linux-nv-oot/drivers/misc/bluedroid_pm.c

// SPDX-License-Identifier: GPL-2.0-only
// SPDX-FileCopyrightText: Copyright (c) 2019-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.

#include <nvidia/conftest.h>

#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/regulator/consumer.h>
#include <linux/rfkill.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/pm_qos.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/of_gpio.h>
#include "bluedroid_pm.h"

#define PROC_DIR	"bluetooth/sleep"

/* 5 seconds of Min CPU configurations during resume */
#define DEFAULT_RESUME_CPU_TIMEOUT	5000000

#define TX_TIMER_INTERVAL 5

/* Macro to enable or disable debug logging */
/* #define BLUEDROID_PM_DBG */
#ifndef BLUEDROID_PM_DBG
#define BDP_DBG(fmt, ...)	pr_debug("%s: " fmt, __func__, ##__VA_ARGS__)
#else
#define BDP_DBG(fmt, ...)	pr_warn("%s: " fmt, __func__, ##__VA_ARGS__)
#endif

#define BDP_WARN(fmt, ...)	pr_warn("%s: " fmt, __func__, ##__VA_ARGS__)
#define BDP_ERR(fmt, ...)	pr_err("%s: " fmt, __func__, ##__VA_ARGS__)

/* status flags for bluedroid_pm_driver */
#define BT_WAKE	0x01

struct bluedroid_pm_data {
	struct gpio_desc *gpio_reset;
	struct gpio_desc *gpio_shutdown;
	struct gpio_desc *host_wake;
	struct gpio_desc *ext_wake;
	int is_blocked;
	unsigned int resume_min_frequency;
	unsigned long flags;
	int host_wake_irq;
	struct regulator *vdd_3v3;
	struct regulator *vdd_1v8;
	struct rfkill *rfkill;
	struct wakeup_source *wake_lock;
	struct pm_qos_request resume_cpu_freq_req;
	bool resumed;
	struct work_struct work;
	spinlock_t lock;
	struct device *dev;
	struct timer_list bluedroid_pm_timer;
};

static struct proc_dir_entry *proc_bt_dir, *bluetooth_sleep_dir;
static bool bluedroid_pm_blocked = 1;

static DEFINE_MUTEX(bt_wlan_sync);

void bt_wlan_lock(void)
{
	mutex_lock(&bt_wlan_sync);
}
EXPORT_SYMBOL(bt_wlan_lock);

void bt_wlan_unlock(void)
{
	mutex_unlock(&bt_wlan_sync);
}
EXPORT_SYMBOL(bt_wlan_unlock);

/** bluedroid_m busy timer */

static void bluedroid_pm_timer_expire(struct timer_list *timer);

static void bluedroid_work(struct work_struct *data)
{
	struct bluedroid_pm_data *bluedroid_pm =
			container_of(data, struct bluedroid_pm_data, work);
	struct device *dev = bluedroid_pm->dev;
	char *resumed[2] = { "BT_STATE=RESUMED", NULL };
	char **uevent_envp = NULL;
	unsigned long flags;

	spin_lock_irqsave(&bluedroid_pm->lock, flags);
	if (!bluedroid_pm->is_blocked && bluedroid_pm->resumed)
		uevent_envp = resumed;
	spin_unlock_irqrestore(&bluedroid_pm->lock, flags);

	if (uevent_envp) {
		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, uevent_envp);
		BDP_DBG("is_blocked=%d, resumed=%d, uevent %s\n",
			bluedroid_pm->is_blocked, bluedroid_pm->resumed,
			uevent_envp[0]);
	} else {
		BDP_DBG("is_blocked=%d, resumed=%d, no uevent\n",
			bluedroid_pm->is_blocked, bluedroid_pm->resumed);
	}
}

static irqreturn_t bluedroid_pm_hostwake_isr(int irq, void *dev_id)
{
	/* schedule a tasklet to handle the change in the host wake line */
	return IRQ_HANDLED;
}

static int bluedroid_pm_gpio_get_value(struct gpio_desc *gpio)
{
	if (gpiod_cansleep(gpio))
		return gpiod_get_value_cansleep(gpio);
	else
		return gpiod_get_value(gpio);
}

static void bluedroid_pm_gpio_set_value(struct gpio_desc *gpio, int value)
{
	if (gpiod_cansleep(gpio))
		gpiod_set_value_cansleep(gpio, value);
	else
		gpiod_set_value(gpio, value);
}

