From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Brandt Date: Mon, 06 Aug 2018 14:18:17 +0000 Subject: RE: [PATCH/RFC 4/4] sh-sci: Derive regshift value from DT compatible value Message-Id: List-Id: References: <20180806140755.24087-1-geert+renesas@glider.be> <20180806140755.24087-5-geert+renesas@glider.be> In-Reply-To: <20180806140755.24087-5-geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Geert Uytterhoeven , Laurent Pinchart , Ulrich Hecht , Yoshinori Sato Cc: Greg Kroah-Hartman , Jiri Slaby , "linux-renesas-soc@vger.kernel.org" , "linux-sh@vger.kernel.org" , "linux-serial@vger.kernel.org" Hi Geert, On Monday, August 06, 2018 1, linux-sh-owner@vger.kernel.org wrote: > Deriving the proper regshift value from the register block size is > fragile (it may have been rounded up in DT, and the mapping granularity > is usually PAGE_SIZE anyway), and turned out to be inappropriate for > earlycon support (the size is not easily available). > > On DT systems, derive it from the compatible value instead. > This requires adding an entry for RZ/A2 serial ports, which use an > atypical regshift value. I had a simple patch to add support for CONFIG_DEBUG_LL for RZ/A2 because earlycon never worked because of RZ/A2's different register locations. I'll have to see how things change (better?) with this patch. Chris From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relmlor3.renesas.com ([210.160.252.173]:35408 "EHLO relmlie2.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729374AbeHFQ1n (ORCPT ); Mon, 6 Aug 2018 12:27:43 -0400 From: Chris Brandt To: Geert Uytterhoeven , Laurent Pinchart , Ulrich Hecht , Yoshinori Sato CC: Greg Kroah-Hartman , Jiri Slaby , "linux-renesas-soc@vger.kernel.org" , "linux-sh@vger.kernel.org" , "linux-serial@vger.kernel.org" Subject: RE: [PATCH/RFC 4/4] sh-sci: Derive regshift value from DT compatible value Date: Mon, 6 Aug 2018 14:18:17 +0000 Message-ID: References: <20180806140755.24087-1-geert+renesas@glider.be> <20180806140755.24087-5-geert+renesas@glider.be> In-Reply-To: <20180806140755.24087-5-geert+renesas@glider.be> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi Geert, On Monday, August 06, 2018 1, linux-sh-owner@vger.kernel.org wrote: > Deriving the proper regshift value from the register block size is > fragile (it may have been rounded up in DT, and the mapping granularity > is usually PAGE_SIZE anyway), and turned out to be inappropriate for > earlycon support (the size is not easily available). >=20 > On DT systems, derive it from the compatible value instead. > This requires adding an entry for RZ/A2 serial ports, which use an > atypical regshift value. I had a simple patch to add support for CONFIG_DEBUG_LL for RZ/A2=20 because earlycon never worked because of RZ/A2's different register locatio= ns. I'll have to see how things change (better?) with this patch. Chris