Rtwo/kernel/motorola/sm8550/drivers/power/reset/silent_boot.c
2025-09-30 19:22:48 -05:00

277 lines
7.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/uaccess.h>
#include <linux/pm.h>
#include <linux/notifier.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/kthread.h>
#include <linux/kernel.h>
#include <asm/arch_timer.h>
#include <asm/div64.h>
#include <linux/silent_mode.h>
static BLOCKING_NOTIFIER_HEAD(pm_silentmode_chain);
static atomic_t pm_silentmode_userspace_cntrl =
ATOMIC_INIT(USERSPACE_CONTROL_DISABLED);
/* silent mode is dependent on BootArgs + HW state*/
static atomic_t pm_silent_mode_enable =
ATOMIC_INIT(MODE_NON_SILENT);
static atomic_t pm_silentmode_hw_state =
ATOMIC_INIT(MODE_GPIO_LOW);
static struct kobject *silent_boot_kobj;
/*
* On the kernel command line specify silent_boot.mode=<mode>
* to set mode in silent mode module.
*/
static char *mode = "nonsilent";
static int silent_mode;
static int silent_mode_param_set(const char *, const struct kernel_param *);
static int silent_mode_param_get(char *, const struct kernel_param *);
static const struct kernel_param_ops silent_mode_param_ops = {
.set = silent_mode_param_set,
.get = silent_mode_param_get,
};
module_param_cb(mode, &silent_mode_param_ops, &mode, 0644);
static int silent_mode_param_set(const char *val, const struct kernel_param *kp)
{
if (!silent_mode) {
int len = strlen("forcednonsilent");
char *s = strstrip((char *)val);
if (strnstr(s, "forcednonsilent", len)) {
silent_mode = -MODE_NON_SILENT;
} else if (strnstr(s, "forcedsilent", len)) {
silent_mode = -MODE_SILENT;
} else if (strnstr(s, "nonsilent", len)) {
silent_mode = MODE_NON_SILENT;
} else if (strnstr(s, "silent", len)) {
silent_mode = MODE_SILENT;
} else {
silent_mode = MODE_NON_SILENT;
pr_debug("silent_mode: No string found: NON_SILENT\n");
}
}
pr_debug("Silent Mode set to %d\n", silent_mode);
return 0;
}
static int silent_mode_param_get(char *buf, const struct kernel_param *kp)
{
return scnprintf(buf, strlen(mode)+1, "%s\n", mode);
}
/*
* pm_silentmode_kernel_set: Check if userspace is controlling this node
* else go ahead and update the node.
*/
static int pm_silentmode_kernel_set(int val)
{
if (!atomic_read(&pm_silentmode_userspace_cntrl)) {
pr_debug("%s: Kernel Control sysfs\n", __func__);
atomic_set(&pm_silent_mode_enable, val);
return 0;
}
pr_debug("%s: Userspace Controls sysfs\n", __func__);
return -USERSPACE_CONTROL_ENABLED;
}
static int pm_silentmode_kernel_get(void)
{
return atomic_read(&pm_silent_mode_enable);
}
static void pm_silentmode_hw_state_set(int val)
{
atomic_set(&pm_silentmode_hw_state, val);
}
int pm_silentmode_hw_state_get(void)
{
return atomic_read(&pm_silentmode_hw_state);
}
EXPORT_SYMBOL(pm_silentmode_hw_state_get);
/*
* External Function to be called by drivers interested in checking
* silent boot mode value and registering a callback if in silent mode
* else return pm_silent_mode_enable value
*/
int register_pm_silentmode_notifier(struct notifier_block *nb)
{
int lsilent = pm_silentmode_kernel_get();
if (lsilent == MODE_SILENT) {
blocking_notifier_chain_register(&pm_silentmode_chain, nb);
pr_debug("%s: ....Registered\n", __func__);
}
return lsilent;
}
EXPORT_SYMBOL(register_pm_silentmode_notifier);
/*
* External function used for unregistering the callback to the silent mode
