Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752467AbbDQIp2 (ORCPT ); Fri, 17 Apr 2015 04:45:28 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:47457 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbbDQIpT (ORCPT ); Fri, 17 Apr 2015 04:45:19 -0400 Message-ID: <5530C815.7070008@ti.com> Date: Fri, 17 Apr 2015 11:45:09 +0300 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Peter Chen CC: , , , , , , , , , Subject: Re: [RFC][PATCH v2 01/13] usb: otg-fsm: Add documentation for struct otg_fsm References: <1429008120-5395-1-git-send-email-rogerq@ti.com> <1429008120-5395-2-git-send-email-rogerq@ti.com> <20150416113231.GA3181@shlinux2> In-Reply-To: <20150416113231.GA3181@shlinux2> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6359 Lines: 190 On 16/04/15 14:32, Peter Chen wrote: > On Tue, Apr 14, 2015 at 01:41:48PM +0300, Roger Quadros wrote: >> struct otg_fsm is the interface to the OTG state machine. >> >> Document the input, output and internal state variables. >> Definations are taken from Table 7-2 and Table 7-4 of >> the USB OTG & EH Specification Rev.2.0 >> >> Re-arrange some of the members as per use case for more >> clarity. >> >> Signed-off-by: Roger Quadros >> --- >> include/linux/usb/otg-fsm.h | 80 +++++++++++++++++++++++++++++++++++++++++---- >> 1 file changed, 73 insertions(+), 7 deletions(-) >> >> diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h >> index b6ba1bf..c5b74c5 100644 >> --- a/include/linux/usb/otg-fsm.h >> +++ b/include/linux/usb/otg-fsm.h >> @@ -57,37 +57,103 @@ enum otg_fsm_timer { >> NUM_OTG_FSM_TIMERS, >> }; >> >> -/* OTG state machine according to the OTG spec */ >> +/** >> + * struct otg_fsm - OTG state machine according to the OTG spec >> + * >> + * OTG hardware Inputs >> + * >> + * Common inputs for A and B device > > What's the intention you leave two spaces at above line? It is just to indicate the subgroup. i.e. 1) common inputs 2) a-device inputs 3) b-device inputs, etc > >> + * @id: TRUE for B-device, FALSE for A-device. >> + * @adp_change: TRUE when current ADP measurement (n) value, compared to the >> + * ADP measurement taken at n-2, differs by more than CADP_THR >> + * @power_up: TRUE when the OTG device first powers up its USB system and >> + * ADP measurement taken if ADP capable >> + * >> + * A-Device state inputs >> + * @a_srp_det: TRUE if the A-device detects SRP >> + * @a_vbus_vld: TRUE when VBUS voltage is in regulation >> + * @b_conn: TRUE if the A-device detects connection from the B-device >> + * @a_bus_resume: TRUE when the B-device detects that the A-device is signaling >> + * a resume (K state) >> + * B-Device state inputs >> + * @a_bus_suspend: TRUE when the B-device detects that the A-device has put the bus into suspend >> + * @a_conn: TRUE if the B-device detects a connection from the A-device >> + * @b_se0_srp: TRUE when the line has been at SE0 for more than the minimum >> + * time before generating SRP >> + * @b_ssend_srp: TRUE when the VBUS has been below VOTG_SESS_VLD for more than >> + * the minimum time before generating SRP >> + * @b_sess_vld: TRUE when the B-device detects that the voltage on VBUS is >> + * above VOTG_SESS_VLD >> + * @test_device: TRUE when the B-device switches to B-Host and detects an OTG test device >> + * FIXME: must be set by host/hub driver > > Yes, according to pid/vid pair. > >> + * >> + * Application inputs (A-Device) >> + * @a_bus_drop: TRUE when A-device application needs to power down the bus >> + * @a_bus_req: TRUE when A-device application wants to use the bus. >> + * FALSE to suspend the bus >> + * >> + * Application inputs (B-Device) >> + * @b_bus_req: TRUE during the time that the Application running on the >> + * B-device wants to use the bus >> + * >> + * Auxilary inputs >> + * @a_sess_vld: ?? > > See OTG spec 1.3, and obsolete now. OK. I will mark it obsolete. > >> + * @b_bus_suspend: ?? >> + * @b_bus_resume: ?? > > They are used at current otg fsm, just for B-host. These 2 are also present only in otg v1.3 spec and absent in v2.0 spec. b_bus_suspend has been replaced by a_bidl_adis_tmout to transition from a_peripheral to a_wait_bcon. b_bus_resume has been replaced by a_bus_req to transition between a_suspend and a_host. So I'll mark them as obsolete as well. > >> + * >> + * OTG Output status. Read only for users. updated by otg_ops() helpers >> + * >> + * Outputs for Both A and B device >> + * @drv_vbus: TRUE when A-device is driving VBUS >> + * @loc_conn: TRUE when the local device has signaled that it is connected to the bus >> + * @loc_sof: TRUE when the local device is generating activity on the bus >> + * @adp_prb: TRUE when the local device is in the process of doing ADP probing >> + * >> + * Outputs for B-device state >> + * @adp_sns: TRUE when the B-device is in the process of carrying out ADP sensing >> + * @data_pulse: TRUE when the B-device is performing data line pulsing >> + * >> + * Internal Variables >> + * >> + * a_set_b_hnp_en: TRUE when the A-device has successfully set the b_hnp_enable bit in the B-device. >> + * FIXME: OTG fsm uses otg->host->b_hnp_enable instead > > a_set_b_hnp_en is for otg 2.0 and it should instead of > otg->host->b_hnp_enable at otg fsm. both are the same thing. Just that there is no way for HCD drivers to directly access otg_fsm data structure so we rely on otg->host->b_hnp_enable. > >> + * b_srp_done: TRUE when the B-device has completed initiating SRP >> + * b_hnp_enable: TRUE when the B-device has accepted the SetFeature(b_hnp_enable) B-device >> + * FIXME: OTG fsm uses otg->gadget->b_hnp_enable instead > > Yes > >> + * a_clr_err: Asserted (by application ?) to clear a_vbus_err due to an overcurrent condition >> + * and causes the A-device to transition to a_wait_vfall >> + */ >> struct otg_fsm { >> /* Input */ >> int id; >> int adp_change; >> int power_up; >> - int test_device; >> - int a_bus_drop; >> - int a_bus_req; >> int a_srp_det; >> int a_vbus_vld; >> int b_conn; >> int a_bus_resume; >> int a_bus_suspend; >> int a_conn; >> - int b_bus_req; >> int b_se0_srp; >> int b_ssend_srp; >> int b_sess_vld; >> + int test_device; >> + int a_bus_drop; >> + int a_bus_req; >> + int b_bus_req; >> + >> /* Auxilary inputs */ >> int a_sess_vld; >> int b_bus_resume; >> int b_bus_suspend; >> >> /* Output */ >> - int data_pulse; >> int drv_vbus; >> int loc_conn; >> int loc_sof; >> int adp_prb; >> int adp_sns; >> + int data_pulse; >> >> /* Internal variables */ >> int a_set_b_hnp_en; >> @@ -95,7 +161,7 @@ struct otg_fsm { >> int b_hnp_enable; >> int a_clr_err; >> >> - /* Informative variables */ >> + /* Informative variables. All unused as of now */ >> int a_bus_drop_inf; >> int a_bus_req_inf; >> int a_clr_err_inf; >> -- >> 2.1.0 >> > cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/