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Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
322 lines
6.0 KiB
C
322 lines
6.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* V4L2 clock service
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*
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* Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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*/
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#include <linux/atomic.h>
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#include <linux/clk.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <media/v4l2-clk.h>
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#include <media/v4l2-subdev.h>
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static DEFINE_MUTEX(clk_lock);
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static LIST_HEAD(clk_list);
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static struct v4l2_clk *v4l2_clk_find(const char *dev_id)
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{
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struct v4l2_clk *clk;
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list_for_each_entry(clk, &clk_list, list)
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if (!strcmp(dev_id, clk->dev_id))
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return clk;
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return ERR_PTR(-ENODEV);
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}
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struct v4l2_clk *v4l2_clk_get(struct device *dev, const char *id)
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{
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struct v4l2_clk *clk;
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struct clk *ccf_clk = clk_get(dev, id);
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char clk_name[V4L2_CLK_NAME_SIZE];
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if (PTR_ERR(ccf_clk) == -EPROBE_DEFER)
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return ERR_PTR(-EPROBE_DEFER);
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if (!IS_ERR_OR_NULL(ccf_clk)) {
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clk = kzalloc(sizeof(*clk), GFP_KERNEL);
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if (!clk) {
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clk_put(ccf_clk);
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return ERR_PTR(-ENOMEM);
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}
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clk->clk = ccf_clk;
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return clk;
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}
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mutex_lock(&clk_lock);
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clk = v4l2_clk_find(dev_name(dev));
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/* if dev_name is not found, try use the OF name to find again */
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if (PTR_ERR(clk) == -ENODEV && dev->of_node) {
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v4l2_clk_name_of(clk_name, sizeof(clk_name), dev->of_node);
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clk = v4l2_clk_find(clk_name);
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}
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if (!IS_ERR(clk))
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atomic_inc(&clk->use_count);
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mutex_unlock(&clk_lock);
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return clk;
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}
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EXPORT_SYMBOL(v4l2_clk_get);
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void v4l2_clk_put(struct v4l2_clk *clk)
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{
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struct v4l2_clk *tmp;
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if (IS_ERR(clk))
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return;
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if (clk->clk) {
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clk_put(clk->clk);
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kfree(clk);
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return;
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}
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mutex_lock(&clk_lock);
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list_for_each_entry(tmp, &clk_list, list)
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if (tmp == clk)
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atomic_dec(&clk->use_count);
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mutex_unlock(&clk_lock);
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}
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EXPORT_SYMBOL(v4l2_clk_put);
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static int v4l2_clk_lock_driver(struct v4l2_clk *clk)
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{
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struct v4l2_clk *tmp;
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int ret = -ENODEV;
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mutex_lock(&clk_lock);
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list_for_each_entry(tmp, &clk_list, list)
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if (tmp == clk) {
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ret = !try_module_get(clk->ops->owner);
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if (ret)
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ret = -EFAULT;
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break;
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}
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mutex_unlock(&clk_lock);
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return ret;
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}
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static void v4l2_clk_unlock_driver(struct v4l2_clk *clk)
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{
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module_put(clk->ops->owner);
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}
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int v4l2_clk_enable(struct v4l2_clk *clk)
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{
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int ret;
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if (clk->clk)
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return clk_prepare_enable(clk->clk);
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ret = v4l2_clk_lock_driver(clk);
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if (ret < 0)
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return ret;
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mutex_lock(&clk->lock);
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if (++clk->enable == 1 && clk->ops->enable) {
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ret = clk->ops->enable(clk);
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if (ret < 0)
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clk->enable--;
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}
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mutex_unlock(&clk->lock);
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return ret;
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}
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EXPORT_SYMBOL(v4l2_clk_enable);
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/*
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* You might Oops if you try to disabled a disabled clock, because then the
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* driver isn't locked and could have been unloaded by now, so, don't do that
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*/
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void v4l2_clk_disable(struct v4l2_clk *clk)
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{
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int enable;
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if (clk->clk)
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return clk_disable_unprepare(clk->clk);
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mutex_lock(&clk->lock);
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enable = --clk->enable;
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if (WARN(enable < 0, "Unbalanced %s() on %s!\n", __func__,
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clk->dev_id))
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clk->enable++;
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else if (!enable && clk->ops->disable)
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clk->ops->disable(clk);
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mutex_unlock(&clk->lock);
