Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751508AbdFFRgR (ORCPT ); Tue, 6 Jun 2017 13:36:17 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:37695 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751291AbdFFRgP (ORCPT ); Tue, 6 Jun 2017 13:36:15 -0400 Message-ID: <1496770570.22734.3.camel@collabora.co.uk> Subject: Re: [RFC] usb-phy-generic: Add support to SMSC USB3315 From: Fabien Lahoudere To: Peter Chen Cc: Stephen Boyd , Peter Chen , Peter Senna Tschudin , Felipe Balbi , Greg Kroah-Hartman , "open list:USB PHY LAYER" , open list Date: Tue, 06 Jun 2017 19:36:10 +0200 In-Reply-To: <20170606015528.GB26189@b29397-desktop> References: <20170419061413.20961-1-peter.senna@collabora.com> <20170420085046.GA11378@b29397-desktop> <1495563396.12055.93.camel@collabora.co.uk> <20170523210022.GN20170@codeaurora.org> <1495708587.12055.97.camel@collabora.co.uk> <1495789230.12055.104.camel@collabora.co.uk> <20170602220010.GQ20170@codeaurora.org> <1496653020.31741.2.camel@collabora.co.uk> <20170605094330.GA21071@b29397-desktop> <1496656346.31741.4.camel@collabora.co.uk> <20170606015528.GB26189@b29397-desktop> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6467 Lines: 174 Hi Peter, On Tue, 2017-06-06 at 09:55 +0800, Peter Chen wrote: > On Mon, Jun 05, 2017 at 11:52:26AM +0200, Fabien Lahoudere wrote: > > On Mon, 2017-06-05 at 17:43 +0800, Peter Chen wrote: > > > On Mon, Jun 05, 2017 at 10:57:00AM +0200, Fabien Lahoudere wrote: > > > > On Fri, 2017-06-02 at 15:00 -0700, Stephen Boyd wrote: > > > > > On 05/26, Fabien Lahoudere wrote: > > > > > > Hello > > > > > > > > > > > > I modify ci_hrdc_imx_probe to bypass "data->phy = devm_usb_get_phy_by_phandle(&pdev- > > > > > > >dev, > > > > > > "fsl,usbphy", 0);". Everything works as expected and call ci_ulpi_init. > > > > > > > > > > > > The problem is that in ci_ulpi_init, before calling "ci->ulpi = > > > > > > ulpi_register_interface(ci- > > > > > > > dev, > > > > > > > > > > > > &ci->ulpi_ops);" (to initialize our phy), "hw_phymode_configure(ci);" is called which is > > > > > > the > > > > > > original function that make our system to hang. > > > > > > > > > > > > Our phy is not initialised before calling ulpi_register_interface so I don't understand > > > > > > how > > > > > > the > > > > > > phy > > > > > > can reply if it is not out of reset state. > > > > > > > > > > I haven't see any problem in hw_phymode_configure(). What's the > > > > > value of ci->platdata->phy_mode? USBPHY_INTERFACE_MODE_ULPI? If > > > > > you phy needs to be taken out of reset to reply to the ulpi reads > > > > > of the vendor/product ids, then it sounds like you have a similar > > > > > situation to what I had. I needed to turn on some regulators to > > > > > get those reads to work, otherwise they would fail, but knowing > > > > > what needed to be turned on basically meant I needed to probe the > > > > > ulpi driver so probing the ids wasn't going to be useful. So on > > > > > my device the reads for the ids go through, but they get all > > > > > zeroes back, which is actually ok because there aren't any bits > > > > > set on my devices anyway. After the reads see 0, we fallback to > > > > > DT matching, which avoids the "bring it out of reset/power it on" > > > > > sorts of problems entirely. > > > > > > > > > > > > > Yes the phy mode is configured to USBPHY_INTERFACE_MODE_ULPI. > > > > Indeed, this phy need to be out of reset to work. For example everything works fine if I > > > > call  > > > > "_ci_usb_phy_init(ci);" before calling "hw_phymode_configure(ci);" > > > > This function only init reset GPIO and clock. > > > > > > > > For information, the original patch I have to fix the issue: > > > > > > > > diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c > > > > index 79ad8e9..21aaff1 100644 > > > > --- a/drivers/usb/chipidea/core.c > > > > +++ b/drivers/usb/chipidea/core.c > > > > @@ -391,6 +391,7 @@ static int ci_usb_phy_init(struct ci_hdrc *ci) > > > >   case USBPHY_INTERFACE_MODE_UTMI: > > > >   case USBPHY_INTERFACE_MODE_UTMIW: > > > >   case USBPHY_INTERFACE_MODE_HSIC: > > > > + case USBPHY_INTERFACE_MODE_ULPI: > > > >   ret = _ci_usb_phy_init(ci); > > > >   if (!ret) > > > >   hw_wait_phy_stable(); > > > > @@ -398,7 +399,6 @@ static int ci_usb_phy_init(struct ci_hdrc *ci) > > > >   return ret; > > > >   hw_phymode_configure(ci); > > > >   break; > > > > - case USBPHY_INTERFACE_MODE_ULPI: > > > >   case USBPHY_INTERFACE_MODE_SERIAL: > > > >   hw_phymode_configure(ci); > > > >   ret = _ci_usb_phy_init(ci); > > > > --  > > > > > > Currently, the hw_phymode_configure is called twice for ULPI PHY, the > > > two execution are between _ci_usb_phy_init, would you test which one > > > causes hang? If the second causes hang, you can make a patch for > > > hw_phymode_configure that if the required PORTSC_PTS is the same > > > the value in register, do noop. > > > > The first one hangs, _ci_usb_phy_init is not called due to hang. > > > > So, you need to comment out hw_phymode_configure at ci_ulpi_init, and you > can't get vid/pid correctly, right? If it is, we may need to add power on > sequence at chipidea core driver (ci_hdrc_probe) for clock and reset things. > > http://www.spinics.net/lists/linux-usb/msg157134.html > > I am wondering if we can call ci_usb_phy_init before calling ci_ulpi_init, > since we need to let hardware be ready before reading vid/pid. > Stephen & Fabien, does that work for you? > I test the following patch and it works. But I am not sure that we can move safely ci_ulpi_init. I will investigate more tomorrow if it is a problem for other phys. Is it a good approach? Subject: [PATCH 1/1] power on phy before getting vid/pid Signed-off-by: Fabien Lahoudere ---  drivers/usb/chipidea/core.c | 12 ++++++++----  drivers/usb/chipidea/ulpi.c | 19 +++++++++++++++++++  2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c index 79ad8e9..26889e1 100644 --- a/drivers/usb/chipidea/core.c +++ b/drivers/usb/chipidea/core.c @@ -879,10 +879,6 @@ static int ci_hdrc_probe(struct platform_device *pdev)   return -ENODEV;   }   - ret = ci_ulpi_init(ci); - if (ret) - return ret; -   if (ci->platdata->phy) {   ci->phy = ci->platdata->phy;   } else if (ci->platdata->usb_phy) { @@ -909,6 +905,14 @@ static int ci_hdrc_probe(struct platform_device *pdev)   ci->usb_phy = NULL;   }   + /*  +    We move this in order to have phy reset and gpio information +    before calling ci_ulpi_init. + */ + ret = ci_ulpi_init(ci); + if (ret) + return ret; +   ret = ci_usb_phy_init(ci);   if (ret) {   dev_err(dev, "unable to init phy: %d\n", ret); diff --git a/drivers/usb/chipidea/ulpi.c b/drivers/usb/chipidea/ulpi.c index 1219583..1c272e4 100644 --- a/drivers/usb/chipidea/ulpi.c +++ b/drivers/usb/chipidea/ulpi.c @@ -73,9 +73,28 @@ static int ci_ulpi_write(struct device *dev, u8 addr, u8 val)    int ci_ulpi_init(struct ci_hdrc *ci)  { +        int ret;   if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)   return 0;   + /*  +    This is the content of _ci_usb_phy_init from core.c to power on the phy. +    Duplicated for test purpose only. + */ + if (ci->phy) { + ret = phy_init(ci->phy); + if (ret) + return ret; + + ret = phy_power_on(ci->phy); + if (ret) { + phy_exit(ci->phy); + return ret; + } + } else { + ret = usb_phy_init(ci->usb_phy); + } +   /*    * Set PORTSC correctly so we can read/write ULPI registers for    * identification purposes --  1.8.3.1 Thanks Fabien