From patchwork Wed Mar 2 10:19:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Woody Lin X-Patchwork-Id: 548019 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 6AF9DC433F5 for ; Wed, 2 Mar 2022 10:20:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240952AbiCBKUl (ORCPT ); Wed, 2 Mar 2022 05:20:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231748AbiCBKUl (ORCPT ); Wed, 2 Mar 2022 05:20:41 -0500 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 668789134D for ; Wed, 2 Mar 2022 02:19:58 -0800 (PST) Received: by mail-pf1-x44a.google.com with SMTP id k130-20020a628488000000b004f362b45f28so1026749pfd.9 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=Fq02AztH2CX+/9EDwOi7e6Y98FgXLcFYk8jyEQNDSfQqDYCP6SnrZKrJXdfslo4Lj3 Rk+PcOnPzD0fCfwovrlADezgLb1nR2HIS1n+5kWIB7QeJ9+cPsls/UjOPBLfO+9/c7ME V7uE1vxyV2Lt4mHEdFSljqQDVCQCfqCnKFW67MgJZxEYKwVa9QxiAl2XSUfXVTpExwxz xpHsQucEdA4D8BzFfHy6w8elEILUx82MHS6bi8BuNSeOtbezaZVKRBQNW8yvi6WgJFmR TKXZJ5rJlvV87pqp/YlUFP2lKN07p7n6edwRhmIhCuJK+zdqdTrqYCLceVQ6awMh6hfa a8lQ== X-Gm-Message-State: AOAM532iNamZxiuJ+4rHoLaXo+FZkqlyQGng/PqSFZJwbBpP4bkY3JQc p3SjuC/Rd/4gzbQNcXwc8FAvToEAmtkWxA== 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-samsung-soc@vger.kernel.org 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, u32 reg, u32 val) struct samsung_early_console_data { u32 txfull_mask; + u32 rxfifo_mask; }; 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); } +static int samsung_early_read(struct console *con, char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + struct samsung_early_console_data *data = dev->port.private_data; + int ch, ufstat, num_read = 0; + + while (num_read < n) { + ufstat = rd_regl(&dev->port, S3C2410_UFSTAT); + if (!(ufstat & data->rxfifo_mask)) + break; + ch = rd_reg(&dev->port, S3C2410_URXH); + if (ch == NO_POLL_CHAR) + break; + + s[num_read++] = ch; + } + + return num_read; +} + static int __init samsung_early_console_setup(struct earlycon_device *device, const char *opt) { @@ -2990,12 +3011,14 @@ static int __init samsung_early_console_setup(struct earlycon_device *device, return -ENODEV; device->con->write = samsung_early_write; + device->con->read = samsung_early_read; return 0; } /* S3C2410 */ static struct samsung_early_console_data s3c2410_early_console_data = { .txfull_mask = S3C2410_UFSTAT_TXFULL, + .rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK, }; static int __init s3c2410_early_console_setup(struct earlycon_device *device, @@ -3011,6 +3034,7 @@ OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart", /* S3C2412, S3C2440, S3C64xx */ static struct samsung_early_console_data s3c2440_early_console_data = { .txfull_mask = S3C2440_UFSTAT_TXFULL, + .rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK, }; static int __init s3c2440_early_console_setup(struct earlycon_device *device, @@ -3030,6 +3054,7 @@ OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart", /* S5PV210, Exynos */ static struct samsung_early_console_data s5pv210_early_console_data = { .txfull_mask = S5PV210_UFSTAT_TXFULL, + .rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK, }; static int __init s5pv210_early_console_setup(struct earlycon_device *device,