From patchwork Sat Mar 12 16:58:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Peter X-Patchwork-Id: 550845 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 39094C433FE for ; Sat, 12 Mar 2022 16:59:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232249AbiCLRAF (ORCPT ); Sat, 12 Mar 2022 12:00:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232240AbiCLRAC (ORCPT ); Sat, 12 Mar 2022 12:00:02 -0500 Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E64D9D4DD; Sat, 12 Mar 2022 08:58:53 -0800 (PST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 9872D5C00F3; Sat, 12 Mar 2022 11:58:52 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Sat, 12 Mar 2022 11:58:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=svenpeter.dev; h=cc:cc:content-transfer-encoding:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm1; bh=yPyexJVh3nRaxA wi8JDvJedOH1n8cn7H4dOuQSm5pMQ=; b=mP3A81rmOnDN954FUwfziId5V4zNcy EUBi5wuMsyK/0cn8QwDAfUkuGgSv43dWV2mdg9RJexoFxGHk04xWCdZJWRm3v7DQ F3Qsr2yB/ZninI302Ne3aK9u5d+HsonemWLIa7UBbLfxMbF8qbRJmABn1fOHLC3L oxWZA+oGD8skHbPnUwpXHL5Jeqy/kGIaH2QJVHBpnNhTsL4hf1vQQNTmOcm00Zy+ +4/RXVTxtKyTIiMIzhHGGCUsGGhOvbtunBFChbxTyk2/nwStDMeu79mJEh/nu8jh t1mWHm/QQ60igh4dvscBEx6uA6Yz2pb11vu/MiPcEOUJgnET3BQ9Ma+A== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding:date:date :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=yPyexJ Vh3nRaxAwi8JDvJedOH1n8cn7H4dOuQSm5pMQ=; b=c7JItLhFUGX2o/he+5Vfj8 xBNZbhb543rnEkf/0ViawMFKWy8QNFEBtSKK7ILjpIbODXHy6dbfCKLxljr6gfY8 4P8GWmF5x/+peBz0SE8pNyU4DVOKQJQ9lvq3L3OtGQ/5D3IBmlnMuIMQb7mnG6/X 7shJmPSobzkP+XV9tsHjWwUDHqmyk6HLCd+O4xJ7K3BwdQLT8EnU77u+6iVwtOgn TstuKi9XP8LeLNcKw2RAzHJeJ2eUjCV51Zor1aa/19fTXV11UervhnZEV37le6M1 KEu4suaxcGusVSTx+HsyH2YsrMFZabTz6TuDr9FdMnBlA8Wsrby5XU61LCFBJMVw == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddruddvgedgleehucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpefuvhgvnhcu rfgvthgvrhcuoehsvhgvnhesshhvvghnphgvthgvrhdruggvvheqnecuggftrfgrthhtvg hrnheptedvkeetleeuffffhfekteetffeggffgveehieelueefvddtueffveevlefhfeej necuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepshhvvg hnsehsvhgvnhhpvghtvghrrdguvghv X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sat, 12 Mar 2022 11:58:50 -0500 (EST) From: Sven Peter To: Srinivas Kandagatla Cc: Sven Peter , Rob Herring , Krzysztof Kozlowsk , Joey Gouly , Hector Martin , Alyssa Rosenzweig , Mark Kettenis , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] nvmem: Add Apple eFuse driver Date: Sat, 12 Mar 2022 17:58:37 +0100 Message-Id: <20220312165837.40687-2-sven@svenpeter.dev> X-Mailer: git-send-email 2.30.1 (Apple Git-130) In-Reply-To: <20220312165837.40687-1-sven@svenpeter.dev> References: <20220312165837.40687-1-sven@svenpeter.dev> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Apple SoCs contain eFuses used to store factory-programmed data such as calibration values for the PCIe or the Type-C PHY. They are organized as 32bit values exposed as MMIO. Signed-off-by: Sven Peter --- v2 -> v3: - removed .owner = THIS_MODULE again since it's already done by the core as pointed out by Krzysztof Kozlowski v1 -> v2: - fixed sparse warning about __iomem by introducing struct apple_efuses_priv as done in other nvmem drivers - make sure the driver actually works as a module by setting .owner to THIS_MODULE and adding MODULE_DEVICE_TABLE pointed out by Joey Gouly MAINTAINERS | 1 + drivers/nvmem/Kconfig | 12 ++++++ drivers/nvmem/Makefile | 2 + drivers/nvmem/apple-efuses.c | 80 ++++++++++++++++++++++++++++++++++++ 4 files changed, 95 insertions(+) create mode 100644 drivers/nvmem/apple-efuses.c diff --git a/MAINTAINERS b/MAINTAINERS index 24deb0e8f731..a93318a1dda8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1781,6 +1781,7 @@ F: drivers/i2c/busses/i2c-pasemi-core.c F: drivers/i2c/busses/i2c-pasemi-platform.c F: drivers/irqchip/irq-apple-aic.c F: drivers/mailbox/apple-mailbox.c +F: drivers/nvmem/apple-efuses.c F: drivers/pinctrl/pinctrl-apple-gpio.c F: drivers/soc/apple/* F: drivers/watchdog/apple_wdt.c diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index da414617a54d..bba29d1aec96 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -300,4 +300,16 @@ config NVMEM_BRCM_NVRAM This driver provides support for Broadcom's NVRAM that can be accessed using I/O mapping. +config NVMEM_APPLE_EFUSES + tristate "Apple eFuse support" + depends on ARCH_APPLE || COMPILE_TEST + default ARCH_APPLE + help + Say y here to enable support for reading eFuses on Apple SoCs + such as the M1. These are e.g. used to store factory programmed + calibration data required for the PCIe or the USB-C PHY. + + This driver can also be built as a module. If so, the module will + be called nvmem-apple-efuses. + endif diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index dcbbde35b6a8..1a8e54691d3e 100644 --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -61,3 +61,5 @@ obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o nvmem-rmem-y := rmem.o obj-$(CONFIG_NVMEM_BRCM_NVRAM) += nvmem_brcm_nvram.o nvmem_brcm_nvram-y := brcm_nvram.o +obj-$(CONFIG_NVMEM_APPLE_EFUSES) += nvmem-apple-efuses.o +nvmem-apple-efuses-y := apple-efuses.o diff --git a/drivers/nvmem/apple-efuses.c b/drivers/nvmem/apple-efuses.c new file mode 100644 index 000000000000..9b7c87102104 --- /dev/null +++ b/drivers/nvmem/apple-efuses.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Apple SoC eFuse driver + * + * Copyright (C) The Asahi Linux Contributors + */ + +#include +#include +#include +#include +#include + +struct apple_efuses_priv { + void __iomem *fuses; +}; + +static int apple_efuses_read(void *context, unsigned int offset, void *val, + size_t bytes) +{ + struct apple_efuses_priv *priv = context; + u32 *dst = val; + + while (bytes >= sizeof(u32)) { + *dst++ = readl_relaxed(priv->fuses + offset); + bytes -= sizeof(u32); + offset += sizeof(u32); + } + + return 0; +} + +static int apple_efuses_probe(struct platform_device *pdev) +{ + struct apple_efuses_priv *priv; + struct resource *res; + struct nvmem_config config = { + .dev = &pdev->dev, + .read_only = true, + .reg_read = apple_efuses_read, + .stride = sizeof(u32), + .word_size = sizeof(u32), + .name = "apple_efuses_nvmem", + .id = NVMEM_DEVID_AUTO, + .root_only = true, + }; + + priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(priv->fuses)) + return PTR_ERR(priv->fuses); + + config.priv = priv; + config.size = resource_size(res); + + return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config)); +} + +static const struct of_device_id apple_efuses_of_match[] = { + { .compatible = "apple,efuses", }, + {} +}; + +MODULE_DEVICE_TABLE(of, apple_efuses_of_match); + +static struct platform_driver apple_efuses_driver = { + .driver = { + .name = "apple_efuses", + .of_match_table = apple_efuses_of_match, + }, + .probe = apple_efuses_probe, +}; + +module_platform_driver(apple_efuses_driver); + +MODULE_AUTHOR("Sven Peter "); +MODULE_LICENSE("GPL");