From patchwork Thu Jul 13 22:36:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 9839671 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CE4B8602D8 for ; Thu, 13 Jul 2017 22:38:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0196627F8F for ; Thu, 13 Jul 2017 22:38:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EA4812808F; Thu, 13 Jul 2017 22:38:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B00C27F8F for ; Thu, 13 Jul 2017 22:38:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752072AbdGMWis (ORCPT ); Thu, 13 Jul 2017 18:38:48 -0400 Received: from mailout3.hostsharing.net ([176.9.242.54]:55085 "EHLO mailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751216AbdGMWir (ORCPT ); Thu, 13 Jul 2017 18:38:47 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailout3.hostsharing.net (Postfix) with ESMTPS id 39274101DE6BF; Fri, 14 Jul 2017 00:38:46 +0200 (CEST) Received: from localhost (5-38-90-81.adsl.cmo.de [81.90.38.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 55093604DB9F; Fri, 14 Jul 2017 00:38:44 +0200 (CEST) X-Mailbox-Line: From c137d15be96c954f405bda5acaaf730cccc8e601 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Fri, 14 Jul 2017 00:36:19 +0200 Subject: [PATCH v3 6/6] spi: Use Apple device properties in absence of ACPI resources MIME-Version: 1.0 To: "Rafael J. Wysocki" Cc: Ronald Tschalaer , Federico Lorenzi , Mika Westerberg , Andy Shevchenko , Lv Zheng , Leif Liddy , Daniel Roschka , Mark Brown , linux-acpi@vger.kernel.org, linux-spi@vger.kernel.org Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP MacBooks and MacBook Pros introduced since 2015 return empty _CRS data for SPI slaves, causing device initialization to fail. Most of the information that would normally be conveyed via _CRS is available through ACPI device properties instead, so take advantage of them. The meaning and appropriate usage of the device properties was reverse engineered by Ronald Tschalär and carried over from these commits authored by him: https://github.com/cb22/macbook12-spi-driver/commit/9a416d699ef4 https://github.com/cb22/macbook12-spi-driver/commit/0c34936ed9a1 According to Ronald, the device properties have the following meaning: spiSclkPeriod /* period in ns */ spiWordSize /* in number of bits */ spiBitOrder /* 1 = MSB_FIRST, 0 = LSB_FIRST */ spiSPO /* clock polarity: 0 = low, 1 = high */ spiSPH /* clock phase: 0 = first, 1 = second */ spiCSDelay /* delay between cs and receive on reads in 10 us */ resetA2RUsec /* active-to-receive delay? */ resetRecUsec /* receive delay? */ Cc: Federico Lorenzi Reported-by: Leif Liddy Tested-by: Ronald Tschalär Acked-by: Mark Brown Acked-by: Mika Westerberg Signed-off-by: Lukas Wunner Reviewed-by: Andy Shevchenko --- Changes v2 -> v3: - Check buffer length for extra safety. Rename "o" to "obj", use 32 bit division to calculate max_speed_hz. (Andy) drivers/spi/spi.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 4fcbb0aa71d3..cce133057700 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1693,6 +1693,35 @@ static void of_register_spi_devices(struct spi_controller *ctlr) { } #endif #ifdef CONFIG_ACPI +static void acpi_spi_parse_apple_properties(struct spi_device *spi) +{ + struct acpi_device *dev = ACPI_COMPANION(&spi->dev); + const union acpi_object *obj; + + if (!is_apple_system) + return; + + if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length >= 4) + spi->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; + + if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8) + spi->bits_per_word = *(u64 *)obj->buffer.pointer; + + if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) + spi->mode |= SPI_LSB_FIRST; + + if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + spi->mode |= SPI_CPOL; + + if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + spi->mode |= SPI_CPHA; +} + static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) { struct spi_device *spi = data; @@ -1766,6 +1795,8 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, acpi_spi_add_resource, spi); acpi_dev_free_resource_list(&resource_list); + acpi_spi_parse_apple_properties(spi); + if (ret < 0 || !spi->max_speed_hz) { spi_dev_put(spi); return AE_OK;