From patchwork Tue Nov 13 10:22:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lubomir Rintel X-Patchwork-Id: 10680199 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C1DF118F0 for ; Tue, 13 Nov 2018 10:23:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B1C1229BAF for ; Tue, 13 Nov 2018 10:23:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A4AE129BB3; Tue, 13 Nov 2018 10:23:19 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 E8BC229BAF for ; Tue, 13 Nov 2018 10:23:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732197AbeKMUUi (ORCPT ); Tue, 13 Nov 2018 15:20:38 -0500 Received: from shell.v3.sk ([90.176.6.54]:38312 "EHLO shell.v3.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732362AbeKMUUi (ORCPT ); Tue, 13 Nov 2018 15:20:38 -0500 Received: from localhost (localhost [127.0.0.1]) by zimbra.v3.sk (Postfix) with ESMTP id 884F9C6B32; Tue, 13 Nov 2018 11:23:08 +0100 (CET) Received: from shell.v3.sk ([127.0.0.1]) by localhost (zimbra.v3.sk [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id BFl_KRM1NhgE; Tue, 13 Nov 2018 11:22:55 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by zimbra.v3.sk (Postfix) with ESMTP id AFD9DC6AF3; Tue, 13 Nov 2018 11:22:47 +0100 (CET) X-Virus-Scanned: amavisd-new at zimbra.v3.sk Received: from shell.v3.sk ([127.0.0.1]) by localhost (zimbra.v3.sk [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id Kr3S2njupcVL; Tue, 13 Nov 2018 11:22:44 +0100 (CET) Received: from belphegor.brq.redhat.com (nat-pool-brq-t.redhat.com [213.175.37.10]) by zimbra.v3.sk (Postfix) with ESMTPSA id 0D7F4C6B2B; Tue, 13 Nov 2018 11:22:42 +0100 (CET) From: Lubomir Rintel To: Mark Brown , Geert Uytterhoeven Cc: James Cameron , Rob Herring , Mark Rutland , Eric Miao , Haojian Zhuang , Daniel Mack , Robert Jarzmik , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lubomir Rintel Subject: [PATCH v3 5/6] spi: pxa2xx: Add ready signal Date: Tue, 13 Nov 2018 11:22:27 +0100 Message-Id: <20181113102228.820214-6-lkundrak@v3.sk> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181113102228.820214-1-lkundrak@v3.sk> References: <20181113102228.820214-1-lkundrak@v3.sk> MIME-Version: 1.0 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 Strobe a GPIO line when the slave TX FIFO is filled. This is how the Embedded Controller on an OLPC XO-1.75 machine, that happens to be a SPI master, learns that it can initiate a transaction. Signed-off-by: Lubomir Rintel Tested-by: Pavel Machek Reviewed-by: Geert Uytterhoeven --- Changes since v2 - Avoid an useless delay if there's no ready GPIO - Remove useless (int)PTR_ERR(...) casts from pxa2xx_spi_probe() (thanks to Geert Uytterhoeven) drivers/spi/spi-pxa2xx.c | 16 +++++++++++++++- drivers/spi/spi-pxa2xx.h | 3 +++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 54ae77f1227c..7e5aab0af501 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1081,6 +1081,11 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *master, if (spi_controller_is_slave(master)) { while (drv_data->write(drv_data)) ; + if (drv_data->gpiod_ready) { + gpiod_set_value(drv_data->gpiod_ready, 1); + udelay(1); + gpiod_set_value(drv_data->gpiod_ready, 0); + } } /* @@ -1778,7 +1783,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) if (PTR_ERR(gpiod) == -ENOENT) continue; - status = (int)PTR_ERR(gpiod); + status = PTR_ERR(gpiod); goto out_error_clock_enabled; } else { drv_data->cs_gpiods[i] = gpiod; @@ -1786,6 +1791,15 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) } } + if (platform_info->is_slave) { + drv_data->gpiod_ready = devm_gpiod_get_optional(dev, + "ready", GPIOD_OUT_LOW); + if (IS_ERR(drv_data->gpiod_ready)) { + status = PTR_ERR(drv_data->gpiod_ready); + goto out_error_clock_enabled; + } + } + pm_runtime_set_autosuspend_delay(&pdev->dev, 50); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_active(&pdev->dev); diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h index 513c53aaeab2..4e324da66ef7 100644 --- a/drivers/spi/spi-pxa2xx.h +++ b/drivers/spi/spi-pxa2xx.h @@ -64,6 +64,9 @@ struct driver_data { /* GPIOs for chip selects */ struct gpio_desc **cs_gpiods; + + /* Optional slave FIFO ready signal */ + struct gpio_desc *gpiod_ready; }; struct chip_data {