[PATCH] [not for merge] gpiolib: update and test new gpioirq chip infra

From: Grygorii Strashko
Date: Fri Nov 03 2017 - 18:24:51 EST


changes in gpiolib:
- move set_parent to gpiochip_irq_map() and use parents instead of map for only
one parent
- add gpio_irq_chip->first_irq for static IRQ allocation
- fix nested = true if parent_handler not set
- fix gpiochip_irqchip_remove() if parent_handler not set
- get of_node from gpiodev
- fix lock_key: drivers do not need to set it, but looks a bit overcomplicated
as lock_class_key will be created for each gpiochip_add_data() call.
Honestly, do not seem better way :(

GPIO OMAP driver updated to use new gpioirq chip infra and tested on am335x-evm.
seems it's working - can see irqs from keys.

Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/gpio/gpio-omap.c | 36 ++++++++++++++--------------
drivers/gpio/gpiolib.c | 58 +++++++++++++++++++--------------------------
include/linux/gpio/driver.h | 32 ++++++++++++++++++++++++-
3 files changed, 73 insertions(+), 53 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index ce27d6a..4048f18 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1054,6 +1054,7 @@ static void omap_gpio_mod_init(struct gpio_bank *bank)

static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
{
+ struct gpio_irq_chip *irq;
static int gpio;
int irq_base = 0;
int ret;
@@ -1081,16 +1082,6 @@ static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
}
bank->chip.ngpio = bank->width;

- ret = gpiochip_add_data(&bank->chip, bank);
- if (ret) {
- dev_err(bank->chip.parent,
- "Could not register gpio chip %d\n", ret);
- return ret;
- }
-
- if (!bank->is_mpuio)
- gpio += bank->width;
-
#ifdef CONFIG_ARCH_OMAP1
/*
* REVISIT: Once we have OMAP1 supporting SPARSE_IRQ, we can drop
@@ -1111,25 +1102,34 @@ static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
irqc->irq_set_wake = NULL;
}

- ret = gpiochip_irqchip_add(&bank->chip, irqc,
- irq_base, handle_bad_irq,
- IRQ_TYPE_NONE);
+ irq = &bank->chip.irq;
+ irq->chip = irqc;
+// irq->domain_ops = not required;
+ irq->handler = handle_bad_irq;
+// irq->lock_key = not required;
+ irq->default_type = IRQ_TYPE_NONE;
+// irq->parent_handler = not used by this driver;
+// irq->parent_handler_data = not used by this driver;
+ irq->num_parents = 1;
+ irq->parents = &bank->irq;
+ irq->first_irq = irq_base;

+ ret = gpiochip_add_data(&bank->chip, bank);
if (ret) {
dev_err(bank->chip.parent,
- "Couldn't add irqchip to gpiochip %d\n", ret);
- gpiochip_remove(&bank->chip);
- return -ENODEV;
+ "Could not register gpio chip %d\n", ret);
+ return ret;
}

- gpiochip_set_chained_irqchip(&bank->chip, irqc, bank->irq, NULL);
-
ret = devm_request_irq(bank->chip.parent, bank->irq,
omap_gpio_irq_handler,
0, dev_name(bank->chip.parent), bank);
if (ret)
gpiochip_remove(&bank->chip);

+ if (!bank->is_mpuio)
+ gpio += bank->width;
+
return ret;
}

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5bc99d0..d11b4df 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -72,7 +72,8 @@ 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 int gpiochip_add_irqchip_key(struct gpio_chip *gpiochip,
+ struct lock_class_key *lock_key);
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);
@@ -1121,7 +1122,8 @@ static void gpiochip_setup_devs(void)
* chip->base is invalid or already associated with a different chip.
* Otherwise it returns zero as a success code.
*/
-int gpiochip_add_data(struct gpio_chip *chip, void *data)
+int gpiochip_add_data_key(struct gpio_chip *chip, void *data,
+ struct lock_class_key *irq_lock_key)
{
unsigned long flags;
int status = 0;
@@ -1267,7 +1269,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
if (status)
goto err_remove_from_list;