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v4l2_clk_unlock_driver(clk);
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}
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EXPORT_SYMBOL(v4l2_clk_disable);
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unsigned long v4l2_clk_get_rate(struct v4l2_clk *clk)
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{
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int ret;
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if (clk->clk)
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return clk_get_rate(clk->clk);
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ret = v4l2_clk_lock_driver(clk);
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if (ret < 0)
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return ret;
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mutex_lock(&clk->lock);
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if (!clk->ops->get_rate)
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ret = -ENOSYS;
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else
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ret = clk->ops->get_rate(clk);
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mutex_unlock(&clk->lock);
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v4l2_clk_unlock_driver(clk);
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return ret;
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}
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EXPORT_SYMBOL(v4l2_clk_get_rate);
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int v4l2_clk_set_rate(struct v4l2_clk *clk, unsigned long rate)
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{
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int ret;
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if (clk->clk) {
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long r = clk_round_rate(clk->clk, rate);
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if (r < 0)
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return r;
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return clk_set_rate(clk->clk, r);
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}
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ret = v4l2_clk_lock_driver(clk);
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if (ret < 0)
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return ret;
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mutex_lock(&clk->lock);
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if (!clk->ops->set_rate)
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ret = -ENOSYS;
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else
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ret = clk->ops->set_rate(clk, rate);
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mutex_unlock(&clk->lock);
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v4l2_clk_unlock_driver(clk);
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return ret;
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}
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EXPORT_SYMBOL(v4l2_clk_set_rate);
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struct v4l2_clk *v4l2_clk_register(const struct v4l2_clk_ops *ops,
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const char *dev_id,
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void *priv)
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{
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struct v4l2_clk *clk;
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int ret;
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if (!ops || !dev_id)
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return ERR_PTR(-EINVAL);
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clk = kzalloc(sizeof(struct v4l2_clk), GFP_KERNEL);
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if (!clk)
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return ERR_PTR(-ENOMEM);
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clk->dev_id = kstrdup(dev_id, GFP_KERNEL);
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if (!clk->dev_id) {
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ret = -ENOMEM;
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goto ealloc;
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}
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clk->ops = ops;
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clk->priv = priv;
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atomic_set(&clk->use_count, 0);
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mutex_init(&clk->lock);
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mutex_lock(&clk_lock);
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if (!IS_ERR(v4l2_clk_find(dev_id))) {
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mutex_unlock(&clk_lock);
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ret = -EEXIST;
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goto eexist;
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}
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list_add_tail(&clk->list, &clk_list);
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mutex_unlock(&clk_lock);
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return clk;
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eexist:
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ealloc:
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kfree(clk->dev_id);
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kfree(clk);
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return ERR_PTR(ret);
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}
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EXPORT_SYMBOL(v4l2_clk_register);
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void v4l2_clk_unregister(struct v4l2_clk *clk)
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{
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if (WARN(atomic_read(&clk->use_count),
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"%s(): Refusing to unregister ref-counted %s clock!\n",
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__func__, clk->dev_id))
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return;
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mutex_lock(&clk_lock);
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list_del(&clk->list);
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mutex_unlock(&clk_lock);
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kfree(clk->dev_id);
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kfree(clk);
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}
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EXPORT_SYMBOL(v4l2_clk_unregister);
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struct v4l2_clk_fixed {
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unsigned long rate;
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struct v4l2_clk_ops ops;
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};
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static unsigned long fixed_get_rate(struct v4l2_clk *clk)
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{
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struct v4l2_clk_fixed *priv = clk->priv;
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return priv->rate;
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}
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struct v4l2_clk *__v4l2_clk_register_fixed(const char *dev_id,
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unsigned long rate, struct module *owner)
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{
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struct v4l2_clk *clk;
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struct v4l2_clk_fixed *priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return ERR_PTR(-ENOMEM);
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priv->rate = rate;
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priv->ops.get_rate = fixed_get_rate;
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priv->ops.owner = owner;
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clk = v4l2_clk_register(&priv->ops, dev_id, priv);
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if (IS_ERR(clk))
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kfree(priv);
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return clk;
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}
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EXPORT_SYMBOL(__v4l2_clk_register_fixed);
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void v4l2_clk_unregister_fixed(struct v4l2_clk *clk)
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{
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kfree(clk->priv);
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v4l2_clk_unregister(clk);
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}
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EXPORT_SYMBOL(v4l2_clk_unregister_fixed);
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