2022-01-11 01:41:04

by Axe Yang (杨磊)

[permalink] [raw]
Subject: [PATCH v2 0/3]mmc: mediatek: add support for SDIO async irq

Change in v2:
- change flag name from 'cap-sdio-async-int' to 'cap-sdio-async-irq'
- change corresponding macro names from xxx_INT to xxx_IRQ
- resort new member in msdc_host structure
- refine function msdc_request_dat1_eint_irq()
- rename msdc_{suspend,resume} function names, add suffix '_noirq'
- add MMC_CAP2_NO_SDIO judgement before parse eint related pin setting

Axe Yang (3):
dt-bindings: mmc: add cap-sdio-async-irq flag
mmc: core: Add support for SDIO async interrupt
mmc: mediatek: add support for SDIO eint irq

.../bindings/mmc/mmc-controller.yaml | 5 +
drivers/mmc/core/host.c | 2 +
drivers/mmc/core/sdio.c | 17 +++
drivers/mmc/host/mtk-sd.c | 124 ++++++++++++++++--
include/linux/mmc/card.h | 3 +-
include/linux/mmc/host.h | 1 +
include/linux/mmc/sdio.h | 5 +
7 files changed, 148 insertions(+), 9 deletions(-)

--
2.18.0



2022-01-11 01:41:10

by Axe Yang (杨磊)

[permalink] [raw]
Subject: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

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 named state_dat1 and state_eint
are mandatory. And cap-sdio-async-irq flag is necessary since this
feature depends on asynchronous interrupt:
&mmcX {
...
pinctrl-names = "default", "state_uhs", "state_eint",
"state_dat1";
...
pinctrl-2 = <&mmc2_pins_eint>;
pinctrl-3 = <&mmc2_pins_dat1>;
...
cap-sdio-async-irq;
...
};

Signed-off-by: Axe Yang <[email protected]>
---
drivers/mmc/host/mtk-sd.c | 124 +++++++++++++++++++++++++++++++++++---
1 file changed, 116 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 65037e1d7723..d78e05c89c29 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) 2014-2022 MediaTek Inc.
* Author: Chaotian.Jing <[email protected]>
*/

@@ -9,6 +9,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
+#include <linux/gpio/consumer.h>
#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/irq.h>
@@ -440,8 +441,12 @@ struct msdc_host {
struct pinctrl *pinctrl;
struct pinctrl_state *pins_default;
struct pinctrl_state *pins_uhs;
+ struct pinctrl_state *pins_eint;
+ struct pinctrl_state *pins_dat1;
struct delayed_work req_timeout;
int irq; /* host interrupt */
+ int eint_irq; /* device interrupt */
+ int sdio_irq_cnt; /* irq enable cnt */
struct reset_control *reset;

struct clk *src_clk; /* msdc source clock */
@@ -465,6 +470,7 @@ struct msdc_host {
bool hs400_tuning; /* hs400 mode online tuning */
bool internal_cd; /* Use internal card-detect logic */
bool cqhci; /* support eMMC hw cmdq */
+ bool sdio_eint_ready; /* Ready to support SDIO eint interrupt */
struct msdc_save_para save_para; /* used when gate HCLK */
struct msdc_tune_para def_tune_para; /* default tune setting */
struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
@@ -1527,10 +1533,12 @@ static void msdc_enable_sdio_irq(struct mmc_host *mmc, int enb)
__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 && !mmc->card->cccr.enable_async_irq) {
+ if (enb)
+ 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)
@@ -2461,6 +2469,49 @@ static const struct mmc_host_ops mt_msdc_ops = {
.hw_reset = msdc_hw_reset,
};

