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gpio: tqmx86: fix broken IRQ_TYPE_EDGE_BOTH interrupt type

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The TQMx86 GPIO controller only supports falling and rising edge
triggers, but not both. Fix this by implementing a software both-edge
mode that toggles the edge type after every interrupt.

Fixes: b868db94a6 ("gpio: tqmx86: Add GPIO from for this IO controller")
Co-developed-by: Gregor Herburger <gregor.herburger@tq-group.com>
Signed-off-by: Gregor Herburger <gregor.herburger@tq-group.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/515324f0491c4d44f4ef49f170354aca002d81ef.1717063994.git.matthias.schiffer@ew.tq-group.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Matthias Schiffer 2024-05-30 12:20:02 +02:00 committed by Bartosz Golaszewski
parent 08af509efd
commit 90dd7de4ef
1 changed files with 42 additions and 4 deletions
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46
drivers/gpio/gpio-tqmx86.c
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@ -32,6 +32,10 @@
#define TQMX86_GPII_NONE 0
#define TQMX86_GPII_FALLING BIT(0)
#define TQMX86_GPII_RISING BIT(1)
/* Stored in irq_type as a trigger type, but not actually valid as a register
* value, so the name doesn't use "GPII"
*/
#define TQMX86_INT_BOTH (BIT(0) | BIT(1))
#define TQMX86_GPII_MASK (BIT(0) | BIT(1))
#define TQMX86_GPII_BITS 2
/* Stored in irq_type with GPII bits */
@ -113,9 +117,15 @@ static void tqmx86_gpio_irq_config(struct tqmx86_gpio_data *gpio, int offset)
{
u8 type = TQMX86_GPII_NONE, gpiic;
if (gpio->irq_type[offset] & TQMX86_INT_UNMASKED)
if (gpio->irq_type[offset] & TQMX86_INT_UNMASKED) {
type = gpio->irq_type[offset] & TQMX86_GPII_MASK;
if (type == TQMX86_INT_BOTH)
type = tqmx86_gpio_get(&gpio->chip, offset + TQMX86_NGPO)
? TQMX86_GPII_FALLING
: TQMX86_GPII_RISING;
}
gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
gpiic &= ~(TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS));
gpiic |= type << (offset * TQMX86_GPII_BITS);
@ -169,7 +179,7 @@ static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
new_type = TQMX86_GPII_FALLING;
break;
case IRQ_TYPE_EDGE_BOTH:
new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
new_type = TQMX86_INT_BOTH;
break;
default:
return -EINVAL; /* not supported */
@ -189,8 +199,8 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
struct gpio_chip *chip = irq_desc_get_handler_data(desc);
struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
struct irq_chip *irq_chip = irq_desc_get_chip(desc);
unsigned long irq_bits;
int i = 0;
unsigned long irq_bits, flags;
int i;
u8 irq_status;
chained_irq_enter(irq_chip, desc);
@ -199,6 +209,34 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
irq_bits = irq_status;
raw_spin_lock_irqsave(&gpio->spinlock, flags);
for_each_set_bit(i, &irq_bits, TQMX86_NGPI) {
/*
* Edge-both triggers are implemented by flipping the edge
* trigger after each interrupt, as the controller only supports
* either rising or falling edge triggers, but not both.
*
* Internally, the TQMx86 GPIO controller has separate status
* registers for rising and falling edge interrupts. GPIIC
* configures which bits from which register are visible in the
* interrupt status register GPIIS and defines what triggers the
* parent IRQ line. Writing to GPIIS always clears both rising
* and falling interrupt flags internally, regardless of the
* currently configured trigger.
*
* In consequence, we can cleanly implement the edge-both
* trigger in software by first clearing the interrupt and then
* setting the new trigger based on the current GPIO input in
* tqmx86_gpio_irq_config() - even if an edge arrives between
* reading the input and setting the trigger, we will have a new
* interrupt pending.
*/
if ((gpio->irq_type[i] & TQMX86_GPII_MASK) == TQMX86_INT_BOTH)
tqmx86_gpio_irq_config(gpio, i);
}
raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
for_each_set_bit(i, &irq_bits, TQMX86_NGPI)
generic_handle_domain_irq(gpio->chip.irq.domain,
i + TQMX86_NGPO);