diff options
author | Alban Bedel <albeu@free.fr> | 2016-01-28 19:44:32 (GMT) |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2016-02-10 10:15:24 (GMT) |
commit | 2b8f89e19b6d83d97019358328cbed22bbb0505e (patch) | |
tree | 14ee908f82178fd98737beafef94a40141e90dc7 /drivers/gpio/gpio-ath79.c | |
parent | 2f890cf0dfe421ecd2095d8cabb89e7207b499ee (diff) | |
download | linux-2b8f89e19b6d83d97019358328cbed22bbb0505e.tar.xz |
gpio: ath79: Add support for the interrupt controller
Add support for the interrupt controller using GPIOLIB_IRQCHIP.
Both edges isn't supported by the chip and has to be emulated
by switching the polarity on each interrupt.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-ath79.c')
-rw-r--r-- | drivers/gpio/gpio-ath79.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c index 6b15792..0d94c0b 100644 --- a/drivers/gpio/gpio-ath79.c +++ b/drivers/gpio/gpio-ath79.c @@ -15,18 +15,205 @@ #include <linux/gpio/driver.h> #include <linux/platform_data/gpio-ath79.h> #include <linux/of_device.h> +#include <linux/interrupt.h> +#include <linux/irq.h> #define AR71XX_GPIO_REG_OE 0x00 #define AR71XX_GPIO_REG_IN 0x04 #define AR71XX_GPIO_REG_SET 0x0c #define AR71XX_GPIO_REG_CLEAR 0x10 +#define AR71XX_GPIO_REG_INT_ENABLE 0x14 +#define AR71XX_GPIO_REG_INT_TYPE 0x18 +#define AR71XX_GPIO_REG_INT_POLARITY 0x1c +#define AR71XX_GPIO_REG_INT_PENDING 0x20 +#define AR71XX_GPIO_REG_INT_MASK 0x24 + struct ath79_gpio_ctrl { struct gpio_chip gc; void __iomem *base; spinlock_t lock; + unsigned long both_edges; +}; + +static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + + return container_of(gc, struct ath79_gpio_ctrl, gc); +} + +static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg) +{ + return readl(ctrl->base + reg); +} + +static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl, + unsigned reg, u32 val) +{ + return writel(val, ctrl->base + reg); +} + +static bool ath79_gpio_update_bits( + struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits) +{ + u32 old_val, new_val; + + old_val = ath79_gpio_read(ctrl, reg); + new_val = (old_val & ~mask) | (bits & mask); + + if (new_val != old_val) + ath79_gpio_write(ctrl, reg, new_val); + + return new_val != old_val; +} + +static void ath79_gpio_irq_unmask(struct irq_data *data) +{ + struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); + u32 mask = BIT(irqd_to_hwirq(data)); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); + spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static void ath79_gpio_irq_mask(struct irq_data *data) +{ + struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); + u32 mask = BIT(irqd_to_hwirq(data)); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); + spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static void ath79_gpio_irq_enable(struct irq_data *data) +{ + struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); + u32 mask = BIT(irqd_to_hwirq(data)); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); + spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static void ath79_gpio_irq_disable(struct irq_data *data) +{ + struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); + u32 mask = BIT(irqd_to_hwirq(data)); + unsigned long flags; + + spin_lock_irqsave(&ctrl->lock, flags); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0); + spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static int ath79_gpio_irq_set_type(struct irq_data *data, + unsigned int flow_type) +{ + struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); + u32 mask = BIT(irqd_to_hwirq(data)); + u32 type = 0, polarity = 0; + unsigned long flags; + bool disabled; + + switch (flow_type) { + case IRQ_TYPE_EDGE_RISING: + polarity |= mask; + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_EDGE_BOTH: + break; + + case IRQ_TYPE_LEVEL_HIGH: + polarity |= mask; + case IRQ_TYPE_LEVEL_LOW: + type |= mask; + break; + + default: + return -EINVAL; + } + + spin_lock_irqsave(&ctrl->lock, flags); + + if (flow_type == IRQ_TYPE_EDGE_BOTH) { + ctrl->both_edges |= mask; + polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN); + } else { + ctrl->both_edges &= ~mask; + } + + /* As the IRQ configuration can't be loaded atomically we + * have to disable the interrupt while the configuration state + * is invalid. + */ + disabled = ath79_gpio_update_bits( + ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0); + + ath79_gpio_update_bits( + ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type); + ath79_gpio_update_bits( + ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity); + + if (disabled) + ath79_gpio_update_bits( + ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); + + spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static struct irq_chip ath79_gpio_irqchip = { + .name = "gpio-ath79", + .irq_enable = ath79_gpio_irq_enable, + .irq_disable = ath79_gpio_irq_disable, + .irq_mask = ath79_gpio_irq_mask, + .irq_unmask = ath79_gpio_irq_unmask, + .irq_set_type = ath79_gpio_irq_set_type, }; +static void ath79_gpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + struct ath79_gpio_ctrl *ctrl = + container_of(gc, struct ath79_gpio_ctrl, gc); + unsigned long flags, pending; + u32 both_edges, state; + int irq; + + chained_irq_enter(irqchip, desc); + + spin_lock_irqsave(&ctrl->lock, flags); + + pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING); + + /* Update the polarity of the both edges irqs */ + both_edges = ctrl->both_edges & pending; + if (both_edges) { + state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN); + ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY, + both_edges, ~state); + } + + spin_unlock_irqrestore(&ctrl->lock, flags); + + if (pending) { + for_each_set_bit(irq, &pending, gc->ngpio) + generic_handle_irq( + irq_linear_revmap(gc->irqdomain, irq)); + } + + chained_irq_exit(irqchip, desc); +} + static const struct of_device_id ath79_gpio_of_match[] = { { .compatible = "qca,ar7100-gpio" }, { .compatible = "qca,ar9340-gpio" }, @@ -95,7 +282,25 @@ static int ath79_gpio_probe(struct platform_device *pdev) return err; } + if (np && !of_property_read_bool(np, "interrupt-controller")) + return 0; + + err = gpiochip_irqchip_add(&ctrl->gc, &ath79_gpio_irqchip, 0, + handle_simple_irq, IRQ_TYPE_NONE); + if (err) { + dev_err(&pdev->dev, "failed to add gpiochip_irqchip\n"); + goto gpiochip_remove; + } + + gpiochip_set_chained_irqchip(&ctrl->gc, &ath79_gpio_irqchip, + platform_get_irq(pdev, 0), + ath79_gpio_irq_handler); + return 0; + +gpiochip_remove: + gpiochip_remove(&ctrl->gc); + return err; } static int ath79_gpio_remove(struct platform_device *pdev) |