/**
 * Handles bluedroid_pm busy timer expiration.
 * @param data: bluedroid_pm structure.
 */
static void bluedroid_pm_timer_expire(struct timer_list *timer)
{
#if defined(timer_container_of) /* Linux v6.16 */
	struct bluedroid_pm_data *bluedroid_pm = timer_container_of(bluedroid_pm,
						timer, bluedroid_pm_timer);
#else
	struct bluedroid_pm_data *bluedroid_pm = from_timer(bluedroid_pm,
						timer, bluedroid_pm_timer);
#endif

	/*
	 * if bluedroid_pm data is NULL or timer is deleted with TX busy.
	 * return from the function.
	 */
	if (!bluedroid_pm || test_bit(BT_WAKE, &bluedroid_pm->flags))
		return;

	if (!bluedroid_pm_gpio_get_value(bluedroid_pm->host_wake)) {
		/* BT can sleep */
		BDP_DBG("Tx and Rx are idle, BT sleeping");
		bluedroid_pm_gpio_set_value(bluedroid_pm->ext_wake, 0);
		__pm_relax(bluedroid_pm->wake_lock);
	} else {
		/* BT Rx is busy, Reset Timer */
		BDP_DBG("Rx is busy, restarting the timer");
		mod_timer(&bluedroid_pm->bluedroid_pm_timer,
					jiffies + (TX_TIMER_INTERVAL * HZ));
	}
}

static int bluedroid_pm_rfkill_set_power(void *data, bool blocked)
{
	struct bluedroid_pm_data *bluedroid_pm = data;
	int ret = 0;

	mdelay(100);
	if (blocked) {
		if (!IS_ERR(bluedroid_pm->gpio_shutdown))
			bluedroid_pm_gpio_set_value(
				bluedroid_pm->gpio_shutdown, 0);
		if (!IS_ERR(bluedroid_pm->gpio_reset))
			bluedroid_pm_gpio_set_value(
				bluedroid_pm->gpio_reset, 0);
		if (bluedroid_pm->vdd_3v3)
			ret |= regulator_disable(bluedroid_pm->vdd_3v3);
		if (bluedroid_pm->vdd_1v8)
			ret |= regulator_disable(bluedroid_pm->vdd_1v8);
		if (!IS_ERR(bluedroid_pm->ext_wake))
			__pm_relax(bluedroid_pm->wake_lock);
		if (bluedroid_pm->resume_min_frequency)
			cpu_latency_qos_remove_request(&bluedroid_pm->resume_cpu_freq_req);
	} else {
		if (bluedroid_pm->vdd_3v3)
			ret |= regulator_enable(bluedroid_pm->vdd_3v3);
		if (bluedroid_pm->vdd_1v8)
			ret |= regulator_enable(bluedroid_pm->vdd_1v8);
		if (!IS_ERR(bluedroid_pm->gpio_shutdown))
			bluedroid_pm_gpio_set_value(
				bluedroid_pm->gpio_shutdown, 1);
		if (!IS_ERR(bluedroid_pm->gpio_reset))
			bluedroid_pm_gpio_set_value(
				bluedroid_pm->gpio_reset, 1);
		if (bluedroid_pm->resume_min_frequency)
			cpu_latency_qos_add_request(&bluedroid_pm->resume_cpu_freq_req,
						PM_QOS_DEFAULT_VALUE);