+static irqreturn_t msdc_sdio_eint_irq(int irq, void *dev_id)
+{
+ unsigned long flags;
+ struct msdc_host *host = (struct msdc_host *)dev_id;
+ struct mmc_host *mmc = mmc_from_priv(host);
+
+ spin_lock_irqsave(&host->lock, flags);
+ if (likely(host->sdio_irq_cnt > 0)) {
+ disable_irq_nosync(host->eint_irq);
+ disable_irq_wake(host->eint_irq);
+ host->sdio_irq_cnt--;
+ }
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ sdio_signal_irq(mmc);
+
+ return IRQ_HANDLED;
+}
+
+static int msdc_request_dat1_eint_irq(struct msdc_host *host)
+{
+ struct gpio_desc *desc;
+ int irq, ret;
+
+ desc = devm_gpiod_get(host->dev, "eint", GPIOD_IN);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ ret = gpiod_to_irq(desc);
+ if (ret < 0)
+ return ret;
+
+ irq = ret;
+ ret = devm_request_threaded_irq(host->dev, irq, NULL, msdc_sdio_eint_irq,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_NO_AUTOEN,
+ "sdio-eint", host);
+
+ if (!ret)
+ host->eint_irq = irq;
+
+ return ret;
+}
+
static const struct cqhci_host_ops msdc_cmdq_ops = {
.enable = msdc_cqe_enable,
.disable = msdc_cqe_disable,
@@ -2631,6 +2682,23 @@ static int msdc_drv_probe(struct platform_device *pdev)
goto host_free;
}

+ if (!(mmc->caps2 & MMC_CAP2_NO_SDIO)) {
+ /* Support for SDIO eint irq */
+ host->pins_eint = pinctrl_lookup_state(host->pinctrl, "state_eint");
+ if (IS_ERR(host->pins_eint)) {
+ dev_dbg(&pdev->dev, "Cannot find pinctrl eint!\n");
+ } else {
+ host->pins_dat1 = pinctrl_lookup_state(host->pinctrl, "state_dat1");
+ if (IS_ERR(host->pins_dat1)) {
+ ret = dev_err_probe(&pdev->dev, PTR_ERR(host->pins_dat1),
+ "Cannot find pinctrl dat1!\n");
+ goto host_free;
+ }
+
+ host->sdio_eint_ready = true;
+ }
+ }
+
msdc_of_property_parse(pdev, host);

host->dev = &pdev->dev;
@@ -2722,6 +2790,16 @@ static int msdc_drv_probe(struct platform_device *pdev)
if (ret)
goto release;

+ if (host->sdio_eint_ready) {
+ ret = msdc_request_dat1_eint_irq(host);
+ if (ret) {
+ dev_err(host->dev, "Failed to register data1 eint irq!\n");
+ goto release;
+ }
+
+ pinctrl_select_state(host->pinctrl, host->pins_dat1);
+ }
+
pm_runtime_set_active(host->dev);
pm_runtime_set_autosuspend_delay(host->dev, MTK_MMC_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(host->dev);
@@ -2841,16 +2919,31 @@ static void msdc_restore_reg(struct msdc_host *host)

static int __maybe_unused msdc_runtime_suspend(struct device *dev)
{
+ unsigned long flags;
struct mmc_host *mmc = dev_get_drvdata(dev);
struct msdc_host *host = mmc_priv(mmc);

msdc_save_reg(host);
+
+ if (host->sdio_eint_ready) {
+ disable_irq(host->irq);
+ pinctrl_select_state(host->pinctrl, host->pins_eint);
+ spin_lock_irqsave(&host->lock, flags);
+ if (host->sdio_irq_cnt == 0) {
+ enable_irq(host->eint_irq);
+ enable_irq_wake(host->eint_irq);
+ host->sdio_irq_cnt++;
+ }
+ sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+ spin_unlock_irqrestore(&host->lock, flags);
+ }
msdc_gate_clock(host);
return 0;
}

static int __maybe_unused msdc_runtime_resume(struct device *dev)
{
+ unsigned long flags;
struct mmc_host *mmc = dev_get_drvdata(dev);
struct msdc_host *host = mmc_priv(mmc);
int ret;
@@ -2860,10 +2953,25 @@ static int __maybe_unused msdc_runtime_resume(struct device *dev)
return ret;

msdc_restore_reg(host);
+
+ if (host->sdio_eint_ready) {
+ spin_lock_irqsave(&host->lock, flags);
+ if (host->sdio_irq_cnt > 0) {
+ disable_irq_nosync(host->eint_irq);
+ disable_irq_wake(host->eint_irq);
+ host->sdio_irq_cnt--;
+ sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+ } else {
+ sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_SDIOIRQ);
+ }
+ spin_unlock_irqrestore(&host->lock, flags);
+ pinctrl_select_state(host->pinctrl, host->pins_uhs);
+ enable_irq(host->irq);
+ }
return 0;
}

