[linux-2.6-block.git] / drivers / mmc / core / pwrseq.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2014 Linaro Ltd
 *
 * Author: Ulf Hansson <ulf.hansson@linaro.org>
 *
 *  MMC power sequence management
 */
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>

#include <linux/mmc/host.h>

#include "pwrseq.h"

static DEFINE_MUTEX(pwrseq_list_mutex);
static LIST_HEAD(pwrseq_list);

int mmc_pwrseq_alloc(struct mmc_host *host)
{
	struct device_node *np;
	struct mmc_pwrseq *p;

	np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
	if (!np)
		return 0;

	mutex_lock(&pwrseq_list_mutex);
	list_for_each_entry(p, &pwrseq_list, pwrseq_node) {
		if (p->dev->of_node == np) {
			if (!try_module_get(p->owner))
				dev_err(host->parent,
					"increasing module refcount failed\n");
			else
				host->pwrseq = p;

			break;
		}
	}

	of_node_put(np);
	mutex_unlock(&pwrseq_list_mutex);

	if (!host->pwrseq)
		return -EPROBE_DEFER;

	dev_info(host->parent, "allocated mmc-pwrseq\n");

	return 0;
}

void mmc_pwrseq_pre_power_on(struct mmc_host *host)
{
	struct mmc_pwrseq *pwrseq = host->pwrseq;

	if (pwrseq && pwrseq->ops->pre_power_on)
		pwrseq->ops->pre_power_on(host);
}

void mmc_pwrseq_post_power_on(struct mmc_host *host)
{
	struct mmc_pwrseq *pwrseq = host->pwrseq;

	if (pwrseq && pwrseq->ops->post_power_on)
		pwrseq->ops->post_power_on(host);
}

void mmc_pwrseq_power_off(struct mmc_host *host)
{
	struct mmc_pwrseq *pwrseq = host->pwrseq;

	if (pwrseq && pwrseq->ops->power_off)
		pwrseq->ops->power_off(host);
}

void mmc_pwrseq_reset(struct mmc_host *host)
{
	struct mmc_pwrseq *pwrseq = host->pwrseq;

	if (pwrseq && pwrseq->ops->reset)
		pwrseq->ops->reset(host);
}

void mmc_pwrseq_free(struct mmc_host *host)
{
	struct mmc_pwrseq *pwrseq = host->pwrseq;

	if (pwrseq) {
		module_put(pwrseq->owner);
		host->pwrseq = NULL;
	}
}

int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq)
{
	if (!pwrseq || !pwrseq->ops || !pwrseq->dev)
		return -EINVAL;

	mutex_lock(&pwrseq_list_mutex);
	list_add(&pwrseq->pwrseq_node, &pwrseq_list);
	mutex_unlock(&pwrseq_list_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(mmc_pwrseq_register);

