From patchwork Thu Jan 26 14:20:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 1732315 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-rtc-owner@vger.kernel.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=QgfzUw6M; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4P2jc044Hlz23hg for ; Fri, 27 Jan 2023 01:23:12 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231603AbjAZOXI (ORCPT ); Thu, 26 Jan 2023 09:23:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231899AbjAZOXD (ORCPT ); Thu, 26 Jan 2023 09:23:03 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D7CC17CF1; Thu, 26 Jan 2023 06:23:00 -0800 (PST) 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 8DA2361853; Thu, 26 Jan 2023 14:22:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6E4EC43616; Thu, 26 Jan 2023 14:22:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674742978; bh=ZZphE2HmPTraJC6heuasLA305OKL2tD5mgsLEy+bUwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QgfzUw6MTIQ9TB7L/rKCDX8h4K11VTvdXUKrzG/YdIrKd7aj7epWzmH3N8YtkZM8K yEEKgqRWpMU0dy05/0BjXv+cu2iAnGsKflO2hgt6laCJw4+XFsc1BXGsu0/ldoLTsy GiQmFKmD1ewencAUyJ1/TdguBvSX1awuW59JvAYSux4rFQrUOKLh5qF7tTdV1m1LAx RPFSU9+lPS/oLdB9t/8ipJ19wpYQidLwI2TZVLOI1sFuz4WFbaBzuagEaunocq6T25 aMZL96JlNK3HEVUaXybGRQ8f8ZTrAXxUU1aMXqbczi4AUG3B5NKzKg1wkTIQtCXQEQ Q5T2uOOwlDfaA== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1pL39d-0006j4-L8; Thu, 26 Jan 2023 15:23:05 +0100 From: Johan Hovold To: Alexandre Belloni , Bjorn Andersson Cc: Andy Gross , Konrad Dybcio , Alessandro Zummo , Rob Herring , Krzysztof Kozlowski , Maximilian Luz , linux-arm-msm@vger.kernel.org, linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH 19/24] rtc: pm8xxx: add support for uefi offset Date: Thu, 26 Jan 2023 15:20:52 +0100 Message-Id: <20230126142057.25715-20-johan+linaro@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230126142057.25715-1-johan+linaro@kernel.org> References: <20230126142057.25715-1-johan+linaro@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On many Qualcomm platforms the PMIC RTC control and time registers are read-only so that the RTC time can not be updated. Instead an offset needs be stored in some machine-specific non-volatile memory, which the driver can take into account. Add support for storing a 32-bit offset from the GPS time epoch in a UEFI variable so that the RTC time can be set on such platforms. The UEFI variable is 882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo and holds a 12-byte structure where the first four bytes is a GPS time offset in little-endian byte order. Signed-off-by: Johan Hovold --- drivers/rtc/rtc-pm8xxx.c | 122 +++++++++++++++++++++++++++++++++++++-- include/linux/rtc.h | 1 + 2 files changed, 119 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index 25bdd804b4d2..6c2324baeec6 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -5,6 +5,7 @@ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. * Copyright (c) 2023, Linaro Limited */ +#include #include #include #include @@ -17,6 +18,7 @@ #include #include +#include #include /* RTC_CTRL register bit fields */ @@ -46,6 +48,11 @@ struct pm8xxx_rtc_regs { unsigned int alarm_en; }; +struct qcom_uefi_rtc_info { + __le32 offset_gps; + u8 reserved[8]; +} __packed; + /** * struct pm8xxx_rtc - RTC driver internal structure * @rtc: RTC device @@ -54,6 +61,7 @@ struct pm8xxx_rtc_regs { * @alarm_irq: alarm irq number * @regs: register description * @dev: device structure + * @rtc_info: qcom uefi rtc-info structure * @nvmem_cell: nvmem cell for offset * @offset: offset from epoch in seconds */ @@ -61,13 +69,101 @@ struct pm8xxx_rtc { struct rtc_device *rtc; struct regmap *regmap; bool allow_set_time; + bool use_uefi; int alarm_irq; const struct pm8xxx_rtc_regs *regs; struct device *dev; + struct qcom_uefi_rtc_info rtc_info; struct nvmem_cell *nvmem_cell; u32 offset; }; +#ifdef CONFIG_EFI + +MODULE_IMPORT_NS(EFIVAR); + +#define QCOM_UEFI_NAME L"RTCInfo" +#define QCOM_UEFI_GUID EFI_GUID(0x882f8c2b, 0x9646, 0x435f, \ + 0x8d, 0xe5, 0xf2, 0x08, 0xff, 0x80, 0xc1, 0xbd) +#define QCOM_UEFI_ATTRS (EFI_VARIABLE_NON_VOLATILE | \ + EFI_VARIABLE_BOOTSERVICE_ACCESS | \ + EFI_VARIABLE_RUNTIME_ACCESS) + +static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd) +{ + struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info; + unsigned long size = sizeof(*rtc_info); + struct device *dev = rtc_dd->dev; + efi_status_t status; + u32 offset_gps; + int rc; + + rc = efivar_lock(); + if (rc) + return rc; + + status = efivar_get_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID, NULL, + &size, rtc_info); + efivar_unlock(); + + if (status != EFI_SUCCESS) { + dev_err(dev, "failed to read UEFI offset: %lu\n", status); + return efi_status_to_err(status); + } + + if (size != sizeof(*rtc_info)) { + dev_err(dev, "unexpected UEFI structure size %lu\n", size); + return -EINVAL; + } + + dev_dbg(dev, "uefi_rtc_info = %*ph\n", (int)size, rtc_info); + + /* Convert from GPS to Unix time offset */ + offset_gps = le32_to_cpu(rtc_info->offset_gps); + rtc_dd->offset = offset_gps + (u32)RTC_TIMESTAMP_BEGIN_GPS; + + return 0; +} + +static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) +{ + struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info; + unsigned long size = sizeof(*rtc_info); + struct device *dev = rtc_dd->dev; + efi_status_t status; + u32 offset_gps; + + /* Convert from Unix to GPS time offset */ + offset_gps = offset - (u32)RTC_TIMESTAMP_BEGIN_GPS; + + rtc_info->offset_gps = cpu_to_le32(offset_gps); + + dev_dbg(dev, "efi_rtc_info = %*ph\n", (int)size, rtc_info); + + status = efivar_set_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID, + QCOM_UEFI_ATTRS, size, rtc_info); + if (status != EFI_SUCCESS) { + dev_err(dev, "failed to write UEFI offset: %lx\n", status); + return efi_status_to_err(status); + } + + return 0; +} + +#else /* CONFIG_EFI */ + +static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd) +{ + return -ENODEV; +} + +static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) +{ + return -ENODEV; +} + +#endif /* CONFIG_EFI */ + static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd) { size_t len; @@ -112,10 +208,13 @@ static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset) static int pm8xxx_rtc_read_offset(struct pm8xxx_rtc *rtc_dd) { - if (!rtc_dd->nvmem_cell) + if (!rtc_dd->nvmem_cell && !rtc_dd->use_uefi) return 0; - return pm8xxx_rtc_read_nvmem_offset(rtc_dd); + if (rtc_dd->nvmem_cell) + return pm8xxx_rtc_read_nvmem_offset(rtc_dd); + else + return pm8xxx_rtc_read_uefi_offset(rtc_dd); } static int pm8xxx_rtc_read_raw(struct pm8xxx_rtc *rtc_dd, u32 *secs) @@ -155,7 +254,7 @@ static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs) u32 offset; int rc; - if (!rtc_dd->nvmem_cell) + if (!rtc_dd->nvmem_cell && !rtc_dd->use_uefi) return -ENODEV; rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs); @@ -167,7 +266,11 @@ static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs) if (offset == rtc_dd->offset) return 0; - rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset); + if (rtc_dd->nvmem_cell) + rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset); + else + rc = pm8xxx_rtc_write_uefi_offset(rtc_dd, offset); + if (rc) return rc; @@ -488,6 +591,17 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev) if (rc != -ENOENT) return rc; rtc_dd->nvmem_cell = NULL; + + /* Use UEFI storage as fallback if available */ + rtc_dd->use_uefi = of_property_read_bool(pdev->dev.of_node, + "qcom,uefi-rtc-info"); + } + + if (rtc_dd->use_uefi && !efivar_is_available()) { + if (IS_ENABLED(CONFIG_EFI)) + return -EPROBE_DEFER; + dev_warn(&pdev->dev, "efivars not available\n"); + rtc_dd->use_uefi = false; } rtc_dd->regs = match->data; diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 1fd9c6a21ebe..1ecee2fe4214 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -169,6 +169,7 @@ struct rtc_device { /* useful timestamps */ #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */ #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */ +#define RTC_TIMESTAMP_BEGIN_GPS 315964800LL /* 1980-01-06 00:00:00 */ #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */ #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */