From patchwork Fri Apr 30 10:58:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 12233021 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 22001C433ED for ; Fri, 30 Apr 2021 10:59:04 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CBACF61400 for ; Fri, 30 Apr 2021 10:59:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CBACF61400 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EA3FC6E462; Fri, 30 Apr 2021 10:58:52 +0000 (UTC) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0B70D6E1BE for ; Fri, 30 Apr 2021 10:58:49 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 93C54B290; Fri, 30 Apr 2021 10:58:47 +0000 (UTC) From: Thomas Zimmermann To: daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, mripard@kernel.org, kraxel@redhat.com, corbet@lwn.net, lgirdwood@gmail.com, broonie@kernel.org, sam@ravnborg.org, robh@kernel.org, emil.l.velikov@gmail.com, geert+renesas@glider.be, hdegoede@redhat.com, bluescreen_avenger@verizon.net, gregkh@linuxfoundation.org Subject: [PATCH v5 8/9] drm/simpledrm: Acquire regulators from DT device node Date: Fri, 30 Apr 2021 12:58:39 +0200 Message-Id: <20210430105840.30515-9-tzimmermann@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210430105840.30515-1-tzimmermann@suse.de> References: <20210430105840.30515-1-tzimmermann@suse.de> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Maxime Ripard , virtualization@lists.linux-foundation.org, Thomas Zimmermann , dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Make sure required hardware regulators are enabled while the firmware framebuffer is in use. The basic code has been taken from the simplefb driver and adapted to DRM. Regulators are released automatically via devres helpers. v2: * use strscpy() Signed-off-by: Thomas Zimmermann Acked-by: Maxime Ripard Tested-by: nerdopolis --- drivers/gpu/drm/tiny/simpledrm.c | 128 +++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c index 996318500abf..9d522473cd7c 100644 --- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include @@ -197,6 +198,11 @@ struct simpledrm_device { unsigned int clk_count; struct clk **clks; #endif + /* regulators */ +#if defined CONFIG_OF && defined CONFIG_REGULATOR + unsigned int regulator_count; + struct regulator **regulators; +#endif /* simplefb settings */ struct drm_display_mode mode; @@ -316,6 +322,125 @@ static int simpledrm_device_init_clocks(struct simpledrm_device *sdev) } #endif +#if defined CONFIG_OF && defined CONFIG_REGULATOR + +#define SUPPLY_SUFFIX "-supply" + +/* + * Regulator handling code. + * + * Here we handle the num-supplies and vin*-supply properties of our + * "simple-framebuffer" dt node. This is necessary so that we can make sure + * that any regulators needed by the display hardware that the bootloader + * set up for us (and for which it provided a simplefb dt node), stay up, + * for the life of the simplefb driver. + * + * When the driver unloads, we cleanly disable, and then release the + * regulators. + * + * We only complain about errors here, no action is taken as the most likely + * error can only happen due to a mismatch between the bootloader which set + * up simplefb, and the regulator definitions in the device tree. Chances are + * that there are no adverse effects, and if there are, a clean teardown of + * the fb probe will not help us much either. So just complain and carry on, + * and hope that the user actually gets a working fb at the end of things. + */ + +static void simpledrm_device_release_regulators(void *res) +{ + struct simpledrm_device *sdev = simpledrm_device_of_dev(res); + unsigned int i; + + for (i = 0; i < sdev->regulator_count; ++i) { + if (sdev->regulators[i]) { + regulator_disable(sdev->regulators[i]); + regulator_put(sdev->regulators[i]); + } + } +} + +static int simpledrm_device_init_regulators(struct simpledrm_device *sdev) +{ + struct drm_device *dev = &sdev->dev; + struct platform_device *pdev = sdev->pdev; + struct device_node *of_node = pdev->dev.of_node; + struct property *prop; + struct regulator *regulator; + const char *p; + unsigned int count = 0, i = 0; + int ret; + + if (dev_get_platdata(&pdev->dev) || !of_node) + return 0; + + /* Count the number of regulator supplies */ + for_each_property_of_node(of_node, prop) { + p = strstr(prop->name, SUPPLY_SUFFIX); + if (p && p != prop->name) + ++count; + } + + if (!count) + return 0; + + sdev->regulators = drmm_kzalloc(dev, + count * sizeof(sdev->regulators[0]), + GFP_KERNEL); + if (!sdev->regulators) + return -ENOMEM; + + for_each_property_of_node(of_node, prop) { + char name[32]; /* 32 is max size of property name */ + size_t len; + + p = strstr(prop->name, SUPPLY_SUFFIX); + if (!p || p == prop->name) + continue; + len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1; + strscpy(name, prop->name, min(sizeof(name), len)); + + regulator = regulator_get_optional(&pdev->dev, name); + if (IS_ERR(regulator)) { + ret = PTR_ERR(regulator); + if (ret == -EPROBE_DEFER) + goto err; + drm_err(dev, "regulator %s not found: %d\n", + name, ret); + continue; + } + + ret = regulator_enable(regulator); + if (ret) { + drm_err(dev, "failed to enable regulator %u: %d\n", + i, ret); + regulator_put(regulator); + } + + sdev->regulators[i++] = regulator; + } + sdev->regulator_count = i; + + return devm_add_action_or_reset(&pdev->dev, + simpledrm_device_release_regulators, + sdev); + +err: + while (i) { + --i; + if (sdev->regulators[i]) { + regulator_disable(sdev->regulators[i]); + regulator_put(sdev->regulators[i]); + } + } + return ret; +} +#else +static int simpledrm_device_init_regulators(struct simpledrm_device *sdev) +{ + return 0; +} +#endif + /* * Simplefb settings */ @@ -658,6 +783,9 @@ simpledrm_device_create(struct drm_driver *drv, struct platform_device *pdev) platform_set_drvdata(pdev, sdev); ret = simpledrm_device_init_clocks(sdev); + if (ret) + return ERR_PTR(ret); + ret = simpledrm_device_init_regulators(sdev); if (ret) return ERR_PTR(ret); ret = simpledrm_device_init_fb(sdev);