@@ -9828,6 +9828,15 @@ F: include/linux/pm_*
F: include/linux/powercap.h
F: drivers/powercap/
+POWER SEQUENCE LIBRARY
+M: Peter Chen <Peter.Chen@nxp.com>
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git
+L: linux-pm@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/power/pwrseq/
+F: drivers/power/pwrseq/
+F: include/linux/power/pwrseq.h
+
POWER SUPPLY CLASS/SUBSYSTEM and DRIVERS
M: Sebastian Reichel <sre@kernel.org>
L: linux-pm@vger.kernel.org
@@ -1,3 +1,4 @@
source "drivers/power/avs/Kconfig"
source "drivers/power/reset/Kconfig"
source "drivers/power/supply/Kconfig"
+source "drivers/power/pwrseq/Kconfig"
@@ -1,3 +1,4 @@
obj-$(CONFIG_POWER_AVS) += avs/
obj-$(CONFIG_POWER_RESET) += reset/
obj-$(CONFIG_POWER_SUPPLY) += supply/
+obj-$(CONFIG_POWER_SEQUENCE) += pwrseq/
new file mode 100644
@@ -0,0 +1,20 @@
+#
+# Power Sequence library
+#
+
+menuconfig POWER_SEQUENCE
+ bool "Power sequence control"
+ help
+ It is used for drivers which needs to do power sequence
+ (eg, turn on clock, toggle reset gpio) before the related
+ devices can be found by hardware, eg, USB bus.
+
+if POWER_SEQUENCE
+
+config PWRSEQ_GENERIC
+ bool "Generic power sequence control"
+ depends on OF
+ help
+ This is the generic power sequence control library, and is
+ supposed to support common power sequence usage.
+endif
new file mode 100644
@@ -0,0 +1,2 @@
+obj-$(CONFIG_POWER_SEQUENCE) += core.o
+obj-$(CONFIG_PWRSEQ_GENERIC) += pwrseq_generic.o
new file mode 100644
@@ -0,0 +1,335 @@
+/*
+ * core.c power sequence core file
+ *
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Author: Peter Chen <peter.chen@nxp.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ */
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/power/pwrseq.h>
+
+static DEFINE_MUTEX(pwrseq_list_mutex);
+static LIST_HEAD(pwrseq_list);
+
+static int pwrseq_get(struct device_node *np, struct pwrseq *p)
+{
+ if (p && p->get)
+ return p->get(np, p);
+
+ return -ENOTSUPP;
+}
+
+static int pwrseq_on(struct pwrseq *p)
+{
+ if (p && p->on)
+ return p->on(p);
+
+ return -ENOTSUPP;
+}
+
+static void pwrseq_off(struct pwrseq *p)
+{
+ if (p && p->off)
+ p->off(p);
+}
+
+static void pwrseq_put(struct pwrseq *p)
+{
+ if (p && p->put)
+ p->put(p);
+}
+
+/**
+ * pwrseq_register - Add pwrseq instance to global pwrseq list
+ *
+ * @pwrseq: the pwrseq instance
+ */
+void pwrseq_register(struct pwrseq *pwrseq)
+{
+ mutex_lock(&pwrseq_list_mutex);
+ list_add(&pwrseq->node, &pwrseq_list);
+ mutex_unlock(&pwrseq_list_mutex);
+}
+EXPORT_SYMBOL_GPL(pwrseq_register);
+
+/**
+ * pwrseq_unregister - Remove pwrseq instance from global pwrseq list
+ *
+ * @pwrseq: the pwrseq instance
+ */
+void pwrseq_unregister(struct pwrseq *pwrseq)
+{
+ mutex_lock(&pwrseq_list_mutex);
+ list_del(&pwrseq->node);
+ mutex_unlock(&pwrseq_list_mutex);
+}
+EXPORT_SYMBOL_GPL(pwrseq_unregister);
+
+static struct pwrseq *pwrseq_find_available_instance(struct device_node *np)
+{
+ struct pwrseq *pwrseq;
+
+ mutex_lock(&pwrseq_list_mutex);
+ list_for_each_entry(pwrseq, &pwrseq_list, node) {
+ if (pwrseq->used)
+ continue;
+
+ /* compare compatible string for pwrseq node */
+ if (of_match_node(pwrseq->pwrseq_of_match_table, np)) {
+ pwrseq->used = true;
+ mutex_unlock(&pwrseq_list_mutex);
+ return pwrseq;
+ }
+
+ /* return generic pwrseq instance */
+ if (!strcmp(pwrseq->pwrseq_of_match_table->compatible,
+ "generic")) {
+ pr_debug("using generic pwrseq instance for %s\n",
+ np->full_name);
+ pwrseq->used = true;
+ mutex_unlock(&pwrseq_list_mutex);
+ return pwrseq;
+ }
+ }
+ mutex_unlock(&pwrseq_list_mutex);
+ pr_debug("Can't find any pwrseq instances for %s\n", np->full_name);
+
+ return NULL;
+}
+
+/**
+ * of_pwrseq_on - Carry out power sequence on for device node
+ *
+ * @np: the device node would like to power on
+ *
+ * Carry out a single device power on. If multiple devices
+ * need to be handled, use of_pwrseq_on_list() instead.
