gpio: 104-idio-16: make use of raw_spinlock variants
The 104-idio-16 gpio driver currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel. Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.
A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.
Signed-off-by: Julia Cartwright <julia@ni.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
index 7053cf7..5281e1c 100644
--- a/drivers/gpio/gpio-104-idio-16.c
+++ b/drivers/gpio/gpio-104-idio-16.c
@@ -50,7 +50,7 @@
*/
struct idio_16_gpio {
struct gpio_chip chip;
- spinlock_t lock;
+ raw_spinlock_t lock;
unsigned long irq_mask;
unsigned base;
unsigned out_state;
@@ -99,7 +99,7 @@
if (offset > 15)
return;
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
if (value)
idio16gpio->out_state |= mask;
@@ -111,7 +111,7 @@
else
outb(idio16gpio->out_state, idio16gpio->base);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
@@ -120,7 +120,7 @@
struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
unsigned long flags;
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
idio16gpio->out_state &= ~*mask;
idio16gpio->out_state |= *mask & *bits;
@@ -130,7 +130,7 @@
if ((*mask >> 8) & 0xFF)
outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
static void idio_16_irq_ack(struct irq_data *data)
@@ -147,11 +147,11 @@
idio16gpio->irq_mask &= ~mask;
if (!idio16gpio->irq_mask) {
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
outb(0, idio16gpio->base + 2);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@@ -166,11 +166,11 @@
idio16gpio->irq_mask |= mask;
if (!prev_irq_mask) {
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
inb(idio16gpio->base + 2);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@@ -201,11 +201,11 @@
for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
- spin_lock(&idio16gpio->lock);
+ raw_spin_lock(&idio16gpio->lock);
outb(0, idio16gpio->base + 1);
- spin_unlock(&idio16gpio->lock);
+ raw_spin_unlock(&idio16gpio->lock);
return IRQ_HANDLED;
}
@@ -249,7 +249,7 @@
idio16gpio->base = base[id];
idio16gpio->out_state = 0xFFFF;
- spin_lock_init(&idio16gpio->lock);
+ raw_spin_lock_init(&idio16gpio->lock);
err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
if (err) {