From a0a584f0e92af068f4308586bad1ca5ea1e28d79 Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:57 -0600 Subject: [PATCH] gpio: ws16c48: make use of raw_spinlock variants The ws16c48 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 Acked-by: William Breathitt Gray Signed-off-by: Linus Walleij --- drivers/gpio/gpio-ws16c48.c | 46 ++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 23 deletions(-) diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c index 901b5ccb032d..87d63695dfcf 100644 --- a/drivers/gpio/gpio-ws16c48.c +++ b/drivers/gpio/gpio-ws16c48.c @@ -51,7 +51,7 @@ struct ws16c48_gpio { struct gpio_chip chip; unsigned char io_state[6]; unsigned char out_state[6]; - spinlock_t lock; + raw_spinlock_t lock; unsigned long irq_mask; unsigned long flow_mask; unsigned base; @@ -73,13 +73,13 @@ static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset) const unsigned mask = BIT(offset % 8); unsigned long flags; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); ws16c48gpio->io_state[port] |= mask; ws16c48gpio->out_state[port] &= ~mask; outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return 0; } @@ -92,7 +92,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip, const unsigned mask = BIT(offset % 8); unsigned long flags; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); ws16c48gpio->io_state[port] &= ~mask; if (value) @@ -101,7 +101,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip, ws16c48gpio->out_state[port] &= ~mask; outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return 0; } @@ -114,17 +114,17 @@ static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset) unsigned long flags; unsigned port_state; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); /* ensure that GPIO is set for input */ if (!(ws16c48gpio->io_state[port] & mask)) { - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return -EINVAL; } port_state = inb(ws16c48gpio->base + port); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return !!(port_state & mask); } @@ -136,11 +136,11 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) const unsigned mask = BIT(offset % 8); unsigned long flags; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); /* ensure that GPIO is set for output */ if (ws16c48gpio->io_state[port] & mask) { - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return; } @@ -150,7 +150,7 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) ws16c48gpio->out_state[port] &= ~mask; outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); } static void ws16c48_gpio_set_multiple(struct gpio_chip *chip, @@ -178,14 +178,14 @@ static void ws16c48_gpio_set_multiple(struct gpio_chip *chip, iomask = mask[BIT_WORD(i)] & ~ws16c48gpio->io_state[port]; bitmask = iomask & bits[BIT_WORD(i)]; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); /* update output state data and set device gpio register */ ws16c48gpio->out_state[port] &= ~iomask; ws16c48gpio->out_state[port] |= bitmask; outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); /* prepare for next gpio register set */ mask[BIT_WORD(i)] >>= gpio_reg_size; @@ -207,7 +207,7 @@ static void ws16c48_irq_ack(struct irq_data *data) if (port > 2) return; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); port_state = ws16c48gpio->irq_mask >> (8*port); @@ -216,7 +216,7 @@ static void ws16c48_irq_ack(struct irq_data *data) outb(port_state | mask, ws16c48gpio->base + 8 + port); outb(0xC0, ws16c48gpio->base + 7); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); } static void ws16c48_irq_mask(struct irq_data *data) @@ -232,7 +232,7 @@ static void ws16c48_irq_mask(struct irq_data *data) if (port > 2) return; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); ws16c48gpio->irq_mask &= ~mask; @@ -240,7 +240,7 @@ static void ws16c48_irq_mask(struct irq_data *data) outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); outb(0xC0, ws16c48gpio->base + 7); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); } static void ws16c48_irq_unmask(struct irq_data *data) @@ -256,7 +256,7 @@ static void ws16c48_irq_unmask(struct irq_data *data) if (port > 2) return; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); ws16c48gpio->irq_mask |= mask; @@ -264,7 +264,7 @@ static void ws16c48_irq_unmask(struct irq_data *data) outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); outb(0xC0, ws16c48gpio->base + 7); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); } static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) @@ -280,7 +280,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) if (port > 2) return -EINVAL; - spin_lock_irqsave(&ws16c48gpio->lock, flags); + raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); switch (flow_type) { case IRQ_TYPE_NONE: @@ -292,7 +292,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) ws16c48gpio->flow_mask &= ~mask; break; default: - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return -EINVAL; } @@ -300,7 +300,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port); outb(0xC0, ws16c48gpio->base + 7); - spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); return 0; } @@ -387,7 +387,7 @@ static int ws16c48_probe(struct device *dev, unsigned int id) ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple; ws16c48gpio->base = base[id]; - spin_lock_init(&ws16c48gpio->lock); + raw_spin_lock_init(&ws16c48gpio->lock); err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio); if (err) { -- 2.20.1