[PATCH 6/6 v6] gpio-pch: Support interrupt function

[Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>]

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
 drivers/gpio/Kconfig    |    1 +
 drivers/gpio/gpio-pch.c |  187 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 188 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2967002..bd64a55 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -352,6 +352,7 @@ config GPIO_LANGWELL
 config GPIO_PCH
 	tristate "Intel EG20T PCH / OKI SEMICONDUCTOR ML7223 IOH GPIO"
 	depends on PCI && X86
+	select GENERIC_IRQ_CHIP
 	help
 	  This driver is for PCH(Platform controller Hub) GPIO of Intel Topcliff
 	  which is an IOH(Input/Output Hub) for x86 embedded processor.
diff --git a/drivers/gpio/gpio-pch.c b/drivers/gpio/gpio-pch.c
index 7f773af..46b5209 100644
--- a/drivers/gpio/gpio-pch.c
+++ b/drivers/gpio/gpio-pch.c
@@ -17,6 +17,17 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#define PCH_EDGE_FALLING	0
+#define PCH_EDGE_RISING		BIT(0)
+#define PCH_LEVEL_L		BIT(1)
+#define PCH_LEVEL_H		(BIT(0) | BIT(1))
+#define PCH_EDGE_BOTH		BIT(2)
+#define PCH_IM_MASK		(BIT(0) | BIT(1) | BIT(2))
+
+#define PCH_IRQ_BASE		24
 
 struct pch_regs {
 	u32	ien;
@@ -50,6 +61,8 @@ static int gpio_pins[] = {
 
 /**
  * struct pch_gpio_reg_data - The register store data.
+ * @ien_reg:	To store contents of IEN register.
+ * @imask_reg:	To store contents of IMASK register.
  * @po_reg:	To store contents of PO register.
  * @pm_reg:	To store contents of PM register.
  * @im0_reg:	To store contents of IM0 register.
@@ -58,6 +71,8 @@ static int gpio_pins[] = {
  *		       (Only ML7223 Bus-n)
  */
 struct pch_gpio_reg_data {
+	u32 ien_reg;
+	u32 imask_reg;
 	u32 po_reg;
 	u32 pm_reg;
 	u32 im0_reg;
@@ -73,6 +88,8 @@ struct pch_gpio_reg_data {
  * @gpio:			Data for GPIO infrastructure.
  * @pch_gpio_reg:		Memory mapped Register data is saved here
  *				when suspend.
+ * @lock:			Used for register access protection
+ * @irq_base:		Save base of IRQ number for interrupt
  * @ioh:		IOH ID
  * @spinlock:		Used for register access protection in
  *				interrupt context pch_irq_mask,
@@ -85,6 +102,7 @@ struct pch_gpio {
 	struct gpio_chip gpio;
 	struct pch_gpio_reg_data pch_gpio_reg;
 	struct mutex lock;
+	int irq_base;
 	enum pch_type_t ioh;
 	spinlock_t spinlock;
 };
@@ -155,6 +173,8 @@ static int pch_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
  */
 static void pch_gpio_save_reg_conf(struct pch_gpio *chip)
 {
+	chip->pch_gpio_reg.ien_reg = ioread32(&chip->reg->ien);
+	chip->pch_gpio_reg.imask_reg = ioread32(&chip->reg->imask);
 	chip->pch_gpio_reg.po_reg = ioread32(&chip->reg->po);
 	chip->pch_gpio_reg.pm_reg = ioread32(&chip->reg->pm);
 	chip->pch_gpio_reg.im0_reg = ioread32(&chip->reg->im0);
@@ -170,6 +190,8 @@ static void pch_gpio_save_reg_conf(struct pch_gpio *chip)
  */
 static void pch_gpio_restore_reg_conf(struct pch_gpio *chip)
 {
+	iowrite32(chip->pch_gpio_reg.ien_reg, &chip->reg->ien);
+	iowrite32(chip->pch_gpio_reg.imask_reg, &chip->reg->imask);
 	/* to store contents of PO register */
 	iowrite32(chip->pch_gpio_reg.po_reg, &chip->reg->po);
 	/* to store contents of PM register */
@@ -182,6 +204,12 @@ static void pch_gpio_restore_reg_conf(struct pch_gpio *chip)
 			  &chip->reg->gpio_use_sel);
 }
 