-static int __maybe_unused msdc_suspend(struct device *dev)
+static int __maybe_unused msdc_suspend_noirq(struct device *dev)
{
struct mmc_host *mmc = dev_get_drvdata(dev);
int ret;
@@ -2877,13 +2985,13 @@ static int __maybe_unused msdc_suspend(struct device *dev)
return pm_runtime_force_suspend(dev);
}

-static int __maybe_unused msdc_resume(struct device *dev)
+static int __maybe_unused msdc_resume_noirq(struct device *dev)
{
return pm_runtime_force_resume(dev);
}

static const struct dev_pm_ops msdc_dev_pm_ops = {
- SET_SYSTEM_SLEEP_PM_OPS(msdc_suspend, msdc_resume)
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(msdc_suspend_noirq, msdc_resume_noirq)
SET_RUNTIME_PM_OPS(msdc_runtime_suspend, msdc_runtime_resume, NULL)
};

--
2.25.1


2022-01-11 11:48:25

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:
> Add support for eint irq when MSDC is used as an SDIO host. This

IRQ

> feature requires SDIO device support async irq function. With this

IRQ

> feature,SDIO host can be awakened by SDIO card in suspend state,

feature, SDIO

> 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

MSDC

> to support SDIO eint irq. Pinctrls named state_dat1 and state_eint

IRQ

> are mandatory. And cap-sdio-async-irq flag is necessary since this
> feature depends on asynchronous interrupt:
> &mmcX {
> ...
> pinctrl-names = "default", "state_uhs", "state_eint",
> "state_dat1";
> ...
> pinctrl-2 = <&mmc2_pins_eint>;
> pinctrl-3 = <&mmc2_pins_dat1>;
> ...
> cap-sdio-async-irq;
> ...
> };

...

> - * Copyright (c) 2014-2015 MediaTek Inc.
> + * Copyright (c) 2014-2022 MediaTek Inc.

Shouldn't it be rather like

* Copyright (c) 2014-2015,2022 MediaTek Inc.

?

...

> +static irqreturn_t msdc_sdio_eint_irq(int irq, void *dev_id)
> +{
> + unsigned long flags;
> + struct msdc_host *host = (struct msdc_host *)dev_id;

No casting is needed.

> + struct mmc_host *mmc = mmc_from_priv(host);

Perhaps reversed xmas tree order

struct msdc_host *host = dev_id;
struct mmc_host *mmc = mmc_from_priv(host);
unsigned long flags;

?

But hey, why do you need flags?

> + spin_lock_irqsave(&host->lock, flags);
> + if (likely(host->sdio_irq_cnt > 0)) {
> + disable_irq_nosync(host->eint_irq);
> + disable_irq_wake(host->eint_irq);
> + host->sdio_irq_cnt--;
> + }
> + spin_unlock_irqrestore(&host->lock, flags);
> +
> + sdio_signal_irq(mmc);
> +
> + return IRQ_HANDLED;
> +}

...

> +static int msdc_request_dat1_eint_irq(struct msdc_host *host)
> +{
> + struct gpio_desc *desc;
> + int irq, ret;
> +
> + desc = devm_gpiod_get(host->dev, "eint", GPIOD_IN);
> + if (IS_ERR(desc))
> + return PTR_ERR(desc);
> +
> + ret = gpiod_to_irq(desc);
> + if (ret < 0)
> + return ret;
> +
> + irq = ret;
> + ret = devm_request_threaded_irq(host->dev, irq, NULL, msdc_sdio_eint_irq,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_NO_AUTOEN,
> + "sdio-eint", host);

> +

Redundant blank line.

> + if (!ret)
> + host->eint_irq = irq;
> +
> + return ret;

I guess I have already commented on this, i.e. use standard pattern

if (ret)
return ret;

...
return 0;

> +}

...

> + host->pins_eint = pinctrl_lookup_state(host->pinctrl, "state_eint");
> + if (IS_ERR(host->pins_eint)) {

> + dev_dbg(&pdev->dev, "Cannot find pinctrl eint!\n");

In debug mode of pin control this will bring a duplicate message.

