From patchwork Wed Oct 16 16:15:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jagan Teki X-Patchwork-Id: 1178006 X-Patchwork-Delegate: jagannadh.teki@gmail.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.denx.de (client-ip=81.169.180.215; helo=lists.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=amarulasolutions.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="UNmkF//1"; dkim-atps=neutral Received: from lists.denx.de (dione.denx.de [81.169.180.215]) by ozlabs.org (Postfix) with ESMTP id 46tcqF2Xcwz9sP7 for ; Thu, 17 Oct 2019 03:16:09 +1100 (AEDT) Received: by lists.denx.de (Postfix, from userid 105) id E8530C21DB6; Wed, 16 Oct 2019 16:16:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lists.denx.de X-Spam-Level: X-Spam-Status: No, score=-0.0 required=5.0 tests=RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, T_DKIM_INVALID autolearn=unavailable autolearn_force=no version=3.4.0 Received: from lists.denx.de (localhost [IPv6:::1]) by lists.denx.de (Postfix) with ESMTP id 9760DC21C57; Wed, 16 Oct 2019 16:16:00 +0000 (UTC) Received: by lists.denx.de (Postfix, from userid 105) id D66A5C21C57; Wed, 16 Oct 2019 16:15:59 +0000 (UTC) Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) by lists.denx.de (Postfix) with ESMTPS id 477E1C21BE5 for ; Wed, 16 Oct 2019 16:15:59 +0000 (UTC) Received: by mail-pl1-f195.google.com with SMTP id c3so11502085plo.2 for ; Wed, 16 Oct 2019 09:15:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Xf2lKPvdtftLrHWAs787N+LXTsMuMCdxM2LHIHXr/3s=; b=UNmkF//1wkEs9ARxEj/FTFmDg7TWdeWU8K8R3vPLJ9WBExMAGPps3y7K/nF/1S3W7C A0ZtFmbZmGseSLBzqV1btFG8oxCxiLEIeyBZHL/qzFSk6gybCLwpj71pJE6OoGwFJ6k5 t8I/7+8eMyI7xkNDn4+MKLNra0KuRGp3D3o5k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Xf2lKPvdtftLrHWAs787N+LXTsMuMCdxM2LHIHXr/3s=; b=FdhzfOlHmmrJFmQXYIpx6OmtkSCQSAoVjERUYYAUnILnTOY3vE8q917dNGRfLzdFfF KYoANjb7OdeQWNGEsV9F4epE0Aux2fwGZQZI2ekIl0W3VlKVbqAVW3IaqBsNwMMWCVZ1 OafBhVg+dki5HWIdnc2alBjdooGhMqPIIQGae5EgcOO8a45RT0P2pBepyG8AXfvDD23g suBMFs1DySWTDG2lJ2J21ciyW0Ttp2P5CdtoZ90Mb/7u8K6mimaXwJiQ+jup/jlLcj87 sgInm7bWCehEEw6f+5mR7xkBGAptHvCtCzUuhs4JN63wjBPzALBCxMTfKmvygOqfCf7M u61A== X-Gm-Message-State: APjAAAXFWDUgzBRmoJLn2Dso6J6BTr0jAzvrAXBNG65XytU2vPHGSvZA vfB8SaTEnjygwzluRdc8AdEMwd8k+NM= X-Google-Smtp-Source: APXvYqx7Q35yCXxjMfZjPTLYC8/RKuX+nb9rJwpJE9xvKtfgZNVZsYnDkg6DNOjr+vwK2rtPhtmAoQ== X-Received: by 2002:a17:902:8bc4:: with SMTP id r4mr40250373plo.341.1571242557047; Wed, 16 Oct 2019 09:15:57 -0700 (PDT) Received: from localhost.localdomain ([115.97.180.31]) by smtp.gmail.com with ESMTPSA id x10sm9741783pgl.53.2019.10.16.09.15.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Oct 2019 09:15:54 -0700 (PDT) From: Jagan Teki To: u-boot@lists.denx.de Date: Wed, 16 Oct 2019 21:45:47 +0530 Message-Id: <20191016161547.3079-1-jagan@amarulasolutions.com> X-Mailer: git-send-email 2.18.0.321.gffc6fa0e3 MIME-Version: 1.0 Subject: [U-Boot] [PATCH] spi: Kconfig: Add help text X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.18 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" Add detailed help text for SPI support. Signed-off-by: Jagan Teki --- drivers/spi/Kconfig | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index b8ca2bdedd..0152dff74f 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -1,5 +1,22 @@ menuconfig SPI bool "SPI Support" + help + The "Serial Peripheral Interface" is a low level synchronous + protocol. Chips that support SPI can have data transfer rates + up to several tens of Mbit/sec. Chips are addressed with a + controller and a chipselect. Most SPI slaves don't support + dynamic device discovery; some are even write-only or read-only. + + SPI is widely used by microcontrollers to talk with sensors, + eeprom and flash memory, codecs and various other controller + chips, analog to digital (and d-to-a) converters, and more. + MMC and SD cards can be accessed using SPI protocol; and for + DataFlash cards used in MMC sockets, SPI must always be used. + + SPI is one of a family of similar protocols using a four wire + interface (select, clock, data in, data out) including Microwire + (half duplex), SSP, SSI, and PSP. This driver framework should + work with most such devices and controllers. if SPI