Re: [PATCH V2] pinctrl: add AMD GPIO driver support.

On Mon, 2015-03-09 at 16:02 +0100, Linus Walleij wrote:

On Wed, Mar 4, 2015 at 7:53 AM, Ken Xue [off-list ref] wrote:

quoted

From c2258b4b550d8f61a5eb64fee25d4c0fdd3a1e91 Mon Sep 17 00:00:00 2001
From: Ken Xue <redacted>
Date: Wed, 4 Mar 2015 14:48:36 +0800
Subject: [PATCH] pinctrl: add AMD GPIO driver support.

KERNCZ GPIO is a new IP from AMD. it can be implemented in both x86 and ARM.
Current driver patch only support GPIO in x86.

Signed-off-by: Ken Xue <redacted>

quoted

+#include <linux/io.h>
+#include <linux/gpio.h>

Should still be #include <linux/gpio/driver.h>
isn't it compiling like so?

ok. i will change <linux/gpio.h> to <linux/gpio/driver.h>.
And then i shall add <linux/pinctrl/pinctrl.h> for macro PINCTRL_PIN and
add <asm-generic/gpio.h> for "gpiochip_add_pin_range".

quoted

+static void amd_gpio_irq_mask(struct irq_data *d)
+{
+       u32 pin_reg;
+       unsigned long flags;
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct amd_gpio *gpio_dev = to_amd_gpio(gc);
+
+       spin_lock_irqsave(&gpio_dev->lock, flags);
+       pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
+       pin_reg &= ~(1UL << INTERRUPT_MASK_OFF);
+       writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
+       spin_unlock_irqrestore(&gpio_dev->lock, flags);
+}
+
+static void amd_gpio_irq_unmask(struct irq_data *d)
+{
+       u32 pin_reg;
+       unsigned long flags;
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct amd_gpio *gpio_dev = to_amd_gpio(gc);
+
+       spin_lock_irqsave(&gpio_dev->lock, flags);
+       pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
+       pin_reg |= 1UL << INTERRUPT_MASK_OFF;
+       writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
+       spin_unlock_irqrestore(&gpio_dev->lock, flags);
+}

I don't know if it's necessary to implement both enable/disable
and mask/unmask. I guess you should only mask in the
mask() function and only enable in the enable() function then.

AMD GPIO interrupt is masked by default. I want to unmask GPIO interrupt
when irq is enabled. So that, interrupt can work right after driver
request_threaded_irq.