* driver for notification
*/
int unregister_pm_silentmode_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister
(&pm_silentmode_chain, nb);
}
EXPORT_SYMBOL(unregister_pm_silentmode_notifier);
static void pm_silent_mode_cb_chain(void)
{
pr_debug("%s: SilentMode notify\n", __func__);
blocking_notifier_call_chain(&pm_silentmode_chain, 1, NULL);
}
void pm_silentmode_user_update(struct kobject *kobj, int val)
{
if (kobj != NULL) {
atomic_set(&pm_silentmode_userspace_cntrl,
USERSPACE_CONTROL_ENABLED);
atomic_set(&pm_silent_mode_enable, val);
sysfs_notify(kobj, NULL, "pm_silentmode_kernel_state");
}
}
int pm_silentmode_update(int val, struct kobject *kobj, bool us)
{
if (us) {
pm_silentmode_user_update(kobj, val);
return 0;
}
pr_debug("%s:Driver update to sysfs\n", __func__);
pm_silentmode_kernel_set(val ^ 1);
pm_silentmode_hw_state_set((val ^ 1));
sysfs_notify(silent_boot_kobj, NULL, "pm_silentmode_kernel_state");
sysfs_notify(silent_boot_kobj, NULL, "pm_silentmode_hw_state");
pm_silent_mode_cb_chain();
return 0;
}
EXPORT_SYMBOL(pm_silentmode_update);
int pm_silentmode_status(void)
{
return pm_silentmode_kernel_get();
}
EXPORT_SYMBOL(pm_silentmode_status);
int pm_silentmode_get_mode(void)
{
return silent_mode;
}
EXPORT_SYMBOL(pm_silentmode_get_mode);
#define silentmode_attr(_name) \
static struct kobj_attribute _name##_attr = { \
.attr = { \
.name = __stringify(_name), \
.mode = 0664, \
}, \
.show = _name##_show, \
.store = _name##_store, \
}
static ssize_t pm_silentmode_kernel_state_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%d\n", pm_silentmode_status());
}
static ssize_t pm_silentmode_kernel_state_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
pm_silentmode_update(val, kobj, 1);
return n;
}
silentmode_attr(pm_silentmode_kernel_state);
static ssize_t pm_silentmode_hw_state_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%d\n",
pm_silentmode_hw_state_get());
}
static ssize_t pm_silentmode_hw_state_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t n)
{
return -EINVAL;
}
silentmode_attr(pm_silentmode_hw_state);
static struct attribute *g[] = {
&pm_silentmode_kernel_state_attr.attr,
&pm_silentmode_hw_state_attr.attr,
NULL,
};
static const struct attribute_group attr_group = {
.attrs = g,
};
static int __init pm_silentmode_init(void)
{
int error;
pr_debug("%s: Silent Boot Mode Entered\n", __func__);
/* 1. Set based on Parse Command Line arguments */
if (!silent_mode) {
silent_mode = MODE_NON_SILENT;
}
if (silent_mode == MODE_SILENT || silent_mode == -MODE_SILENT) {
pm_silentmode_hw_state_set(MODE_GPIO_HIGH);
pm_silentmode_kernel_set(1);
} else {
pm_silentmode_hw_state_set(MODE_GPIO_LOW);
pm_silentmode_kernel_set(0);
pr_debug("%s: Silent Boot Mode disabled\n", __func__);
}
silent_boot_kobj = kobject_create_and_add("silent_boot", kernel_kobj);
if (!silent_boot_kobj) {
pr_err("%s: Failed to add silent_boot_kobj\n", __func__);
return -ENOMEM;
}
/* 2. Append sysfs entries under /sys/kernel/ */
error = sysfs_create_group(silent_boot_kobj, &attr_group);
if (error) {
pr_err("%s: failed to create sysfs %d\n", __func__, error);
return error;
}
return 0;
}
postcore_initcall(pm_silentmode_init);
MODULE_DESCRIPTION("Qualcomm Technologies, Inc. PM Silent Mode driver");
MODULE_LICENSE("GPL v2");