From patchwork Tue Nov 9 12:16:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prabhakar Mahadev Lad X-Patchwork-Id: 517676 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42067C433EF for ; Tue, 9 Nov 2021 12:17:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D119611CC for ; Tue, 9 Nov 2021 12:17:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242231AbhKIMTu (ORCPT ); Tue, 9 Nov 2021 07:19:50 -0500 Received: from relmlor2.renesas.com ([210.160.252.172]:34826 "EHLO relmlie6.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S242214AbhKIMTo (ORCPT ); Tue, 9 Nov 2021 07:19:44 -0500 X-IronPort-AV: E=Sophos;i="5.87,220,1631545200"; d="scan'208";a="99983750" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 09 Nov 2021 21:16:57 +0900 Received: from localhost.localdomain (unknown [10.226.36.204]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 070D54392862; Tue, 9 Nov 2021 21:16:54 +0900 (JST) From: Lad Prabhakar To: Geert Uytterhoeven , Greg Kroah-Hartman , Rob Herring , Jiri Slaby , Philipp Zabel Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Prabhakar , Biju Das , Lad Prabhakar Subject: [PATCH v2 3/3] serial: sh-sci: Add support to deassert/assert reset line Date: Tue, 9 Nov 2021 12:16:31 +0000 Message-Id: <20211109121631.26687-4-prabhakar.mahadev-lad.rj@bp.renesas.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211109121631.26687-1-prabhakar.mahadev-lad.rj@bp.renesas.com> References: <20211109121631.26687-1-prabhakar.mahadev-lad.rj@bp.renesas.com> Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On RZ/G2L SoC we need to explicitly deassert the reset line for the device to work, use this opportunity to deassert/assert reset line in sh-sci driver. This patch adds support to read the "resets" property (if available) from DT and perform deassert/assert when required. Also, propagate the error to the caller of sci_parse_dt() instead of returning NULL in case of failure. Signed-off-by: Lad Prabhakar Reviewed-by: Biju Das --- v1->v2 * deassert/assert reset line if available on all SoC's * Updated commit message --- drivers/tty/serial/sh-sci.c | 47 ++++++++++++++++++++++++++++++------- 1 file changed, 39 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 89ee43061d3a..7aced84d2f04 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -3203,23 +3204,53 @@ static const struct of_device_id of_sci_match[] = { }; MODULE_DEVICE_TABLE(of, of_sci_match); +static void sci_reset_control_assert(void *data) +{ + reset_control_assert(data); +} + static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id) { struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id; + struct reset_control *rstc; struct plat_sci_port *p; struct sci_port *sp; const void *data; - int id; + int id, ret; if (!IS_ENABLED(CONFIG_OF) || !np) - return NULL; + return ERR_PTR(-EINVAL); + + of_id = of_match_device(of_sci_match, &pdev->dev); + if (!of_id) + return ERR_PTR(-EINVAL); - data = of_device_get_match_data(&pdev->dev); + rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); + if (IS_ERR(rstc)) { + dev_err(&pdev->dev, "failed to get reset ctrl %ld\n", PTR_ERR(rstc)); + return ERR_PTR(PTR_ERR(rstc)); + } + + ret = reset_control_deassert(rstc); + if (ret) { + dev_err(&pdev->dev, "failed to deassert reset %d\n", ret); + return ERR_PTR(ret); + } + + ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc); + if (ret) { + dev_err(&pdev->dev, "failed to register assert devm action, %d\n", + ret); + return ERR_PTR(ret); + } + + data = of_id->data; p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL); if (!p) - return NULL; + return ERR_PTR(-ENOMEM); /* Get the line number from the aliases node. */ id = of_alias_get_id(np, "serial"); @@ -3227,11 +3258,11 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, id = ffz(sci_ports_in_use); if (id < 0) { dev_err(&pdev->dev, "failed to get alias id (%d)\n", id); - return NULL; + return ERR_PTR(-EINVAL); } if (id >= ARRAY_SIZE(sci_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", id); - return NULL; + return ERR_PTR(-EINVAL); } sp = &sci_ports[id]; @@ -3318,8 +3349,8 @@ static int sci_probe(struct platform_device *dev) if (dev->dev.of_node) { p = sci_parse_dt(dev, &dev_id); - if (p == NULL) - return -EINVAL; + if (IS_ERR(p)) + return PTR_ERR(p); } else { p = dev->dev.platform_data; if (p == NULL) {