On Wed, Oct 09, 2019 at 04:30:21PM +0800, Hui Song wrote:
> From: Song Hui <hui.son...@nxp.com>
>
> More than one gpio controllers can share one interrupt, change the
> driver to request shared irq.
>
> While this will work, it will mess up userspace accounting of the number
> of interrupts per second in tools such as vmstat. The reason is that
> for every GPIO interrupt, /proc/interrupts records the count against GIC
> interrupt 68 or 69, as well as the GPIO itself. So, for every GPIO
> interrupt, the total number of interrupts that the system has seen
> increments by two
>
> Signed-off-by: Laurentiu Tudor <laurentiu.tu...@nxp.com>
> Signed-off-by: Alex Marginean <alexandru.margin...@nxp.com>
> Signed-off-by: Song Hui <hui.son...@nxp.com>
> ---
> Changes in v6:
> - change request_irq to devm_request_irq and add commit message.
> Changes in v5:
> - add traverse every bit function.
> Changes in v4:
> - convert 'pr_err' to 'dev_err'.
> Changes in v3:
> - update the patch description.
> Changes in v2:
> - delete the compatible of ls1088a.
>
> drivers/gpio/gpio-mpc8xxx.c | 31 ++++++++++++++++++++-----------
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
> index 16a47de..f0be284 100644
> --- a/drivers/gpio/gpio-mpc8xxx.c
> +++ b/drivers/gpio/gpio-mpc8xxx.c
> @@ -22,6 +22,7 @@
> #include <linux/irq.h>
> #include <linux/gpio/driver.h>
> #include <linux/bitops.h>
> +#include <linux/interrupt.h>
>
> #define MPC8XXX_GPIO_PINS 32
>
> @@ -127,20 +128,20 @@ static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc,
> unsigned offset)
> return -ENXIO;
> }
>
> -static void mpc8xxx_gpio_irq_cascade(struct irq_desc *desc)
> +static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
> {
> - struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
> - struct irq_chip *chip = irq_desc_get_chip(desc);
> + struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
> struct gpio_chip *gc = &mpc8xxx_gc->gc;
> unsigned int mask;
This needs to be "unsigned long mask;" for for_each_set_bit() not to
complain.
> + int i;
>
> mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
> & gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
> - if (mask)
> + for_each_set_bit(i, &mask, 32)
> generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
> - 32 - ffs(mask)));
> - if (chip->irq_eoi)
> - chip->irq_eoi(&desc->irq_data);
> + 31 - i));
> +
> + return IRQ_HANDLED;
> }
>
> static void mpc8xxx_irq_unmask(struct irq_data *d)
> @@ -388,8 +389,8 @@ static int mpc8xxx_probe(struct platform_device *pdev)
>
> ret = gpiochip_add_data(gc, mpc8xxx_gc);
> if (ret) {
> - pr_err("%pOF: GPIO chip registration failed with status %d\n",
> - np, ret);
> + dev_err(&pdev->dev, "%pOF: GPIO chip registration failed with
> status %d\n",
> + np, ret);
> goto err;
> }
>
> @@ -409,8 +410,16 @@ static int mpc8xxx_probe(struct platform_device *pdev)
> if (devtype->gpio_dir_in_init)
> devtype->gpio_dir_in_init(gc);
>
> - irq_set_chained_handler_and_data(mpc8xxx_gc->irqn,
> - mpc8xxx_gpio_irq_cascade, mpc8xxx_gc);
> + ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
> + mpc8xxx_gpio_irq_cascade,
> + IRQF_NO_THREAD | IRQF_SHARED, "gpio-cascade",
> + mpc8xxx_gc);
> + if (ret) {
> + dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret =
> %d\n",
> + np->full_name, mpc8xxx_gc->irqn, ret);
> + goto err;
> + }
> +
> return 0;
> err:
> iounmap(mpc8xxx_gc->regs);
> --
> 2.9.5
>
>
> _______________________________________________
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> linux-arm-ker...@lists.infradead.org
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>
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