- status = gpiochip_add_irqchip(chip);
+ status = gpiochip_add_irqchip_key(chip, irq_lock_key);
if (status)
goto err_remove_chip;

@@ -1642,6 +1644,7 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *chip = d->host_data;
+ int err = 0;

if (!gpiochip_irqchip_irq_valid(chip, hwirq))
return -ENXIO;
@@ -1658,6 +1661,12 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);

+ if (chip->irq.num_parents == 1)
+ err = irq_set_parent(irq, chip->irq.parents[0]);
+ else if (chip->irq.map)
+ err = irq_set_parent(irq, chip->irq.map[hwirq]);
+ if (err < 0)
+ return err;
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
@@ -1712,30 +1721,18 @@ 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;

- 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;
+ return irq_create_mapping(chip->irq.domain, 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)
+static int gpiochip_add_irqchip_key(struct gpio_chip *gpiochip,
+ struct lock_class_key *lock_key)
{
struct irq_chip *irqchip = gpiochip->irq.chip;
const struct irq_domain_ops *ops;
@@ -1753,17 +1750,8 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
}

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
+ /* called from gpiochip_add_data() and is set properly */
+ np = gpiochip->gpiodev->dev.of_node;

/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
@@ -1789,7 +1777,8 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
ops = &gpiochip_domain_ops;

gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
- 0, ops, gpiochip);
+ gpiochip->irq.first_irq,
+ ops, gpiochip);
if (!gpiochip->irq.domain)
return -EINVAL;

@@ -1818,9 +1807,9 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
}

gpiochip->irq.nested = false;
- } else {
- gpiochip->irq.nested = true;
}
+ /* GPIO driver might not specify parent_handler, but it doesn't mean
+ * it's irq_nested, as driver may use request_irq() */

acpi_gpiochip_request_interrupts(gpiochip);

@@ -1839,7 +1828,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)

acpi_gpiochip_free_interrupts(gpiochip);

- if (gpiochip->irq.chip) {
+ if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
struct gpio_irq_chip *irq = &gpiochip->irq;
unsigned int i;

@@ -1972,7 +1961,8 @@ EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);

#else /* CONFIG_GPIOLIB_IRQCHIP */

-static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip)
+static inline int gpiochip_add_irqchip_key(struct gpio_chip *gpiochip,
+ struct lock_class_key *lock_key)
{
return 0;
}
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 51fc7b0..3254996 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -128,6 +128,15 @@ struct gpio_irq_chip {
* in IRQ domain of the chip.
*/
unsigned long *valid_mask;
+
+ /**
+ * @first_irq:
+ *
+ * Required for static irq allocation.
+ * if set irq_domain_add_simple() will allocate and map all IRQs
+ * during initialization.
+ */
+ unsigned int first_irq;
};

static inline struct gpio_irq_chip *to_gpio_irq_chip(struct irq_chip *chip)
@@ -312,8 +321,29 @@ struct gpio_chip {
extern const char *gpiochip_is_requested(struct gpio_chip *chip,
unsigned offset);

+extern int gpiochip_add_data_key(struct gpio_chip *chip, void *data,
+ struct lock_class_key *irq_lock_key);
+#ifdef CONFIG_LOCKDEP
+/*
+ * Lockdep requires that each irqchip instance be created with a
+ * unique key so as to avoid unnecessary warnings. This upfront
+ * boilerplate static inlines provides such a key for each
+ * unique instance which is created now from inside gpiochip_add_data_key().
+ */
+static inline int gpiochip_add_data(struct gpio_chip *chip, void *data)
+{
+ static struct lock_class_key key;
+
+ return gpiochip_add_data_key(chip, data, key);
+}
+
+#else
+static inline int gpiochip_add_data(struct gpio_chip *chip, void *data)
+{
+ return gpiochip_add_data_key(chip, data, NULL);
+}
+#endif /* CONFIG_LOCKDEP */
/* add/remove chips */
-extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
static inline int gpiochip_add(struct gpio_chip *chip)
{
return gpiochip_add_data(chip, NULL);
--
2.10.5