Re: [PATCH v2 1/3] usb: misc: onboard-hub: support multiple power supplies

From: Matthias Kaehlcke <mka@chromium.org>
To: Benjamin Bara <bbara93@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Benjamin Bara <benjamin.bara@skidata.com>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v2 1/3] usb: misc: onboard-hub: support multiple power supplies
Date: Wed, 21 Jun 2023 14:57:03 +0000	[thread overview]
Message-ID: <ZJMPv6Fm3On0ITFi@google.com> (raw)
In-Reply-To: <20230620-hx3-v2-1-76a53434c713@skidata.com>

Hi,

On Wed, Jun 21, 2023 at 04:26:27PM +0200, Benjamin Bara wrote:
> From: Benjamin Bara <benjamin.bara@skidata.com>
>
> As some of the onboard hubs require multiple power supplies, provide the
> environment to support them.
> 
> Signed-off-by: Benjamin Bara <benjamin.bara@skidata.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?

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;

> +
> +	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/

>  };