[RFC PATCH 01/15] power: add power sequencer subsystem
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Mon Aug 16 17:54:53 PDT 2021
Basing on MMC's pwrseq support code, add separate power sequencer
subsystem. It will be used by other drivers to handle device power up
requirements.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
drivers/power/Kconfig | 1 +
drivers/power/Makefile | 1 +
drivers/power/pwrseq/Kconfig | 11 +
drivers/power/pwrseq/Makefile | 6 +
drivers/power/pwrseq/core.c | 411 ++++++++++++++++++++++++++++++++
include/linux/pwrseq/consumer.h | 88 +++++++
include/linux/pwrseq/driver.h | 71 ++++++
7 files changed, 589 insertions(+)
create mode 100644 drivers/power/pwrseq/Kconfig
create mode 100644 drivers/power/pwrseq/Makefile
create mode 100644 drivers/power/pwrseq/core.c
create mode 100644 include/linux/pwrseq/consumer.h
create mode 100644 include/linux/pwrseq/driver.h
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 696bf77a7042..c87cd2240a74 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
+source "drivers/power/pwrseq/Kconfig"
source "drivers/power/reset/Kconfig"
source "drivers/power/supply/Kconfig"
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index effbf0377f32..1dbce454a8c4 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_POWER_RESET) += reset/
obj-$(CONFIG_POWER_SUPPLY) += supply/
+obj-$(CONFIG_PWRSEQ) += pwrseq/
diff --git a/drivers/power/pwrseq/Kconfig b/drivers/power/pwrseq/Kconfig
new file mode 100644
index 000000000000..8904ec9ed541
--- /dev/null
+++ b/drivers/power/pwrseq/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig PWRSEQ
+ bool "Power Sequencer drivers"
+ help
+ Provides support for special power sequencing drivers.
+
+ Say Y here to enable support for such devices
+
+if PWRSEQ
+
+endif
diff --git a/drivers/power/pwrseq/Makefile b/drivers/power/pwrseq/Makefile
new file mode 100644
index 000000000000..108429ff6445
--- /dev/null
+++ b/drivers/power/pwrseq/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for power sequencer drivers.
+#
+
+obj-$(CONFIG_PWRSEQ) += core.o
diff --git a/drivers/power/pwrseq/core.c b/drivers/power/pwrseq/core.c
new file mode 100644
index 000000000000..20485cae29aa
--- /dev/null
+++ b/drivers/power/pwrseq/core.c
@@ -0,0 +1,411 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright 2021 (c) Linaro Ltd.
+// Author: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
+//
+// Based on phy-core.c:
+// Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwrseq/consumer.h>
+#include <linux/pwrseq/driver.h>
+#include <linux/slab.h>
+
+#define to_pwrseq(a) (container_of((a), struct pwrseq, dev))
+
+static DEFINE_IDA(pwrseq_ida);
+static DEFINE_MUTEX(pwrseq_provider_mutex);
+static LIST_HEAD(pwrseq_provider_list);
+
+struct pwrseq_provider {
+ struct device *dev;
+ struct module *owner;
+ struct list_head list;
+ void *data;
+ struct pwrseq * (*of_xlate)(void *data, struct of_phandle_args *args);
+};
+
+void pwrseq_put(struct device *dev, struct pwrseq *pwrseq)
+{
+ device_link_remove(dev, &pwrseq->dev);
+
+ module_put(pwrseq->owner);
+ put_device(&pwrseq->dev);
+}
+EXPORT_SYMBOL_GPL(pwrseq_put);
+
+static struct pwrseq_provider *of_pwrseq_provider_lookup(struct device_node *node)
+{
+ struct pwrseq_provider *pwrseq_provider;
+
+ list_for_each_entry(pwrseq_provider, &pwrseq_provider_list, list) {
+ if (pwrseq_provider->dev->of_node == node)
+ return pwrseq_provider;
+ }
+
+ return ERR_PTR(-EPROBE_DEFER);
+}
+
+static struct pwrseq *_of_pwrseq_get(struct device *dev, const char *id)
+{
+ struct pwrseq_provider *pwrseq_provider;
+ struct pwrseq *pwrseq;
+ struct of_phandle_args args;
+ char prop_name[64]; /* 64 is max size of property name */
+ int ret;
+
+ snprintf(prop_name, 64, "%s-pwrseq", id);
+ ret = of_parse_phandle_with_args(dev->of_node, prop_name, "#pwrseq-cells", 0, &args);
+ if (ret) {
+ struct device_node *dn;
+
+ /*
+ * Parsing failed. Try locating old bindings for mmc-pwrseq,
+ * which did not use #pwrseq-cells.
