[PATCH] usb: dwc3: meson-g12a: Add support for IRQ based OTG switching

[PATCH] usb: dwc3: meson-g12a: Add support for IRQ based OTG switching

[Neil Armstrong]

Add support for the OTG ID change interrupt to switch between Host
and Device mode.

Tested on the Hardkernel Odroid-N2 board.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 32 ++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index 2aec31a2eacb..e5c5ad0d529e 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -348,6 +348,22 @@ static enum usb_role dwc3_meson_g12a_role_get(struct device *dev)
 		USB_ROLE_HOST : USB_ROLE_DEVICE;
 }
 
+static irqreturn_t dwc3_meson_g12a_irq_thread(int irq, void *data)
+{
+	struct dwc3_meson_g12a *priv = data;
+	enum phy_mode otg_id;
+
+	otg_id = dwc3_meson_g12a_get_id(priv);
+	if (otg_id != priv->otg_phy_mode) {
+		if (dwc3_meson_g12a_otg_mode_set(priv, otg_id))
+			dev_warn(priv->dev, "Failed to switch OTG mode\n");
+	}
+
+	regmap_update_bits(priv->regmap, USB_R5, USB_R5_ID_DIG_IRQ, 0);
+
+	return IRQ_HANDLED;
+}
+
 static struct device *dwc3_meson_g12_find_child(struct device *dev,
 						const char *compatible)
 {
@@ -374,7 +390,7 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
 	void __iomem *base;
 	struct resource *res;
 	enum phy_mode otg_id;
-	int ret, i;
+	int ret, i, irq;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -436,6 +452,19 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
 	/* Get dr_mode */
 	priv->otg_mode = usb_get_dr_mode(dev);
 
+	if (priv->otg_mode == USB_DR_MODE_OTG) {
+		/* Ack irq before registering */
+		regmap_update_bits(priv->regmap, USB_R5,
+				   USB_R5_ID_DIG_IRQ, 0);
+
+		irq = platform_get_irq(pdev, 0);
+		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+						dwc3_meson_g12a_irq_thread,
+						IRQF_ONESHOT, pdev->name, priv);
+		if (ret)
+			return ret;
+	}
+
 	dwc3_meson_g12a_usb_init(priv);
 
 	/* Init PHYs */
@@ -460,7 +489,6 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
 
 	/* Setup OTG mode corresponding to the ID pin */
 	if (priv->otg_mode == USB_DR_MODE_OTG) {
-		/* TOFIX Handle ID mode toggling via IRQ */
 		otg_id = dwc3_meson_g12a_get_id(priv);
 		if (otg_id != priv->otg_phy_mode) {
 			if (dwc3_meson_g12a_otg_mode_set(priv, otg_id))
-- 
2.21.0


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Re: [PATCH] usb: dwc3: meson-g12a: Add support for IRQ based OTG switching

[Martin Blumenstingl]

Hi Neil,

On Tue, Jun 11, 2019 at 3:58 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> Add support for the OTG ID change interrupt to switch between Host
> and Device mode.
>
> Tested on the Hardkernel Odroid-N2 board.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
with the three questions/comments below answered/addressed:
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

> ---
>  drivers/usb/dwc3/dwc3-meson-g12a.c | 32 ++++++++++++++++++++++++++++--
>  1 file changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
> index 2aec31a2eacb..e5c5ad0d529e 100644
> --- a/drivers/usb/dwc3/dwc3-meson-g12a.c
> +++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
the comment block at the start of the driver file also contains a
"TOFIX" which points to the missing IRQ handling
can you please also drop that TOFIX comment in lines 15/16?

> @@ -348,6 +348,22 @@ static enum usb_role dwc3_meson_g12a_role_get(struct device *dev)
>                 USB_ROLE_HOST : USB_ROLE_DEVICE;
>  }
>
> +static irqreturn_t dwc3_meson_g12a_irq_thread(int irq, void *data)
> +{
> +       struct dwc3_meson_g12a *priv = data;
> +       enum phy_mode otg_id;
> +
> +       otg_id = dwc3_meson_g12a_get_id(priv);
> +       if (otg_id != priv->otg_phy_mode) {
> +               if (dwc3_meson_g12a_otg_mode_set(priv, otg_id))
> +                       dev_warn(priv->dev, "Failed to switch OTG mode\n");
> +       }
> +
> +       regmap_update_bits(priv->regmap, USB_R5, USB_R5_ID_DIG_IRQ, 0);
> +
> +       return IRQ_HANDLED;
> +}
> +
>  static struct device *dwc3_meson_g12_find_child(struct device *dev,
>                                                 const char *compatible)
>  {
> @@ -374,7 +390,7 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>         void __iomem *base;
>         struct resource *res;
>         enum phy_mode otg_id;
> -       int ret, i;
> +       int ret, i, irq;
>
>         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>         if (!priv)
> @@ -436,6 +452,19 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>         /* Get dr_mode */
>         priv->otg_mode = usb_get_dr_mode(dev);
>
> +       if (priv->otg_mode == USB_DR_MODE_OTG) {
> +               /* Ack irq before registering */
> +               regmap_update_bits(priv->regmap, USB_R5,
> +                                  USB_R5_ID_DIG_IRQ, 0);
I assume that either the IRQ line is:
- always enabled
- enabled when (USB_R5_ID_DIG_EN_0 | USB_R5_ID_DIG_EN_1 |
USB_R5_ID_DIG_TH_MASK) are set (which we already do in
dwc3_meson_g12a_usb_init)

> +               irq = platform_get_irq(pdev, 0);
do we need to check the IRQ before trying to request it?
drivers/gpu/drm/meson/meson_dw_hdmi.c and drivers/usb/dwc3/host.c for
example error out if irq number is lower than 0

