1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/mmc/core/pwrseq.c b/drivers/mmc/core/pwrseq.c
new file mode 100644
index 000000000..ef675f364
--- /dev/null
+++ b/drivers/mmc/core/pwrseq.c
@@ -0,0 +1,117 @@
+// 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);