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: 12637039 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BDD8CC433EF for ; Wed, 24 Nov 2021 15:08:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E64796E940; Wed, 24 Nov 2021 15:08:24 +0000 (UTC) Received: from asav21.altibox.net (asav21.altibox.net [109.247.116.8]) by gabe.freedesktop.org (Postfix) with ESMTPS id 743BB6E947 for ; Wed, 24 Nov 2021 15:08:23 +0000 (UTC) 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 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 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, linux-fbdev@vger.kernel.org, dave.stevenson@raspberrypi.com, linux-staging@lists.linux.dev, dri-devel@lists.freedesktop.org, =?utf-8?q?Noralf_Tr=C3=B8nnes?= , maxime@cerno.tech Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 Acked-by: Rob Herring Acked-by: David Lechner --- .../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