From patchwork Fri Oct 4 15:18:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamel BOUHARA X-Patchwork-Id: 11174907 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ADD27112B for ; Fri, 4 Oct 2019 15:18:19 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 8BFE1207FF for ; Fri, 4 Oct 2019 15:18:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uVRT9Ttc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BFE1207FF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ScGy/LEOQVs6RsZFVKWIPvrORzC/SfnfOdYeViKyavs=; b=uVRT9TtcsxfTUw ni94dpFRrF5i7HDxXKTjIP3cvZTzrZBr3R7aSTn8z8wbWl6H2XyvAoC521ksvlKRYEcdWLQdM1WlB ueqqjIQreiyuMcewG1FUe4RbmHi0kjdJsnEa6LuPST0THi41fm28cJLmhYxyYLAd/t5Xl0+LZe1wN iKlOIPke+Hvv1Rx5T5sPpVvA//z6SNkpfA63duYnpGsuuNKi4vFjdYJx67Sx7wZHdylyzC3Eze3sK 6jcpBFWFjpd6jO/4GRoP5Y7hpPP4oCLnwwI5xV+bc/8AJEIrGaFqMeLpFGNeo9X4HhU16MVv0Ki4b o4kqWci96UMyN9Q+HNGA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGPLV-00016y-MS; Fri, 04 Oct 2019 15:18:17 +0000 Received: from relay5-d.mail.gandi.net ([217.70.183.197]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGPLS-00015E-3b for linux-arm-kernel@lists.infradead.org; Fri, 04 Oct 2019 15:18:16 +0000 X-Originating-IP: 86.207.98.53 Received: from localhost (aclermont-ferrand-651-1-259-53.w86-207.abo.wanadoo.fr [86.207.98.53]) (Authenticated sender: kamel.bouhara@bootlin.com) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id E92AA1C0008; Fri, 4 Oct 2019 15:18:05 +0000 (UTC) From: Kamel Bouhara To: Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , linux-arm-kernel@lists.infradead.org Subject: [PATCH v6] soc: at91: Add Atmel SFR SN (Serial Number) support Date: Fri, 4 Oct 2019 17:18:02 +0200 Message-Id: <20191004151802.21793-1-kamel.bouhara@bootlin.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191004_081814_414736_9FF1DEB3 X-CRM114-Status: GOOD ( 16.83 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.183.197 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [217.70.183.197 listed in wl.mailspike.net] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kamel Bouhara , Thomas Petazzoni , Tudor Ambarus Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Add support to read SFR's read-only registers providing the SoC Serial Numbers (SN0+SN1) to userspace. ~ # hexdump -n 8 -e'"%d\n"' /sys/bus/nvmem/devices/atmel-sfr0/nvmem 959527243 371539274 Signed-off-by: Kamel Bouhara Tested-by: Tudor Ambarus Reviewed-by: Tudor Ambarus --- Changes in v2: - updated atmel-sfr.c to sfr.c in Makefile - fixed missing drvdata struct definition - added missing syscon header Changes in v3: - Fixed typo: processor in Kconfig - Renamed private struct sfr_priv to atmel_sfr_priv - Dropped the drvdata structure as we have same size for both SN registers in SAMA5D2/4, just hardcoded it for now. - Cleaned up private struct from unused members - Fixed misusage of devm_kzalloc Changes in v5: - Removed the blankline at EOF - Feeded the entropy pool with the SoC SN using add_device_randomness() and do it only once at probe(). Changes in v6: - Fixed missing return of a possible error from atmel_sfr_read() - Added T-b and R-b tags drivers/soc/atmel/Kconfig | 11 +++++ drivers/soc/atmel/Makefile | 1 + drivers/soc/atmel/sfr.c | 99 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 111 insertions(+) create mode 100644 drivers/soc/atmel/sfr.c -- 2.23.0 diff --git a/drivers/soc/atmel/Kconfig b/drivers/soc/atmel/Kconfig index 05528139b023..50caf6db9c0e 100644 --- a/drivers/soc/atmel/Kconfig +++ b/drivers/soc/atmel/Kconfig @@ -5,3 +5,14 @@ config AT91_SOC_ID default ARCH_AT91 help Include support for the SoC bus on the Atmel ARM SoCs. + +config AT91_SOC_SFR + tristate "Special Function Registers support" + depends on ARCH_AT91 || COMPILE_TEST + help + This is a driver for the Special Function Registers available on + Atmel SAMA5Dx SoCs, providing access to specific aspects of the + integrated memory, bridge implementations, processor etc. + + This driver can also be built as a module. If so, the module + will be called sfr. diff --git a/drivers/soc/atmel/Makefile b/drivers/soc/atmel/Makefile index 7ca355d10553..d849a897cd77 100644 --- a/drivers/soc/atmel/Makefile +++ b/drivers/soc/atmel/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_AT91_SOC_ID) += soc.o +obj-$(CONFIG_AT91_SOC_SFR) += sfr.o diff --git a/drivers/soc/atmel/sfr.c b/drivers/soc/atmel/sfr.c new file mode 100644 index 000000000000..0525eef49d1a --- /dev/null +++ b/drivers/soc/atmel/sfr.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sfr.c - driver for special function registers + * + * Copyright (C) 2019 Bootlin. + * + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#define SFR_SN0 0x4c +#define SFR_SN_SIZE 8 + +struct atmel_sfr_priv { + struct regmap *regmap; +}; + +static int atmel_sfr_read(void *context, unsigned int offset, + void *buf, size_t bytes) +{ + struct atmel_sfr_priv *priv = context; + + return regmap_bulk_read(priv->regmap, SFR_SN0 + offset, + buf, bytes / 4); +} + +static struct nvmem_config atmel_sfr_nvmem_config = { + .name = "atmel-sfr", + .read_only = true, + .word_size = 4, + .stride = 4, + .size = SFR_SN_SIZE, + .reg_read = atmel_sfr_read, +}; + +static int atmel_sfr_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct nvmem_device *nvmem; + struct atmel_sfr_priv *priv; + u8 sn[SFR_SN_SIZE]; + int ret; + + priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = syscon_node_to_regmap(np); + if (IS_ERR(priv->regmap)) { + dev_err(dev, "cannot get parent's regmap\n"); + return PTR_ERR(priv->regmap); + } + + atmel_sfr_nvmem_config.dev = dev; + atmel_sfr_nvmem_config.priv = priv; + + nvmem = devm_nvmem_register(dev, &atmel_sfr_nvmem_config); + if (IS_ERR(nvmem)) { + dev_err(dev, "error registering nvmem config\n"); + return PTR_ERR(nvmem); + } + + ret = atmel_sfr_read(priv, 0, sn, SFR_SN_SIZE); + if (ret == 0) + add_device_randomness(sn, SFR_SN_SIZE); + + return ret; +} + +static const struct of_device_id atmel_sfr_dt_ids[] = { + { + .compatible = "atmel,sama5d2-sfr", + }, { + .compatible = "atmel,sama5d4-sfr", + }, { + /* sentinel */ + }, +}; +MODULE_DEVICE_TABLE(of, atmel_sfr_dt_ids); + +static struct platform_driver atmel_sfr_driver = { + .probe = atmel_sfr_probe, + .driver = { + .name = "atmel-sfr", + .of_match_table = atmel_sfr_dt_ids, + }, +}; +module_platform_driver(atmel_sfr_driver); + +MODULE_AUTHOR("Kamel Bouhara "); +MODULE_DESCRIPTION("Atmel SFR SN driver for SAMA5D2/4 SoC family"); +MODULE_LICENSE("GPL v2");