[PATCH 15/17] gpio: omap: Convert to immutable irq_chip

From: Linus Walleij
Date: Thu Feb 16 2023 - 04:38:39 EST


Convert the driver to immutable irq-chip with a bit of
intuition.

This driver require some special care: .irq_ack() was copied
from dummy_irq_chip where it was defined as noop. This only
makes sense if using handle_edge_irq() that will unconditionally
call .irq_ack() to avoid a crash, but this driver is not ever
using handle_edge_irq() so just avoid assigning .irq_ack().

A separate chip had to be created for the non-wakeup instance.

Cc: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/gpio/gpio-omap.c | 68 ++++++++++++++++++++++++++++++++----------------
1 file changed, 45 insertions(+), 23 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 292e62c06008..a5ee3ed31533 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
+#include <linux/seq_file.h>
#include <linux/syscore_ops.h>
#include <linux/err.h>
#include <linux/clk.h>
@@ -47,6 +48,7 @@ struct gpio_regs {
struct gpio_bank {
void __iomem *base;
const struct omap_gpio_reg_offs *regs;
+ struct device *dev;

int irq;
u32 non_wakeup_gpios;
@@ -681,6 +683,7 @@ static void omap_gpio_mask_irq(struct irq_data *d)
omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
omap_set_gpio_irqenable(bank, offset, 0);
raw_spin_unlock_irqrestore(&bank->lock, flags);
+ gpiochip_disable_irq(&bank->chip, offset);
}

static void omap_gpio_unmask_irq(struct irq_data *d)
@@ -690,6 +693,7 @@ static void omap_gpio_unmask_irq(struct irq_data *d)
u32 trigger = irqd_get_trigger_type(d);
unsigned long flags;

+ gpiochip_enable_irq(&bank->chip, offset);
raw_spin_lock_irqsave(&bank->lock, flags);
omap_set_gpio_irqenable(bank, offset, 1);

@@ -708,6 +712,40 @@ static void omap_gpio_unmask_irq(struct irq_data *d)
raw_spin_unlock_irqrestore(&bank->lock, flags);
}

+static void omap_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+ struct gpio_bank *bank = omap_irq_data_get_bank(d);
+
+ seq_printf(p, dev_name(bank->dev));
+}
+
+static const struct irq_chip omap_gpio_irq_chip = {
+ .irq_startup = omap_gpio_irq_startup,
+ .irq_shutdown = omap_gpio_irq_shutdown,
+ .irq_mask = omap_gpio_mask_irq,
+ .irq_unmask = omap_gpio_unmask_irq,
+ .irq_set_type = omap_gpio_irq_type,
+ .irq_set_wake = omap_gpio_wake_enable,
+ .irq_bus_lock = omap_gpio_irq_bus_lock,
+ .irq_bus_sync_unlock = gpio_irq_bus_sync_unlock,
+ .irq_print_chip = omap_gpio_irq_print_chip,
+ .flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static const struct irq_chip omap_gpio_irq_chip_nowake = {
+ .irq_startup = omap_gpio_irq_startup,
+ .irq_shutdown = omap_gpio_irq_shutdown,
+ .irq_mask = omap_gpio_mask_irq,
+ .irq_unmask = omap_gpio_unmask_irq,
+ .irq_set_type = omap_gpio_irq_type,
+ .irq_bus_lock = omap_gpio_irq_bus_lock,
+ .irq_bus_sync_unlock = gpio_irq_bus_sync_unlock,
+ .irq_print_chip = omap_gpio_irq_print_chip,
+ .flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
/*---------------------------------------------------------------------*/

static int omap_mpuio_suspend_noirq(struct device *dev)
@@ -986,8 +1024,7 @@ static void omap_gpio_mod_init(struct gpio_bank *bank)
writel_relaxed(0, base + bank->regs->ctrl);
}

-static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc,
- struct device *pm_dev)
+static int omap_gpio_chip_init(struct gpio_bank *bank, struct device *pm_dev)
{
struct gpio_irq_chip *irq;
static int gpio;
@@ -1023,12 +1060,12 @@ static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc,
}
bank->chip.ngpio = bank->width;

+ irq = &bank->chip.irq;
/* MPUIO is a bit different, reading IRQ status clears it */
if (bank->is_mpuio && !bank->regs->wkup_en)
- irqc->irq_set_wake = NULL;
-
- irq = &bank->chip.irq;
- irq->chip = irqc;
+ gpio_irq_chip_set_chip(irq, &omap_gpio_irq_chip_nowake);
+ else
+ gpio_irq_chip_set_chip(irq, &omap_gpio_irq_chip);
irq->handler = handle_bad_irq;
irq->default_type = IRQ_TYPE_NONE;
irq->num_parents = 1;
@@ -1361,7 +1398,6 @@ static int omap_gpio_probe(struct platform_device *pdev)
struct device_node *node = dev->of_node;
const struct omap_gpio_platform_data *pdata;
struct gpio_bank *bank;
- struct irq_chip *irqc;
int ret;

pdata = device_get_match_data(dev);
@@ -1374,21 +1410,7 @@ static int omap_gpio_probe(struct platform_device *pdev)
if (!bank)
return -ENOMEM;

- irqc = devm_kzalloc(dev, sizeof(*irqc), GFP_KERNEL);
- if (!irqc)
- return -ENOMEM;
-
- irqc->irq_startup = omap_gpio_irq_startup,
- irqc->irq_shutdown = omap_gpio_irq_shutdown,
- irqc->irq_ack = dummy_irq_chip.irq_ack,
- irqc->irq_mask = omap_gpio_mask_irq,
- irqc->irq_unmask = omap_gpio_unmask_irq,
- irqc->irq_set_type = omap_gpio_irq_type,
- irqc->irq_set_wake = omap_gpio_wake_enable,
- irqc->irq_bus_lock = omap_gpio_irq_bus_lock,
- irqc->irq_bus_sync_unlock = gpio_irq_bus_sync_unlock,
- irqc->name = dev_name(&pdev->dev);
- irqc->flags = IRQCHIP_MASK_ON_SUSPEND;
+ bank->dev = dev;

bank->irq = platform_get_irq(pdev, 0);
if (bank->irq <= 0) {
@@ -1452,7 +1474,7 @@ static int omap_gpio_probe(struct platform_device *pdev)

omap_gpio_mod_init(bank);

- ret = omap_gpio_chip_init(bank, irqc, dev);
+ ret = omap_gpio_chip_init(bank, dev);
if (ret) {
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);

--
2.34.1