(it's great to see that this only required a small patch to make it work :))


Martin

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Re: [PATCH] usb: dwc3: meson-g12a: Add support for IRQ based OTG switching

[Neil Armstrong]

On 11/06/2019 20:08, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Tue, Jun 11, 2019 at 3:58 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>
>> Add support for the OTG ID change interrupt to switch between Host
>> and Device mode.
>>
>> Tested on the Hardkernel Odroid-N2 board.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> with the three questions/comments below answered/addressed:
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> 
>> ---
>>  drivers/usb/dwc3/dwc3-meson-g12a.c | 32 ++++++++++++++++++++++++++++--
>>  1 file changed, 30 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
>> index 2aec31a2eacb..e5c5ad0d529e 100644
>> --- a/drivers/usb/dwc3/dwc3-meson-g12a.c
>> +++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
> the comment block at the start of the driver file also contains a
> "TOFIX" which points to the missing IRQ handling
> can you please also drop that TOFIX comment in lines 15/16?

Indeed, thanks for pointing that !

> 
>> @@ -348,6 +348,22 @@ static enum usb_role dwc3_meson_g12a_role_get(struct device *dev)
>>                 USB_ROLE_HOST : USB_ROLE_DEVICE;
>>  }
>>
>> +static irqreturn_t dwc3_meson_g12a_irq_thread(int irq, void *data)
>> +{
>> +       struct dwc3_meson_g12a *priv = data;
>> +       enum phy_mode otg_id;
>> +
>> +       otg_id = dwc3_meson_g12a_get_id(priv);
>> +       if (otg_id != priv->otg_phy_mode) {
>> +               if (dwc3_meson_g12a_otg_mode_set(priv, otg_id))
>> +                       dev_warn(priv->dev, "Failed to switch OTG mode\n");
>> +       }
>> +
>> +       regmap_update_bits(priv->regmap, USB_R5, USB_R5_ID_DIG_IRQ, 0);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>>  static struct device *dwc3_meson_g12_find_child(struct device *dev,
>>                                                 const char *compatible)
>>  {
>> @@ -374,7 +390,7 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>>         void __iomem *base;
>>         struct resource *res;
>>         enum phy_mode otg_id;
>> -       int ret, i;
>> +       int ret, i, irq;
>>
>>         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>         if (!priv)
>> @@ -436,6 +452,19 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>>         /* Get dr_mode */
>>         priv->otg_mode = usb_get_dr_mode(dev);
>>
>> +       if (priv->otg_mode == USB_DR_MODE_OTG) {
>> +               /* Ack irq before registering */
>> +               regmap_update_bits(priv->regmap, USB_R5,
>> +                                  USB_R5_ID_DIG_IRQ, 0);
> I assume that either the IRQ line is:
> - always enabled
> - enabled when (USB_R5_ID_DIG_EN_0 | USB_R5_ID_DIG_EN_1 |
> USB_R5_ID_DIG_TH_MASK) are set (which we already do in
> dwc3_meson_g12a_usb_init)

Can't say... I suspect the (USB_R5_ID_DIG_EN_0 | USB_R5_ID_DIG_EN_1 |
> USB_R5_ID_DIG_TH_MASK) enables the detection.
The regmap_update_bits(USB_R5_ID_DIG_IRQ) is only here to make sure the "current"
irq event is masked, whatever the previous init.

Or I misunderstood question ?

> 
>> +               irq = platform_get_irq(pdev, 0);
> do we need to check the IRQ before trying to request it?
> drivers/gpu/drm/meson/meson_dw_hdmi.c and drivers/usb/dwc3/host.c for
> example error out if irq number is lower than 0

No, devm_request_threaded_irq() will fail if -1 is given, I've using this scheme
for a while now !

Neil

> 
> (it's great to see that this only required a small patch to make it work :))

yeah, I was impressed when I wrote it, I expected much more work

> 
> 
> Martin


Thanks,
Neil
> 


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Re: [PATCH] usb: dwc3: meson-g12a: Add support for IRQ based OTG switching

[Martin Blumenstingl]

Hi Neil,

On Wed, Jun 12, 2019 at 5:13 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
[...]
> >> @@ -436,6 +452,19 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
> >>         /* Get dr_mode */
> >>         priv->otg_mode = usb_get_dr_mode(dev);
> >>
> >> +       if (priv->otg_mode == USB_DR_MODE_OTG) {
> >> +               /* Ack irq before registering */
> >> +               regmap_update_bits(priv->regmap, USB_R5,
> >> +                                  USB_R5_ID_DIG_IRQ, 0);
> > I assume that either the IRQ line is:
> > - always enabled
> > - enabled when (USB_R5_ID_DIG_EN_0 | USB_R5_ID_DIG_EN_1 |
> > USB_R5_ID_DIG_TH_MASK) are set (which we already do in
> > dwc3_meson_g12a_usb_init)
>
> Can't say... I suspect the (USB_R5_ID_DIG_EN_0 | USB_R5_ID_DIG_EN_1 |
> > USB_R5_ID_DIG_TH_MASK) enables the detection.
> The regmap_update_bits(USB_R5_ID_DIG_IRQ) is only here to make sure the "current"
> irq event is masked, whatever the previous init.
>
> Or I misunderstood question ?
that perfectly answers my question - thank you!

> >
> >> +               irq = platform_get_irq(pdev, 0);
> > do we need to check the IRQ before trying to request it?
> > drivers/gpu/drm/meson/meson_dw_hdmi.c and drivers/usb/dwc3/host.c for
> > example error out if irq number is lower than 0
>
> No, devm_request_threaded_irq() will fail if -1 is given, I've using this scheme
> for a while now !
OK, it wasn't obvious to me when I looked at devm_request_threaded_irq.
thank you for clarifying this


Martin

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