	}
	bluedroid_pm->is_blocked = blocked;
	mdelay(100);

	return ret;
}

static const struct rfkill_ops bluedroid_pm_rfkill_ops = {
	.set_block = bluedroid_pm_rfkill_set_power,
};

static ssize_t lpm_read_proc(struct file *file, char __user *buf, size_t size,
					loff_t *ppos)
{
	char msg[50];
#if defined(NV_PDE_DATA_LOWER_CASE_PRESENT) /* Linux v5.17 */
	struct bluedroid_pm_data *bluedroid_pm = pde_data(file_inode(file));
#else
	struct bluedroid_pm_data *bluedroid_pm = PDE_DATA(file_inode(file));
#endif

	sprintf(msg, "BT LPM Status: TX %x, RX %x\n",
			bluedroid_pm_gpio_get_value(bluedroid_pm->ext_wake),
			bluedroid_pm_gpio_get_value(bluedroid_pm->host_wake));
	return simple_read_from_buffer(buf, size, ppos, msg, strlen(msg));
}

static ssize_t lpm_write_proc(struct file *file, const char __user *buffer,
					size_t count, loff_t *ppos)
{
	char *buf;
#if defined(NV_PDE_DATA_LOWER_CASE_PRESENT) /* Linux v5.17 */
	struct bluedroid_pm_data *bluedroid_pm = pde_data(file_inode(file));
#else
	struct bluedroid_pm_data *bluedroid_pm = PDE_DATA(file_inode(file));
#endif

	if (count < 1)
		return -EINVAL;

	buf = kmalloc(count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	if (copy_from_user(buf, buffer, count)) {
		kfree(buf);
		return -EFAULT;
	}

	if (!bluedroid_pm->is_blocked) {
		if (buf[0] == '0') {
			if (!bluedroid_pm_gpio_get_value(
				bluedroid_pm->host_wake)) {
				/* BT can sleep */
				BDP_DBG("Tx and Rx are idle, BT sleeping");
					bluedroid_pm_gpio_set_value(
						bluedroid_pm->ext_wake, 0);
					__pm_relax(bluedroid_pm->wake_lock);
				} else {
					/* Reset Timer */
					BDP_DBG("Rx is busy, restarting the timer");
					mod_timer(&bluedroid_pm->bluedroid_pm_timer,
						jiffies + (TX_TIMER_INTERVAL * HZ));
				}
			clear_bit(BT_WAKE, &bluedroid_pm->flags);
		} else if (buf[0] == '1') {
			BDP_DBG("Tx is busy, wake_lock taken, delete timer");
			bluedroid_pm_gpio_set_value(
				bluedroid_pm->ext_wake, 1);
			__pm_stay_awake(bluedroid_pm->wake_lock);
#if defined(NV_TIMER_DELETE_PRESENT) /* Linux v6.15 */
			timer_delete(&bluedroid_pm->bluedroid_pm_timer);
#else
			del_timer(&bluedroid_pm->bluedroid_pm_timer);
#endif
			set_bit(BT_WAKE, &bluedroid_pm->flags);
		} else {
			kfree(buf);
			return -EINVAL;
		}
	}

	kfree(buf);
	return count;
}

static const struct proc_ops lpm_fops = {
	.proc_read		= lpm_read_proc,
	.proc_write		= lpm_write_proc,
	.proc_lseek		= default_llseek,
};

static void remove_bt_proc_interface(void)
{
	remove_proc_entry("lpm", bluetooth_sleep_dir);
	remove_proc_entry("sleep", proc_bt_dir);
	remove_proc_entry("bluetooth", NULL);
}

static int create_bt_proc_interface(void *drv_data)
{
	int retval;
	struct proc_dir_entry *ent;

	proc_bt_dir = proc_mkdir("bluetooth", NULL);
	if (proc_bt_dir == NULL) {
		BDP_ERR("Unable to create /proc/bluetooth directory");
		return -ENOMEM;
	}

	bluetooth_sleep_dir = proc_mkdir("sleep", proc_bt_dir);
	if (bluetooth_sleep_dir == NULL) {
		BDP_ERR("Unable to create /proc/bluetooth directory");
		retval = -ENOMEM;
		goto free_bluetooth;
	}

