Subject: [PATCH v4] pinctrl: mediatek: Implement wake handler and suspend resume

From: [email-masked] (Sudeep Holla)
Date: Tue, 8 Sep 2015 17:50:46 +0100

On 08/09/15 10:28, Sudeep Holla wrote:
>
>
> On 06/09/15 11:39, maoguang meng wrote:
>> On Wed, 2015-09-02 at 14:02 +0800, Daniel Kurtz wrote:
>>> Hi maoguang,
>>>
>>> On Tue, Aug 25, 2015 at 12:27 AM, Sudeep Holla <[email-masked]> wrote:
>>>>
>>>>
>>>> On 14/08/15 09:38, maoguang.meng at mediatek.com wrote:
>>>>>
>>>>> From: Maoguang Meng <[email-masked]>
>>>>>
>>>>> This patch implement irq_set_wake to get who is wakeup source and
>>>>> setup on suspend resume.
>>>>>
>>>>> Signed-off-by: Maoguang Meng <[email-masked]>
>>>>>
>>> [snip]
>>>
>>> Can you please respond to Sudeep's questions:
>>>
>>>> Does this pinmux controller:
>>>>
>>>> 1. Support wake-up configuration ? If not, you need to use
>>>>      IRQCHIP_SKIP_SET_WAKE. I don't see any value in writing the
>>>>      mask_{set,clear} if the same registers are used for {en,dis}able
>>
>>     YES.
>>     we can call enable_irq_wake(irq) to config this irq as a wake-up
>> source.
>>
>
> No that doesn't answer my question. Yes you can always call
> enable_irq_wake(irq) as along as you have irq_set_wake implemented.
> But my question was does this pinmux controller support wake-up
> configuration.
>
> IMHO, by looking at the implementation I can confirm *NO*, it doesn't.
> So please stop copy-pasting the implementation from other drivers.
> The reason is you operate on the same mask_{set,clear} which you use
> to {en,dis}able the interrupts which means you don't have to do anything
> to configure an interrupt as a wakeup source other than just keeping
> them enabled. Hopefully this clarifies.
>
>>>>
>>>> 2. Is in always on domain ? If not, you need save/restore only to
>>>>      resume back the functionality. Generally we can set
>>>>      IRQCHIP_MASK_ON_SUSPEND to ensure non-wake-up interrupts are
>>>>      disabled during suspend and re-enabled in resume path. You just
>>>>      save/restore raw values without tracking the wake-up source.
>>
>>     YES.
>>
>
> Again *YES* for what part of my question. If it's always-on, then you
> don't need this suspend/resume callbacks at all, so I assume the answer
> is *NO*.
>

IIUC this pinmux controller, something like below should work.

---->8

 From 7c26992bce047efb66a6ba8d2ffec2b272499df7 Mon Sep 17 00:00:00 2001
From: Sudeep Holla <[email-masked]>
Date: Tue, 8 Sep 2015 17:35:38 +0100
Subject: [PATCH] pinctrl: mediatek: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND

The mediatek pinmux controller doesn't provides any facility to configure
the wakeup sources. So instead of providing redundant irq_set_wake
functionality, SKIP_SET_WAKE could be set to it. Also there's no need to
maintain 2 sets of masks.

This patch enables IRQCHIP_SKIP_SET_WAKE and IRQCHIP_MASK_ON_SUSPEND and
also removes wake_mask.

Cc: Linus Walleij <[email-masked]>
Cc: Matthias Brugger <[email-masked]>
Cc: Hongzhou Yang <[email-masked]>
Cc: Yingjoe Chen <[email-masked]>
Cc: Maoguang Meng <[email-masked]>
Cc: Chaotian Jing <[email-masked]>
Cc: linux-gpio at vger.kernel.org
Cc: linux-mediatek at lists.infradead.org
Signed-off-by: Sudeep Holla <[email-masked]>
---
  drivers/pinctrl/mediatek/pinctrl-mtk-common.c | 24 
+-----------------------
  drivers/pinctrl/mediatek/pinctrl-mtk-common.h |  1 -
  2 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c 
b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
index 7726c6caaf83..d8e194a5bb31 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common.c
@@ -1063,20 +1063,6 @@ static int mtk_eint_set_type(struct irq_data *d,
  	return 0;
  }

-static int mtk_eint_irq_set_wake(struct irq_data *d, unsigned int on)
-{
-	struct mtk_pinctrl *pctl = irq_data_get_irq_chip_data(d);
-	int shift = d->hwirq & 0x1f;
-	int reg = d->hwirq >> 5;
-
-	if (on)
-		pctl->wake_mask[reg] |= BIT(shift);
-	else
-		pctl->wake_mask[reg] &= ~BIT(shift);
-
-	return 0;
-}
-
  static void mtk_eint_chip_write_mask(const struct mtk_eint_offsets *chip,
  		void __iomem *eint_reg_base, u32 *buf)
  {
@@ -1112,7 +1098,6 @@ static int mtk_eint_suspend(struct device *device)

  	reg = pctl->eint_reg_base;
  	mtk_eint_chip_read_mask(eint_offsets, reg, pctl->cur_mask);
-	mtk_eint_chip_write_mask(eint_offsets, reg, pctl->wake_mask);

  	return 0;
  }
@@ -1153,9 +1138,9 @@ static struct irq_chip mtk_pinctrl_irq_chip = {
  	.irq_unmask = mtk_eint_unmask,
  	.irq_ack = mtk_eint_ack,
  	.irq_set_type = mtk_eint_set_type,
-	.irq_set_wake = mtk_eint_irq_set_wake,
  	.irq_request_resources = mtk_pinctrl_irq_request_resources,
  	.irq_release_resources = mtk_pinctrl_irq_release_resources,
+	.flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
  };

  static unsigned int mtk_eint_init(struct mtk_pinctrl *pctl)
@@ -1393,13 +1378,6 @@ int mtk_pctrl_init(struct platform_device *pdev,
  	}

  	ports_buf = pctl->devdata->eint_offsets.ports;
-	pctl->wake_mask = devm_kcalloc(&pdev->dev, ports_buf,
-					sizeof(*pctl->wake_mask), GFP_KERNEL);
-	if (!pctl->wake_mask) {
-		ret = -ENOMEM;
-		goto chip_error;
-	}
-
  	pctl->cur_mask = devm_kcalloc(&pdev->dev, ports_buf,
  					sizeof(*pctl->cur_mask), GFP_KERNEL);
  	if (!pctl->cur_mask) {
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common.h 
b/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
index 55a534338931..acd804a945d8 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common.h
@@ -267,7 +267,6 @@ struct mtk_pinctrl {
  	void __iomem		*eint_reg_base;
  	struct irq_domain	*domain;
  	int			*eint_dual_edges;
-	u32 *wake_mask;
  	u32 *cur_mask;
  };

-- 
1.9.1