From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B69E1231A21; Mon, 29 Sep 2025 06:27:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759127220; cv=none; b=irZRzPZqSknu+qThN0NbCniHNCm87dNmRHGlG7dH4vH+33oT7TzkDAIqhM8ZLS96Mm5mZ+syJ+alVmjap5aoDlkRwKDMIrEJ/a7dtc1Z/zUQQWgtZhbh4gvVB2YZm5IJ+n8iFTeAlaFRay7uO2qdBQ5pdGY8rIDQTqUedydDtqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759127220; c=relaxed/simple; bh=YNr2IXX+FEDhdPm3XMK+GnoSYVTDwv1s5NcrSp4kehE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZTPzGx/DXZ8QPgopK35FEdU6bJx1k8I6tc0KrEhk862rVHB18DlzcuSDgTczXogl28dq+J3J1WDZi240385NLZJUz0BAM2Ir9tPJwMiSAspgEzyceNuq7xfPEX+dOQOjCrS7XlgExtv6DB6D5gjxTCGb4KlmFsDKpA4I0A6tBXU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qHx+XT5l; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qHx+XT5l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C40FEC4CEF4; Mon, 29 Sep 2025 06:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759127220; bh=YNr2IXX+FEDhdPm3XMK+GnoSYVTDwv1s5NcrSp4kehE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qHx+XT5ljIFU/BApDIy0waMYHfa0mwQnhXGgLSTanImnAX2Ef6NA1Wmdhc4AjUb7a sIEi1OR1R70gH/QJI1bUuiyoRsn9vi+sYTfb5csunWkQOxilfpK4Jzap9ZBEN48yWg bqutEQ3dUHrvTw0iG7FieSgvRdPpge0fsqAHLrK/Sncb3O0XTSif8ce1e7JLGG7QZZ n6X9FXKIm3rSRIeKyHgp227sZvvEteDI10HAv+36b29jBcrrcK4C+gmfHFdJQGQX7M 5HRk1RfhfxfactSB6dPJ/f3j4NU6bmhfagAgs6VzkXf+Fa/E48jPQBADfJM1xpGQL2 GTugBYQytAnGA== Message-ID: Date: Mon, 29 Sep 2025 08:26:56 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 2/3] serial: 8250: Add Loongson uart driver support To: Binbin Zhou , Binbin Zhou , Huacai Chen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Greg Kroah-Hartman , Haowei Zheng Cc: Huacai Chen , Xuerui Wang , loongarch@lists.linux.dev, devicetree@vger.kernel.org, linux-serial@vger.kernel.org References: <9823e7afe713450e210dab9dba6fa18683dc1fe0.1758676290.git.zhoubinbin@loongson.cn> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 24. 09. 25, 8:29, Binbin Zhou wrote: > Add the driver for on-chip UART used on Loongson family chips. > > The hardware is similar to 8250, but there are the following > differences: > - Some chips (such as Loongson-2K2000) have added a fractional division > register to obtain the required baud rate accurately, so the > {get,set}_divisor callback is overridden. > - Due to hardware defects, quirk handling is required for > UART_MCR/UART_MSR. So how hard would be to implement this in 8250 using existing (or new) callbacks+quirks? > --- /dev/null > +++ b/drivers/tty/serial/8250/8250_loongson.c > @@ -0,0 +1,202 @@ ... > +struct loongson_uart_data { > + int line; > + int mcr_invert; > + int msr_invert; These two should be unsigned. They should be u8, actually. > + struct reset_control *rst; > +}; > + > +static unsigned int serial_fixup(struct uart_port *p, unsigned int offset, unsigned int val) Both 'val' and ret type should be u8. > +{ > + struct loongson_uart_data *ddata = p->private_data; > + > + if (offset == UART_MCR) > + val ^= ddata->mcr_invert; > + > + if (offset == UART_MSR) > + val ^= ddata->msr_invert; > + > + return val; > +} > + > +static u32 loongson_serial_in(struct uart_port *p, unsigned int offset) > +{ > + unsigned int val; u8 > + > + val = readb(p->membase + (offset << p->regshift)); > + > + return serial_fixup(p, offset, val); > +} thanks, -- js suse labs