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Message-ID: <621878fea57e70d56640bf6c50f4b723624060ee.camel@mediatek.com>
Date: Tue, 19 Jul 2022 18:35:03 +0800
From: Axe Yang <axe.yang@...iatek.com>
To: Ulf Hansson <ulf.hansson@...aro.org>
CC: Rob Herring <robh+dt@...nel.org>,
Chaotian Jing <chaotian.jing@...iatek.com>,
Matthias Brugger <matthias.bgg@...il.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
Satya Tangirala <satyat@...gle.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Lucas Stach <dev@...xeye.de>,
"Eric Biggers" <ebiggers@...gle.com>,
Andrew Jeffery <andrew@...id.au>,
"Stephen Boyd" <swboyd@...omium.org>,
Kiwoong Kim <kwmad.kim@...sung.com>,
Yue Hu <huyue2@...ong.com>, Tian Tao <tiantao6@...ilicon.com>,
<angelogioacchino.delregno@...labora.com>,
<linux-mmc@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>,
<Project_Global_Chrome_Upstream_Group@...iatek.com>,
Yong Mao <yong.mao@...iatek.com>
Subject: Re: [PATCH v13 3/3] mmc: mediatek: add support for SDIO eint wakup
IRQ
On Mon, 2022-07-18 at 14:21 +0200, Ulf Hansson wrote:
> On Thu, 23 Jun 2022 at 11:05, Axe Yang <axe.yang@...iatek.com> wrote:
> >
> > Add support for eint IRQ when MSDC is used as an SDIO host. This
> > feature requires SDIO device support async IRQ function. With this
> > feature, SDIO host can be awakened by SDIO card in suspend state,
> > without additional pin.
> >
> > MSDC driver will time-share the SDIO DAT1 pin. During suspend, MSDC
> > turn off clock and switch SDIO DAT1 pin to GPIO mode. And during
> > resume, switch GPIO function back to DAT1 mode then turn on clock.
> >
> > Some device tree property should be added or modified in MSDC node
> > to support SDIO eint IRQ. Pinctrls "state_eint" is mandatory. Since
> > this feature depends on asynchronous interrupts, "wakeup-source",
> > "keep-power-in-suspend" and "cap-sdio-irq" flags are necessary, and
> > the interrupts list should be extended(the interrupt named with
> > sdio_wakeup):
> > &mmcX {
> > ...
> > interrupt-names = "msdc", "sdio_wakeup";
> > interrupts-extended = <...>,
> > <&pio xxx
> > IRQ_TYPE_LEVEL_LOW>;
> > ...
> > pinctrl-names = "default", "state_uhs",
> > "state_eint";
> > ...
> > pinctrl-2 = <&mmc2_pins_eint>;
> > ...
> > cap-sdio-irq;
> > keep-power-in-suspend;
> > wakeup-source;
> > ...
> > };
> >
> > Co-developed-by: Yong Mao <yong.mao@...iatek.com>
> > Signed-off-by: Yong Mao <yong.mao@...iatek.com>
> > Signed-off-by: Axe Yang <axe.yang@...iatek.com>
>
> My apologies for the delay in reviewing this.
It is okay. Glad to receive your reply.
>
> > ---
> > drivers/mmc/host/mtk-sd.c | 84
> > ++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 78 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> > index 195dc897188b..f907b96cfd87 100644
> > --- a/drivers/mmc/host/mtk-sd.c
> > +++ b/drivers/mmc/host/mtk-sd.c
> > @@ -1,6 +1,6 @@
> > // SPDX-License-Identifier: GPL-2.0-only
> > /*
> > - * Copyright (c) 2014-2015 MediaTek Inc.
> > + * Copyright (c) 2014-2015, 2022 MediaTek Inc.