	/* Creating read/write "btwake" entry */
	ent = proc_create_data("lpm", 0622, bluetooth_sleep_dir, &lpm_fops, drv_data);
	if (ent == NULL) {
		BDP_ERR("Unable to create /proc/%s/btwake entry", PROC_DIR);
		retval = -ENOMEM;
		goto free_sleep;
	}
	return 0;

free_sleep:
	remove_proc_entry("sleep", proc_bt_dir);
free_bluetooth:
	remove_proc_entry("bluetooth", NULL);
	return retval;
}

/*
 * This API is added to set block state by ext driver,
 * when bluedroid_pm rfkill is not used but host_wake functionality to be used.
 * Eg: btwilink driver
 */
void bluedroid_pm_set_ext_state(bool blocked)
{
	bluedroid_pm_blocked = blocked;
}
EXPORT_SYMBOL(bluedroid_pm_set_ext_state);

static int bluedroid_pm_probe(struct platform_device *pdev)
{
	static struct bluedroid_pm_data *bluedroid_pm;
	struct rfkill *rfkill;
	int ret;
	bool enable = false;  /* off */
	struct device_node *node;

	bluedroid_pm = devm_kzalloc(&pdev->dev, sizeof(*bluedroid_pm), GFP_KERNEL);
	if (!bluedroid_pm)
		return -ENOMEM;

	node = pdev->dev.of_node;

	if (of_get_property(node, "avdd-supply", NULL)) {
		bluedroid_pm->vdd_3v3 = regulator_get(&pdev->dev, "avdd");
		if (IS_ERR(bluedroid_pm->vdd_3v3)) {
			pr_warn("%s: regulator avdd not available\n", __func__);
			bluedroid_pm->vdd_3v3 = NULL;
		}
	}
	if (of_get_property(node, "dvdd-supply", NULL)) {
		bluedroid_pm->vdd_1v8 = regulator_get(&pdev->dev, "dvdd");
		if (IS_ERR(bluedroid_pm->vdd_1v8)) {
			pr_warn("%s: regulator dvdd not available\n", __func__);
			bluedroid_pm->vdd_1v8 = NULL;
		}
	}

	bluedroid_pm->gpio_reset =
		devm_gpiod_get_optional(&pdev->dev, "bluedroid_pm,reset",
								 GPIOD_OUT_HIGH);

	if (PTR_ERR(bluedroid_pm->gpio_reset) == -EPROBE_DEFER)
		BDP_DBG("Reset gpio get failure.\n");

	bluedroid_pm->gpio_shutdown =
		devm_gpiod_get_optional(&pdev->dev, "bluedroid_pm,shutdown",
								 GPIOD_ASIS);

	if (PTR_ERR(bluedroid_pm->gpio_shutdown) == -EPROBE_DEFER)
		BDP_DBG("shutdown gpio get failure.\n");

	bluedroid_pm->host_wake =
		devm_gpiod_get_optional(&pdev->dev, "bluedroid_pm,host-wake",
								 GPIOD_ASIS);

	if (PTR_ERR(bluedroid_pm->host_wake) == -EPROBE_DEFER)
		BDP_DBG("host_wake gpio get failure.\n");

	bluedroid_pm->host_wake_irq = platform_get_irq(pdev, 0);
	bluedroid_pm->ext_wake =
		devm_gpiod_get_optional(&pdev->dev, "bluedroid_pm,ext-wake",
								 GPIOD_ASIS);

	if (PTR_ERR(bluedroid_pm->ext_wake) == -EPROBE_DEFER)
		BDP_DBG("ext_wake gpio get failure.\n");

	/* Update resume_min_frequency, if pdata is passed from board files */
	of_property_read_u32(node, "resume_min_frequency",
			     &bluedroid_pm->resume_min_frequency);

	if (IS_ERR(bluedroid_pm->gpio_reset))
		BDP_DBG("Reset gpio not registered.\n");
	else
		gpiod_direction_output(bluedroid_pm->gpio_reset, enable);

	if (IS_ERR(bluedroid_pm->gpio_shutdown))
		BDP_DBG("shutdown gpio not registered\n");
	else
		gpiod_direction_output(bluedroid_pm->gpio_shutdown, enable);