+ */
+ if (strcmp(id, "mmc"))
+ return ERR_PTR(-ENODEV);
+
+ dn = of_parse_phandle(dev->of_node, prop_name, 0);
+ if (!dn)
+ return ERR_PTR(-ENODEV);
+
+ args.np = dn;
+ args.args_count = 0;
+ }
+
+ mutex_lock(&pwrseq_provider_mutex);
+ pwrseq_provider = of_pwrseq_provider_lookup(args.np);
+ if (IS_ERR(pwrseq_provider) || !try_module_get(pwrseq_provider->owner)) {
+ pwrseq = ERR_PTR(-EPROBE_DEFER);
+ goto out_unlock;
+ }
+
+ if (!of_device_is_available(args.np)) {
+ dev_warn(pwrseq_provider->dev, "Requested pwrseq is disabled\n");
+ pwrseq = ERR_PTR(-ENODEV);
+ goto out_put_module;
+ }
+
+ pwrseq = pwrseq_provider->of_xlate(pwrseq_provider->data, &args);
+
+out_put_module:
+ module_put(pwrseq_provider->owner);
+
+out_unlock:
+ mutex_unlock(&pwrseq_provider_mutex);
+ of_node_put(args.np);
+
+ return pwrseq;
+}
+
+struct pwrseq *__must_check pwrseq_get(struct device *dev, const char *id)
+{
+ struct pwrseq *pwrseq;
+ struct device_link *link;
+
+ pwrseq = _of_pwrseq_get(dev, id);
+ if (IS_ERR(pwrseq))
+ return pwrseq;
+
+ if (!try_module_get(pwrseq->owner))
+ return ERR_PTR(-EPROBE_DEFER);
+
+ get_device(&pwrseq->dev);
+ link = device_link_add(dev, &pwrseq->dev, DL_FLAG_STATELESS);
+ if (!link)
+ dev_dbg(dev, "failed to create device link to %s\n",
+ dev_name(pwrseq->dev.parent));
+
+ return pwrseq;
+}
+EXPORT_SYMBOL_GPL(pwrseq_get);
+
+static void devm_pwrseq_release(struct device *dev, void *res)
+{
+ struct pwrseq *pwrseq = *(struct pwrseq **)res;
+
+ pwrseq_put(dev, pwrseq);
+}
+
+struct pwrseq *__must_check devm_pwrseq_get(struct device *dev, const char *id)
+{
+ struct pwrseq **ptr, *pwrseq;
+
+ ptr = devres_alloc(devm_pwrseq_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ pwrseq = pwrseq_get(dev, id);
+ if (!IS_ERR(pwrseq)) {
+ *ptr = pwrseq;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return pwrseq;
+}
+EXPORT_SYMBOL_GPL(devm_pwrseq_get);
+
+struct pwrseq *__must_check pwrseq_get_optional(struct device *dev, const char *id)
+{
+ struct pwrseq *pwrseq = pwrseq_get(dev, id);
+
+ if (pwrseq == ERR_PTR(-ENODEV))
+ return NULL;
+
+ return pwrseq;
+}
+EXPORT_SYMBOL_GPL(pwrseq_get_optional);
+
+struct pwrseq *__must_check devm_pwrseq_get_optional(struct device *dev, const char *id)
+{
+ struct pwrseq **ptr, *pwrseq;
+
+ ptr = devres_alloc(devm_pwrseq_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ pwrseq = pwrseq_get_optional(dev, id);
+ if (!IS_ERR_OR_NULL(pwrseq)) {
+ *ptr = pwrseq;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return pwrseq;
+}
+EXPORT_SYMBOL_GPL(devm_pwrseq_get_optional);
+
+int pwrseq_pre_power_on(struct pwrseq *pwrseq)
+{
+ if (pwrseq && pwrseq->ops->pre_power_on)
+ return pwrseq->ops->pre_power_on(pwrseq);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pwrseq_pre_power_on);