> > * Author: Chaotian.Jing <chaotian.jing@...iatek.com>
> > */
> >
> > @@ -20,6 +20,7 @@
> > #include <linux/platform_device.h>
> > #include <linux/pm.h>
> > #include <linux/pm_runtime.h>
> > +#include <linux/pm_wakeirq.h>
> > #include <linux/regulator/consumer.h>
> > #include <linux/slab.h>
> > #include <linux/spinlock.h>
> > @@ -440,8 +441,10 @@ struct msdc_host {
> > struct pinctrl *pinctrl;
> > struct pinctrl_state *pins_default;
> > struct pinctrl_state *pins_uhs;
> > + struct pinctrl_state *pins_eint;
> > struct delayed_work req_timeout;
> > int irq; /* host interrupt */
> > + int eint_irq; /* interrupt from sdio device for
> > waking up system */
> > struct reset_control *reset;
> >
> > struct clk *src_clk; /* msdc source clock */
> > @@ -1520,17 +1523,46 @@ static void __msdc_enable_sdio_irq(struct
> > msdc_host *host, int enb)
> >
> > static void msdc_enable_sdio_irq(struct mmc_host *mmc, int enb)
> > {
> > - unsigned long flags;
> > struct msdc_host *host = mmc_priv(mmc);
> > + unsigned long flags;
> > + int ret;
> >
> > spin_lock_irqsave(&host->lock, flags);
> > __msdc_enable_sdio_irq(host, enb);
> > spin_unlock_irqrestore(&host->lock, flags);
> >
> > - if (enb)
> > - pm_runtime_get_noresume(host->dev);
> > - else
> > - pm_runtime_put_noidle(host->dev);
> > + if (mmc_card_enable_async_irq(mmc->card) && host-
> > >pins_eint) {
> > + if (enb) {
> > + /*
> > + * In
> > dev_pm_set_dedicated_wake_irq_reverse(), eint pin will be set to
> > + * GPIO mode. We need to restore it to SDIO
> > DAT1 mode after that.
> > + * Since the current pinstate is pins_uhs,
> > to ensure pinctrl select take
> > + * affect successfully, we change the
> > pinstate to pins_eint firstly.
> > + */
> > + pinctrl_select_state(host->pinctrl, host-
> > >pins_eint);
>
> I am sorry, but I don't understand what goes on here. Why do you need
> to change the pinctrl setting to "pins_eint" here?
>
> The bellow call to dev_pm_set_dedicated_wake_irq_reverse() doesn't
> change the pinctrl setting as the comment suggests above.
>
Actually, the pinctrl setting is changed:
In dev_pm_set_dedicated_wake_irq_reverse() -> ... ->
request_threaded_irq() -> __setup_irq() -> irq_request_resources() ->
mtk_eint_irq_request_resources()-> mtk_xt_set_gpio_as_eint(), the SDIO
DAT1 pin will be force reset to GPIO mode:
https://elixir.bootlin.com/linux/latest/source/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c#L339
So, I have to call pinctrl_select_state() to restore SDIO DAT1 pin
mode(pins_uhs). But pinctrl_select_state() return directly because MSDC
driver still wrongly thinks current DAT1 state is SDIO DAT1 mode:
https://elixir.bootlin.com/linux/latest/source/drivers/pinctrl/core.c#L1344
, which means I have to call pinctrl_select_state() in pairs: Change
pinctrl to another state(pins_eint), then change it back to pins_uhs
mode.
> dev_pm_set_dedicated_wake_irq_reverse() will register the wakeirq,
> but
> more importantly, it should also leave the wakeirq disabled, right?
Yes. wakeirq will be registered, and disabled. But SDIO DAT1 pin mode
will be changed too.
>
> > + ret =
> > dev_pm_set_dedicated_wake_irq_reverse(host->dev, host->eint_irq);
> > +
> > + if (ret) {
> > + dev_err(host->dev, "Failed to
> > register SDIO wakeup irq!\n");
> > + host->pins_eint = NULL;
> > + pm_runtime_get_noresume(host->dev);
> > + } else {
> > + dev_dbg(host->dev, "SDIO eint irq:
> > %d!\n", host->eint_irq);
> > + }
> > +
> > + pinctrl_select_state(host->pinctrl, host-
> > >pins_uhs);
>
> According to my comment above, I also don't understand why you need
> this. Why can't you just leave the pinctrl in the "pins_uhs" state?
>
I have to call pinctrl_select_state() in pairs.
