From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3AB0C433E1 for ; Fri, 26 Jun 2020 21:02:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2B362070A for ; Fri, 26 Jun 2020 21:02:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593205358; bh=HEZBVtlHQxGYn7Bipu7rRk1VvjlZFYk1uNRxz+AhoJY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Tev2uYt2zytsOsh4ffU56r1cVnokm1YvdQUaW6Hc6aDQxJdy0PGeOF1NNUZ5i5GV9 fuz0QEl+SEnNtwTF1/Zq4lW5dvx0PKqY76NlRfqrOPZwQxjJGdqhtCEz8iyU/RO+lu VDPvLz5RhCpPs9sgpvkHfRfWc7Msj/0JWBv3Si9Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726073AbgFZVCh (ORCPT ); Fri, 26 Jun 2020 17:02:37 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:44038 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbgFZVCg (ORCPT ); Fri, 26 Jun 2020 17:02:36 -0400 Received: by mail-pg1-f196.google.com with SMTP id r18so5446699pgk.11; Fri, 26 Jun 2020 14:02:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=FPqpR3Q9MP7aTmsoIH+Dq2vjzFrcdsAUpPCgSp+MH9A=; b=gqqlT2rumbSHxaO9ekHmOluqCZYFhxaTl0wMUpoucL32CNh3Q+9pWNNTY82lANUV5M Y2nADrgkYmu6eNcuUJizVV+79r4yy3PiECiUyEajVdwAFJ4/UCujbze8f0cONOwjdbbp wdnGC5WFpzUmnTi2ec027FIzJC6vk5A48qzEekx0dEmKqoyVnF0zykvfU8NkR8LfCOCh caregKBa5EGk8TkkGNDsGvsiBoRKed+EB550ZArGT7PRja/SoKcNXuklTOCjk2JsGqzb 2JfLpoeTVAyvAigdKutLggLaoTokKfF059DZ3Ntu5etHe21ujSpG/Vv3Uu+/U0DX1O5d xKNQ== X-Gm-Message-State: AOAM532Fit9/Eo8KG44vMZUPgGJmZtq0TMfLXhhnzvh7IF59jhEtWxOu m+x4OpacU6RRlPgATCKnbVA= X-Google-Smtp-Source: ABdhPJzh5+RYjdzUEqWl80n7fPSBxcIVBClfzU74lEzoscgoLKgVGqc8PLvRupo60RCLYxaSwe31AA== X-Received: by 2002:a63:5a54:: with SMTP id k20mr568669pgm.226.1593205355679; Fri, 26 Jun 2020 14:02:35 -0700 (PDT) Received: from localhost ([2601:647:5b00:1161:a4cc:eef9:fbc0:2781]) by smtp.gmail.com with ESMTPSA id m20sm28646641pfk.52.2020.06.26.14.02.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Jun 2020 14:02:35 -0700 (PDT) Date: Fri, 26 Jun 2020 14:02:34 -0700 From: Moritz Fischer To: Luca Ceresoli Cc: linux-fpga@vger.kernel.org, Moritz Fischer , Rob Herring , Michal Simek , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Anatolij Gustschin Subject: Re: [PATCH v2 2/2] fpga manager: xilinx-spi: check INIT_B pin during write_init Message-ID: <20200626210234.GB2259@epycbox.lan> References: <20200622133723.23326-1-luca@lucaceresoli.net> <20200622133723.23326-2-luca@lucaceresoli.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200622133723.23326-2-luca@lucaceresoli.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 22, 2020 at 03:37:23PM +0200, Luca Ceresoli wrote: > The INIT_B pin reports the status during startup and after the end of the > programming process. However the current driver completely ignores it. > > Check the pin status during startup to make sure programming is never > started too early and also to detect any hardware issues in the FPGA > connection. > > This is optional for backward compatibility. If INIT_B is not passed by > device tree, just fallback to the old udelays. > > Signed-off-by: Luca Ceresoli > > --- > > Changes in v2: > - rename DT property init_b-gpios to init-b-gpios (Rob Herring suggested to > not use '_' in property names) > - improve wait_for_init_b() documentation and variable naming > --- > drivers/fpga/xilinx-spi.c | 55 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 54 insertions(+), 1 deletion(-) > > diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c > index 799ae04301be..2967aa2a74e2 100644 > --- a/drivers/fpga/xilinx-spi.c > +++ b/drivers/fpga/xilinx-spi.c > @@ -23,6 +23,7 @@ > struct xilinx_spi_conf { > struct spi_device *spi; > struct gpio_desc *prog_b; > + struct gpio_desc *init_b; > struct gpio_desc *done; > }; > > @@ -36,11 +37,45 @@ static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr) > return FPGA_MGR_STATE_UNKNOWN; > } > > +/** > + * wait_for_init_b - wait for the INIT_B pin to have a given state, or wait > + * a given delay if the pin is unavailable > + * > + * @mgr: The FPGA manager object > + * @value: Value INIT_B to wait for (1 = asserted = low) > + * @alt_udelay: Delay to wait if the INIT_B GPIO is not available > + * > + * Returns 0 when the INIT_B GPIO reached the given state or -ETIMEDOUT if > + * too much time passed waiting for that. If no INIT_B GPIO is available > + * then always return 0. > + */ > +static int wait_for_init_b(struct fpga_manager *mgr, int value, > + unsigned long alt_udelay) > +{ > + struct xilinx_spi_conf *conf = mgr->priv; > + unsigned long timeout = jiffies + msecs_to_jiffies(1000); > + > + if (conf->init_b) { > + while (time_before(jiffies, timeout)) { > + /* dump_state(conf, "wait for init_d .."); */ > + if (gpiod_get_value(conf->init_b) == value) > + return 0; > + usleep_range(100, 400); > + } > + return -ETIMEDOUT; > + } > + > + udelay(alt_udelay); > + > + return 0; > +} > + > static int xilinx_spi_write_init(struct fpga_manager *mgr, > struct fpga_image_info *info, > const char *buf, size_t count) > { > struct xilinx_spi_conf *conf = mgr->priv; > + int err; > > if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) { > dev_err(&mgr->dev, "Partial reconfiguration not supported.\n"); > @@ -49,10 +84,21 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr, > > gpiod_set_value(conf->prog_b, 1); > > - udelay(1); /* min is 500 ns */ > + err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */ > + if (err) { > + dev_err(&mgr->dev, "INIT_B pin did not go low\n"); > + gpiod_set_value(conf->prog_b, 0); > + return err; > + } > > gpiod_set_value(conf->prog_b, 0); > > + err = wait_for_init_b(mgr, 0, 0); > + if (err) { > + dev_err(&mgr->dev, "INIT_B pin did not go high\n"); > + return err; > + } > + > if (gpiod_get_value(conf->done)) { > dev_err(&mgr->dev, "Unexpected DONE pin state...\n"); > return -EIO; > @@ -154,6 +200,13 @@ static int xilinx_spi_probe(struct spi_device *spi) > return PTR_ERR(conf->prog_b); > } > > + conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN); > + if (IS_ERR(conf->init_b)) { > + dev_err(&spi->dev, "Failed to get INIT_B gpio: %ld\n", > + PTR_ERR(conf->init_b)); > + return PTR_ERR(conf->init_b); > + } > + > conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN); > if (IS_ERR(conf->done)) { > dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n", > -- > 2.27.0 > Will apply to for-next, Thanks!