+
+int pwrseq_power_on(struct pwrseq *pwrseq)
+{
+ if (pwrseq && pwrseq->ops->power_on)
+ return pwrseq->ops->power_on(pwrseq);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pwrseq_power_on);
+
+void pwrseq_power_off(struct pwrseq *pwrseq)
+{
+ if (pwrseq && pwrseq->ops->power_off)
+ pwrseq->ops->power_off(pwrseq);
+}
+EXPORT_SYMBOL_GPL(pwrseq_power_off);
+
+void pwrseq_reset(struct pwrseq *pwrseq)
+{
+ if (pwrseq && pwrseq->ops->reset)
+ pwrseq->ops->reset(pwrseq);
+}
+EXPORT_SYMBOL_GPL(pwrseq_reset);
+
+static void pwrseq_dev_release(struct device *dev)
+{
+ struct pwrseq *pwrseq = to_pwrseq(dev);
+
+ ida_free(&pwrseq_ida, pwrseq->id);
+ of_node_put(dev->of_node);
+ kfree(pwrseq);
+}
+
+static struct class pwrseq_class = {
+ .name = "pwrseq",
+ .dev_release = pwrseq_dev_release,
+};
+
+struct pwrseq *__pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops, void *data)
+{
+ struct pwrseq *pwrseq;
+ int ret;
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ pwrseq = kzalloc(sizeof(*pwrseq), GFP_KERNEL);
+ if (!pwrseq)
+ return ERR_PTR(-ENOMEM);
+
+ ret = ida_alloc(&pwrseq_ida, GFP_KERNEL);
+ if (ret < 0)
+ goto free_pwrseq;
+
+ pwrseq->id = ret;
+
+ device_initialize(&pwrseq->dev);
+
+ pwrseq->dev.class = &pwrseq_class;
+ pwrseq->dev.parent = dev;
+ pwrseq->dev.of_node = of_node_get(dev->of_node);
+ pwrseq->ops = ops;
+ pwrseq->owner = owner;
+
+ dev_set_drvdata(&pwrseq->dev, data);
+
+ ret = dev_set_name(&pwrseq->dev, "pwrseq-%s.%u", dev_name(dev), pwrseq->id);
+ if (ret)
+ goto put_dev;
+
+ ret = device_add(&pwrseq->dev);
+ if (ret)
+ goto put_dev;
+
+ if (pm_runtime_enabled(dev)) {
+ pm_runtime_enable(&pwrseq->dev);
+ pm_runtime_no_callbacks(&pwrseq->dev);
+ }
+
+ return pwrseq;
+
+put_dev:
+ /* will call pwrseq_dev_release() to free resources */
+ put_device(&pwrseq->dev);
+
+ return ERR_PTR(ret);
+
+free_pwrseq:
+ kfree(pwrseq);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(__pwrseq_create);
+
+void pwrseq_destroy(struct pwrseq *pwrseq)
+{
+ pm_runtime_disable(&pwrseq->dev);
+ device_unregister(&pwrseq->dev);
+}
+EXPORT_SYMBOL_GPL(pwrseq_destroy);
+
+static void devm_pwrseq_destroy(struct device *dev, void *res)
+{
+ struct pwrseq *pwrseq = *(struct pwrseq **)res;
+
+ pwrseq_destroy(pwrseq);
+}
+
+struct pwrseq *__devm_pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops, void *data)
+{
+ struct pwrseq **ptr, *pwrseq;
+
+ ptr = devres_alloc(devm_pwrseq_destroy, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ pwrseq = __pwrseq_create(dev, owner, ops, data);
+ if (!IS_ERR(pwrseq)) {
+ *ptr = pwrseq;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return pwrseq;
+}