> > + } else {
> > + dev_pm_clear_wake_irq(host->dev);
> > + }
> > + } else {
> > + if (enb) {
> > + /* Ensure host->pins_eint is NULL */
> > + host->pins_eint = NULL;
> > + pm_runtime_get_noresume(host->dev);
> > + } else {
> > + pm_runtime_put_noidle(host->dev);
> > + }
> > + }
> > }
> >
> > static irqreturn_t msdc_cmdq_irq(struct msdc_host *host, u32
> > intsts)
> > @@ -2631,6 +2663,20 @@ static int msdc_drv_probe(struct
> > platform_device *pdev)
> > goto host_free;
> > }
> >
> > + /* Support for SDIO eint irq ? */
> > + if ((mmc->pm_caps & MMC_PM_WAKE_SDIO_IRQ) && (mmc->pm_caps
> > & MMC_PM_KEEP_POWER)) {
> > + host->eint_irq = platform_get_irq_byname(pdev,
> > "sdio_wakeup");
> > + if (host->eint_irq > 0) {
> > + host->pins_eint =
> > pinctrl_lookup_state(host->pinctrl, "state_eint");
> > + if (IS_ERR(host->pins_eint)) {
> > + dev_err(&pdev->dev, "Cannot find
> > pinctrl eint!\n");
> > + host->pins_eint = NULL;
> > + } else {
> > + device_init_wakeup(&pdev->dev,
> > true);
> > + }
> > + }
> > + }
> > +
> > msdc_of_property_parse(pdev, host);
> >
> > host->dev = &pdev->dev;
> > @@ -2845,6 +2891,13 @@ static int __maybe_unused
> > msdc_runtime_suspend(struct device *dev)
> > struct msdc_host *host = mmc_priv(mmc);
> >
> > msdc_save_reg(host);
> > +
> > + if (host->pins_eint) {
> > + disable_irq(host->irq);
> > + pinctrl_select_state(host->pinctrl, host-
> > >pins_eint);
> > + if (sdio_irq_claimed(mmc))
> > + __msdc_enable_sdio_irq(host, 0);
> > + }
>
> This above code isn't entirely correct. Just because you have
> "pins_eint", doesn't mean that you have a wakeirq being registered,
> as
> that also depends on whether there is an SDIO irq claimed.
>
> So, I think this should rather be:
>
> if (sdio_irq_claimed(mmc)) {
> if (host->pins_eint) {
> disable_irq(host->irq);
> pinctrl_select_state(host->pinctrl, host->pins_eint);
> }
>
> __msdc_enable_sdio_irq(host, 0);
> }
>
Agree, will adjust the logic in next version. Thanks.
> > msdc_gate_clock(host);
> > return 0;
> > }
> > @@ -2860,12 +2913,18 @@ static int __maybe_unused
> > msdc_runtime_resume(struct device *dev)
> > return ret;
> >
> > msdc_restore_reg(host);
> > +
> > + if (host->pins_eint) {
>
> Similar comment as above. You need to check sdio_irq_claimed() here
> too.
Okay.
>
> > + pinctrl_select_state(host->pinctrl, host-
> > >pins_uhs);
> > + enable_irq(host->irq);
> > + }
> > return 0;
> > }
> >
> > static int __maybe_unused msdc_suspend(struct device *dev)
> > {
> > struct mmc_host *mmc = dev_get_drvdata(dev);
> > + struct msdc_host *host = mmc_priv(mmc);
> > int ret;
> >
> > if (mmc->caps2 & MMC_CAP2_CQE) {
> > @@ -2874,11 +2933,24 @@ static int __maybe_unused
> > msdc_suspend(struct device *dev)
> > return ret;
> > }
> >
> > + /*
> > + * Bump up runtime PM usage counter otherwise dev-
> > >power.needs_force_resume will
> > + * not be marked as 1, pm_runtime_force_resume() will go
> > out directly.
> > + */
> > + if (host->pins_eint)
>
> This works, but can be improved by checking sdio_irq_claimed() too.
Sure. Will update it in next version.
>
> > + pm_runtime_get_noresume(dev);
> > +
> > return pm_runtime_force_suspend(dev);
> > }
> >
> > static int __maybe_unused msdc_resume(struct device *dev)
> > {
> > + struct mmc_host *mmc = dev_get_drvdata(dev);
> > + struct msdc_host *host = mmc_priv(mmc);
> > +
> > + if (host->pins_eint)
> > + pm_runtime_put_noidle(dev);
>
> Ditto.
Will update it in next version.
>
> > +
> > return pm_runtime_force_resume(dev);
> > }
> >
>
> Kind regards
> Uffe
Regards,
Axe
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