From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2A0DC433EF for ; Mon, 6 Jun 2022 18:14:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ercDc4zB/yDxfCYJcpC3zbyhnSbjalNRymlijvCQZoc=; b=lNtUgp3RhmvSLs 60YiD4P7QrVmWKy7HeDzh3tgbBDAwwQWb3z5acn/vyxz8qpZkBEiLfGLltOq0TglmhZuuQF1fXocj dgV/cyopZQU8ewhxc3XL7tlMt1O+CVch0E9UgJVuIYSGqSSpsYIavAe6O8vaMXEzcKo6DTfhCAJc7 XlJljoY7Bg40zR0Fg2sLqDWBMMSJG7iwni3HZ2cLmYtA8QmnvLLmr094WAws6sOMDE/FaXwGEomTi 1ktDvHnJy2YCxvl4Ar0xRJvqYysJ8yschZTqOKt6wtN9CwfyClyuKKjP3Y2CLBE4/j3/cyjXNH/WV jELrJCK+q3UNcRkhjIBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyHDq-002IBE-P1; Mon, 06 Jun 2022 18:13:02 +0000 Received: from netrider.rowland.org ([192.131.102.5]) by bombadil.infradead.org with smtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyHDn-002IA1-C2 for linux-arm-kernel@lists.infradead.org; Mon, 06 Jun 2022 18:13:01 +0000 Received: (qmail 377508 invoked by uid 1000); 6 Jun 2022 14:12:52 -0400 Date: Mon, 6 Jun 2022 14:12:52 -0400 From: Alan Stern To: =?iso-8859-1?Q?Cl=E9ment_L=E9ger?= Subject: Re: [PATCH] usb: host: ohci-at91: add support to enter suspend using SMC Message-ID: References: <20220606141802.165252-1-clement.leger@bootlin.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220606141802.165252-1-clement.leger@bootlin.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220606_111259_597577_1EEFBE3F X-CRM114-Status: GOOD ( 28.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexandre Belloni , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Claudiu Beznea , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jun 06, 2022 at 04:18:02PM +0200, Cl=E9ment L=E9ger wrote: > When Linux is running under OP-TEE, the SFR is set as secured and thus > the AT91_OHCIICR_USB_SUSPEND register isn't accessible. Add a SMC to > do the appropriate call to suspend the controller. > The SMC id is fetched from the device-tree property > "microchip,suspend-smc-id". if present, then the syscon regmap is not > used to enter suspend and a SMC is issued. > = > Signed-off-by: Cl=E9ment L=E9ger > --- Acked-by: Alan Stern However, this is a little weird... You've written = usb_hcd_at91_probe() so that the SMC is detected in preference to the = regmap, but then you wrote ohci_at91_port_suspend() so that the regmap = is used in preference to the SMC. It's not wrong, but it is confusing = to read. Do you want to rewrite the patch to make the two routines agree on which = mechanism to use by default? Alan Stern > drivers/usb/host/ohci-at91.c | 69 ++++++++++++++++++++++++------------ > 1 file changed, 46 insertions(+), 23 deletions(-) > = > diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c > index a24aea3d2759..e73fda4af278 100644 > --- a/drivers/usb/host/ohci-at91.c > +++ b/drivers/usb/host/ohci-at91.c > @@ -13,6 +13,7 @@ > * This file is licenced under the GPL. > */ > = > +#include > #include > #include > #include > @@ -55,6 +56,7 @@ struct ohci_at91_priv { > bool clocked; > bool wakeup; /* Saved wake-up state for resume */ > struct regmap *sfr_regmap; > + u32 smc_id; > }; > /* interface and function clocks; sometimes also an AHB clock */ > = > @@ -135,6 +137,19 @@ static void at91_stop_hc(struct platform_device *pde= v) > = > static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_devic= e *); > = > +static u32 at91_dt_suspend_smc(struct device *dev) > +{ > + u32 smc_id; > + > + if (!dev->of_node) > + return 0; > + > + if (of_property_read_u32(dev->of_node, "microchip,suspend-smc-id", &smc= _id)) > + return 