From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753582AbbCISxs (ORCPT ); Mon, 9 Mar 2015 14:53:48 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:59911 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751011AbbCISxp (ORCPT ); Mon, 9 Mar 2015 14:53:45 -0400 Message-ID: <54FDEC36.5080403@codeaurora.org> Date: Mon, 09 Mar 2015 11:53:42 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "Ivan T. Ivanov" CC: Mark Brown , linus.walleij@linaro.org, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH 2/2] spi: qup: Request CS GPIO's during probe References: <1425655578-22400-1-git-send-email-iivanov@mm-sol.com> <1425655578-22400-2-git-send-email-iivanov@mm-sol.com> <54F9F31A.3050501@codeaurora.org> <1425889207.2440.9.camel@mm-sol.com> In-Reply-To: <1425889207.2440.9.camel@mm-sol.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/09/15 01:20, Ivan T. Ivanov wrote: > Hi Stephen, > >> On Mar 6, 2015, at 8:34 PM, Stephen Boyd wrote: >> On 03/06/15 07:26, Ivan T. Ivanov wrote: >>> Ensure that driver is owner of the GPIO's used for CS signals. >> Why? What happens if we don’t? > We can have wrong DT configuration, which could reconfigure > GPIO’s without any warning or error. Ouch. That sounds bad. Can you please add this information to the commit text? > >>> Signed-off-by: Ivan T. Ivanov >>> --- >>> drivers/spi/spi-qup.c | 17 ++++++++++++++++- >>> 1 file changed, 16 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c >>> index 2b2c359..a07ba46 100644 >>> --- a/drivers/spi/spi-qup.c >>> +++ b/drivers/spi/spi-qup.c >>> @@ -14,11 +14,13 @@ >>> #include >>> #include >>> #include >>> +#include >>> #include >>> #include >>> #include >>> #include >>> #include >>> +#include >>> #include >>> #include >>> #include >>> @@ -499,7 +501,7 @@ static int spi_qup_probe(struct platform_device *pdev) >>> struct device *dev; >>> void __iomem *base; >>> u32 max_freq, iomode, num_cs; >>> - int ret, irq, size; >>> + int ret, irq, size, cs, cs_gpio; >>> >>> dev = &pdev->dev; >>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >>> @@ -556,6 +558,19 @@ static int spi_qup_probe(struct platform_device *pdev) >>> else >>> master->num_chipselect = num_cs; >>> >>> + for (cs = 0; cs < master->num_chipselect; cs++) { >>> + cs_gpio = of_get_named_gpio(dev->of_node, "cs-gpios", cs); >>> + >>> + if (!gpio_is_valid(cs_gpio)) >>> + continue; >>> + >>> + ret = devm_gpio_request(&pdev->dev, cs_gpio, "spi-qup-cs"); >>> + if (ret) { >>> + dev_err(&pdev->dev, "can't get cs gpios\n"); >>> + goto error; >>> + } >>> + } >>> + >>> master->bus_num = pdev->id; >> Is this related to [1]? In that case I was just relying on DT/pinctrl to >> properly request the gpios. > But the DT/pinctrl did not request GPIO’s, it just configure them. > For some reason we are ending without any pinctrl_map of type > PIN_MAP_TYPE_MUX_GROUP, which is used for pin reservation. > Ah ok. I seem to be misremembering the details. Can you please use the gpiod interfaces here (devm_gpiod_get_index)? That's more modern. Also, don't print any error because -EPROBE_DEFER may come out and because __gpiod_get_index() already prints an error on failure at the debug level. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project