From patchwork Thu Nov 13 19:22:26 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: 5300041 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 E4A3C9F2F1 for ; Thu, 13 Nov 2014 19:23:22 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E9ACD201F4 for ; Thu, 13 Nov 2014 19:23:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D53B0201C8 for ; Thu, 13 Nov 2014 19:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754246AbaKMTXS (ORCPT ); Thu, 13 Nov 2014 14:23:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43334 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754241AbaKMTXO (ORCPT ); Thu, 13 Nov 2014 14:23:14 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sADJMVeb023658 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 13 Nov 2014 14:22:31 -0500 Received: from shalem.localdomain.com (vpn1-4-120.ams2.redhat.com [10.36.4.120]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sADJMRgh005667; Thu, 13 Nov 2014 14:22:28 -0500 From: Hans de Goede To: Tomi Valkeinen Cc: Stephen Warren , Jean-Christophe Plagniol-Villard , Grant Likely , Rob Herring , Luc Verhaegen , Maxime Ripard , 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 v6] simplefb: add clock handling code Date: Thu, 13 Nov 2014 20:22:26 +0100 Message-Id: <1415906546-2408-1-git-send-email-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-7.9 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 changes in v6: -Wrap the clock code in #ifdef CONFIG_OF, as simplefb is used on non devicetree platforms too --- drivers/video/fbdev/simplefb.c | 106 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 105 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index cdcf1fe..868099a 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 +168,103 @@ static int simplefb_parse_pd(struct platform_device *pdev, struct simplefb_par { u32 palette[PSEUDO_PALETTE_SIZE]; +#ifdef CONFIG_OF + int clk_count; + struct clk **clks; +#endif }; +/* + * 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) +{ +#ifdef CONFIG_OF + 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; + } + } + } +#endif + return 0; +} + +static void +simplefb_clocks_destroy(struct simplefb_par *par) +{ +#ifdef CONFIG_OF + 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); +#endif +} + static int simplefb_probe(struct platform_device *pdev) { int ret; @@ -236,6 +332,10 @@ 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 +347,15 @@ 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 +366,10 @@ 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;