+ *
+ * Return a pointer to the power sequence instance on success,
+ * or an error code otherwise.
+ */
+struct pwrseq *of_pwrseq_on(struct device_node *np)
+{
+ struct pwrseq *pwrseq;
+ int ret;
+
+ pwrseq = pwrseq_find_available_instance(np);
+ if (!pwrseq)
+ return ERR_PTR(-ENOENT);
+
+ ret = pwrseq_get(np, pwrseq);
+ if (ret) {
+ /* Mark current pwrseq as unused */
+ pwrseq->used = false;
+ return ERR_PTR(ret);
+ }
+
+ ret = pwrseq_on(pwrseq);
+ if (ret)
+ goto pwr_put;
+
+ return pwrseq;
+
+pwr_put:
+ pwrseq_put(pwrseq);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_on);
+
+/**
+ * of_pwrseq_off - Carry out power sequence off for this pwrseq instance
+ *
+ * @pwrseq: the pwrseq instance which related device would like to be off
+ *
+ * This API is used to power off single device, it is the opposite
+ * operation for of_pwrseq_on.
+ */
+void of_pwrseq_off(struct pwrseq *pwrseq)
+{
+ pwrseq_off(pwrseq);
+ pwrseq_put(pwrseq);
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_off);
+
+/**
+ * of_pwrseq_on_list - Carry out power sequence on for list
+ *
+ * @np: the device node would like to power on
+ * @head: the list head for pwrseq list on this bus
+ *
+ * This API is used to power on multiple devices at single bus.
+ * If there are several devices on bus (eg, USB bus), uses this
+ * this API. Otherwise, use of_pwrseq_on instead. After the device
+ * is powered on successfully, it will be added to pwrseq list for
+ * this bus. The caller needs to use mutex_lock for concurrent.
+ *
+ * Return 0 on success, or an error value otherwise.
+ */
+int of_pwrseq_on_list(struct device_node *np, struct list_head *head)
+{
+ struct pwrseq *pwrseq;
+ struct pwrseq_list_per_dev *pwrseq_list_node;
+
+ pwrseq_list_node = kzalloc(sizeof(*pwrseq_list_node), GFP_KERNEL);
+ if (!pwrseq_list_node)
+ return -ENOMEM;
+
+ pwrseq = of_pwrseq_on(np);
+ if (IS_ERR(pwrseq)) {
+ kfree(pwrseq_list_node);
+ return PTR_ERR(pwrseq);
+ }
+
+ pwrseq_list_node->pwrseq = pwrseq;
+ list_add(&pwrseq_list_node->list, head);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_on_list);
+
+/**
+ * of_pwrseq_off_list - Carry out power sequence off for the list
+ *
+ * @head: the list head for pwrseq instance list on this bus
+ *
+ * This API is used to power off all devices on this bus, it is
+ * the opposite operation for of_pwrseq_on_list.
+ * The caller needs to use mutex_lock for concurrent.
+ */
+void of_pwrseq_off_list(struct list_head *head)
+{
+ struct pwrseq *pwrseq;
+ struct pwrseq_list_per_dev *pwrseq_list_node, *tmp_node;
+
+ list_for_each_entry_safe(pwrseq_list_node, tmp_node, head, list) {
+ pwrseq = pwrseq_list_node->pwrseq;
+ of_pwrseq_off(pwrseq);
+ list_del(&pwrseq_list_node->list);
+ kfree(pwrseq_list_node);
+ }
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_off_list);
+
+/**
+ * pwrseq_suspend - Carry out power sequence suspend for this pwrseq instance
+ *
+ * @pwrseq: the pwrseq instance
+ *
+ * This API is used to do suspend operation on pwrseq instance.
