From patchwork Fri Oct 3 11:52:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 5021951 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BF377C11AB for ; Fri, 3 Oct 2014 11:52:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CEE5C201F2 for ; Fri, 3 Oct 2014 11:52:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4372201D3 for ; Fri, 3 Oct 2014 11:52:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751986AbaJCLw5 (ORCPT ); Fri, 3 Oct 2014 07:52:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55794 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752283AbaJCLw4 (ORCPT ); Fri, 3 Oct 2014 07:52:56 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s93BqPUM028768 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 3 Oct 2014 07:52:25 -0400 Received: from shalem.localdomain.com (vpn1-7-74.ams2.redhat.com [10.36.7.74]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s93Bq6ef016813; Fri, 3 Oct 2014 07:52:22 -0400 From: Hans de Goede To: Tomi Valkeinen Cc: Stephen Warren , Jean-Christophe Plagniol-Villard , Grant Likely , Rob Herring , Luc Verhaegen , Maxime Ripard , Mike Turquette , linux-fbdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree , linux-sunxi@googlegroups.com, Hans de Goede Subject: [PATCH v2 5/5] simplefb: add clock handling code Date: Fri, 3 Oct 2014 13:52:05 +0200 Message-Id: <1412337125-14388-6-git-send-email-hdegoede@redhat.com> In-Reply-To: <1412337125-14388-1-git-send-email-hdegoede@redhat.com> References: <1412337125-14388-1-git-send-email-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Luc Verhaegen This claims and enables clocks listed in the simple framebuffer dt node. This is needed so that the display engine, in case the required clocks are known by the kernel code and are described in the dt, will remain properly enabled. Signed-off-by: Luc Verhaegen [hdegoede@redhat.com: drop dev_err on kzalloc failure] Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/video/fbdev/simplefb.c | 100 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 98 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index b7d5c08..f329cc1 100644 --- a/drivers/video/fbdev/simplefb.c +++ b/drivers/video/fbdev/simplefb.c @@ -26,6 +26,7 @@ #include #include #include +#include static struct fb_fix_screeninfo simplefb_fix = { .id = "simple", @@ -165,8 +166,98 @@ static int simplefb_parse_pd(struct platform_device *pdev, return 0; } +/* + * Clock handling code. + * + * Here we handle the clocks property of our "simple-framebuffer" dt node. + * This is necessary so that we can make sure that any clocks needed by + * the display engine 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 clocks. + */ +struct simplefb_clock { + struct list_head list; + struct clk *clock; +}; + +/* + * 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 clock 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 +simplefb_clocks_init(struct platform_device *pdev, struct list_head *list) +{ + struct device_node *np = pdev->dev.of_node; + int clock_count, i; + + INIT_LIST_HEAD(list); + + if (dev_get_platdata(&pdev->dev) || !np) + return; + + clock_count = of_clk_get_parent_count(np); + for (i = 0; i < clock_count; i++) { + struct simplefb_clock *entry; + struct clk *clock = of_clk_get(np, i); + int ret; + + if (IS_ERR(clock)) { + dev_err(&pdev->dev, "%s: clock %d not found: %ld\n", + __func__, i, PTR_ERR(clock)); + continue; + } + + ret = clk_prepare_enable(clock); + if (ret) { + dev_err(&pdev->dev, + "%s: failed to enable clock %d: %d\n", + __func__, i, ret); + clk_put(clock); + continue; + } + + entry = kzalloc(sizeof(struct simplefb_clock), GFP_KERNEL); + if (!entry) { + clk_disable_unprepare(clock); + clk_put(clock); + continue; + } + + entry->clock = clock; + /* + * add to the front of the list, so we disable clocks in the + * correct order. + */ + list_add(&entry->list, list); + } +} + +static void +simplefb_clocks_destroy(struct list_head *list) +{ + struct list_head *pos, *n; + + list_for_each_safe(pos, n, list) { + struct simplefb_clock *entry = + container_of(pos, struct simplefb_clock, list); + + list_del(&entry->list); + + clk_disable_unprepare(entry->clock); + clk_put(entry->clock); + kfree(entry); + } +} + struct simplefb_par { u32 palette[PSEUDO_PALETTE_SIZE]; + struct list_head clock_list[1]; }; static int simplefb_probe(struct platform_device *pdev) @@ -236,6 +327,8 @@ static int simplefb_probe(struct platform_device *pdev) } info->pseudo_palette = par->palette; + simplefb_clocks_init(pdev, par->clock_list); + dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n", info->fix.smem_start, info->fix.smem_len, info->screen_base); @@ -247,14 +340,15 @@ static int simplefb_probe(struct platform_device *pdev) ret = register_framebuffer(info); if (ret < 0) { dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret); - goto error_unmap; + goto error_clocks; } dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node); return 0; - error_unmap: + error_clocks: + simplefb_clocks_destroy(par->clock_list); iounmap(info->screen_base); error_fb_release: @@ -266,8 +360,10 @@ static int simplefb_probe(struct platform_device *pdev) static int simplefb_remove(struct platform_device *pdev) { struct fb_info *info = platform_get_drvdata(pdev); + struct simplefb_par *par = info->par; unregister_framebuffer(info); + simplefb_clocks_destroy(par->clock_list); framebuffer_release(info); return 0;