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Date: Fri, 27 May 2011 01:08:33 -0600
From: Grant Likely <grant.likely@...retlab.ca>
To: Tomoya MORINAGA <tomoya-linux@....okisemi.com>
Cc: linux-kernel@...r.kernel.org,
alexander.stein@...tec-electronic.com, qi.wang@...el.com,
yong.y.wang@...el.com, joel.clark@...el.com,
kok.howg.ewe@...el.com, toshiharu-linux@....okisemi.com
Subject: Re: [PATCH v2 3/3] pch_gpio: support interrupt function
On Fri, May 27, 2011 at 02:04:51PM +0900, Tomoya MORINAGA wrote:
> Support interrupt function.
>
> Signed-off-by: Tomoya MORINAGA <tomoya-linux@....okisemi.com>
> ---
> drivers/gpio/Kconfig | 2 +-
> drivers/gpio/pch_gpio.c | 153 +++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 154 insertions(+), 1 deletions(-)
>
Hi Tomoya,
Comments below.
g.
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index c0326da..6e0f1a2 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -329,7 +329,7 @@ config GPIO_LANGWELL
> Say Y here to support Intel Langwell/Penwell GPIO.
>
> config GPIO_PCH
> - tristate "Intel EG20T PCH / OKI SEMICONDUCTOR ML7223 IOH GPIO"
> + bool "Intel EG20T PCH / OKI SEMICONDUCTOR ML7223 IOH GPIO"
> depends on PCI && X86
> help
> This driver is for PCH(Platform controller Hub) GPIO of Intel Topcliff
> diff --git a/drivers/gpio/pch_gpio.c b/drivers/gpio/pch_gpio.c
> index b46c2bd..92d7523 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 +66,7 @@ struct pch_gpio_reg_data {
> * @gpio: Data for GPIO infrastructure.
> * @pch_gpio_reg: Memory mapped Register data is saved here
> * when suspend.
> + * @lock: spin_lock variable
> */
> struct pch_gpio {
> void __iomem *base;
> @@ -63,6 +75,8 @@ struct pch_gpio {
> struct gpio_chip gpio;
> struct pch_gpio_reg_data pch_gpio_reg;
> struct mutex lock;
> + int irq_base;
> + spinlock_t spinlock;
> };
>
> static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
> @@ -146,6 +160,12 @@ 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 +180,102 @@ 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 pch_gpio *chip = irq_data_get_irq_chip_data(d);
> +
> + 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)
> +{
> +}
> +
> +static void pch_irq_mask(struct irq_data *d)
> +{
> +}
These cannot be empty. Otherwise Linux has no way to tell incoming
irqs to go away while it is handling them.
> +
> +static struct irq_chip pch_irqchip = {
> + .name = "PCH-GPIO",
> + .irq_mask = pch_irq_mask,
> + .irq_unmask = pch_irq_unmask,
> + .irq_set_type = pch_irq_type,
> +};
> +
> +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)) {
> + 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 int __devinit pch_gpio_probe(struct pci_dev *pdev,
> @@ -167,6 +283,8 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev,
> {
> s32 ret;
> struct pch_gpio *chip;
> + int irq_base;
> + int i;
>
> chip = kzalloc(sizeof(*chip), GFP_KERNEL);
> if (chip == NULL)
> @@ -202,8 +320,41 @@ 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;
> + }
> +
> + for (i = 0; i < GPIO_NUM_PINS; i++) {
> + irq_set_chip_and_handler(i + irq_base, &pch_irqchip,
> + handle_simple_irq);
> + irq_set_chip_data(i + irq_base, chip);
> + }
> +
> + /* Initialize interrupt ien register */
> + iowrite32(0, &chip->reg->ien);
> +
Take a look at the new irq_chip_generic infrastructure. You don't
need to implement a memory mapped irq controller from scratch anymore.
Most of the access functions can be taken directly from
irq_chip_generic instead.
> 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 +375,8 @@ 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
>
--
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