The WAIT pins support either rising or falling edge interrupts
so add irqchip support to the gpiochip model.

Signed-off-by: Roger Quadros <rog...@ti.com>
---
 drivers/memory/omap-gpmc.c | 132 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index fdf19eeb..764e24a 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -13,6 +13,7 @@
  * published by the Free Software Foundation.
  */
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/err.h>
@@ -227,6 +228,7 @@ struct omap3_gpmc_regs {
 struct gpmc_device {
        struct device *dev;
        struct gpio_chip gpio_chip;
+       struct irq_chip irq_chip;
 };
 
 static struct resource gpmc_mem_root;
@@ -1944,6 +1946,99 @@ err:
        return ret;
 }
 
+static int gpmc_irq_endis(unsigned long hwirq, bool endis)
+{
+       u32 regval;
+
+       /* WAITPIN starts at BIT 8 */
+       hwirq += 8;
+
+       regval = gpmc_read_reg(GPMC_IRQENABLE);
+       if (endis)
+               regval |= BIT(hwirq);
+       else
+               regval &= ~BIT(hwirq);
+       gpmc_write_reg(GPMC_IRQENABLE, regval);
+
+       return 0;
+}
+
+static void gpmc_irq_edge_config(unsigned long hwirq, bool rising_edge)
+{
+       u32 regval;
+
+       /* WAITPIN starts at BIT 8 */
+       hwirq += 8;
+
+       regval = gpmc_read_reg(GPMC_CONFIG);
+       if (rising_edge)
+               regval &= ~BIT(hwirq);
+       else
+               regval |= BIT(hwirq);
+
+       gpmc_write_reg(GPMC_CONFIG, regval);
+}
+
+static void gpmc_irq_mask(struct irq_data *d)
+{
+       gpmc_irq_endis(d->hwirq, false);
+}
+
+static void gpmc_irq_unmask(struct irq_data *d)
+{
+       gpmc_irq_endis(d->hwirq, true);
+}
+
+static void gpmc_irq_ack(struct irq_data *d)
+{
+       unsigned hwirq = d->hwirq + 8;
+
+       /* Setting bit to 1 clears (or Acks) the interrupt */
+       gpmc_write_reg(GPMC_IRQSTATUS, BIT(hwirq));
+}
+
+static int gpmc_irq_set_type(struct irq_data *d, unsigned trigger)
+{
+       /* We can support either rising or falling edge at a time */
+       if (trigger == IRQ_TYPE_EDGE_FALLING)
+               gpmc_irq_edge_config(d->hwirq, false);
+       else if (trigger == IRQ_TYPE_EDGE_RISING)
+               gpmc_irq_edge_config(d->hwirq, true);
+       else
+               return -EINVAL;
+
+       return 0;
+}
+
+static irqreturn_t gpmc_handle_irq(int irq, void *data)
+{
+       int hwirq, virq;
+       u32 regval;
+       struct gpmc_device *gpmc = data;
+
+       regval = gpmc_read_reg(GPMC_IRQSTATUS);
+       regval >>= 8;   /* we're only interested in WAIT pins */
+
+       if (!regval)
+               return IRQ_NONE;
+
+       for (hwirq = 0; hwirq < gpmc->gpio_chip.ngpio; hwirq++) {
+               if (regval & BIT(hwirq)) {
+                       virq = irq_find_mapping(gpmc->gpio_chip.irqdomain,
+                                               hwirq);
+                       if (!virq) {
+                               dev_warn(gpmc_dev,
+                                        "spurious irq detected hwirq %d, virq 
%d\n",
+                                        hwirq, virq);
+                       }
+
+                       generic_handle_irq(virq);
+               }
+       }
+
+       return IRQ_HANDLED;
+}
+
 static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
 {
        return 1;       /* we're input only */
@@ -1978,6 +2073,7 @@ static int gpmc_gpio_get(struct gpio_chip *chip, unsigned 
offset)
 static int gpmc_gpio_init(struct gpmc_device *gpmc)
 {
        int ret;
+       u32 regval;
 
        gpmc->gpio_chip.dev = gpmc->dev;
        gpmc->gpio_chip.owner = THIS_MODULE;
@@ -1996,7 +2092,43 @@ static int gpmc_gpio_init(struct gpmc_device *gpmc)
                return ret;
        }
 
+       /* Disable interrupts */
+       gpmc_write_reg(GPMC_IRQENABLE, 0);
+
+       /* clear interrupts */
+       regval = gpmc_read_reg(GPMC_IRQSTATUS);
+       gpmc_write_reg(GPMC_IRQSTATUS, regval);
+
+       gpmc->irq_chip.name = DEVICE_NAME;
+       gpmc->irq_chip.irq_ack = gpmc_irq_ack;
+       gpmc->irq_chip.irq_mask = gpmc_irq_mask;
+       gpmc->irq_chip.irq_unmask = gpmc_irq_unmask;
+       gpmc->irq_chip.irq_set_type = gpmc_irq_set_type;
+
+       ret = gpiochip_irqchip_add(&gpmc->gpio_chip, &gpmc->irq_chip, 0,
+                                  handle_edge_irq, IRQ_TYPE_NONE);
+
+       if (ret) {
+               dev_err(gpmc->dev, "could not add irqchip to gpiochip: %d\n",
+                       ret);
+               goto fail;
+       }
+
+       /* We're sharing this IRQ with OMAP NAND driver */
+       ret = devm_request_irq(gpmc->dev, gpmc_irq, gpmc_handle_irq,
+                              IRQF_SHARED, DEVICE_NAME, gpmc);
+       if (ret) {
+               dev_err(gpmc->dev, "could not request gpmc irq (%d): %d\n",
+                       gpmc_irq, ret);
+               goto fail;
+       }
+
        return 0;
+
+fail:
+       gpiochip_remove(&gpmc->gpio_chip);
+
+       return ret;
 }
 
 static void gpmc_gpio_exit(struct gpmc_device *gpmc)
-- 
2.1.4

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