0; > + > + return smc_id; > +} > + > static struct regmap *at91_dt_syscon_sfr(void) > { > struct regmap *regmap; > @@ -215,9 +230,13 @@ static int usb_hcd_at91_probe(const struct hc_driver= *driver, > goto err; > } > = > - ohci_at91->sfr_regmap =3D at91_dt_syscon_sfr(); > - if (!ohci_at91->sfr_regmap) > - dev_dbg(dev, "failed to find sfr node\n"); > + ohci_at91->smc_id =3D at91_dt_suspend_smc(dev); > + if (!ohci_at91->smc_id) { > + dev_dbg(dev, "failed to find sfr suspend smc id, using regmap\n"); > + ohci_at91->sfr_regmap =3D at91_dt_syscon_sfr(); > + if (!ohci_at91->sfr_regmap) > + dev_dbg(dev, "failed to find sfr node\n"); > + } > = > board =3D hcd->self.controller->platform_data; > ohci =3D hcd_to_ohci(hcd); > @@ -303,24 +322,30 @@ static int ohci_at91_hub_status_data(struct usb_hcd= *hcd, char *buf) > return length; > } > = > -static int ohci_at91_port_suspend(struct regmap *regmap, u8 set) > +static int ohci_at91_port_suspend(struct ohci_at91_priv *ohci_at91, u8 s= et) > { > + struct regmap *regmap =3D ohci_at91->sfr_regmap; > u32 regval; > int ret; > = > - if (!regmap) > - return 0; > + if (regmap) { > + ret =3D regmap_read(regmap, AT91_SFR_OHCIICR, ®val); > + if (ret) > + return ret; > = > - ret =3D regmap_read(regmap, AT91_SFR_OHCIICR, ®val); > - if (ret) > - return ret; > + if (set) > + regval |=3D AT91_OHCIICR_USB_SUSPEND; > + else > + regval &=3D ~AT91_OHCIICR_USB_SUSPEND; > = > - if (set) > - regval |=3D AT91_OHCIICR_USB_SUSPEND; > - else > - regval &=3D ~AT91_OHCIICR_USB_SUSPEND; > + regmap_write(regmap, AT91_SFR_OHCIICR, regval); > + } else if (ohci_at91->smc_id) { > + struct arm_smccc_res res; > = > - regmap_write(regmap, AT91_SFR_OHCIICR, regval); > + arm_smccc_smc(ohci_at91->smc_id, set, 0, 0, 0, 0, 0, 0, &res); > + if (res.a0) > + return -EINVAL; > + } > = > return 0; > } > @@ -357,9 +382,8 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd,= u16 typeReq, u16 wValue, > = > case USB_PORT_FEAT_SUSPEND: > dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n"); > - if (valid_port(wIndex) && ohci_at91->sfr_regmap) { > - ohci_at91_port_suspend(ohci_at91->sfr_regmap, > - 1); > + if (valid_port(wIndex)) { > + ohci_at91_port_suspend(ohci_at91, 1); > return 0; > } > break; > @@ -400,9 +424,8 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd,= u16 typeReq, u16 wValue, > = > case USB_PORT_FEAT_SUSPEND: > dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n"); > - if (valid_port(wIndex) && ohci_at91->sfr_regmap) { > - ohci_at91_port_suspend(ohci_at91->sfr_regmap, > - 0); > + if (valid_port(wIndex)) { > + ohci_at91_port_suspend(ohci_at91, 0); > return 0; > } > break; > @@ -630,10 +653,10 @@ ohci_hcd_at91_drv_suspend(struct device *dev) > /* flush the writes */ > (void) ohci_readl (ohci, &ohci->regs->control); > msleep(1); > - ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1); > + ohci_at91_port_suspend(ohci_at91, 1); > at91_stop_clock(ohci_at91); > } else { > - ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1); > + ohci_at91_port_suspend(ohci_at91, 1); > } > = > return ret; > @@ -645,7 +668,7 @@ ohci_hcd_at91_drv_resume(struct device *dev) > struct usb_hcd *hcd =3D dev_get_drvdata(dev); > struct ohci_at91_priv *ohci_at91 =3D hcd_to_ohci_at91_priv(hcd); > = > - ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0); > + ohci_at91_port_suspend(ohci_at91, 0); > = > if (ohci_at91->wakeup) > disable_irq_wake(hcd->irq); > -- = > 2.36.1 > = _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel