From patchwork Wed Nov 12 16:15:52 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: 5290831 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 71A8D9F472 for ; Wed, 12 Nov 2014 16:16:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8657A2017D for ; Wed, 12 Nov 2014 16:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 426A8201BB for ; Wed, 12 Nov 2014 16:16:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753255AbaKLQQx (ORCPT ); Wed, 12 Nov 2014 11:16:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35400 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753009AbaKLQQx (ORCPT ); Wed, 12 Nov 2014 11:16:53 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sACGGGxM024503 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 12 Nov 2014 11:16:16 -0500 Received: from shalem.localdomain.com (vpn1-6-39.ams2.redhat.com [10.36.6.39]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sACGFsUo010837; Wed, 12 Nov 2014 11:16:13 -0500 From: Hans de Goede To: Tomi Valkeinen Cc: Stephen Warren , Jean-Christophe Plagniol-Villard , Grant Likely , Rob Herring , Luc Verhaegen , Maxime Ripard , Mike Turquette , David Herrmann , Geert Uytterhoeven , linux-fbdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree , linux-sunxi@googlegroups.com, Hans de Goede Subject: [PATCH v5 5/5] simplefb: add clock handling code Date: Wed, 12 Nov 2014 17:15:52 +0100 Message-Id: <1415808952-23549-6-git-send-email-hdegoede@redhat.com> In-Reply-To: <1415808952-23549-1-git-send-email-hdegoede@redhat.com> References: <1415808952-23549-1-git-send-email-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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: Change clks from list to dynamic array] Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede Acked-by: Geert Uytterhoeven Reviewed-by: Maxime Ripard Reviewed-by: David Herrmann Acked-by: Grant Likely --- Changes in v4: -change clks from linkedlist to dynamic allocated array -propagate EPROBE_DEFER up from simplefb_clocks_init to simplefb_probe --- drivers/video/fbdev/simplefb.c | 101 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 100 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index cdcf1fe..cd96edd 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", @@ -167,8 +168,98 @@ static int simplefb_parse_pd(struct platform_device *pdev, struct simplefb_par { u32 palette[PSEUDO_PALETTE_SIZE]; + int clk_count; + struct clk **clks; }; +/* + * 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. + * + * 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 int +simplefb_clocks_init(struct simplefb_par *par, struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct clk *clock; + int i, ret; + + if (dev_get_platdata(&pdev->dev) || !np) + return 0; + + par->clk_count = of_clk_get_parent_count(np); + if (par->clk_count <= 0) + return 0; + + par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL); + if (!par->clks) + return -ENOMEM; + + for (i = 0; i < par->clk_count; i++) { + clock = of_clk_get(np, i); + if (IS_ERR(clock)) { + if (PTR_ERR(clock) == -EPROBE_DEFER) { + while (--i >= 0) { + if (par->clks[i]) + clk_put(par->clks[i]); + } + kfree(par->clks); + return -EPROBE_DEFER; + } + dev_err(&pdev->dev, "%s: clock %d not found: %ld\n", + __func__, i, PTR_ERR(clock)); + continue; + } + par->clks[i] = clock; + } + + for (i = 0; i < par->clk_count; i++) { + if (par->clks[i]) { + ret = clk_prepare_enable(par->clks[i]); + if (ret) { + dev_err(&pdev->dev, + "%s: failed to enable clock %d: %d\n", + __func__, i, ret); + clk_put(par->clks[i]); + par->clks[i] = NULL; + } + } + } + + return 0; +} + +static void +simplefb_clocks_destroy(struct simplefb_par *par) +{ + int i; + + if (!par->clks) + return; + + for (i = 0; i < par->clk_count; i++) { + if (par->clks[i]) { + clk_disable_unprepare(par->clks[i]); + clk_put(par->clks[i]); + } + } + + kfree(par->clks); +} + static int simplefb_probe(struct platform_device *pdev) { int ret; @@ -236,6 +327,10 @@ static int simplefb_probe(struct platform_device *pdev) } info->pseudo_palette = par->palette; + ret = simplefb_clocks_init(par, pdev); + if (ret < 0) + goto error_unmap; + 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); @@ -247,13 +342,15 @@ 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_clocks: + simplefb_clocks_destroy(par); error_unmap: iounmap(info->screen_base); error_fb_release: @@ -264,8 +361,10 @@ error_fb_release: 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); framebuffer_release(info); return 0;