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 <dbaryshkov@xxxxxxxxx>
---
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
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