linux-kernel - Re: [PATCH 1/7] usb: typec: tipd: Only update power status on IRQ

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Date:   Mon, 4 Apr 2022 16:22:25 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
Cc:     linux-usb@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Sven Peter <sven@...npeter.dev>,
        Guido Günther <agx@...xcpu.org>,
        Angus Ainslie <angus@...ea.ca>,
        Hector Martin <marcan@...can.st>,
        Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
        linux-kernel@...r.kernel.org, kernel@...i.sm
Subject: Re: [PATCH 1/7] usb: typec: tipd: Only update power status on IRQ

On Thu, Mar 17, 2022 at 04:45:12PM +0100, Sebastian Krzyszkowiak wrote:
> From: Guido Günther <agx@...xcpu.org>
> 
> Instead of refetching power status cache it and only update it when a
> change is signalled via irq. This simplifies tracing and adding more
> supply properties in follow up patches.
> 
> Signed-off-by: Guido Günther <agx@...xcpu.org>
> Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>

Reviewed-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>

> ---
>  drivers/usb/typec/tipd/core.c | 32 ++++++++++++--------------------
>  1 file changed, 12 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 16b4560216ba..dfbba5ae9487 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -93,6 +93,8 @@ struct tps6598x {
>  	struct power_supply *psy;
>  	struct power_supply_desc psy_desc;
>  	enum power_supply_usb_type usb_type;
> +
> +	u16 pwr_status;
>  };
>  
>  static enum power_supply_property tps6598x_psy_props[] = {
> @@ -230,17 +232,12 @@ static int tps6598x_connect(struct tps6598x *tps, u32 status)
>  {
>  	struct typec_partner_desc desc;
>  	enum typec_pwr_opmode mode;
> -	u16 pwr_status;
>  	int ret;
>  
>  	if (tps->partner)
>  		return 0;
>  
> -	ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &pwr_status);
> -	if (ret < 0)
> -		return ret;
> -
> -	mode = TPS_POWER_STATUS_PWROPMODE(pwr_status);
> +	mode = TPS_POWER_STATUS_PWROPMODE(tps->pwr_status);
>  
>  	desc.usb_pd = mode == TYPEC_PWR_MODE_PD;
>  	desc.accessory = TYPEC_ACCESSORY_NONE; /* XXX: handle accessories */
> @@ -455,6 +452,7 @@ static bool tps6598x_read_power_status(struct tps6598x *tps)
>  		dev_err(tps->dev, "failed to read power status: %d\n", ret);
>  		return false;
>  	}
> +	tps->pwr_status = pwr_status;
>  	trace_tps6598x_power_status(pwr_status);
>  
>  	return true;
> @@ -601,15 +599,8 @@ static const struct regmap_config tps6598x_regmap_config = {
>  static int tps6598x_psy_get_online(struct tps6598x *tps,
>  				   union power_supply_propval *val)
>  {
> -	int ret;
> -	u16 pwr_status;
> -
> -	ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &pwr_status);
> -	if (ret < 0)
> -		return ret;
> -
> -	if (TPS_POWER_STATUS_CONNECTION(pwr_status) &&
> -	    TPS_POWER_STATUS_SOURCESINK(pwr_status)) {
> +	if (TPS_POWER_STATUS_CONNECTION(tps->pwr_status) &&
> +	    TPS_POWER_STATUS_SOURCESINK(tps->pwr_status)) {
>  		val->intval = 1;
>  	} else {
>  		val->intval = 0;
> @@ -622,15 +613,11 @@ static int tps6598x_psy_get_prop(struct power_supply *psy,
>  				 union power_supply_propval *val)
>  {
>  	struct tps6598x *tps = power_supply_get_drvdata(psy);
> -	u16 pwr_status;
>  	int ret = 0;
>  
>  	switch (psp) {
>  	case POWER_SUPPLY_PROP_USB_TYPE:
> -		ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &pwr_status);
> -		if (ret < 0)
> -			return ret;
> -		if (TPS_POWER_STATUS_PWROPMODE(pwr_status) == TYPEC_PWR_MODE_PD)
> +		if (TPS_POWER_STATUS_PWROPMODE(tps->pwr_status) == TYPEC_PWR_MODE_PD)
>  			val->intval = POWER_SUPPLY_USB_TYPE_PD;
>  		else
>  			val->intval = POWER_SUPPLY_USB_TYPE_C;
> @@ -837,6 +824,11 @@ static int tps6598x_probe(struct i2c_client *client)
>  	fwnode_handle_put(fwnode);
>  
>  	if (status & TPS_STATUS_PLUG_PRESENT) {
> +		ret = tps6598x_read16(tps, TPS_REG_POWER_STATUS, &tps->pwr_status);
> +		if (ret < 0) {
> +			dev_err(tps->dev, "failed to read power status: %d\n", ret);
> +			goto err_role_put;
> +		}
>  		ret = tps6598x_connect(tps, status);
>  		if (ret)
>  			dev_err(&client->dev, "failed to register partner\n");
> -- 
> 2.35.1

-- 
heikki