+EXPORT_SYMBOL_GPL(__devm_pwrseq_create);
+
+struct pwrseq_provider *__of_pwrseq_provider_register(struct device *dev,
+ struct module *owner,
+ struct pwrseq * (*of_xlate)(void *data,
+ struct of_phandle_args *args),
+ void *data)
+{
+ struct pwrseq_provider *pwrseq_provider;
+
+ pwrseq_provider = kzalloc(sizeof(*pwrseq_provider), GFP_KERNEL);
+ if (!pwrseq_provider)
+ return ERR_PTR(-ENOMEM);
+
+ pwrseq_provider->dev = dev;
+ pwrseq_provider->owner = owner;
+ pwrseq_provider->of_xlate = of_xlate;
+ pwrseq_provider->data = data;
+
+ mutex_lock(&pwrseq_provider_mutex);
+ list_add_tail(&pwrseq_provider->list, &pwrseq_provider_list);
+ mutex_unlock(&pwrseq_provider_mutex);
+
+ return pwrseq_provider;
+}
+EXPORT_SYMBOL_GPL(__of_pwrseq_provider_register);
+
+void of_pwrseq_provider_unregister(struct pwrseq_provider *pwrseq_provider)
+{
+ if (IS_ERR(pwrseq_provider))
+ return;
+
+ mutex_lock(&pwrseq_provider_mutex);
+ list_del(&pwrseq_provider->list);
+ kfree(pwrseq_provider);
+ mutex_unlock(&pwrseq_provider_mutex);
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_provider_unregister);
+
+static void devm_pwrseq_provider_unregister(struct device *dev, void *res)
+{
+ struct pwrseq_provider *pwrseq_provider = *(struct pwrseq_provider **)res;
+
+ of_pwrseq_provider_unregister(pwrseq_provider);
+}
+
+struct pwrseq_provider *__devm_of_pwrseq_provider_register(struct device *dev,
+ struct module *owner,
+ struct pwrseq * (*of_xlate)(void *data,
+ struct of_phandle_args *args),
+ void *data)
+{
+ struct pwrseq_provider **ptr, *pwrseq_provider;
+
+ ptr = devres_alloc(devm_pwrseq_provider_unregister, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ pwrseq_provider = __of_pwrseq_provider_register(dev, owner, of_xlate, data);
+ if (!IS_ERR(pwrseq_provider)) {
+ *ptr = pwrseq_provider;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return pwrseq_provider;
+}
+EXPORT_SYMBOL_GPL(__devm_of_pwrseq_provider_register);
+
+struct pwrseq *of_pwrseq_xlate_onecell(void *data, struct of_phandle_args *args)
+{
+ struct pwrseq_onecell_data *pwrseq_data = data;
+ unsigned int idx;
+
+ if (args->args_count != 1)
+ return ERR_PTR(-EINVAL);
+
+ idx = args->args[0];
+ if (idx >= pwrseq_data->num) {
+ pr_err("%s: invalid index %u\n", __func__, idx);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return pwrseq_data->pwrseqs[idx];
+}
+
+static int __init pwrseq_core_init(void)
+{
+ return class_register(&pwrseq_class);
+}
+device_initcall(pwrseq_core_init);
diff --git a/include/linux/pwrseq/consumer.h b/include/linux/pwrseq/consumer.h
new file mode 100644
index 000000000000..fbcdc1fc0751
--- /dev/null
+++ b/include/linux/pwrseq/consumer.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2021 Linaro Ltd.