+static int pch_gpio_to_irq(struct gpio_chip *gpio, unsigned offset)
+{
+	struct pch_gpio *chip = container_of(gpio, struct pch_gpio, gpio);
+	return chip->irq_base + offset;
+}
+
 static void pch_gpio_setup(struct pch_gpio *chip)
 {
 	struct gpio_chip *gpio = &chip->gpio;
@@ -196,6 +224,130 @@ static void pch_gpio_setup(struct pch_gpio *chip)
 	gpio->base = -1;
 	gpio->ngpio = gpio_pins[chip->ioh];
 	gpio->can_sleep = 0;
+	gpio->to_irq = pch_gpio_to_irq;
+}
+
+static int pch_irq_type(struct irq_data *d, unsigned int type)
+{
+	u32 im;
+	u32 *im_reg;
+	u32 ien;
+	u32 im_pos;
+	int ch;
+	unsigned long flags;
+	u32 val;
+	int irq = d->irq;
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct pch_gpio *chip = gc->private;
+
+	ch = irq - chip->irq_base;
+	if (irq <= chip->irq_base + 7) {
+		im_reg = &chip->reg->im0;
+		im_pos = ch;
+	} else {
+		im_reg = &chip->reg->im1;
+		im_pos = ch - 8;
+	}
+	dev_dbg(chip->dev, "%s:irq=%d type=%d ch=%d pos=%d\n",
+		__func__, irq, type, ch, im_pos);
+
+	spin_lock_irqsave(&chip->spinlock, flags);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		val = PCH_EDGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		val = PCH_EDGE_FALLING;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		val = PCH_EDGE_BOTH;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		val = PCH_LEVEL_H;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		val = PCH_LEVEL_L;
+		break;
+	case IRQ_TYPE_PROBE:
+		goto end;
+	default:
+		dev_warn(chip->dev, "%s: unknown type(%dd)",
+			__func__, type);
+		goto end;
+	}
+
+	/* Set interrupt mode */
+	im = ioread32(im_reg) & ~(PCH_IM_MASK << (im_pos * 4));
+	iowrite32(im | (val << (im_pos * 4)), im_reg);
+
+	/* iclr */
+	iowrite32(BIT(ch), &chip->reg->iclr);
+
+	/* IMASKCLR */
+	iowrite32(BIT(ch), &chip->reg->imaskclr);
+
+	/* Enable interrupt */
+	ien = ioread32(&chip->reg->ien);
+	iowrite32(ien | BIT(ch), &chip->reg->ien);
+end:
+	spin_unlock_irqrestore(&chip->spinlock, flags);
+
+	return 0;
+}
+
+static void pch_irq_unmask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct pch_gpio *chip = gc->private;
+
+	iowrite32(1 << (d->irq - chip->irq_base), &chip->reg->imaskclr);
+}
+
+static void pch_irq_mask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct pch_gpio *chip = gc->private;
+
+	iowrite32(1 << (d->irq - chip->irq_base), &chip->reg->imask);
+}
+
+static irqreturn_t pch_gpio_handler(int irq, void *dev_id)
+{
+	struct pch_gpio *chip = dev_id;
+	u32 reg_val = ioread32(&chip->reg->istatus);
+	int i;
+	int ret = IRQ_NONE;
+
+	for (i = 0; i < gpio_pins[chip->ioh]; i++) {
+		if (reg_val & BIT(i)) {
+			dev_dbg(chip->dev, "%s:[%d]:irq=%d  status=0x%x\n",
+				__func__, i, irq, reg_val);
+			iowrite32(BIT(i), &chip->reg->iclr);
+			generic_handle_irq(chip->irq_base + i);
+			ret = IRQ_HANDLED;
+		}
+	}
+	return ret;
+}
+
+static __devinit void pch_gpio_alloc_generic_chip(struct pch_gpio *chip,
+				unsigned int irq_start, unsigned int num)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	gc = irq_alloc_generic_chip("pch_gpio", 1, irq_start, chip->base,
+				    handle_simple_irq);
+	gc->private = chip;
+	ct = gc->chip_types;
+
+	ct->chip.irq_mask = pch_irq_mask;
+	ct->chip.irq_unmask = pch_irq_unmask;
+	ct->chip.irq_set_type = pch_irq_type;
+
+	irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
+			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);
 }
 
 static int __devinit pch_gpio_probe(struct pci_dev *pdev,
@@ -203,6 +355,7 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev,
 {
 	s32 ret;
 	struct pch_gpio *chip;
+	int irq_base;
 
 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 	if (chip == NULL)
@@ -245,8 +398,36 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev,
 		goto err_gpiochip_add;
 	}
 
+	irq_base = irq_alloc_descs(-1, 0, gpio_pins[chip->ioh], GFP_KERNEL);
+	if (irq_base < 0) {
+		dev_warn(&pdev->dev, "PCH gpio: Failed to get IRQ base num\n");
+		chip->irq_base = -1;
+		goto end;
+	}
+	chip->irq_base = irq_base;
+
+	ret = request_irq(pdev->irq, pch_gpio_handler,
+			     IRQF_SHARED, KBUILD_MODNAME, chip);
+	if (ret != 0) {
+		dev_err(&pdev->dev,
+			"%s request_irq failed\n", __func__);
+		goto err_request_irq;
+	}
+
+	pch_gpio_alloc_generic_chip(chip, irq_base, gpio_pins[chip->ioh]);
+
+	/* Initialize interrupt ien register */
+	iowrite32(0, &chip->reg->ien);
+end:
 	return 0;
 
+err_request_irq:
+	irq_free_descs(irq_base, gpio_pins[chip->ioh]);
+
+	ret = gpiochip_remove(&chip->gpio);
+	if (ret)
+		dev_err(&pdev->dev, "%s gpiochip_remove failed\n", __func__);
+
 err_gpiochip_add:
 	pci_iounmap(pdev, chip->base);
 
@@ -267,6 +448,12 @@ static void __devexit pch_gpio_remove(struct pci_dev *pdev)
 	int err;
 	struct pch_gpio *chip = pci_get_drvdata(pdev);
 
+	if (chip->irq_base != -1) {
+		free_irq(pdev->irq, chip);
+
+		irq_free_descs(chip->irq_base, gpio_pins[chip->ioh]);
+	}
+
 	err = gpiochip_remove(&chip->gpio);
 	if (err)
 		dev_err(&pdev->dev, "Failed gpiochip_remove\n");
-- 
1.7.4.4