From patchwork Fri Oct 19 22:20:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guennadi Liakhovetski X-Patchwork-Id: 1620111 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id E2ABFDF2AB for ; Fri, 19 Oct 2012 22:20:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933115Ab2JSWUb (ORCPT ); Fri, 19 Oct 2012 18:20:31 -0400 Received: from moutng.kundenserver.de ([212.227.17.9]:54271 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933091Ab2JSWUa (ORCPT ); Fri, 19 Oct 2012 18:20:30 -0400 Received: from axis700.grange (dslb-094-220-153-062.pools.arcor-ip.net [94.220.153.62]) by mrelayeu.kundenserver.de (node=mreu1) with ESMTP (Nemesis) id 0MBFrN-1TZ05p2DKf-00AkGr; Sat, 20 Oct 2012 00:20:21 +0200 Received: by axis700.grange (Postfix, from userid 1000) id 2FC8740BDC; Sat, 20 Oct 2012 00:20:20 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by axis700.grange (Postfix) with ESMTP id 2CC9740BDA; Sat, 20 Oct 2012 00:20:20 +0200 (CEST) Date: Sat, 20 Oct 2012 00:20:20 +0200 (CEST) From: Guennadi Liakhovetski X-X-Sender: lyakh@axis700.grange To: Linux Media Mailing List cc: Hans Verkuil , Sylwester Nawrocki , Sylwester Nawrocki , Laurent Pinchart , Magnus Damm , linux-sh@vger.kernel.org Subject: [PATCH 1/2] media: V4L2: add temporary clock helpers In-Reply-To: Message-ID: References: MIME-Version: 1.0 X-Provags-ID: V02:K0:mhw7HFT2sm1yoMWWfSUUpciV7qSijMAvyWgw28dSFCQ 8K29C1NWGenSqyiPkEUnD2vDameJGHg/+2UZi+8gwp21Zr1xOY j8q931KZsk3PTpcRTKZO9yMzabGrz85wYXVReUI4Fiz6MkmMQk 7LP0lLb493OKjjEM4sokysEytdYQ1xfsXGDgiW/snBrKYli9kv T1dmE0uFKEaF3YfItlJRLYUWITkdiPJ95sSMecqu+D9Wwg1Sws 7hn6aePM23QlF/Tw6rCG0z3ZLAwXPTTjiLWsgwpwShSz3ZI6q1 OkLGjE8l4+a4s9797Rsb9EtqtGwDZrN9bs/K9aNRapd02dZxXC ilezy+bPBcCT3R16mlAIqqns0/tK0YrYSRNTPjooJqPTguTVrg eIebll+JzqlQA== Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Typical video devices like camera sensors require an external clock source. Many such devices cannot even access their hardware registers without a running clock. These clock sources should be controlled by their consumers. This should be performed, using the generic clock framework. Unfortunately so far only very few systems have been ported to that framework. This patch adds a set of temporary helpers, mimicking the generic clock API, to V4L2. Platforms, adopting the clock API, should switch to using it. Eventually this temporary API should be removed. Signed-off-by: Guennadi Liakhovetski --- drivers/media/v4l2-core/Makefile | 2 +- drivers/media/v4l2-core/v4l2-clk.c | 126 ++++++++++++++++++++++++++++++++++++ include/media/v4l2-clk.h | 48 ++++++++++++++ 3 files changed, 175 insertions(+), 1 deletions(-) create mode 100644 drivers/media/v4l2-core/v4l2-clk.c create mode 100644 include/media/v4l2-clk.h diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile index 00f64d6..cb5fede 100644 --- a/drivers/media/v4l2-core/Makefile +++ b/drivers/media/v4l2-core/Makefile @@ -5,7 +5,7 @@ tuner-objs := tuner-core.o videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \ - v4l2-event.o v4l2-ctrls.o v4l2-subdev.o + v4l2-event.o v4l2-ctrls.o v4l2-subdev.o v4l2-clk.o ifeq ($(CONFIG_COMPAT),y) videodev-objs += v4l2-compat-ioctl32.o endif diff --git a/drivers/media/v4l2-core/v4l2-clk.c b/drivers/media/v4l2-core/v4l2-clk.c new file mode 100644 index 0000000..7d457e4 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-clk.c @@ -0,0 +1,126 @@ +/* + * V4L2 clock service + * + * Copyright (C) 2012, Guennadi Liakhovetski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +#include +#include + +static DEFINE_MUTEX(clk_lock); +static LIST_HEAD(v4l2_clk); + +struct v4l2_clk *v4l2_clk_get(struct v4l2_subdev *sd, const char *id) +{ + struct v4l2_clk *clk = NULL; + + mutex_lock(&clk_lock); + if (!id) { + if (list_is_singular(&v4l2_clk)) { + clk = list_entry(&v4l2_clk, struct v4l2_clk, list); + if (!strstr(sd->name, clk->dev_id)) + clk = ERR_PTR(-ENODEV); + } else { + clk = ERR_PTR(-EINVAL); + } + } else { + list_for_each_entry(clk, &v4l2_clk, list) { + if (!strcmp(id, clk->id) && + !strcmp(sd->name, clk->dev_id)) + break; + } + if (&clk->list == &v4l2_clk) + clk = ERR_PTR(-ENODEV); + } + mutex_unlock(&clk_lock); + + if (!IS_ERR(clk) && + !try_module_get(clk->ops->owner)) + clk = ERR_PTR(-ENODEV); + + return clk; +} +EXPORT_SYMBOL(v4l2_clk_get); + +void v4l2_clk_put(struct v4l2_clk *clk) +{ + if (!IS_ERR(clk)) + module_put(clk->ops->owner); +} +EXPORT_SYMBOL(v4l2_clk_put); + +int v4l2_clk_enable(struct v4l2_clk *clk) +{ + if (!clk->ops->enable) + return -ENOSYS; + return clk->ops->enable(clk); +} +EXPORT_SYMBOL(v4l2_clk_enable); + +void v4l2_clk_disable(struct v4l2_clk *clk) +{ + if (clk->ops->disable) + clk->ops->disable(clk); +} +EXPORT_SYMBOL(v4l2_clk_disable); + +unsigned long v4l2_clk_get_rate(struct v4l2_clk *clk) +{ + if (!clk->ops->get_rate) + return -ENOSYS; + return clk->ops->get_rate(clk); +} +EXPORT_SYMBOL(v4l2_clk_get_rate); + +int v4l2_clk_set_rate(struct v4l2_clk *clk, unsigned long rate) +{ + if (!clk->ops->set_rate) + return -ENOSYS; + return clk->ops->set_rate(clk, rate); +} +EXPORT_SYMBOL(v4l2_clk_set_rate); + +struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops, + const char *dev_name, + const char *name) +{ + struct v4l2_clk *clk; + + if (!ops || !ops->owner || (!list_empty(&v4l2_clk) && !name)) + return ERR_PTR(-EINVAL); + + clk = kzalloc(sizeof(struct v4l2_clk), GFP_KERNEL); + if (!clk) + return ERR_PTR(-ENOMEM); + + clk->ops = ops; + clk->id = name; + clk->dev_id = dev_name; + + mutex_lock(&clk_lock); + list_add_tail(&clk->list, &v4l2_clk); + mutex_unlock(&clk_lock); + + return clk; +} +EXPORT_SYMBOL(v4l2_clk_register); + +void v4l2_clk_unregister(struct v4l2_clk *clk) +{ + mutex_lock(&clk_lock); + list_del(&clk->list); + mutex_unlock(&clk_lock); + + kfree(clk); +} +EXPORT_SYMBOL(v4l2_clk_unregister); diff --git a/include/media/v4l2-clk.h b/include/media/v4l2-clk.h new file mode 100644 index 0000000..0c05ab3 --- /dev/null +++ b/include/media/v4l2-clk.h @@ -0,0 +1,48 @@ +/* + * V4L2 clock service + * + * Copyright (C) 2012, Guennadi Liakhovetski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * ATTENTION: This is a temporary API and it shall be replaced by the generic + * clock API, when the latter becomes widely available. + */ + +#ifndef MEDIA_V4L2_CLK_H +#define MEDIA_V4L2_CLK_H + +#include + +struct module; +struct v4l2_subdev; + +struct v4l2_clk { + struct list_head list; + const struct v4l2_clk_ops *ops; + const char *dev_id; + const char *id; +}; + +struct v4l2_clk_ops { + struct module *owner; + int (*enable)(struct v4l2_clk *clk); + void (*disable)(struct v4l2_clk *clk); + unsigned long (*get_rate)(struct v4l2_clk *clk); + int (*set_rate)(struct v4l2_clk *clk, unsigned long); +}; + +struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops, + const char *dev_name, + const char *name); +void v4l2_clk_unregister(struct v4l2_clk *clk); +struct v4l2_clk *v4l2_clk_get(struct v4l2_subdev *sd, const char *id); +void v4l2_clk_put(struct v4l2_clk *clk); +int v4l2_clk_enable(struct v4l2_clk *clk); +void v4l2_clk_disable(struct v4l2_clk *clk); +unsigned long v4l2_clk_get_rate(struct v4l2_clk *clk); +int v4l2_clk_set_rate(struct v4l2_clk *clk, unsigned long rate); + +#endif