linux-kernel - Re: [PATCH v1 4/4] usb: typec: tcpci: Implement callback for apply

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Message-ID: <20210517143828.GC3434992@roeck-us.net>
Date:   Mon, 17 May 2021 07:38:28 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Badhri Jagan Sridharan <badhri@...gle.com>
Cc:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        Kyle Tso <kyletso@...gle.com>, stable@...r.kernel.org
Subject: Re: [PATCH v1 4/4] usb: typec: tcpci: Implement callback for apply_rc

On Fri, May 14, 2021 at 10:26:13PM -0700, Badhri Jagan Sridharan wrote:
> APPLY RC is defined as ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and
> POWER_CONTROL.AutodischargeDisconnect is 0. When ROLE_CONTROL.CC1 ==
> ROLE_CONTROL.CC2, set the other CC to OPEN.
> 
> Fixes: f321a02caebd ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support")
> Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>

Reviewed-by: Guenter Roeck <linux@...ck-us.net>

> ---
>  drivers/usb/typec/tcpm/tcpci.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 25b480752266..34b5095cc84f 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -115,6 +115,32 @@ static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
>  	return 0;
>  }
>  
> +int tcpci_apply_rc(struct tcpc_dev *tcpc, enum typec_cc_status cc, enum typec_cc_polarity polarity)
> +{
> +	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> +	unsigned int reg;
> +	int ret;
> +
> +	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * APPLY_RC state is when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and vbus autodischarge on
> +	 * disconnect is disabled. Bail out when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2.
> +	 */
> +	if (((reg & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) >>
> +	     TCPC_ROLE_CTRL_CC2_SHIFT) !=
> +	    ((reg & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) >>
> +	     TCPC_ROLE_CTRL_CC1_SHIFT))
> +		return 0;
> +
> +	return regmap_update_bits(tcpci->regmap, TCPC_ROLE_CTRL, polarity == TYPEC_POLARITY_CC1 ?
> +				  TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT :
> +				  TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT,
> +				  TCPC_ROLE_CTRL_CC_OPEN);
> +}
> +
>  static int tcpci_start_toggling(struct tcpc_dev *tcpc,
>  				enum typec_port_type port_type,
>  				enum typec_cc_status cc)
> @@ -728,6 +754,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
>  	tcpci->tcpc.get_vbus = tcpci_get_vbus;
>  	tcpci->tcpc.set_vbus = tcpci_set_vbus;
>  	tcpci->tcpc.set_cc = tcpci_set_cc;
> +	tcpci->tcpc.apply_rc = tcpci_apply_rc;
>  	tcpci->tcpc.get_cc = tcpci_get_cc;
>  	tcpci->tcpc.set_polarity = tcpci_set_polarity;
>  	tcpci->tcpc.set_vconn = tcpci_set_vconn;
> -- 
> 2.31.1.751.gd2f1c929bd-goog
>