void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq)
{
	if (pwrseq) {
		mutex_lock(&pwrseq_list_mutex);
		list_del(&pwrseq->pwrseq_node);
		mutex_unlock(&pwrseq_list_mutex);
	}
}
EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);
Commit	Line	Data
af873fce	1	// SPDX-License-Identifier: GPL-2.0-only
3aa8793f UH	2	/*
	3	* Copyright (C) 2014 Linaro Ltd
	4	*
	5	* Author: Ulf Hansson <ulf.hansson@linaro.org>
	6	*
3aa8793f UH	7	* MMC power sequence management
3aa8793f UH	8	*/
8c96f89c	9	#include <linux/kernel.h>
8c96f89c	10	#include <linux/err.h>
d97a1e5d	11	#include <linux/module.h>
8c96f89c	12	#include <linux/of.h>
8c96f89c	13
3aa8793f UH	14	#include <linux/mmc/host.h>
	15
	16	#include "pwrseq.h"
	17
d97a1e5d SK	18	static DEFINE_MUTEX(pwrseq_list_mutex);
d97a1e5d SK	19	static LIST_HEAD(pwrseq_list);
3aa8793f UH	20
	21	int mmc_pwrseq_alloc(struct mmc_host *host)
	22	{
8c96f89c	23	struct device_node *np;
d97a1e5d	24	struct mmc_pwrseq *p;
8c96f89c UH	25
	26	np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
	27	if (!np)
	28	return 0;
	29
d97a1e5d SK	30	mutex_lock(&pwrseq_list_mutex);
	31	list_for_each_entry(p, &pwrseq_list, pwrseq_node) {
	32	if (p->dev->of_node == np) {
	33	if (!try_module_get(p->owner))
	34	dev_err(host->parent,
	35	"increasing module refcount failed\n");
	36	else
	37	host->pwrseq = p;
8c96f89c	38
d97a1e5d SK	39	break;
d97a1e5d SK	40	}
8c96f89c UH	41	}
8c96f89c UH	42
d97a1e5d SK	43	of_node_put(np);
	44	mutex_unlock(&pwrseq_list_mutex);
	45
	46	if (!host->pwrseq)
	47	return -EPROBE_DEFER;
0f12a0ce	48
0f12a0ce	49	dev_info(host->parent, "allocated mmc-pwrseq\n");
8c96f89c	50
d97a1e5d	51	return 0;
3aa8793f UH	52	}
	53
	54	void mmc_pwrseq_pre_power_on(struct mmc_host *host)
	55	{
	56	struct mmc_pwrseq *pwrseq = host->pwrseq;
	57
d97a1e5d	58	if (pwrseq && pwrseq->ops->pre_power_on)
3aa8793f UH	59	pwrseq->ops->pre_power_on(host);
	60	}
	61
	62	void mmc_pwrseq_post_power_on(struct mmc_host *host)
	63	{
	64	struct mmc_pwrseq *pwrseq = host->pwrseq;
	65
d97a1e5d	66	if (pwrseq && pwrseq->ops->post_power_on)
3aa8793f UH	67	pwrseq->ops->post_power_on(host);
	68	}
	69
	70	void mmc_pwrseq_power_off(struct mmc_host *host)
	71	{
	72	struct mmc_pwrseq *pwrseq = host->pwrseq;
	73
d97a1e5d	74	if (pwrseq && pwrseq->ops->power_off)
3aa8793f UH	75	pwrseq->ops->power_off(host);
	76	}
	77
773a9ef8 UH	78	void mmc_pwrseq_reset(struct mmc_host *host)
	79	{
	80	struct mmc_pwrseq *pwrseq = host->pwrseq;
	81
	82	if (pwrseq && pwrseq->ops->reset)
	83	pwrseq->ops->reset(host);
	84	}
	85
3aa8793f UH	86	void mmc_pwrseq_free(struct mmc_host *host)
	87	{
	88	struct mmc_pwrseq *pwrseq = host->pwrseq;
	89
d97a1e5d SK	90	if (pwrseq) {
	91	module_put(pwrseq->owner);
	92	host->pwrseq = NULL;
	93	}
	94	}
	95
	96	int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq)
	97	{
	98	if (!pwrseq \|\| !pwrseq->ops \|\| !pwrseq->dev)
	99	return -EINVAL;
0f12a0ce	100
d97a1e5d SK	101	mutex_lock(&pwrseq_list_mutex);
	102	list_add(&pwrseq->pwrseq_node, &pwrseq_list);
	103	mutex_unlock(&pwrseq_list_mutex);
	104
	105	return 0;
	106	}
	107	EXPORT_SYMBOL_GPL(mmc_pwrseq_register);
	108
	109	void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq)
	110	{
	111	if (pwrseq) {
	112	mutex_lock(&pwrseq_list_mutex);
	113	list_del(&pwrseq->pwrseq_node);
	114	mutex_unlock(&pwrseq_list_mutex);
	115	}
3aa8793f	116	}
d97a1e5d	117	EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);