> + } else {
> + host->pins_dat1 = pinctrl_lookup_state(host->pinctrl, "state_dat1");
> + if (IS_ERR(host->pins_dat1)) {
> + ret = dev_err_probe(&pdev->dev, PTR_ERR(host->pins_dat1),
> + "Cannot find pinctrl dat1!\n");
> + goto host_free;
> + }
> +
> + host->sdio_eint_ready = true;
> + }
> + }


--
With Best Regards,
Andy Shevchenko



2022-01-13 07:59:01

by Axe Yang (杨磊)

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq


Andy, thank you for the review.
But for the comment for 'dev_dbg', can you explain more about that?

On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:
> > Add support for eint irq when MSDC is used as an SDIO host. This
>
> IRQ
>
> > feature requires SDIO device support async irq function. With this
>
> IRQ
>
> > feature,SDIO host can be awakened by SDIO card in suspend state,
>
> feature, SDIO
>
> > 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
>
> MSDC
>
> > to support SDIO eint irq. Pinctrls named state_dat1 and state_eint
>
> IRQ
>
> > are mandatory. And cap-sdio-async-irq flag is necessary since this
> > feature depends on asynchronous interrupt:
> > &mmcX {
> > ...
> > pinctrl-names = "default", "state_uhs",
> > "state_eint",
> > "state_dat1";
> > ...
> > pinctrl-2 = <&mmc2_pins_eint>;
> > pinctrl-3 = <&mmc2_pins_dat1>;
> > ...
> > cap-sdio-async-irq;
> > ...
> > };
>
> ...
>
> > - * Copyright (c) 2014-2015 MediaTek Inc.
> > + * Copyright (c) 2014-2022 MediaTek Inc.
>
> Shouldn't it be rather like
>
> * Copyright (c) 2014-2015,2022 MediaTek Inc.
>
> ?
>
> ...
>
> > +static irqreturn_t msdc_sdio_eint_irq(int irq, void *dev_id)
> > +{
> > + unsigned long flags;
> > + struct msdc_host *host = (struct msdc_host *)dev_id;
>
> No casting is needed.
>
> > + struct mmc_host *mmc = mmc_from_priv(host);
>
> Perhaps reversed xmas tree order
>
> struct msdc_host *host = dev_id;
> struct mmc_host *mmc = mmc_from_priv(host);
> unsigned long flags;
>
> ?
>
> But hey, why do you need flags?
>
> > + spin_lock_irqsave(&host->lock, flags);
> > + if (likely(host->sdio_irq_cnt > 0)) {
> > + disable_irq_nosync(host->eint_irq);
> > + disable_irq_wake(host->eint_irq);
> > + host->sdio_irq_cnt--;
> > + }
> > + spin_unlock_irqrestore(&host->lock, flags);
> > +
> > + sdio_signal_irq(mmc);
> > +
> > + return IRQ_HANDLED;
> > +}
>
> ...
>
> > +static int msdc_request_dat1_eint_irq(struct msdc_host *host)
> > +{
> > + struct gpio_desc *desc;
> > + int irq, ret;
> > +
> > + desc = devm_gpiod_get(host->dev, "eint", GPIOD_IN);
> > + if (IS_ERR(desc))
> > + return PTR_ERR(desc);
> > +
> > + ret = gpiod_to_irq(desc);
> > + if (ret < 0)
> > + return ret;
> > +
> > + irq = ret;
> > + ret = devm_request_threaded_irq(host->dev, irq, NULL,
> > msdc_sdio_eint_irq,
> > + IRQF_TRIGGER_LOW | IRQF_ONESHOT
> > | IRQF_NO_AUTOEN,
> > + "sdio-eint", host);
> > +
>
> Redundant blank line.
>
> > + if (!ret)
> > + host->eint_irq = irq;
> > +
> > + return ret;
>
> I guess I have already commented on this, i.e. use standard pattern
>
> if (ret)
> return ret;
>
> ...
> return 0;
>
> > +}
>
> ...
>
> > + host->pins_eint = pinctrl_lookup_state(host->pinctrl,
> > "state_eint");
> > + if (IS_ERR(host->pins_eint)) {
> > + dev_dbg(&pdev->dev, "Cannot find pinctrl
> > eint!\n");
>
> In debug mode of pin control this will bring a duplicate message.

Can you explain more about this comment?
I don't understand what the 'duplicate message' refers for.

