From patchwork Wed Nov 24 15:07:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Noralf_Tr=C3=B8nnes?= X-Patchwork-Id: 517041 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 30ADAC43219 for ; Wed, 24 Nov 2021 15:08:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229656AbhKXPLk (ORCPT ); Wed, 24 Nov 2021 10:11:40 -0500 Received: from asav21.altibox.net ([109.247.116.8]:53580 "EHLO asav21.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229701AbhKXPLj (ORCPT ); Wed, 24 Nov 2021 10:11:39 -0500 Received: from localhost.localdomain (211.81-166-168.customer.lyse.net [81.166.168.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: noralf.tronnes@ebnett.no) by asav21.altibox.net (Postfix) with ESMTPSA id 618D4800A7; Wed, 24 Nov 2021 16:08:21 +0100 (CET) From: =?utf-8?q?Noralf_Tr=C3=B8nnes?= To: robh+dt@kernel.org, david@lechnology.com Cc: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-staging@lists.linux.dev, dave.stevenson@raspberrypi.com, maxime@cerno.tech, =?utf-8?q?Noralf_Tr?= =?utf-8?q?=C3=B8nnes?= Subject: [PATCH 3/6] dt-bindings: display: sitronix,st7735r: Remove spi-max-frequency limit Date: Wed, 24 Nov 2021 16:07:54 +0100 Message-Id: <20211124150757.17929-4-noralf@tronnes.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211124150757.17929-1-noralf@tronnes.org> References: <20211124150757.17929-1-noralf@tronnes.org> MIME-Version: 1.0 X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=ZLv5Z0zb c=1 sm=1 tr=0 a=OYZzhG0JTxDrWp/F2OJbnw==:117 a=OYZzhG0JTxDrWp/F2OJbnw==:17 a=IkcTkHD0fZMA:10 a=M51BFTxLslgA:10 a=SJz97ENfAAAA:8 a=3IttHYtGSP5F0p6lhesA:9 a=7Zwj6sZBwVKJAoWSPKxL6X1jA+E=:19 a=QEXdDO2ut3YA:10 a=vFet0B0WnEQeilDPIY6i:22 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The datasheet lists the minimum Serial clock cycle (Write) as 66ns which is 15MHz. Mostly it can do much better than that and is in fact often run at 32MHz. With a clever driver that runs configuration commands at a low speed and only the pixel data at the maximum speed the configuration can't be messed up by transfer errors and the speed is only limited by the amount of pixel glitches that one is able to tolerate. Signed-off-by: Noralf Trønnes --- .../devicetree/bindings/display/sitronix,st7735r.yaml | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml b/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml index f81d0d0d51fe..157b1a7b18f9 100644 --- a/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml +++ b/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml @@ -32,15 +32,13 @@ properties: - okaya,rh128128t - const: sitronix,st7715r - spi-max-frequency: - maximum: 32000000 - dc-gpios: maxItems: 1 description: Display data/command selection (D/CX) backlight: true reg: true + spi-max-frequency: true reset-gpios: true rotation: true