From patchwork Tue Mar 21 12:43:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Ungerer X-Patchwork-Id: 9636549 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 8A260602CC for ; Tue, 21 Mar 2017 12:47:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7B7F727C0B for ; Tue, 21 Mar 2017 12:47:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6F82227E22; Tue, 21 Mar 2017 12:47:56 +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 1BB6727C0B for ; Tue, 21 Mar 2017 12:47:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757239AbdCUMr4 (ORCPT ); Tue, 21 Mar 2017 08:47:56 -0400 Received: from icp-osb-irony-out4.external.iinet.net.au ([203.59.1.220]:36616 "EHLO icp-osb-irony-out4.external.iinet.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757092AbdCUMrz (ORCPT ); Tue, 21 Mar 2017 08:47:55 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2AvAgCqH9FY/zXSMGdeHAEBBAEBCgEBg1GBa41ykDIBAQEGlmeCDhqGCAKDDD8YAQIBAQEBAQEBayiFFgYnUhAYJxJXGYl3DKxJOiYCiioBMYYJilSFGQWcTQGSSIpshj+TXh84gQQjFggkCEGGaS41iUEBAQE X-IPAS-Result: A2AvAgCqH9FY/zXSMGdeHAEBBAEBCgEBg1GBa41ykDIBAQEGlmeCDhqGCAKDDD8YAQIBAQEBAQEBayiFFgYnUhAYJxJXGYl3DKxJOiYCiioBMYYJilSFGQWcTQGSSIpshj+TXh84gQQjFggkCEGGaS41iUEBAQE X-IronPort-AV: E=Sophos;i="5.36,198,1486396800"; d="scan'208";a="246776697" Received: from unknown (HELO goober.accelecon.com) ([103.48.210.53]) by icp-osb-irony-out4.iinet.net.au with ESMTP; 21 Mar 2017 20:43:49 +0800 From: Greg Ungerer To: linux-spi@vger.kernel.org Cc: shawnguo@kernel.org, kernel@pengutronix.de, fabio.estevam@nxp.com, Greg Ungerer Subject: [PATCHv2 1/2] spi: imx: fix use of native chip-selects with devicetree Date: Tue, 21 Mar 2017 22:43:24 +1000 Message-Id: <1490100205-31309-2-git-send-email-gerg@linux-m68k.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1490100205-31309-1-git-send-email-gerg@linux-m68k.org> References: <1490100205-31309-1-git-send-email-gerg@linux-m68k.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 The commonly used mechanism of specifying the hardware or native chip-select on an SPI device in devicetree (that is "cs-gpios = <0>") does not result in the native chip-select being configured for use. So external SPI devices that require use of the native chip-select will not work. You can successfully specify native chip-selects if using a platform setup by specifying the cs-gpio as negative offset by 32. And that works correctly. You cannot use the same method in devicetree. The logic in the spi-imx.c driver during probe uses core spi function of_spi_register_master() in spi.c to parse the "cs-gpios" devicetree tag. For valid GPIO values that will be recorded for use, all other entries in the cs_gpios list will be set to -ENOENT. So entries like "<0>" will be set to -ENOENT in the cs_gpios list. When the SPI device registers are setup the code will use the GPIO listed in the cs_gpios list for the desired chip-select. If the cs_gpio is less then 0 then it is intended to be for a native chip-select, and its cs_gpio value is added to 32 to get the chipselect number to use. Problem is that with devicetree this can only ever be -ENOENT (which is -2), and that alone results in an invalid chip-select number. But also doesn't allow selection of the native chip-select at all. To fix, if the cs_gpio specified for this spi device is not a valid GPIO then use the "chip_select" (that is the native chip-select number) for hardware setup. Signed-off-by: Greg Ungerer --- drivers/spi/spi-imx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) v2: added documentation to patch set diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 9a7c62f..dbb482c 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -516,8 +516,8 @@ static int mx31_config(struct spi_device *spi, struct spi_imx_config *config) reg |= MX31_CSPICTRL_POL; if (spi->mode & SPI_CS_HIGH) reg |= MX31_CSPICTRL_SSPOL; - if (spi->cs_gpio < 0) - reg |= (spi->cs_gpio + 32) << + if (!gpio_is_valid(spi->cs_gpio)) + reg |= (spi->chip_select) << (is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT : MX31_CSPICTRL_CS_SHIFT); @@ -608,8 +608,8 @@ static int mx21_config(struct spi_device *spi, struct spi_imx_config *config) reg |= MX21_CSPICTRL_POL; if (spi->mode & SPI_CS_HIGH) reg |= MX21_CSPICTRL_SSPOL; - if (spi->cs_gpio < 0) - reg |= (spi->cs_gpio + 32) << MX21_CSPICTRL_CS_SHIFT; + if (!gpio_is_valid(spi->cs_gpio)) + reg |= spi->chip_select << MX21_CSPICTRL_CS_SHIFT; writel(reg, spi_imx->base + MXC_CSPICTRL);