>
> > + } else {
> > + host->pins_dat1 = pinctrl_lookup_state(host-
> > >pinctrl, "state_dat1");
> > + if (IS_ERR(host->pins_dat1)) {
> > + ret = dev_err_probe(&pdev->dev,
> > PTR_ERR(host->pins_dat1),
> > + "Cannot find
> > pinctrl dat1!\n");
> > + goto host_free;
> > + }
> > +
> > + host->sdio_eint_ready = true;
> > + }
> > + }
>
>


2022-01-13 10:49:15

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

On Thu, Jan 13, 2022 at 03:58:52PM +0800, Axe Yang wrote:

> But for the comment for 'dev_dbg', can you explain more about that?

Sure.

> On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> > On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:

...

> > > + host->pins_eint = pinctrl_lookup_state(host->pinctrl,
> > > "state_eint");
> > > + if (IS_ERR(host->pins_eint)) {
> > > + dev_dbg(&pdev->dev, "Cannot find pinctrl
> > > eint!\n");
> >
> > In debug mode of pin control this will bring a duplicate message.
>
> Can you explain more about this comment?
> I don't understand what the 'duplicate message' refers for.

Have you chance to read the implementation of pinctrl_lookup_state()?

--
With Best Regards,
Andy Shevchenko



2022-01-14 03:06:43

by Axe Yang (杨磊)

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

On Thu, 2022-01-13 at 12:47 +0200, Andy Shevchenko wrote:
> On Thu, Jan 13, 2022 at 03:58:52PM +0800, Axe Yang wrote:
>
> > But for the comment for 'dev_dbg', can you explain more about that?
>
> Sure.
>
> > On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> > > On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:
>
> ..
>
> > > > + host->pins_eint = pinctrl_lookup_state(host-
> > > > >pinctrl,
> > > > "state_eint");
> > > > + if (IS_ERR(host->pins_eint)) {
> > > > + dev_dbg(&pdev->dev, "Cannot find
> > > > pinctrl
> > > > eint!\n");
> > >
> > > In debug mode of pin control this will bring a duplicate message.
> >
> > Can you explain more about this comment?
> > I don't understand what the 'duplicate message' refers for.
>
> Have you chance to read the implementation of pinctrl_lookup_state()?

I have read pinctrl_lookup_state(), and if the 'duplicate message' you
were talking about is 'using pinctrl dummy state...':

https://elixir.bootlin.com/linux/latest/source/drivers/pinctrl/core.c#L1214
No, this message will not appear in debug mode if pins_eint not found
because pinctrl_dummy_state is always FALSE. MTK Soc do not need dummy
state support.

--
Best Regard,
Axe Yang


2022-01-14 13:40:34

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

On Fri, Jan 14, 2022 at 11:06:36AM +0800, Axe Yang wrote:
> On Thu, 2022-01-13 at 12:47 +0200, Andy Shevchenko wrote:
> > On Thu, Jan 13, 2022 at 03:58:52PM +0800, Axe Yang wrote:
> > > On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> > > > On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:

...

> > > > > + host->pins_eint = pinctrl_lookup_state(host-
> > > > > >pinctrl,
> > > > > "state_eint");
> > > > > + if (IS_ERR(host->pins_eint)) {
> > > > > + dev_dbg(&pdev->dev, "Cannot find
> > > > > pinctrl
> > > > > eint!\n");
> > > >
> > > > In debug mode of pin control this will bring a duplicate message.
> > >
> > > Can you explain more about this comment?
> > > I don't understand what the 'duplicate message' refers for.
> >
> > Have you chance to read the implementation of pinctrl_lookup_state()?
>
> I have read pinctrl_lookup_state(), and if the 'duplicate message' you
> were talking about is 'using pinctrl dummy state...':
>
> https://elixir.bootlin.com/linux/latest/source/drivers/pinctrl/core.c#L1214
> No, this message will not appear in debug mode if pins_eint not found
> because pinctrl_dummy_state is always FALSE. MTK Soc do not need dummy
> state support.

I see, thanks for explanation. I'm wondering how good or bad would be
the idea of adding a debug message on the !pinctrl_dummy_state case.

--
With Best Regards,
Andy Shevchenko



2022-01-17 15:58:48

by Axe Yang (杨磊)

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

Andy, patchset v3 is uploaded. I fixed most of the defect you pointed
out.
And in msdc_sdio_eint_irq(), you asked why do we need flags, the flags
is for spin lock irq save/restore, so I keep it.

