_drvdata(pdev);
+
+       for (i = 0; i < gpio_mockup_params_nr >> 1; i++)
+               irq_free_descs(chips[i].gc.irq_base, chips[i].gc.ngpio);
+
+       return 0;
+}
+
 static struct platform_driver gpio_mockup_driver = {
        .driver = {
                .name = GPIO_MOCKUP_NAME,
        },
        .probe = gpio_mockup_probe,
+       .remove = gpio_mockup_remove,
 };
 
 static struct platform_device *pdev;