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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D824C6FA86 for ; Thu, 15 Sep 2022 17:21:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229898AbiIORV0 (ORCPT ); Thu, 15 Sep 2022 13:21:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229761AbiIORVY (ORCPT ); Thu, 15 Sep 2022 13:21:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6600084EC8; Thu, 15 Sep 2022 10:21:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DE33A6183D; Thu, 15 Sep 2022 17:21:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1EEEC433D7; Thu, 15 Sep 2022 17:21:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663262481; bh=8Z9OF3dpMMKqRQV+noqKTBcpxIWR9RZt2S0c7B86zec=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R2j2DA9Rg0AJZ7EyJN24tGi8kvSQEIvnfIs/Sh6cbG4+Iwsv+qhKVSCt98ZEKxXlT mgxQoHfU8WyEt9p0y6f+KxFnssKbqo3VmJ9/0SVsRKxP9Xw2k/8ZUBbNdqM3icrD+f SHKVjQTtkrodN1ISrvpGVAfQzCE0BM+16y1CVLMWJ4eqcERUWkKNfUek5TGJfiEoyR wIL6mO2sOreUNUNoqwKMO6TXYpMVmX6pTsB+IPCIUpp0ZXwkQI1MLMJ/lcWriDJ8ku ezMgxTnhGlpIgrt3DU5tqH5Wpg1BW83fkDKpD5n3BSN/S5qEV738uW9abE68bc6bD0 xwqRw2/dOJgLg== Date: Thu, 15 Sep 2022 12:21:18 -0500 From: Bjorn Andersson To: Hiren Gohel Cc: Andy Gross , Konrad Dybcio , Philipp Zabel , linux-kernel@vger.kernel.org, Udipto Goswami , Pratham Pratap , linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] usb: phy: qusb: Use scm call to update value in register Message-ID: <20220915172118.q2bsjlfcau33z6pa@builder.lan> References: <1663249627-21151-1-git-send-email-quic_vhiren@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1663249627-21151-1-git-send-email-quic_vhiren@quicinc.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 15, 2022 at 07:17:07PM +0530, Hiren Gohel wrote: > Registers used by vendors to control any functionality could be > implemented by making the register secured. In such cases the > register cannot be updated with a new value since the normal > write ops will fail. > > Hence, use the scm_call to do a secure write to the register. > This looks reasonable, but we need a caller of this API in order to merge this patch. > Signed-off-by: Hiren Gohel > --- > drivers/firmware/qcom_scm.c | 19 +++++++++++++++++++ > drivers/firmware/qcom_scm.h | 1 + > include/linux/qcom_scm.h | 2 ++ > 3 files changed, 22 insertions(+) > > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c > index cdbfe54..7131df8 100644 > --- a/drivers/firmware/qcom_scm.c > +++ b/drivers/firmware/qcom_scm.c > @@ -400,6 +400,25 @@ int qcom_scm_set_remote_state(u32 state, u32 id) > } > EXPORT_SYMBOL(qcom_scm_set_remote_state); > > +void qcom_scm_phy_update_scm_level_shifter(u32 val) That second "scm" doesn't seem necessary. > +{ > + int ret; > + struct qcom_scm_desc desc = { > + .svc = QCOM_SCM_SVC_BOOT, > + .cmd = QCOM_SCM_QUSB2PHY_LVL_SHIFTER_CMD_ID, > + .owner = ARM_SMCCC_OWNER_SIP > + }; > + > + desc.args[0] = val; > + desc.args[1] = 0; > + desc.arginfo = QCOM_SCM_ARGS(2); > + > + ret = qcom_scm_call(__scm->dev, &desc, NULL); Would it not make sense to return this error to the caller? Regards, Bjorn > + if (ret) > + pr_err("Failed to update scm level shifter=0x%x\n", ret); > +} > +EXPORT_SYMBOL(qcom_scm_phy_update_scm_level_shifter); > + > static int __qcom_scm_set_dload_mode(struct device *dev, bool enable) > { > struct qcom_scm_desc desc = { > diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h > index 0d51eef..0a8c25b 100644 > --- a/drivers/firmware/qcom_scm.h > +++ b/drivers/firmware/qcom_scm.h > @@ -81,6 +81,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc, > #define QCOM_SCM_BOOT_SET_ADDR_MC 0x11 > #define QCOM_SCM_BOOT_SET_REMOTE_STATE 0x0a > #define QCOM_SCM_FLUSH_FLAG_MASK 0x3 > +#define QCOM_SCM_QUSB2PHY_LVL_SHIFTER_CMD_ID 0x1B > #define QCOM_SCM_BOOT_MAX_CPUS 4 > #define QCOM_SCM_BOOT_MC_FLAG_AARCH64 BIT(0) > #define QCOM_SCM_BOOT_MC_FLAG_COLDBOOT BIT(1) > diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h > index f8335644..3e5cbe9 100644 > --- a/include/linux/qcom_scm.h > +++ b/include/linux/qcom_scm.h > @@ -124,4 +124,6 @@ extern int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 payload_reg, u32 payload_val, > extern int qcom_scm_lmh_profile_change(u32 profile_id); > extern bool qcom_scm_lmh_dcvsh_available(void); > > +extern void qcom_scm_phy_update_scm_level_shifter(u32 val); > + > #endif > -- > 2.7.4 >