+ */
+
+#ifndef __LINUX_PWRSEQ_CONSUMER_H__
+#define __LINUX_PWRSEQ_CONSUMER_H__
+
+struct pwrseq;
+struct device;
+
+#if defined(CONFIG_PWRSEQ)
+
+struct pwrseq *__must_check pwrseq_get(struct device *dev, const char *id);
+struct pwrseq *__must_check devm_pwrseq_get(struct device *dev, const char *id);
+
+struct pwrseq *__must_check pwrseq_get_optional(struct device *dev, const char *id);
+struct pwrseq *__must_check devm_pwrseq_get_optional(struct device *dev, const char *id);
+
+void pwrseq_put(struct device *dev, struct pwrseq *pwrseq);
+
+int pwrseq_pre_power_on(struct pwrseq *pwrseq);
+int pwrseq_power_on(struct pwrseq *pwrseq);
+void pwrseq_power_off(struct pwrseq *pwrseq);
+void pwrseq_reset(struct pwrseq *pwrseq);
+
+#else
+
+static inline struct pwrseq *__must_check
+pwrseq_get(struct device *dev, const char *id)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct pwrseq *__must_check
+devm_pwrseq_get(struct device *dev, const char *id)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct pwrseq *__must_check
+pwrseq_get_optional(struct device *dev, const char *id)
+{
+ return NULL;
+}
+
+static inline struct pwrseq *__must_check
+devm_pwrseq_get_optional(struct device *dev, const char *id)
+{
+ return NULL;
+}
+
+static inline void pwrseq_put(struct device *dev, struct pwrseq *pwrseq)
+{
+}
+
+static inline int pwrseq_pre_power_on(struct pwrseq *pwrseq)
+{
+ return -ENOSYS;
+}
+
+static inline int pwrseq_power_on(struct pwrseq *pwrseq)
+{
+ return -ENOSYS;
+}
+
+static inline void pwrseq_power_off(struct pwrseq *pwrseq)
+{
+}
+
+static inline void pwrseq_reset(struct pwrseq *pwrseq)
+{
+}
+
+#endif
+
+static inline int pwrseq_full_power_on(struct pwrseq *pwrseq)
+{
+ int ret;
+
+ ret = pwrseq_pre_power_on(pwrseq);
+ if (ret)
+ return ret;
+
+ return pwrseq_power_on(pwrseq);
+}
+
+#endif /* __LINUX_PWRSEQ_CONSUMER_H__ */
diff --git a/include/linux/pwrseq/driver.h b/include/linux/pwrseq/driver.h
new file mode 100644
index 000000000000..6d7c66525134
--- /dev/null
+++ b/include/linux/pwrseq/driver.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2021 Linaro Ltd.
+ */
+
+#ifndef __LINUX_PWRSEQ_DRIVER_H__
+#define __LINUX_PWRSEQ_DRIVER_H__
+
+#include <linux/of.h>
+
+struct pwrseq;
+
+struct pwrseq_ops {
+ int (*pre_power_on)(struct pwrseq *pwrseq);
+ int (*power_on)(struct pwrseq *pwrseq);
+ void (*power_off)(struct pwrseq *pwrseq);
+ void (*reset)(struct pwrseq *pwrseq);
+};
+
+struct pwrseq {
+ struct device dev;
+ const struct pwrseq_ops *ops;
+ unsigned int id;
+ struct module *owner;
+};
+
+struct pwrseq *__pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops, void *data);
+struct pwrseq *__devm_pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops, void *data);
+
+#define pwrseq_create(dev, ops, data) __pwrseq_create((dev), THIS_MODULE, (ops), (data))
+#define devm_pwrseq_create(dev, ops, data) __devm_pwrseq_create((dev), THIS_MODULE, (ops), (data))
+
+void pwrseq_destroy(struct pwrseq *pwrseq);
+
+static inline void *pwrseq_get_data(struct pwrseq *pwrseq)
+{
+ return dev_get_drvdata(&pwrseq->dev);
+}
+
+#define of_pwrseq_provider_register(dev, xlate, data) \
+ __of_pwrseq_provider_register((dev), THIS_MODULE, (xlate), (data))
+
+#define devm_of_pwrseq_provider_register(dev, xlate, data) \
+ __devm_of_pwrseq_provider_register((dev), THIS_MODULE, (xlate), (data))
+
+struct pwrseq_provider *__of_pwrseq_provider_register(struct device *dev,
+ struct module *owner,
+ struct pwrseq * (*of_xlate)(void *data,
+ struct of_phandle_args *args),
+ void *data);
+struct pwrseq_provider *__devm_of_pwrseq_provider_register(struct device *dev,
+ struct module *owner,
+ struct pwrseq * (*of_xlate)(void *data,
+ struct of_phandle_args *args),
+ void *data);
+void of_pwrseq_provider_unregister(struct pwrseq_provider *pwrseq_provider);
+
+static inline struct pwrseq *of_pwrseq_xlate_single(void *data,
+ struct of_phandle_args *args)
+{
+ return data;
+}
+
+struct pwrseq_onecell_data {
+ unsigned int num;
+ struct pwrseq *pwrseqs[];
+};
+
+struct pwrseq *of_pwrseq_xlate_onecell(void *data, struct of_phandle_args *args);
+
+#endif /* __LINUX_PWRSEQ_DRIVER_H__ */
--
2.30.2
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