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,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 892C5C433DB for ; Tue, 19 Jan 2021 08:11:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32FA920878 for ; Tue, 19 Jan 2021 08:11:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731581AbhASILE (ORCPT ); Tue, 19 Jan 2021 03:11:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730780AbhASIK1 (ORCPT ); Tue, 19 Jan 2021 03:10:27 -0500 Received: from xavier.telenet-ops.be (xavier.telenet-ops.be [IPv6:2a02:1800:120:4::f00:14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D00BCC061573 for ; Tue, 19 Jan 2021 00:09:45 -0800 (PST) Received: from ramsan.of.borg ([84.195.186.194]) by xavier.telenet-ops.be with bizsmtp id JY9g2400H4C55Sk01Y9gdg; Tue, 19 Jan 2021 09:09:43 +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 1l1m56-004oHH-3o; Tue, 19 Jan 2021 09:09:40 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1l1m55-007gn0-Dl; Tue, 19 Jan 2021 09:09:39 +0100 From: Geert Uytterhoeven To: Stafford Horne , Karol Gugala , Mateusz Holenko Cc: Gabriel Somlo , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v4] drivers/soc/litex: Add restart handler Date: Tue, 19 Jan 2021 09:09:38 +0100 Message-Id: <20210119080938.1832733-1-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 register a restart handler, which resets the LiteX SoC by writing 1 to CSR_CTRL_RESET_ADDR. Signed-off-by: Geert Uytterhoeven --- v4: - Drop bogus "a" from description, - Get rid of static litex_soc_ctrl_device and litex_reset_nb instances, - Unregister handler on driver unbind, v3: - Rebase on top of openrisc/for-next, 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 | 42 +++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c index da17ba56b7956c84..a7dd5be9fd5bd8ad 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 #define SCRATCH_REG_OFF 0x04 #define SCRATCH_REG_VALUE 0x12345678 @@ -66,8 +71,19 @@ static int litex_check_csr_access(void __iomem *reg_addr) struct litex_soc_ctrl_device { void __iomem *base; + struct notifier_block reset_nb; }; +static int litex_reset_handler(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev = + container_of(this, struct litex_soc_ctrl_device, reset_nb); + + litex_write32(soc_ctrl_dev->base + RESET_REG_OFF, RESET_REG_VALUE); + return NOTIFY_DONE; +} + static const struct of_device_id litex_soc_ctrl_of_match[] = { {.compatible = "litex,soc-controller"}, {}, @@ -78,6 +94,7 @@ 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) @@ -87,7 +104,29 @@ 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; + + platform_set_drvdata(pdev, soc_ctrl_dev); + + soc_ctrl_dev->reset_nb.notifier_call = litex_reset_handler; + soc_ctrl_dev->reset_nb.priority = 128; + error = register_restart_handler(&soc_ctrl_dev->reset_nb); + if (error) { + dev_warn(&pdev->dev, "cannot register restart handler: %d\n", + error); + } + + return 0; +} + +static int litex_soc_ctrl_remove(struct platform_device *pdev) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev = platform_get_drvdata(pdev); + + unregister_restart_handler(&soc_ctrl_dev->reset_nb); + return 0; } static struct platform_driver litex_soc_ctrl_driver = { @@ -96,6 +135,7 @@ static struct platform_driver litex_soc_ctrl_driver = { .of_match_table = of_match_ptr(litex_soc_ctrl_of_match) }, .probe = litex_soc_ctrl_probe, + .remove = litex_soc_ctrl_remove, }; module_platform_driver(litex_soc_ctrl_driver); -- 2.25.1