On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:
> > Add support for eint irq when MSDC is used as an SDIO host. This
>
> IRQ
>
> > feature requires SDIO device support async irq function. With this
>
> IRQ
>
> > feature,SDIO host can be awakened by SDIO card in suspend state,
>
> feature, SDIO
>
> > 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
>
> MSDC
>
> > to support SDIO eint irq. Pinctrls named state_dat1 and state_eint
>
> IRQ
>
> > are mandatory. And cap-sdio-async-irq flag is necessary since this
> > feature depends on asynchronous interrupt:
> > &mmcX {
> > ...
> > pinctrl-names = "default", "state_uhs",
> > "state_eint",
> > "state_dat1";
> > ...
> > pinctrl-2 = <&mmc2_pins_eint>;
> > pinctrl-3 = <&mmc2_pins_dat1>;
> > ...
> > cap-sdio-async-irq;
> > ...
> > };
>
> ...
>
> > - * Copyright (c) 2014-2015 MediaTek Inc.
> > + * Copyright (c) 2014-2022 MediaTek Inc.
>
> Shouldn't it be rather like
>
> * Copyright (c) 2014-2015,2022 MediaTek Inc.
>
> ?
>
> ...
>
> > +static irqreturn_t msdc_sdio_eint_irq(int irq, void *dev_id)
> > +{
> > + unsigned long flags;
> > + struct msdc_host *host = (struct msdc_host *)dev_id;
>
> No casting is needed.
>
> > + struct mmc_host *mmc = mmc_from_priv(host);
>
> Perhaps reversed xmas tree order
>
> struct msdc_host *host = dev_id;
> struct mmc_host *mmc = mmc_from_priv(host);
> unsigned long flags;
>
> ?
>
> But hey, why do you need flags?

falgs is for spin lock irq save/restore.

>
> > + spin_lock_irqsave(&host->lock, flags);
> > + if (likely(host->sdio_irq_cnt > 0)) {
> > + disable_irq_nosync(host->eint_irq);
> > + disable_irq_wake(host->eint_irq);
> > + host->sdio_irq_cnt--;
> > + }
> > + spin_unlock_irqrestore(&host->lock, flags);
> > +
> > + sdio_signal_irq(mmc);
> > +
> > + return IRQ_HANDLED;
> > +}
>
> ...
>
> > +static int msdc_request_dat1_eint_irq(struct msdc_host *host)
> > +{
> > + struct gpio_desc *desc;
> > + int irq, ret;
> > +
> > + desc = devm_gpiod_get(host->dev, "eint", GPIOD_IN);
> > + if (IS_ERR(desc))
> > + return PTR_ERR(desc);
> > +
> > + ret = gpiod_to_irq(desc);
> > + if (ret < 0)
> > + return ret;
> > +
> > + irq = ret;
> > + ret = devm_request_threaded_irq(host->dev, irq, NULL,
> > msdc_sdio_eint_irq,
> > + IRQF_TRIGGER_LOW | IRQF_ONESHOT
> > | IRQF_NO_AUTOEN,
> > + "sdio-eint", host);
> > +
>
> Redundant blank line.
>
> > + if (!ret)
> > + host->eint_irq = irq;
> > +
> > + return ret;
>
> I guess I have already commented on this, i.e. use standard pattern
>
> if (ret)
> return ret;
>
> ...
> return 0;
>
> > +}
>
> ...
>
> > + host->pins_eint = pinctrl_lookup_state(host->pinctrl,
> > "state_eint");
> > + if (IS_ERR(host->pins_eint)) {
> > + dev_dbg(&pdev->dev, "Cannot find pinctrl
> > eint!\n");
>
> In debug mode of pin control this will bring a duplicate message.
>
> > + } else {
> > + host->pins_dat1 = pinctrl_lookup_state(host-
> > >pinctrl, "state_dat1");
> > + if (IS_ERR(host->pins_dat1)) {
> > + ret = dev_err_probe(&pdev->dev,
> > PTR_ERR(host->pins_dat1),
> > + "Cannot find
> > pinctrl dat1!\n");
> > + goto host_free;
> > + }
> > +
> > + host->sdio_eint_ready = true;
> > + }
> > + }
>
>