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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01F19C433FE for ; Wed, 19 Jan 2022 06:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351658AbiASGAz (ORCPT ); Wed, 19 Jan 2022 01:00:55 -0500 Received: from mail-sh.amlogic.com ([58.32.228.43]:6385 "EHLO mail-sh.amlogic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349845AbiASGAs (ORCPT ); Wed, 19 Jan 2022 01:00:48 -0500 Received: from [10.18.29.173] (10.18.29.173) by mail-sh.amlogic.com (10.18.11.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.14; Wed, 19 Jan 2022 14:00:45 +0800 Message-ID: <21eea0cd-5bf1-dec6-a776-f417aefa5bda@amlogic.com> Date: Wed, 19 Jan 2022 14:00:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH V6 3/5] tty: serial: meson: Describes the calculation of the UART baud rate clock using a clock frame Content-Language: en-US To: Jiri Slaby , , , , CC: Greg Kroah-Hartman , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl References: <20220118030911.12815-1-yu.tu@amlogic.com> <20220118030911.12815-4-yu.tu@amlogic.com> <7a8016ba-730b-f599-2032-31cf03990a55@kernel.org> From: Yu Tu In-Reply-To: <7a8016ba-730b-f599-2032-31cf03990a55@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.18.29.173] X-ClientProxiedBy: mail-sh.amlogic.com (10.18.11.5) To mail-sh.amlogic.com (10.18.11.5) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jiri, Thank you very much for your patient reply.I learned a lot from your response. On 2022/1/18 17:39, Jiri Slaby wrote: > [ EXTERNAL EMAIL ] > > On 18. 01. 22, 4:09, Yu Tu wrote: >> Using the common Clock code to describe the UART baud rate clock >> makes it easier for the UART driver to be compatible with the >> baud rate requirements of the UART IP on different meson chips. > ... >> --- a/drivers/tty/serial/meson_uart.c >> +++ b/drivers/tty/serial/meson_uart.c > ... >> @@ -629,57 +640,105 @@ static struct uart_driver meson_uart_driver = { >>       .cons        = MESON_SERIAL_CONSOLE, >>   }; >> -static inline struct clk *meson_uart_probe_clock(struct device *dev, >> -                         const char *id) >> -{ >> -    struct clk *clk = NULL; >> -    int ret; >> - >> -    clk = devm_clk_get(dev, id); >> -    if (IS_ERR(clk)) >> -        return clk; >> - >> -    ret = clk_prepare_enable(clk); >> -    if (ret) { >> -        dev_err(dev, "couldn't enable clk\n"); >> -        return ERR_PTR(ret); >> -    } >> - >> -    devm_add_action_or_reset(dev, >> -            (void(*)(void *))clk_disable_unprepare, >> -            clk); >> - >> -    return clk; >> -} >> +static struct clk_div_table xtal_div_table[] = { > > This can be const, right? You are right. > >> +    {0, 3}, >> +    {1, 1}, >> +    {2, 2}, >> +    {3, 2}, > > Not sure if you didn't remove too much whitespace. I think it should be > like: "{ 0, 3 },". But I actually don't care, it's a minor thing. > Ok, I will correct it if it needs to be changed. > I cannot comment on the rest (clk and OF part) as my knowledge is pretty > limited there. Leaving up to others. > Anyway, thanks for your reply. > thanks,