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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 559ADC433DB for ; Mon, 4 Jan 2021 16:46:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26C52224DF for ; Mon, 4 Jan 2021 16:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727739AbhADQpr (ORCPT ); Mon, 4 Jan 2021 11:45:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbhADQpq (ORCPT ); Mon, 4 Jan 2021 11:45:46 -0500 Received: from baptiste.telenet-ops.be (baptiste.telenet-ops.be [IPv6:2a02:1800:120:4::f00:13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A218C061574 for ; Mon, 4 Jan 2021 08:45:06 -0800 (PST) Received: from ramsan.of.borg ([84.195.186.194]) by baptiste.telenet-ops.be with bizsmtp id Cgl32400H4C55Sk01gl3d3; Mon, 04 Jan 2021 17:45:03 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kwSyc-001AP6-Th; Mon, 04 Jan 2021 17:45:02 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1kwSyc-005V5O-BI; Mon, 04 Jan 2021 17:45:02 +0100 From: Geert Uytterhoeven To: Karol Gugala , Mateusz Holenko Cc: Gabriel Somlo , Stafford Horne , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Geert Uytterhoeven Subject: [PATCH v2] drivers/soc/litex: Add restart handler Date: Mon, 4 Jan 2021 17:45:00 +0100 Message-Id: <20210104164500.1311091-1-geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let the LiteX SoC Controller a register a restart handler, which resets the LiteX SoC by writing 1 to CSR_CTRL_RESET_ADDR. Signed-off-by: Geert Uytterhoeven --- Tested with linux-on-litex-vexriscv. This patch is based on upstream, i.e. not on top of Gabriel Somlo's "[PATCH v5 0/4] drivers/soc/litex: support 32-bit subregisters, 64-bit CPUs" (https://lore.kernel.org/lkml/20201227161320.2194830-1-gsomlo@gmail.com/) v2: - Rebase on top of v5.11-rc1, - Change reset handler priority to recommended default value of 128 (was 192). (v1 was not sent to a mailing list) --- drivers/soc/litex/litex_soc_ctrl.c | 33 +++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c index 1217cafdfd4d1d2b..d729ad50d4ffca5e 100644 --- a/drivers/soc/litex/litex_soc_ctrl.c +++ b/drivers/soc/litex/litex_soc_ctrl.c @@ -15,6 +15,11 @@ #include #include #include +#include + +/* reset register located at the base address */ +#define RESET_REG_OFF 0x00 +#define RESET_REG_VALUE 0x00000001 /* * LiteX SoC Generator, depending on the configuration, can split a single @@ -136,8 +141,20 @@ static int litex_check_csr_access(void __iomem *reg_addr) return 0; } -struct litex_soc_ctrl_device { +static struct litex_soc_ctrl_device { void __iomem *base; +} *soc_ctrl_dev; + +static int litex_reset_handler(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + litex_write32(soc_ctrl_dev->base + RESET_REG_OFF, RESET_REG_VALUE); + return NOTIFY_DONE; +} + +static struct notifier_block litex_reset_nb = { + .notifier_call = litex_reset_handler, + .priority = 128, }; static const struct of_device_id litex_soc_ctrl_of_match[] = { @@ -149,7 +166,7 @@ MODULE_DEVICE_TABLE(of, litex_soc_ctrl_of_match); static int litex_soc_ctrl_probe(struct platform_device *pdev) { - struct litex_soc_ctrl_device *soc_ctrl_dev; + int error; soc_ctrl_dev = devm_kzalloc(&pdev->dev, sizeof(*soc_ctrl_dev), GFP_KERNEL); if (!soc_ctrl_dev) @@ -159,7 +176,17 @@ static int litex_soc_ctrl_probe(struct platform_device *pdev) if (IS_ERR(soc_ctrl_dev->base)) return PTR_ERR(soc_ctrl_dev->base); - return litex_check_csr_access(soc_ctrl_dev->base); + error = litex_check_csr_access(soc_ctrl_dev->base); + if (error) + return error; + + error = register_restart_handler(&litex_reset_nb); + if (error) { + dev_warn(&pdev->dev, "cannot register restart handler: %d\n", + error); + } + + return 0; } static struct platform_driver litex_soc_ctrl_driver = { -- 2.25.1