[PATCH resend 1/2] gpio: pcf857x: Propagate wake-up setting to parent irq controller

From: Geert Uytterhoeven
Date: Mon Jan 12 2015 - 11:04:53 EST


The pcf857x GPIO and interrupt controller uses dummy_irq_chip, which
does not implement irq_chip.irq_set_wake() and does not set
IRQCHIP_SKIP_SET_WAKE.

This causes two s2ram issues if wake-up is enabled for the pcf857x GPIO
pins:
1. During resume from s2ram, the following warning is printed:

WARNING: CPU: 0 PID: 1046 at kernel/irq/manage.c:537 irq_set_irq_wake+0x9c/0xf8()
Unbalanced IRQ 113 wake disable

2. Wake-up through the pcf857x GPIO pins may fail, as the parent
interrupt controller may be suspended.

Migrate the pcf857x GPIO and interrupt controller from dummy_irq_chip to
its own irq_chip. This irq chip implements irq_chip.irq_set_wake() to
propagate its wake-up setting to the parent interrupt controller.

This fixes wake-up through gpio-keys on sh73a0/kzm9g, where the pcf857x
interrupt is cascaded to irq-renesas-intc-irqpin, and the latter must
not be suspended when wake-up is enabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
Resend: Use Santosh' new email address

drivers/gpio/gpio-pcf857x.c | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
index 236708ad0a5ba0ab..22dbecb004cf6c5b 100644
--- a/drivers/gpio/gpio-pcf857x.c
+++ b/drivers/gpio/gpio-pcf857x.c
@@ -218,14 +218,45 @@ static irqreturn_t pcf857x_irq(int irq, void *data)
return IRQ_HANDLED;
}

+/*
+ * NOP functions
+ */
+static void noop(struct irq_data *data) { }
+
+static unsigned int noop_ret(struct irq_data *data)
+{
+ return 0;
+}
+
+static int pcf857x_irq_set_wake(struct irq_data *data, unsigned int on)
+{
+ struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
+
+ irq_set_irq_wake(gpio->client->irq, on);
+ return 0;
+}
+
+static struct irq_chip pcf857x_irq_chip = {
+ .name = "pcf857x",
+ .irq_startup = noop_ret,
+ .irq_shutdown = noop,
+ .irq_enable = noop,
+ .irq_disable = noop,
+ .irq_ack = noop,
+ .irq_mask = noop,
+ .irq_unmask = noop,
+ .irq_set_wake = pcf857x_irq_set_wake,
+};
+
static int pcf857x_irq_domain_map(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hw)
{
struct pcf857x *gpio = domain->host_data;

irq_set_chip_and_handler(irq,
- &dummy_irq_chip,
+ &pcf857x_irq_chip,
handle_level_irq);
+ irq_set_chip_data(irq, gpio);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/