From c69fcea57e9d2b27025235b3205861c3895fa618 Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:54 -0600 Subject: [PATCH] gpio: bcm-kona: make use of raw_spinlock variants The bcm-kona 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 Signed-off-by: Linus Walleij --- drivers/gpio/gpio-bcm-kona.c | 48 ++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c index 41d0ac142580..dfcf56ee3c61 100644 --- a/drivers/gpio/gpio-bcm-kona.c +++ b/drivers/gpio/gpio-bcm-kona.c @@ -67,7 +67,7 @@ struct bcm_kona_gpio { void __iomem *reg_base; int num_bank; - spinlock_t lock; + raw_spinlock_t lock; struct gpio_chip gpio_chip; struct irq_domain *irq_domain; struct bcm_kona_gpio_bank *banks; @@ -95,13 +95,13 @@ static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio, unsigned long flags; int bank_id = GPIO_BANK(gpio); - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id)); val |= BIT(gpio); bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, @@ -111,13 +111,13 @@ static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, unsigned long flags; int bank_id = GPIO_BANK(gpio); - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id)); val &= ~BIT(gpio); bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio) @@ -141,7 +141,7 @@ static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) kona_gpio = gpiochip_get_data(chip); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); /* this function only applies to output pin */ if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN) @@ -154,7 +154,7 @@ static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) writel(val, reg_base + reg_offset); out: - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio) @@ -168,7 +168,7 @@ static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio) kona_gpio = gpiochip_get_data(chip); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN) reg_offset = GPIO_IN_STATUS(bank_id); @@ -178,7 +178,7 @@ static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio) /* read the GPIO bank status */ val = readl(reg_base + reg_offset); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); /* return the specified bit status */ return !!(val & BIT(bit)); @@ -208,14 +208,14 @@ static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) kona_gpio = gpiochip_get_data(chip); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_CONTROL(gpio)); val &= ~GPIO_GPCTR0_IOTR_MASK; val |= GPIO_GPCTR0_IOTR_CMD_INPUT; writel(val, reg_base + GPIO_CONTROL(gpio)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); return 0; } @@ -232,7 +232,7 @@ static int bcm_kona_gpio_direction_output(struct gpio_chip *chip, kona_gpio = gpiochip_get_data(chip); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_CONTROL(gpio)); val &= ~GPIO_GPCTR0_IOTR_MASK; @@ -244,7 +244,7 @@ static int bcm_kona_gpio_direction_output(struct gpio_chip *chip, val |= BIT(bit); writel(val, reg_base + reg_offset); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); return 0; } @@ -288,7 +288,7 @@ static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio, } /* spin lock for read-modify-write of the GPIO register */ - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_CONTROL(gpio)); val &= ~GPIO_GPCTR0_DBR_MASK; @@ -303,7 +303,7 @@ static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio, writel(val, reg_base + GPIO_CONTROL(gpio)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); return 0; } @@ -347,13 +347,13 @@ static void bcm_kona_gpio_irq_ack(struct irq_data *d) kona_gpio = irq_data_get_irq_chip_data(d); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_INT_STATUS(bank_id)); val |= BIT(bit); writel(val, reg_base + GPIO_INT_STATUS(bank_id)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static void bcm_kona_gpio_irq_mask(struct irq_data *d) @@ -368,13 +368,13 @@ static void bcm_kona_gpio_irq_mask(struct irq_data *d) kona_gpio = irq_data_get_irq_chip_data(d); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_INT_MASK(bank_id)); val |= BIT(bit); writel(val, reg_base + GPIO_INT_MASK(bank_id)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static void bcm_kona_gpio_irq_unmask(struct irq_data *d) @@ -389,13 +389,13 @@ static void bcm_kona_gpio_irq_unmask(struct irq_data *d) kona_gpio = irq_data_get_irq_chip_data(d); reg_base = kona_gpio->reg_base; - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_INT_MSKCLR(bank_id)); val |= BIT(bit); writel(val, reg_base + GPIO_INT_MSKCLR(bank_id)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); } static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type) @@ -431,14 +431,14 @@ static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type) return -EINVAL; } - spin_lock_irqsave(&kona_gpio->lock, flags); + raw_spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(reg_base + GPIO_CONTROL(gpio)); val &= ~GPIO_GPCTR0_ITR_MASK; val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT; writel(val, reg_base + GPIO_CONTROL(gpio)); - spin_unlock_irqrestore(&kona_gpio->lock, flags); + raw_spin_unlock_irqrestore(&kona_gpio->lock, flags); return 0; } @@ -655,7 +655,7 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev) bank); } - spin_lock_init(&kona_gpio->lock); + raw_spin_lock_init(&kona_gpio->lock); return 0; -- 2.20.1