From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751412AbaEXA5j (ORCPT ); Fri, 23 May 2014 20:57:39 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:54079 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751017AbaEXA5i (ORCPT ); Fri, 23 May 2014 20:57:38 -0400 From: Stephen Boyd To: Mark Brown Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org, Linus Walleij , Alexandre Courbot , Jean-Christophe PLAGNIOL-VILLARD , Richard Genoud Subject: [PATCH] spi: Set cs-gpios to output direction Date: Fri, 23 May 2014 17:57:34 -0700 Message-Id: <1400893054-16126-1-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.9.0.1.gd5ccf8c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some gpios used for cs-gpios may not be configured for output by default. In these cases gpio_set_value() won't have any effect and so the chip select line won't toggle. Request the cs-gpios and set them to output direction once we know if the chip select is default high or default low. Cc: Linus Walleij Cc: Alexandre Courbot Cc: Jean-Christophe PLAGNIOL-VILLARD Cc: Richard Genoud Signed-off-by: Stephen Boyd --- I wonder if we should request the gpios when the master controller probes or when a spi device is added? We only know what the default value should be when the spi device is added. On the other hand, we should probably fail probe if the gpio controller isn't ready when the spi master controller probes. Also, is it better to convert this over to the gpiod interfaces? drivers/spi/spi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 074f55f5d5ec..00f6365b3f87 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -431,8 +431,10 @@ int spi_add_device(struct spi_device *spi) goto done; } - if (master->cs_gpios) + if (master->cs_gpios) { spi->cs_gpio = master->cs_gpios[spi->chip_select]; + gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); + } /* Drivers may modify this initial i/o setup, but will * normally rely on the device being setup. Devices @@ -1512,8 +1514,11 @@ static int of_spi_register_master(struct spi_master *master) for (i = 0; i < master->num_chipselect; i++) cs[i] = -ENOENT; - for (i = 0; i < nb; i++) + for (i = 0; i < nb; i++) { cs[i] = of_get_named_gpio(np, "cs-gpios", i); + devm_gpio_request(&master->dev, cs[i], "spi-cs"); + } + return 0; } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation