linux-kernel - Re: [PATCH v6 10/14] usb: typec: tcpci: Implement callbacks for FRS

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Date:   Tue, 15 Sep 2020 16:23:49 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Badhri Jagan Sridharan <badhri@...gle.com>
Cc:     Guenter Roeck <linux@...ck-us.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6 10/14] usb: typec: tcpci: Implement callbacks for FRS

On Mon, Aug 31, 2020 at 07:59:23PM -0700, Badhri Jagan Sridharan wrote:
> Implement tcpc.enable_frs to enable TCPC to receive
> Fast role swap signal.
> 
> Additionally set the sink disconnect threshold to 4v
> to prevent disconnect during Fast Role swap.
> 
> Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>

One nitpick below. Otherwise, FWIW:

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

> ---
> Changes since v1:
> - Changing patch version to v6 to fix version number confusion.
> ---
>  drivers/usb/typec/tcpm/tcpci.c | 17 +++++++++++++++++
>  drivers/usb/typec/tcpm/tcpci.h |  8 ++++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index d6a6fac82d48..f9f0af64da5f 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -268,6 +268,22 @@ static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
>  				enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
>  }
>  
> +static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
> +{
> +	struct tcpci *tcpci = tcpc_to_tcpci(dev);
> +	int ret;
> +
> +	/* To prevent disconnect during FRS, set disconnect threshold to 3.5V */
> +	ret = tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, enable ? 0 : 0x8c);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_FAST_ROLE_SWAP_EN, enable ?
> +				 TCPC_FAST_ROLE_SWAP_EN : 0);

	ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_FAST_ROLE_SWAP_EN,
                                 enable ? TCPC_FAST_ROLE_SWAP_EN : 0);

> +
> +	return ret;
> +}
> +
>  static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
>  {
>  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -611,6 +627,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
>  	tcpci->tcpc.set_roles = tcpci_set_roles;
>  	tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
>  	tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
> +	tcpci->tcpc.enable_frs = tcpci_enable_frs;
>  
>  	err = tcpci_parse_config(tcpci);
>  	if (err < 0)
> diff --git a/drivers/usb/typec/tcpm/tcpci.h b/drivers/usb/typec/tcpm/tcpci.h
> index 82f021a82456..5ef07a56d67a 100644
> --- a/drivers/usb/typec/tcpm/tcpci.h
> +++ b/drivers/usb/typec/tcpm/tcpci.h
> @@ -16,6 +16,7 @@
>  #define TCPC_PD_INT_REV			0xa
>  
>  #define TCPC_ALERT			0x10
> +#define TCPC_ALERT_EXTND		BIT(14)
>  #define TCPC_ALERT_EXTENDED_STATUS	BIT(13)
>  #define TCPC_ALERT_VBUS_DISCNCT		BIT(11)
>  #define TCPC_ALERT_RX_BUF_OVF		BIT(10)
> @@ -37,6 +38,9 @@
>  #define TCPC_EXTENDED_STATUS_MASK		0x16
>  #define TCPC_EXTENDED_STATUS_MASK_VSAFE0V	BIT(0)
>  
> +#define TCPC_ALERT_EXTENDED_MASK	0x17
> +#define TCPC_SINK_FAST_ROLE_SWAP	BIT(0)
> +
>  #define TCPC_CONFIG_STD_OUTPUT		0x18
>  
>  #define TCPC_TCPC_CTRL			0x19
> @@ -63,6 +67,7 @@
>  
>  #define TCPC_POWER_CTRL			0x1c
>  #define TCPC_POWER_CTRL_VCONN_ENABLE	BIT(0)
> +#define TCPC_FAST_ROLE_SWAP_EN		BIT(7)
>  
>  #define TCPC_CC_STATUS			0x1d
>  #define TCPC_CC_STATUS_TOGGLING		BIT(5)
> @@ -74,11 +79,14 @@
>  
>  #define TCPC_POWER_STATUS		0x1e
>  #define TCPC_POWER_STATUS_UNINIT	BIT(6)
> +#define TCPC_POWER_STATUS_SOURCING_VBUS	BIT(4)
>  #define TCPC_POWER_STATUS_VBUS_DET	BIT(3)
>  #define TCPC_POWER_STATUS_VBUS_PRES	BIT(2)
>  
>  #define TCPC_FAULT_STATUS		0x1f
>  
> +#define TCPC_ALERT_EXTENDED		0x21
> +
>  #define TCPC_COMMAND			0x23
>  #define TCPC_CMD_WAKE_I2C		0x11
>  #define TCPC_CMD_DISABLE_VBUS_DETECT	0x22
> -- 
> 2.28.0.402.g5ffc5be6b7-goog

thanks,

-- 
heikki