[PATCH 14/15] gpio: locomo: implement per-pin irq handling
From: Dmitry Eremin-Solenikov <hidden>
Date: 2014-10-28 00:02:07
LoCoMo has a possibility to generate per-GPIO edge irqs. Support for that was there in old locomo driver, got 'cleaned up' during old driver IRQ cascading cleanup and is now reimplemented. It is expected that SL-5500 (collie) will use locomo gpio irqs for mmc detection irq. Signed-off-by: Dmitry Eremin-Solenikov <redacted> --- drivers/gpio/gpio-locomo.c | 158 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+)
diff --git a/drivers/gpio/gpio-locomo.c b/drivers/gpio/gpio-locomo.c
index 3b54b07..6ef0fc4 100644
--- a/drivers/gpio/gpio-locomo.c
+++ b/drivers/gpio/gpio-locomo.c@@ -18,13 +18,18 @@ #include <linux/gpio.h> #include <linux/io.h> #include <linux/spinlock.h> +#include <linux/irq.h> #include <linux/mfd/locomo.h> +#define LOCOMO_GPIO_NR_IRQS 16 + struct locomo_gpio { void __iomem *regs; + int irq; spinlock_t lock; struct gpio_chip gpio; + int irq_base; u16 rising_edge; u16 falling_edge;
@@ -114,6 +119,148 @@ static int locomo_gpio_direction_output(struct gpio_chip *chip, return 0; } +static int locomo_gpio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio); + + return lg->irq_base + offset; +} + +static void +locomo_gpio_handler(unsigned int irq, struct irq_desc *desc) +{ + u16 req; + struct locomo_gpio *lg = irq_get_handler_data(irq); + int i = lg->irq_base; + + req = readw(lg->regs + LOCOMO_GIR) & + readw(lg->regs + LOCOMO_GPD); + + while (req) { + if (req & 1) + generic_handle_irq(i); + req >>= 1; + i++; + } +} + +static void locomo_gpio_ack_irq(struct irq_data *d) +{ + struct locomo_gpio *lg = irq_data_get_irq_chip_data(d); + unsigned long flags; + u16 r; + + spin_lock_irqsave(&lg->lock, flags); + + r = readw(lg->regs + LOCOMO_GWE); + r |= (0x0001 << (d->irq - lg->irq_base)); + writew(r, lg->regs + LOCOMO_GWE); + + r = readw(lg->regs + LOCOMO_GIS); + r &= ~(0x0001 << (d->irq - lg->irq_base)); + writew(r, lg->regs + LOCOMO_GIS); + + r = readw(lg->regs + LOCOMO_GWE); + r &= ~(0x0001 << (d->irq - lg->irq_base)); + writew(r, lg->regs + LOCOMO_GWE); + + spin_unlock_irqrestore(&lg->lock, flags); +} + +static void locomo_gpio_mask_irq(struct irq_data *d) +{ + struct locomo_gpio *lg = irq_data_get_irq_chip_data(d); + unsigned long flags; + u16 r; + + spin_lock_irqsave(&lg->lock, flags); + + r = readw(lg->regs + LOCOMO_GIE); + r &= ~(0x0001 << (d->irq - lg->irq_base)); + writew(r, lg->regs + LOCOMO_GIE); + + spin_unlock_irqrestore(&lg->lock, flags); +} + +static void locomo_gpio_unmask_irq(struct irq_data *d) +{ + struct locomo_gpio *lg = irq_data_get_irq_chip_data(d); + unsigned long flags; + u16 r; + + spin_lock_irqsave(&lg->lock, flags); + + r = readw(lg->regs + LOCOMO_GIE); + r |= (0x0001 << (d->irq - lg->irq_base)); + writew(r, lg->regs + LOCOMO_GIE); + + spin_unlock_irqrestore(&lg->lock, flags); +} + +static int locomo_gpio_type(struct irq_data *d, unsigned int type) +{ + unsigned int mask; + struct locomo_gpio *lg = irq_data_get_irq_chip_data(d); + unsigned long flags; + + mask = 1 << (d->irq - lg->irq_base); + + if (type = IRQ_TYPE_PROBE) { + if ((lg->rising_edge | lg->falling_edge) & mask) + return 0; + type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING; + } + + if (type & IRQ_TYPE_EDGE_RISING) + lg->rising_edge |= mask; + else + lg->rising_edge &= ~mask; + if (type & IRQ_TYPE_EDGE_FALLING) + lg->falling_edge |= mask; + else + lg->falling_edge &= ~mask; + + spin_lock_irqsave(&lg->lock, flags); + + writew(lg->rising_edge, lg->regs + LOCOMO_GRIE); + writew(lg->falling_edge, lg->regs + LOCOMO_GFIE); + + spin_unlock_irqrestore(&lg->lock, flags); + + return 0; +} + +static struct irq_chip locomo_gpio_chip = { + .name = "LOCOMO-gpio", + .irq_ack = locomo_gpio_ack_irq, + .irq_mask = locomo_gpio_mask_irq, + .irq_unmask = locomo_gpio_unmask_irq, + .irq_set_type = locomo_gpio_type, +}; + +static void locomo_gpio_setup_irq(struct locomo_gpio *lg) +{ + int irq; + + lg->irq_base = irq_alloc_descs(-1, 0, LOCOMO_GPIO_NR_IRQS, -1); + + /* Install handlers for IRQ_LOCOMO_* */ + for (irq = lg->irq_base; + irq < lg->irq_base + LOCOMO_GPIO_NR_IRQS; + irq++) { + irq_set_chip_and_handler(irq, &locomo_gpio_chip, + handle_edge_irq); + irq_set_chip_data(irq, lg); + set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); + } + + /* + * Install handler for IRQ_LOCOMO_HW. + */ + irq_set_handler_data(lg->irq, lg); + irq_set_chained_handler(lg->irq, locomo_gpio_handler); +} + #ifdef CONFIG_PM_SLEEP static int locomo_gpio_suspend(struct device *dev) {
@@ -169,6 +316,10 @@ static int locomo_gpio_probe(struct platform_device *pdev) if (!lg) return -ENOMEM; + lg->irq = platform_get_irq(pdev, 0); + if (lg->irq < 0) + return -ENXIO; + lg->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(lg->regs)) return PTR_ERR(lg->regs);
@@ -189,11 +340,14 @@ static int locomo_gpio_probe(struct platform_device *pdev) lg->gpio.get = locomo_gpio_get; lg->gpio.direction_input = locomo_gpio_direction_input; lg->gpio.direction_output = locomo_gpio_direction_output; + lg->gpio.to_irq = locomo_gpio_to_irq; ret = gpiochip_add(&lg->gpio); if (ret) return ret; + locomo_gpio_setup_irq(lg); + return 0; }
@@ -208,6 +362,10 @@ static int locomo_gpio_remove(struct platform_device *pdev) return ret; } + irq_set_chained_handler(lg->irq, NULL); + irq_set_handler_data(lg->irq, NULL); + irq_free_descs(lg->irq_base, LOCOMO_GPIO_NR_IRQS); + return 0; }
--
2.1.1