+ *
+ * Return 0 on success, or an error value otherwise.
+ */
+int pwrseq_suspend(struct pwrseq *p)
+{
+ int ret = 0;
+
+ if (p && p->suspend)
+ ret = p->suspend(p);
+ else
+ return ret;
+
+ if (!ret)
+ p->suspended = true;
+ else
+ pr_err("%s failed\n", __func__);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pwrseq_suspend);
+
+/**
+ * pwrseq_resume - Carry out power sequence resume for this pwrseq instance
+ *
+ * @pwrseq: the pwrseq instance
+ *
+ * This API is used to do resume operation on pwrseq instance.
+ *
+ * Return 0 on success, or an error value otherwise.
+ */
+int pwrseq_resume(struct pwrseq *p)
+{
+ int ret = 0;
+
+ if (p && p->resume)
+ ret = p->resume(p);
+ else
+ return ret;
+
+ if (!ret)
+ p->suspended = false;
+ else
+ pr_err("%s failed\n", __func__);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pwrseq_resume);
+
+/**
+ * pwrseq_suspend_list - Carry out power sequence suspend for list
+ *
+ * @head: the list head for pwrseq instance list on this bus
+ *
+ * This API is used to do suspend on all power sequence instances on this bus.
+ * The caller needs to use mutex_lock for concurrent.
+ */
+int pwrseq_suspend_list(struct list_head *head)
+{
+ struct pwrseq *pwrseq;
+ struct pwrseq_list_per_dev *pwrseq_list_node;
+ int ret = 0;
+
+ list_for_each_entry(pwrseq_list_node, head, list) {
+ ret = pwrseq_suspend(pwrseq_list_node->pwrseq);
+ if (ret)
+ break;
+ }
+
+ if (ret) {
+ list_for_each_entry(pwrseq_list_node, head, list) {
+ pwrseq = pwrseq_list_node->pwrseq;
+ if (pwrseq->suspended)
+ pwrseq_resume(pwrseq);
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pwrseq_suspend_list);
+
+/**
+ * pwrseq_resume_list - Carry out power sequence resume for the list
+ *
+ * @head: the list head for pwrseq instance list on this bus
+ *
+ * This API is used to do resume on all power sequence instances on this bus.
+ * The caller needs to use mutex_lock for concurrent.
+ */
+int pwrseq_resume_list(struct list_head *head)
+{
+ struct pwrseq_list_per_dev *pwrseq_list_node;
+ int ret = 0;
+
+ list_for_each_entry(pwrseq_list_node, head, list) {
+ ret = pwrseq_resume(pwrseq_list_node->pwrseq);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pwrseq_resume_list);
new file mode 100644
@@ -0,0 +1,224 @@
+/*
+ * pwrseq_generic.c Generic power sequence handling
+ *
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Author: Peter Chen <peter.chen@nxp.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/slab.h>
+
+#include <linux/power/pwrseq.h>
+
+struct pwrseq_generic {
+ struct pwrseq pwrseq;
+ struct gpio_desc *gpiod_reset;
+ struct clk *clks[PWRSEQ_MAX_CLKS];
+ u32 duration_us;
+ bool suspended;
+};
+
+#define to_generic_pwrseq(p) container_of(p, struct pwrseq_generic, pwrseq)
+
+static int pwrseq_generic_alloc_instance(void);
+static const struct of_device_id generic_id_table[] = {
+ { .compatible = "generic",},
+ { /* sentinel */ }
+};
+
+static int pwrseq_generic_suspend(struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ int clk;
+
+ for (clk = PWRSEQ_MAX_CLKS - 1; clk >= 0; clk--)
+ clk_disable_unprepare(pwrseq_gen->clks[clk]);
+
+ pwrseq_gen->suspended = true;
+ return 0;
+}
+
+static int pwrseq_generic_resume(struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ int clk, ret = 0;
+
+ for (clk = 0; clk < PWRSEQ_MAX_CLKS && pwrseq_gen->clks[clk]; clk++) {
+ ret = clk_prepare_enable(pwrseq_gen->clks[clk]);
+ if (ret) {
+ pr_err("Can't enable clock, ret=%d\n", ret);
+ goto err_disable_clks;
+ }
+ }
+
+ pwrseq_gen->suspended = false;
+ return ret;
+
+err_disable_clks:
+ while (--clk >= 0)
+ clk_disable_unprepare(pwrseq_gen->clks[clk]);
+
+ return ret;
+}
+
+static void pwrseq_generic_put(struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ int clk;
+
+ if (pwrseq_gen->gpiod_reset)
+ gpiod_put(pwrseq_gen->gpiod_reset);
+
+ for (clk = 0; clk < PWRSEQ_MAX_CLKS; clk++)
+ clk_put(pwrseq_gen->clks[clk]);
+
+ pwrseq_unregister(&pwrseq_gen->pwrseq);
+ kfree(pwrseq_gen);
+}
+
+static void pwrseq_generic_off(struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ int clk;
+
+ if (pwrseq_gen->suspended)
+ return;
+
+ for (clk = PWRSEQ_MAX_CLKS - 1; clk >= 0; clk--)
+ clk_disable_unprepare(pwrseq_gen->clks[clk]);
+}
+
+static int pwrseq_generic_on(struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ int clk, ret = 0;
+ struct gpio_desc *gpiod_reset = pwrseq_gen->gpiod_reset;
+
+ for (clk = 0; clk < PWRSEQ_MAX_CLKS && pwrseq_gen->clks[clk]; clk++) {
+ ret = clk_prepare_enable(pwrseq_gen->clks[clk]);
+ if (ret) {
+ pr_err("Can't enable clock, ret=%d\n", ret);
+ goto err_disable_clks;
+ }
+ }
+
+ if (gpiod_reset) {
+ u32 duration_us = pwrseq_gen->duration_us;
+
+ if (duration_us <= 10)
+ udelay(10);
+ else
+ usleep_range(duration_us, duration_us + 100);
+ gpiod_set_value(gpiod_reset, 0);
+ }
+
+ return ret;
+
+err_disable_clks:
+ while (--clk >= 0)
+ clk_disable_unprepare(pwrseq_gen->clks[clk]);
+
+ return ret;
+}
+
+static int pwrseq_generic_get(struct device_node *np, struct pwrseq *pwrseq)
+{
+ struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
+ enum of_gpio_flags flags;
+ int reset_gpio, clk, ret = 0;
+
+ for (clk = 0; clk < PWRSEQ_MAX_CLKS; clk++) {
+ pwrseq_gen->clks[clk] = of_clk_get(np, clk);
+ if (IS_ERR(pwrseq_gen->clks[clk])) {
+ ret = PTR_ERR(pwrseq_gen->clks[clk]);
+ if (ret != -ENOENT)
+ goto err_put_clks;
+ pwrseq_gen->clks[clk] = NULL;
+ break;
+ }
+ }
+
+ reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0, &flags);
+ if (gpio_is_valid(reset_gpio)) {
+ unsigned long gpio_flags;
+
+ if (flags & OF_GPIO_ACTIVE_LOW)
+ gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_LOW;
+ else
+ gpio_flags = GPIOF_OUT_INIT_HIGH;
+
+ ret = gpio_request_one(reset_gpio, gpio_flags,
+ "pwrseq-reset-gpios");
+ if (ret)
+ goto err_put_clks;
+
+ pwrseq_gen->gpiod_reset = gpio_to_desc(reset_gpio);
+ of_property_read_u32(np, "reset-duration-us",
+ &pwrseq_gen->duration_us);
+ } else if (reset_gpio == -ENOENT) {
+ ; /* no such gpio */
+ } else {
+ ret = reset_gpio;
+ pr_err("Failed to get reset gpio on %s, err = %d\n",
+ np->full_name, reset_gpio);
+ goto err_put_clks;
+ }
+
+ /* allocate new one for later pwrseq instance request */
+ ret = pwrseq_generic_alloc_instance();
+ if (ret)
+ goto err_put_gpio;
+
+ return 0;
+
+err_put_gpio:
+ if (pwrseq_gen->gpiod_reset)
+ gpiod_put(pwrseq_gen->gpiod_reset);
+err_put_clks:
+ while (--clk >= 0)
+ clk_put(pwrseq_gen->clks[clk]);
+ return ret;
+}
+
+static int pwrseq_generic_alloc_instance(void)
