Message-ID: <8701196.DvuYhMxLoT@steina-w>
Date:   Thu, 22 Jun 2023 07:16:45 +0200
From:   Alexander Stein <alexander.stein@...tq-group.com>
To:     Benjamin Bara <bbara93@...il.com>,
        Matthias Kaehlcke <mka@...omium.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Benjamin Bara <benjamin.bara@...data.com>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v2 1/3] usb: misc: onboard-hub: support multiple power supplies

Hi,

Am Mittwoch, 21. Juni 2023, 16:57:03 CEST schrieb Matthias Kaehlcke:
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> 
> Hi,
> 
> On Wed, Jun 21, 2023 at 04:26:27PM +0200, Benjamin Bara wrote:
> > From: Benjamin Bara <benjamin.bara@...data.com>
> > 
> > As some of the onboard hubs require multiple power supplies, provide the
> > environment to support them.
> > 
> > Signed-off-by: Benjamin Bara <benjamin.bara@...data.com>
> 
> Overall this looks good to me, a few nits inside.
> 
> > ---
> > v2:
> > - replace (err != 0) with (err)
> > ---
> > 
> >  drivers/usb/misc/onboard_usb_hub.c | 36
> >  ++++++++++++++++++++++++++++-------- drivers/usb/misc/onboard_usb_hub.h
> >  |  1 +
> >  2 files changed, 29 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/usb/misc/onboard_usb_hub.c
> > b/drivers/usb/misc/onboard_usb_hub.c index 12fc6eb67c3b..3de30356a684
> > 100644
> > --- a/drivers/usb/misc/onboard_usb_hub.c
> > +++ b/drivers/usb/misc/onboard_usb_hub.c
> > @@ -27,6 +27,12 @@
> > 
> >  #include "onboard_usb_hub.h"
> > 
> > +#define SUPPLIES_NUM_MAX 2
> 
> MAX_SUPPLIES?

Do we need this MAX_SUPPLIES macro at all? This essentially is 
ARRAY_SIZE(supply_names), no? At least it should be
> #define MAX_SUPPLIES ARRAY_SIZE(supply_names)

> 
> add empty line
> 
> > +static const char * const supply_names[] = {
> > +	"vdd",
> > +	"vdd2",
> > +};
> > +
> > 
> >  static void onboard_hub_attach_usb_driver(struct work_struct *work);
> >  
> >  static struct usb_device_driver onboard_hub_usbdev_driver;
> > 
> > @@ -40,7 +46,8 @@ struct usbdev_node {
> > 
> >  };
> >  
> >  struct onboard_hub {
> > 
> > -	struct regulator *vdd;
> > +	struct regulator_bulk_data supplies[SUPPLIES_NUM_MAX];
> > +	unsigned int supplies_num;
> 
> num_supplies?
> 
> >  	struct device *dev;
> >  	const struct onboard_hub_pdata *pdata;
> >  	struct gpio_desc *reset_gpio;
> > 
> > @@ -55,9 +62,9 @@ static int onboard_hub_power_on(struct onboard_hub *hub)
> > 
> >  {
> >  
> >  	int err;
> > 
> > -	err = regulator_enable(hub->vdd);
> > +	err = regulator_bulk_enable(hub->supplies_num, hub->supplies);
> > 
> >  	if (err) {
> > 
> > -		dev_err(hub->dev, "failed to enable regulator: %d\n", 
err);
> > +		dev_err(hub->dev, "failed to enable supplies: %d\n", err);
> > 
> >  		return err;
> >  	
> >  	}
> > 
> > @@ -75,9 +82,9 @@ static int onboard_hub_power_off(struct onboard_hub
> > *hub)
> > 
> >  	gpiod_set_value_cansleep(hub->reset_gpio, 1);
> > 
> > -	err = regulator_disable(hub->vdd);
> > +	err = regulator_bulk_disable(hub->supplies_num, hub->supplies);
> > 
> >  	if (err) {
> > 
> > -		dev_err(hub->dev, "failed to disable regulator: %d\n", 
err);
> > +		dev_err(hub->dev, "failed to disable supplies: %d\n", 
err);
> > 
> >  		return err;
> >  	
> >  	}
> > 
> > @@ -232,6 +239,7 @@ static int onboard_hub_probe(struct platform_device
> > *pdev)> 
> >  	const struct of_device_id *of_id;
> >  	struct device *dev = &pdev->dev;
> >  	struct onboard_hub *hub;
> > 
> > +	unsigned int i;
> > 
> >  	int err;
> >  	
> >  	hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
> > 
> > @@ -246,9 +254,21 @@ static int onboard_hub_probe(struct platform_device
> > *pdev)> 
> >  	if (!hub->pdata)
> >  	
> >  		return -EINVAL;
> > 
> > -	hub->vdd = devm_regulator_get(dev, "vdd");
> > -	if (IS_ERR(hub->vdd))
> > -		return PTR_ERR(hub->vdd);
> > +	if (hub->pdata->supplies_num > SUPPLIES_NUM_MAX)
> > +		return dev_err_probe(dev, -EINVAL, "max %d supplies 
supported!\n",
> > +				     SUPPLIES_NUM_MAX);
> > +	hub->supplies_num = 1;
> > +	if (hub->pdata->supplies_num > 1)
> > +		hub->supplies_num = hub->pdata->supplies_num;
> 
> Please change the above to:
> 
> 	if (hub->pdata->supplies_num != 0)
> 		hub->supplies_num = hub->pdata->supplies_num;
> 	else
> 		hub->supplies_num = 1;
> 

In the kernel there is also this style:
> hub->supplies_num = hub->pdata->supplies_num? : 1;

But it's up to you which one you prefer.

Best regards,
Alexander

> > +
> > +	for (i = 0; i < SUPPLIES_NUM_MAX; i++)
> > +		hub->supplies[i].supply = supply_names[i];
> > +
> > +	err = devm_regulator_bulk_get(dev, hub->supplies_num, hub-
>supplies);
> > +	if (err) {
> > +		dev_err(dev, "Failed to get regulator supplies: %d\n", 
err);
> > +		return err;
> > +	}
> > 
> >  	hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> >  	
> >  						  GPIOD_OUT_HIGH);
> > 
> > diff --git a/drivers/usb/misc/onboard_usb_hub.h
> > b/drivers/usb/misc/onboard_usb_hub.h index aca5f50eb0da..657190bf1799
> > 100644
> > --- a/drivers/usb/misc/onboard_usb_hub.h
> > +++ b/drivers/usb/misc/onboard_usb_hub.h
> > @@ -8,6 +8,7 @@
> > 
> >  struct onboard_hub_pdata {
> >  
> >  	unsigned long reset_us;		/* reset pulse width in us 
*/
> > 
> > +	unsigned int supplies_num;	/* num of supplies: 0 considered as 1 
*/
> 
> num_supplies?
> 
> s/num of/number of/
> 
> >  };


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