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    Subject[PATCH v3] pch_gpio: Support interrupt function
    Date
    Support interrupt function using irq_chip_generic

    Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
    ---
    drivers/gpio/Kconfig | 1 +
    drivers/gpio/pch_gpio.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++
    2 files changed, 174 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/pch_gpio.c b/drivers/gpio/pch_gpio.c
    index 36919e7..c7fd65d 100644
    --- a/drivers/gpio/pch_gpio.c
    +++ b/drivers/gpio/pch_gpio.c
    @@ -17,10 +17,21 @@
    #include <linux/kernel.h>
    #include <linux/pci.h>
    #include <linux/gpio.h>
    +#include <linux/interrupt.h>
    +#include <linux/irq.h>

    #define PCH_GPIO_ALL_PINS 0xfff /* Mask for GPIO pins 0 to 11 */
    #define GPIO_NUM_PINS 12 /* Specifies number of GPIO PINS GPIO0-GPIO11 */

    +#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 23
    +
    struct pch_regs {
    u32 ien;
    u32 istatus;
    @@ -55,6 +66,10 @@ struct pch_gpio_reg_data {
    * @gpio: Data for GPIO infrastructure.
    * @pch_gpio_reg: Memory mapped Register data is saved here
    * when suspend.
    + * @lock: mutex_lock variable
    + * @irq_base: Save base of IRQ number for interrupt
    + * @spinlock: spin_lock variable
    + * @irq_mask: IRQ mask variable
    */
    struct pch_gpio {
    void __iomem *base;
    @@ -63,6 +78,9 @@ struct pch_gpio {
    struct gpio_chip gpio;
    struct pch_gpio_reg_data pch_gpio_reg;
    struct mutex lock;
    + int irq_base;
    + spinlock_t spinlock;
    + unsigned int irq_mask;
    };

    static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
    @@ -146,6 +164,12 @@ static void pch_gpio_restore_reg_conf(struct pch_gpio *chip)
    iowrite32(chip->pch_gpio_reg.pm_reg, &chip->reg->pm);
    }

    +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;
    @@ -160,6 +184,124 @@ static void pch_gpio_setup(struct pch_gpio *chip)
    gpio->base = -1;
    gpio->ngpio = GPIO_NUM_PINS;
    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);
    +
    + if (type == IRQ_TYPE_EDGE_RISING)
    + val = PCH_EDGE_RISING;
    + else if (type == IRQ_TYPE_EDGE_FALLING)
    + val = PCH_EDGE_FALLING;
    + else if (type == IRQ_TYPE_EDGE_BOTH)
    + val = PCH_EDGE_BOTH;
    + else if (type == IRQ_TYPE_LEVEL_HIGH)
    + val = PCH_LEVEL_L;
    + else if (type == IRQ_TYPE_LEVEL_LOW)
    + val = PCH_LEVEL_H;
    + else if (type == IRQ_TYPE_PROBE)
    + goto end;
    + else {
    + 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;
    +
    + chip->irq_mask |= 1 << (d->irq - chip->irq_base);
    +}
    +
    +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;
    +
    + chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
    +}
    +
    +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_NUM_PINS; i++) {
    + if (reg_val & BIT(i) & chip->irq_mask) {
    + 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,
    @@ -167,6 +309,7 @@ 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)
    @@ -202,8 +345,36 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev,
    goto err_gpiochip_add;
    }

    + irq_base = irq_alloc_descs(-1, PCH_IRQ_BASE, GPIO_NUM_PINS, GFP_KERNEL);
    + if (irq_base < 0) {
    + dev_err(&pdev->dev, "PCH gpio: Failed to get IRQ base num\n");
    + goto err_irq_alloc_descs;
    + }
    + 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_NUM_PINS);
    +
    + /* Initialize interrupt ien register */
    + iowrite32(0, &chip->reg->ien);
    +
    return 0;

    +err_request_irq:
    + irq_free_descs(irq_base, GPIO_NUM_PINS);
    +
    +err_irq_alloc_descs:
    + 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);

    @@ -224,6 +395,8 @@ static void __devexit pch_gpio_remove(struct pci_dev *pdev)
    int err;
    struct pch_gpio *chip = pci_get_drvdata(pdev);

    + irq_free_descs(chip->irq_base, GPIO_NUM_PINS);
    +
    err = gpiochip_remove(&chip->gpio);
    if (err)
    dev_err(&pdev->dev, "Failed gpiochip_remove\n");
    --
    1.7.4.4


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