From patchwork Thu May 7 20:08:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Anderson X-Patchwork-Id: 11534841 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 8BB47159A for ; Thu, 7 May 2020 20:09:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 753B421835 for ; Thu, 7 May 2020 20:09:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="k06JzvMv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbgEGUJj (ORCPT ); Thu, 7 May 2020 16:09:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728635AbgEGUJO (ORCPT ); Thu, 7 May 2020 16:09:14 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2292AC05BD43 for ; Thu, 7 May 2020 13:09:14 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id mq3so3138795pjb.1 for ; Thu, 07 May 2020 13:09:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=JDitJmCYI6w8zpra4JuK0k+hw0gGmgK6hNM/TsrDerA=; b=k06JzvMvr6IYLZzGXi5MfjXYuByqlDZ5Ov7mPhaAbBAYC2WDtJlBDj/9PSIX63fckv yvcOSjPw7/Q1Vr8lprU6X2yuu+hUFrZgmNJmmkEF8/JQfVgtWlgprpvoRq5+dHn2sEWv beDgToAgENRUasSAvNZUqtFk/E56syR3ia0zw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=JDitJmCYI6w8zpra4JuK0k+hw0gGmgK6hNM/TsrDerA=; b=mnJDvmt8G7xpZZkxs1qeN4EawH5XFeHX3EjEfkaSnK3rwurlgCvjb8iMGaKdo3yarJ vazuEOS0m7fnnJI2QD71y+EPcM0wfLUp3P6KNy7UXHSHzzxsTJwijN3nfbcBQtOaCMkz kmF9eGl3N4Bw0glEs6inBGfxNYdIIaGJQhy0nnMWKriPvn0OcQUfqUMgKj7SY0O3/6e7 GqKWFifj0SNOT54fU9vqPqYncuAzCe9Z3wzZAsOL3unV3Gy+O4gfI+XbxlOD/AAly525 cYFG8XLG/4uhK8B6d0PJMgY4OrFogbSB74jl8hqBbnT6DTf5wiU85HgaqdiujAMLUB0e /IWQ== X-Gm-Message-State: AGi0Pua2HZchugnpMKuaSfKL+vcKm6VO2b/YhkIEK4NEpHLPhIqV1wfv PJRHBCL+C814qwTNCqKxsI1M2g== X-Google-Smtp-Source: APiQypJ7eLBdCYVxkzItvTQhjgPKMPikSZLf+2fArLtn+DXLDcEsLN3jFlCfrxAqCJRgj8wo2lxu1w== X-Received: by 2002:a17:902:7593:: with SMTP id j19mr15341546pll.62.1588882153625; Thu, 07 May 2020 13:09:13 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:24fa:e766:52c9:e3b2]) by smtp.gmail.com with ESMTPSA id d203sm5547601pfd.79.2020.05.07.13.09.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 13:09:13 -0700 (PDT) From: Douglas Anderson To: jason.wessel@windriver.com, daniel.thompson@linaro.org, gregkh@linuxfoundation.org Cc: corbet@lwn.net, frowand.list@gmail.com, bjorn.andersson@linaro.org, linux-serial@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, jslaby@suse.com, kgdb-bugreport@lists.sourceforge.net, sumit.garg@linaro.org, will@kernel.org, tglx@linutronix.de, agross@kernel.org, catalin.marinas@arm.com, bp@alien8.de, Douglas Anderson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 10/12] serial: qcom_geni_serial: Support kgdboc_earlycon Date: Thu, 7 May 2020 13:08:48 -0700 Message-Id: <20200507130644.v4.10.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeid> X-Mailer: git-send-email 2.26.2.645.ge9eca65c58-goog In-Reply-To: <20200507200850.60646-1-dianders@chromium.org> References: <20200507200850.60646-1-dianders@chromium.org> MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Implement the read() function in the early console driver. With recent kgdb patches this allows you to use kgdb to debug fairly early into the system boot. We only bother implementing this if polling is enabled since kgdb can't be enabled without that. Signed-off-by: Douglas Anderson Reviewed-by: Greg Kroah-Hartman --- Changes in v4: None Changes in v3: - Renamed earlycon_kgdboc to kgdboc_earlycon. - { ; } ==> { } Changes in v2: None drivers/tty/serial/qcom_geni_serial.c | 32 +++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6119090ce045..6bace1c6bb09 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1090,6 +1090,36 @@ static void qcom_geni_serial_earlycon_write(struct console *con, __qcom_geni_serial_console_write(&dev->port, s, n); } +#ifdef CONFIG_CONSOLE_POLL +static int qcom_geni_serial_earlycon_read(struct console *con, + char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + struct uart_port *uport = &dev->port; + int num_read = 0; + int ch; + + while (num_read < n) { + ch = qcom_geni_serial_get_char(uport); + if (ch == NO_POLL_CHAR) + break; + s[num_read++] = ch; + } + + return num_read; +} + +static void __init qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) +{ + geni_se_setup_s_cmd(se, UART_START_READ, 0); + con->read = qcom_geni_serial_earlycon_read; +} +#else +static inline void qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) { } +#endif + static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, const char *opt) { @@ -1136,6 +1166,8 @@ static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, dev->con->write = qcom_geni_serial_earlycon_write; dev->con->setup = NULL; + qcom_geni_serial_enable_early_read(&se, dev->con); + return 0; } OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",