+{
+ struct pwrseq_generic *pwrseq_gen;
+
+ pwrseq_gen = kzalloc(sizeof(*pwrseq_gen), GFP_KERNEL);
+ if (!pwrseq_gen)
+ return -ENOMEM;
+
+ pwrseq_gen->pwrseq.pwrseq_of_match_table = generic_id_table;
+ pwrseq_gen->pwrseq.get = pwrseq_generic_get;
+ pwrseq_gen->pwrseq.on = pwrseq_generic_on;
+ pwrseq_gen->pwrseq.off = pwrseq_generic_off;
+ pwrseq_gen->pwrseq.put = pwrseq_generic_put;
+ pwrseq_gen->pwrseq.suspend = pwrseq_generic_suspend;
+ pwrseq_gen->pwrseq.resume = pwrseq_generic_resume;
+
+ pwrseq_register(&pwrseq_gen->pwrseq);
+ return 0;
+}
+
+static int __init pwrseq_generic_register(void)
+{
+ return pwrseq_generic_alloc_instance();
+}
+postcore_initcall(pwrseq_generic_register)
new file mode 100644
@@ -0,0 +1,81 @@
+#ifndef __LINUX_PWRSEQ_H
+#define __LINUX_PWRSEQ_H
+
+#include <linux/of.h>
+
+#define PWRSEQ_MAX_CLKS 3
+
+/**
+ * struct pwrseq - the power sequence structure
+ * @pwrseq_of_match_table: the OF device id table this pwrseq library supports
+ * @node: the list pointer to be added to pwrseq list
+ * @get: the API is used to get pwrseq instance from the device node
+ * @on: do power on for this pwrseq instance
+ * @off: do power off for this pwrseq instance
+ * @put: release the resources on this pwrseq instance
+ * @suspend: do suspend operation on this pwrseq instance
+ * @resume: do resume operation on this pwrseq instance
+ * @used: this pwrseq instance is used by device
+ */
+struct pwrseq {
+ const struct of_device_id *pwrseq_of_match_table;
+ struct list_head node;
+ int (*get)(struct device_node *np, struct pwrseq *p);
+ int (*on)(struct pwrseq *p);
+ void (*off)(struct pwrseq *p);
+ void (*put)(struct pwrseq *p);
+ int (*suspend)(struct pwrseq *p);
+ int (*resume)(struct pwrseq *p);
+ bool used;
+ bool suspended;
+};
+
+/* used for power sequence instance list in one driver */
+struct pwrseq_list_per_dev {
+ struct pwrseq *pwrseq;
+ struct list_head list;
+};
+
+#if IS_ENABLED(CONFIG_POWER_SEQUENCE)
+void pwrseq_register(struct pwrseq *pwrseq);
+void pwrseq_unregister(struct pwrseq *pwrseq);
+struct pwrseq *of_pwrseq_on(struct device_node *np);
+void of_pwrseq_off(struct pwrseq *pwrseq);
+int of_pwrseq_on_list(struct device_node *np, struct list_head *head);
+void of_pwrseq_off_list(struct list_head *head);
+int pwrseq_suspend(struct pwrseq *p);
+int pwrseq_resume(struct pwrseq *p);
+int pwrseq_suspend_list(struct list_head *head);
+int pwrseq_resume_list(struct list_head *head);
+#else
+static inline void pwrseq_register(struct pwrseq *pwrseq) {}
+static inline void pwrseq_unregister(struct pwrseq *pwrseq) {}
+static inline struct pwrseq *of_pwrseq_on(struct device_node *np)
+{
+ return NULL;
+}
+static void of_pwrseq_off(struct pwrseq *pwrseq) {}
+static int of_pwrseq_on_list(struct device_node *np, struct list_head *head)
+{
+ return 0;
+}
+static void of_pwrseq_off_list(struct list_head *head) {}
+static int pwrseq_suspend(struct pwrseq *p)
+{
+ return 0;
+}
+static int pwrseq_resume(struct pwrseq *p)
+{
+ return 0;
+}
+static int pwrseq_suspend_list(struct list_head *head)
+{
+ return 0;
+}
+static int pwrseq_resume_list(struct list_head *head)
+{
+ return 0;
+}
+#endif /* CONFIG_POWER_SEQUENCE */
+
+#endif /* __LINUX_PWRSEQ_H */