From nobody Tue Jun 23 16:14:52 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CF55C433EF for ; Wed, 2 Mar 2022 10:20:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240960AbiCBKUr (ORCPT ); Wed, 2 Mar 2022 05:20:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240936AbiCBKUl (ORCPT ); Wed, 2 Mar 2022 05:20:41 -0500 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67A4191AE0 for ; Wed, 2 Mar 2022 02:19:58 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id j5-20020a63e745000000b00378c359fac3so877039pgk.2 for ; Wed, 02 Mar 2022 02:19:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=Yq89WbWr/nKtI2RVDgbrgWiRqIUUvQxU4ZRP/u39Tc4=; b=lm4zJUzyhqzs2nvdFpXSR0vlIVib2Ri38tWVjvsqeYEdwiEB/dxkr1OjSZBdKRIhWP mOqCavmFBymWwOrD0rp4KYZUr0Ol+p86D4yAkeZDMOBUmioLtRyAM0Y1Re2kFojye2S9 /6G7U6K078XM38L9pSWDyY9HW4BfENWa5utIpmtqViWK+Ug7VhxoX0G30P6Y/VM7NA3s 8b6NdWbCkU5JymN+ENB5BeIRq7YDKcgcMbdIW4IuZbqJ1MlPQtNZSq9tFLPP/uvLtCWz rPBhwC6kcAIriegH5SODZ3BROXUxIylYmljIiX+77sNZvgtnxxVDyiMyoxqUfQzcmhKN yNhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=Yq89WbWr/nKtI2RVDgbrgWiRqIUUvQxU4ZRP/u39Tc4=; b=qFgvX4hyKxJa5/xbYb0lsCSpvqXwDQgDwKHKMrCh12h3G/s7euoalNArgGgCzOftd8 uhF9qx2maMN7aF29LQX3A0dfQkxsw81ZUmkr+fS2jEMlo2vHg2Y8oB9yKfyhCmvWNb2F o65FzqEWzAyGMn1Rbkie01x/P3GebktnEUV2YjJF4tJaMFmxfTzlVBz3grcQ7NuIwQYw wNLtTQsuv1v1qkyeKky7jNSYo4/TR1SgHaMq2NDUosbCT31k/fsm0j8t4LJUoXTrkLBG YajPhcubg0FIEXfi5YuA86SjvMetQIfDAXAw1Fi2Qg8j5P0B3Awfz9iGael1sV9Id42N YLkA== X-Gm-Message-State: AOAM530xUxkVcOXfk3qDxyaokhSbmNwDtvAbxYv27g1uJltnDSTRKxcM E7BgZc4VRG/7mdOU5H4Lhf0dbWf1PpvpvA== X-Google-Smtp-Source: ABdhPJzEXQNhD0xqT2s2x//pYYtesl+TerhASD0Ziddn/5GiSvMBYaO6FAMA2Ou6p+she/JPNCFbtFSgjrrJtQ== X-Received: from woodylin.ntc.corp.google.com ([2401:fa00:fc:202:3ddc:5127:fcb7:1fad]) (user=woodylin job=sendgmr) by 2002:a17:903:2285:b0:151:4b38:298e with SMTP id b5-20020a170903228500b001514b38298emr20044336plh.36.1646216397851; Wed, 02 Mar 2022 02:19:57 -0800 (PST) Date: Wed, 2 Mar 2022 18:19:25 +0800 Message-Id: <20220302101925.210810-1-woodylin@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog Subject: [PATCH] serial: samsung: Add samsung_early_read to support early kgdboc From: Woody Lin To: Krzysztof Kozlowski , Alim Akhtar Cc: Greg Kroah-Hartman , Jiri Slaby , linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, woodylin@google.com, markcheng@google.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The 'kgdboc_earlycon_init' looks for boot console that has both .read and .write callbacks. Adds 'samsung_early_read' to samsung_tty.c's early console to support kgdboc. Signed-off-by: Woody Lin --- drivers/tty/serial/samsung_tty.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_= tty.c index d002a4e48ed9..eeb30d016ff1 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -2949,6 +2949,7 @@ static void wr_reg_barrier(struct uart_port *port, u3= 2 reg, u32 val) =20 struct samsung_early_console_data { u32 txfull_mask; + u32 rxfifo_mask; }; =20 static void samsung_early_busyuart(struct uart_port *port) @@ -2983,6 +2984,26 @@ static void samsung_early_write(struct console *con,= const char *s, uart_console_write(&dev->port, s, n, samsung_early_putc); } =20 +static int samsung_early_read(struct console *con, char *s, unsigned int n) +{ + struct earlycon_device *dev =3D con->data; + struct samsung_early_console_data *data =3D dev->port.private_data; + int ch, ufstat, num_read =3D 0; + + while (num_read < n) { + ufstat =3D rd_regl(&dev->port, S3C2410_UFSTAT); + if (!(ufstat & data->rxfifo_mask)) + break; + ch =3D rd_reg(&dev->port, S3C2410_URXH); + if (ch =3D=3D NO_POLL_CHAR) + break; + + s[num_read++] =3D ch; + } + + return num_read; +} + static int __init samsung_early_console_setup(struct earlycon_device *devi= ce, const char *opt) { @@ -2990,12 +3011,14 @@ static int __init samsung_early_console_setup(struc= t earlycon_device *device, return -ENODEV; =20 device->con->write =3D samsung_early_write; + device->con->read =3D samsung_early_read; return 0; } =20 /* S3C2410 */ static struct samsung_early_console_data s3c2410_early_console_data =3D { .txfull_mask =3D S3C2410_UFSTAT_TXFULL, + .rxfifo_mask =3D S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK, }; =20 static int __init s3c2410_early_console_setup(struct earlycon_device *devi= ce, @@ -3011,6 +3034,7 @@ OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart", /* S3C2412, S3C2440, S3C64xx */ static struct samsung_early_console_data s3c2440_early_console_data =3D { .txfull_mask =3D S3C2440_UFSTAT_TXFULL, + .rxfifo_mask =3D S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK, }; =20 static int __init s3c2440_early_console_setup(struct earlycon_device *devi= ce, @@ -3030,6 +3054,7 @@ OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart", /* S5PV210, Exynos */ static struct samsung_early_console_data s5pv210_early_console_data =3D { .txfull_mask =3D S5PV210_UFSTAT_TXFULL, + .rxfifo_mask =3D S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK, }; =20 static int __init s5pv210_early_console_setup(struct earlycon_device *devi= ce, --=20 2.35.1.574.g5d30c73bfb-goog