[1/2] pinctrl: ingenic: Enhance support for IRQ_TYPE_EDGE_BOTH

Message ID 20200622214548.265417-1-paul@crapouillou.net
State Accepted
Commit 1c95348ba327fe8621d3680890c2341523d3524a
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  • [1/2] pinctrl: ingenic: Enhance support for IRQ_TYPE_EDGE_BOTH
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Commit Message

Paul Cercueil June 22, 2020, 9:45 p.m.
Ingenic SoCs don't natively support registering an interrupt for both
rising and falling edges. This has to be emulated in software.

Until now, this was emulated by switching back and forth between
IRQ_TYPE_EDGE_RISING and IRQ_TYPE_EDGE_FALLING according to the level of
the GPIO. While this worked most of the time, when used with GPIOs that
need debouncing, some events would be lost. For instance, between the
time a falling-edge interrupt happens and the interrupt handler
configures the hardware for rising-edge, the level of the pin may have
already risen, and the rising-edge event is lost.

To address that issue, instead of switching back and forth between
IRQ_TYPE_EDGE_RISING and IRQ_TYPE_EDGE_FALLING, we now switch back and
forth between IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_LEVEL_HIGH. Since we
always switch in the interrupt handler, they actually permit to detect
level changes. In the example above, if the pin level rises before
switching the IRQ type from IRQ_TYPE_LEVEL_LOW to IRQ_TYPE_LEVEL_HIGH,
a new interrupt will raise as soon as the handler exits, and the
rising-edge event will be properly detected.

Cc: stable@vger.kernel.org
Fixes: e72394e2ea19 ("pinctrl: ingenic: Merge GPIO functionality")
Reported-by: João Henrique <johnnyonflame@hotmail.com>
Tested-by: João Henrique <johnnyonflame@hotmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/pinctrl/pinctrl-ingenic.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Linus Walleij July 7, 2020, 12:22 p.m. | #1
On Mon, Jun 22, 2020 at 11:46 PM Paul Cercueil <paul@crapouillou.net> wrote:

> Ingenic SoCs don't natively support registering an interrupt for both

> rising and falling edges. This has to be emulated in software.

>

> Until now, this was emulated by switching back and forth between

> IRQ_TYPE_EDGE_RISING and IRQ_TYPE_EDGE_FALLING according to the level of

> the GPIO. While this worked most of the time, when used with GPIOs that

> need debouncing, some events would be lost. For instance, between the

> time a falling-edge interrupt happens and the interrupt handler

> configures the hardware for rising-edge, the level of the pin may have

> already risen, and the rising-edge event is lost.

>

> To address that issue, instead of switching back and forth between

> IRQ_TYPE_EDGE_RISING and IRQ_TYPE_EDGE_FALLING, we now switch back and

> forth between IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_LEVEL_HIGH. Since we

> always switch in the interrupt handler, they actually permit to detect

> level changes. In the example above, if the pin level rises before

> switching the IRQ type from IRQ_TYPE_LEVEL_LOW to IRQ_TYPE_LEVEL_HIGH,

> a new interrupt will raise as soon as the handler exits, and the

> rising-edge event will be properly detected.

>

> Cc: stable@vger.kernel.org

> Fixes: e72394e2ea19 ("pinctrl: ingenic: Merge GPIO functionality")

> Reported-by: João Henrique <johnnyonflame@hotmail.com>

> Tested-by: João Henrique <johnnyonflame@hotmail.com>

> Signed-off-by: Paul Cercueil <paul@crapouillou.net>


I have applied these two as non-urgent fixes for v5.9.

Are they urgent?
Are they causing regressions?
Tell me if they need to be merged to v5.8-rcs.

Yours,
Linus Walleij

Patch

diff --git a/drivers/pinctrl/pinctrl-ingenic.c b/drivers/pinctrl/pinctrl-ingenic.c
index fc0d10411aa9..241e563d5814 100644
--- a/drivers/pinctrl/pinctrl-ingenic.c
+++ b/drivers/pinctrl/pinctrl-ingenic.c
@@ -1813,9 +1813,9 @@  static void ingenic_gpio_irq_ack(struct irq_data *irqd)
 		 */
 		high = ingenic_gpio_get_value(jzgc, irq);
 		if (high)
-			irq_set_type(jzgc, irq, IRQ_TYPE_EDGE_FALLING);
+			irq_set_type(jzgc, irq, IRQ_TYPE_LEVEL_LOW);
 		else
-			irq_set_type(jzgc, irq, IRQ_TYPE_EDGE_RISING);
+			irq_set_type(jzgc, irq, IRQ_TYPE_LEVEL_HIGH);
 	}
 
 	if (jzgc->jzpc->info->version >= ID_JZ4760)
@@ -1851,7 +1851,7 @@  static int ingenic_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
 		 */
 		bool high = ingenic_gpio_get_value(jzgc, irqd->hwirq);
 
-		type = high ? IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
+		type = high ? IRQ_TYPE_LEVEL_LOW : IRQ_TYPE_LEVEL_HIGH;
 	}
 
 	irq_set_type(jzgc, irqd->hwirq, type);