From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH 01/18] staging: typec: tcpm: Add get_usb2_current_limit tcpc_dev callback Date: Sun, 6 Aug 2017 16:29:07 +0200 Message-ID: <5c9f12b9-f121-d33d-33eb-922e9ddbd43c@redhat.com> References: <20170806123555.5124-1-hdegoede@redhat.com> <20170806123555.5124-2-hdegoede@redhat.com> <24f52936-c07e-8e57-6c30-259dd3f36e61@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <24f52936-c07e-8e57-6c30-259dd3f36e61@roeck-us.net> Content-Language: en-US Sender: linux-pm-owner@vger.kernel.org To: Guenter Roeck , Darren Hart , Andy Shevchenko , Wolfram Sang , Sebastian Reichel , Greg Kroah-Hartman , Heikki Krogerus Cc: platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, Liam Breck , Tony Lindgren , linux-pm@vger.kernel.org, devel@driverdev.osuosl.org List-Id: linux-i2c@vger.kernel.org Hi, On 06-08-17 16:18, Guenter Roeck wrote: > On 08/06/2017 05:35 AM, Hans de Goede wrote: >> A Rp signalling the default current limit indicates that we're possibly >> connected to an USB2 power-source. In some cases the type-c >> port-controller may provide the capability to detect the current-limit >> for USB2 power-sources (through e.g. BC1.2 detection). >> >> This commit adds an optional get_usb2_current_limit tcpc_dev callback >> which allows the port-controller to return the detected current-limit >> if the CC pin is pulled up with Rp. >> >> Signed-off-by: Hans de Goede >> --- >> drivers/staging/typec/tcpm.c | 5 ++++- >> drivers/staging/typec/tcpm.h | 1 + >> 2 files changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c >> index 20eb4ebcf8c3..9f5adace4309 100644 >> --- a/drivers/staging/typec/tcpm.c >> +++ b/drivers/staging/typec/tcpm.c >> @@ -660,7 +660,10 @@ static u32 tcpm_get_current_limit(struct tcpm_port *port) >> break; >> case TYPEC_CC_RP_DEF: >> default: >> - limit = 0; >> + if (port->tcpc->get_usb2_current_limit) > > I think this callback should just be get_current_limit. This is only used in the Rp-def case, which usually indicates being connected with an A->C cable to a USB-2 device and the intend is for the callback to implement some USB-2 specific method to detect the supported current-limit, hence the name. If you prefer to name it just get_current_limit I can change it for v2, but IMHO the usb2 part of the name is important as this will not get called when USB-PD negotiation is used, nor when Rp has the Rp15 or Rp30 values. Regards, Hans > >> + limit = port->tcpc->get_usb2_current_limit(port->tcpc); >> + else >> + limit = 0; >> break; >> } >> diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h >> index 19c307d31a5a..01b7d89379a3 100644 >> --- a/drivers/staging/typec/tcpm.h >> +++ b/drivers/staging/typec/tcpm.h >> @@ -108,6 +108,7 @@ struct tcpc_dev { >> int (*init)(struct tcpc_dev *dev); >> int (*get_vbus)(struct tcpc_dev *dev); >> + int (*get_usb2_current_limit)(struct tcpc_dev *dev); /* Optional */ >> int (*set_cc)(struct tcpc_dev *dev, enum typec_cc_status cc); >> int (*get_cc)(struct tcpc_dev *dev, enum typec_cc_status *cc1, >> enum typec_cc_status *cc2); >> >