From patchwork Thu Jun 18 12:27:12 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sifan Naeem X-Patchwork-Id: 6636631 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DE7549F358 for ; Thu, 18 Jun 2015 12:25:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 11DBB2083B for ; Thu, 18 Jun 2015 12:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BA4320827 for ; Thu, 18 Jun 2015 12:25:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753159AbbFRMZc (ORCPT ); Thu, 18 Jun 2015 08:25:32 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:48823 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753799AbbFRMZb (ORCPT ); Thu, 18 Jun 2015 08:25:31 -0400 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 9AAA4B513F4DC; Thu, 18 Jun 2015 13:25:27 +0100 (IST) Received: from hhmail02.hh.imgtec.org (10.100.10.20) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 18 Jun 2015 13:25:29 +0100 Received: from iw-build-3.kl.imgtec.org (192.168.167.63) by hhmail02.hh.imgtec.org (10.100.10.20) with Microsoft SMTP Server (TLS) id 14.3.224.2; Thu, 18 Jun 2015 13:25:29 +0100 From: Sifan Naeem To: CC: , , , Sifan Naeem Subject: [PATCH v2] spi: img-spfi: check for max speed supported by the spfi block Date: Thu, 18 Jun 2015 13:27:12 +0100 Message-ID: <1434630432-10392-1-git-send-email-sifan.naeem@imgtec.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-Originating-IP: [192.168.167.63] Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Maximum speed supported by spfi is limited to 1/4 of the spfi clock. But in some SoCs the maximum speed supported by the spfi block can be limited to less than 1/4 of the spfi clock. In such cases we have to define the limit in the device tree so that the driver can pick it up. Signed-off-by: Sifan Naeem --- changes from v1: coding style fix. .../devicetree/bindings/spi/spi-img-spfi.txt | 1 + drivers/spi/spi-img-spfi.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt index e02fbf1..494db60 100644 --- a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt +++ b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt @@ -21,6 +21,7 @@ Required properties: Optional properties: - img,supports-quad-mode: Should be set if the interface supports quad mode SPI transfers. +- spfi-max-frequency: Maximum speed supported by the spfi block. Example: diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c index acce90a..00f1ac3 100644 --- a/drivers/spi/spi-img-spfi.c +++ b/drivers/spi/spi-img-spfi.c @@ -548,6 +548,7 @@ static int img_spfi_probe(struct platform_device *pdev) struct img_spfi *spfi; struct resource *res; int ret; + u32 max_speed_hz; master = spi_alloc_master(&pdev->dev, sizeof(*spfi)); if (!master) @@ -612,6 +613,19 @@ static int img_spfi_probe(struct platform_device *pdev) master->max_speed_hz = clk_get_rate(spfi->spfi_clk) / 4; master->min_speed_hz = clk_get_rate(spfi->spfi_clk) / 512; + /* + * Maximum speed supported by spfi is limited to the lower value + * between 1/4 of the SPFI clock or to "spfi-max-frequency" + * defined in the device tree. + * If no value is defined in the device tree assume the maximum + * speed supported to be 1/4 of the SPFI clock. + */ + if (!of_property_read_u32(spfi->dev->of_node, "spfi-max-frequency", + &max_speed_hz)) { + if (master->max_speed_hz > max_speed_hz) + master->max_speed_hz = max_speed_hz; + } + master->setup = img_spfi_setup; master->cleanup = img_spfi_cleanup; master->transfer_one = img_spfi_transfer_one;