gpio-pch: Support interrupt function

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 188 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 04499c19e986..de5fea60b385 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -388,6 +388,7 @@ 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 7f773afeb340..46b5209878f6 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");