From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3493875-1519407128-2-15163643317385950968 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-serial-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519407127; b=tEkN0iGxRkwnfo2LBEIT40Yo4f7WGMD6I/U5MOcDUWCdH16 KZRhoczmYPzNMHiJFNmoMfk6oi3swlYY96atteATpFXYbZfxADZPGy+l3dZQ5A9W GFflz4It1tGlW8UJvReuWUel/B0nwu7jzsCWLDsooExFAWh0MWazKND1fpgvaJaP bT3wcmU64aP5t5g9SdVtO4EVxybDE2M1a3oPICvc/A8243gYo6WQaCeTl2hfRSe/ TST4C9Bfo7E96KKSJwmgmUaMbF9nqQLt+uAvtfE1uI/6qOefVBxtzsod0w4kAxPJ rt07OZyFkL3gP2raNhEzkKfJ98G5SeUdqh0cALA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=message-id:subject:from:to:cc:date :in-reply-to:references:content-type:mime-version :content-transfer-encoding:sender:list-id; s=arctest; t= 1519407127; bh=QrCIRLupZcuQMcNelqCHiFLe1oArP0jTaHL9tmOZA48=; b=Y nGRVYnnWXAQ39fw1QolBjVTsCXQR9JyKSvqpVTrZFMbuloRRxuEFMLZEmXTmm5S0 zmsqFNQxGYYiN/glpDdGb/lCS3GBvrIi7/g187EEWM2H5Z22+Oiq5GUafrpaeN40 2pbTyIgPRTDs0zPH4XRn2njI5OYL/j1s6FM8kUgLLm9LpSB3O0mexe9woLY3+qC3 +/ivdBs1gFfVZOkIQdIyPCb++CE7IPieRFGvGOqBLIRCXoMNKEt2GBe0jGtPTA0X 2Uwlt2Aqcj135NebXCXsHDlHrfJ8iX90s6cqCy5LMpPozC3ilMcUwIavlBkXsxtS A7vKgalFYuBPFIQY8rxMA== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linux.intel.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-serial-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linux.intel.com header.result=pass header_org.domain=intel.com header_org.result=pass header_is_org_domain=no Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linux.intel.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-serial-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linux.intel.com header.result=pass header_org.domain=intel.com header_org.result=pass header_is_org_domain=no Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751463AbeBWRcC (ORCPT ); Fri, 23 Feb 2018 12:32:02 -0500 Received: from mga07.intel.com ([134.134.136.100]:1496 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751351AbeBWRcB (ORCPT ); Fri, 23 Feb 2018 12:32:01 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,383,1515484800"; d="scan'208";a="29304156" Message-ID: <1519407117.10722.124.camel@linux.intel.com> Subject: Re: [RFC PATCH 0/2] serial: 8250_dw: IO space + polling mode support From: Andy Shevchenko To: John Garry , gregkh@linuxfoundation.org, jslaby@suse.com, p.zabel@pengutronix.de, heiko@sntech.de, ed.blake@sondrel.com, jhogan@kernel.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com Date: Fri, 23 Feb 2018 19:31:57 +0200 In-Reply-To: <3c4c5f58-a661-13c8-cc1c-8d43828982cb@huawei.com> References: <1519324923-196857-1-git-send-email-john.garry@huawei.com> <1519381801.10722.103.camel@linux.intel.com> <3c4c5f58-a661-13c8-cc1c-8d43828982cb@huawei.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.5-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-serial-owner@vger.kernel.org X-Mailing-List: linux-serial@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Fri, 2018-02-23 at 11:02 +0000, John Garry wrote: > On 23/02/2018 10:30, Andy Shevchenko wrote: > > On Fri, 2018-02-23 at 02:42 +0800, John Garry wrote: > > > There is a requirement > > > Where? > > We require it for a development board for our hip06 platform. Okay, and this particular platform uses Synopsys IP? > > > for supporting an 8250-compatible UART with > > > the following profile/features: > > > - platform device > > > - polling mode (i.e. no interrupt support) > > > - ACPI FW > > > > Elaborate this one, please. > > So we need to define our own HID here, and cannot use PNP compatible > CID > (like PNP0501) as we cannot use the 8250 PNP driver. Why not? What are the impediments? > This is related to the Hisi LPC ACPI support, where we would create > an > MFD (i.e. platform device) for the UART. Why you can't do properly in ACPI? > > > - IO port iotype > > > - 16550-compatible > > > > > > For OF, we have 8250_of.c, and for PNP device we have 8250_pnp.c > > > drivers. However there does not seem to any driver satisfying > > > the above requirements. So this RFC is to find opinion on > > > modifying the Synopsys DW 8250_dw.c driver to support these > > > generic features. > > > > Synopsys 8250 is a particular case of platform drivers. It doesn't > > satisfy "8250-compatible UART" requirement. > Right, but I wanted to try to use the generic parts of the driver to > support this UART to save writing yet another driver. It's still odd. Why this one, why not 8250_foo_bar to touch instead? -- Andy Shevchenko Intel Finland Oy