	/*
	 * make sure at-least one of the GPIO or regulators avaiable to
	 * register with rfkill is defined
	 */
	if (!IS_ERR(bluedroid_pm->gpio_reset) ||
		!IS_ERR(bluedroid_pm->gpio_shutdown) ||
		bluedroid_pm->vdd_1v8 || bluedroid_pm->vdd_3v3) {
		rfkill = rfkill_alloc(pdev->name, &pdev->dev,
				RFKILL_TYPE_BLUETOOTH, &bluedroid_pm_rfkill_ops,
				bluedroid_pm);

		if (unlikely(!rfkill))
			goto free_gpio_shutdown;

		bluedroid_pm->is_blocked = !enable;
		rfkill_set_states(rfkill, bluedroid_pm->is_blocked, false);

		ret = rfkill_register(rfkill);

		if (unlikely(ret))
			goto free_rfkill_alloc;

		bluedroid_pm->rfkill = rfkill;
	}

	if (IS_ERR(bluedroid_pm->host_wake))
		BDP_DBG("gpio_host_wake not registered\n");
	else
		/* configure host_wake as input */
		gpiod_direction_input(bluedroid_pm->host_wake);

	if (bluedroid_pm->host_wake_irq > -1) {
		BDP_DBG("found host_wake irq\n");
		ret = request_irq(bluedroid_pm->host_wake_irq,
					bluedroid_pm_hostwake_isr,
					IRQF_TRIGGER_RISING,
					"bluetooth hostwake", bluedroid_pm);
		if (ret) {
			BDP_ERR("Failed to get host_wake irq\n");
			goto free_host_wake;
		}
	} else
		BDP_DBG("host_wake not registered\n");

	if (IS_ERR(bluedroid_pm->ext_wake)) {
		BDP_DBG("host_wake not registered\n");
	} else {
		/* configure ext_wake as output mode*/
		gpiod_direction_output(bluedroid_pm->ext_wake, 1);

		if (create_bt_proc_interface(bluedroid_pm)) {
			BDP_ERR("Failed to create proc interface");
			goto free_ext_wake;
		}
		/* initialize wake lock */
		bluedroid_pm->wake_lock = wakeup_source_register(&pdev->dev,
							dev_name(&pdev->dev));
		/* Initialize timer */
		timer_setup(&bluedroid_pm->bluedroid_pm_timer,
				bluedroid_pm_timer_expire, 0);
	}

	INIT_WORK(&bluedroid_pm->work, bluedroid_work);
	spin_lock_init(&bluedroid_pm->lock);

	bluedroid_pm->dev = &pdev->dev;
	platform_set_drvdata(pdev, bluedroid_pm);
	BDP_DBG("driver successfully registered");

	return 0;

free_ext_wake:
	if (bluedroid_pm->host_wake_irq > -1)
		free_irq(bluedroid_pm->host_wake_irq, bluedroid_pm);
free_host_wake:
	if (bluedroid_pm->rfkill)
		rfkill_unregister(bluedroid_pm->rfkill);
free_rfkill_alloc:
	if (bluedroid_pm->rfkill)
		rfkill_destroy(bluedroid_pm->rfkill);
free_gpio_shutdown:
	if (bluedroid_pm->vdd_3v3)
		regulator_put(bluedroid_pm->vdd_3v3);
	if (bluedroid_pm->vdd_1v8)
		regulator_put(bluedroid_pm->vdd_1v8);

	return -ENODEV;
}

static int bluedroid_pm_remove(struct platform_device *pdev)
{
	struct bluedroid_pm_data *bluedroid_pm = platform_get_drvdata(pdev);

	cancel_work_sync(&bluedroid_pm->work);
	if (bluedroid_pm->host_wake_irq > -1)
		free_irq(bluedroid_pm->host_wake_irq, bluedroid_pm);
	if (!IS_ERR(bluedroid_pm->ext_wake)) {
		wakeup_source_unregister(bluedroid_pm->wake_lock);
		remove_bt_proc_interface();
#if defined(NV_TIMER_DELETE_PRESENT) /* Linux v6.15 */
		timer_delete(&bluedroid_pm->bluedroid_pm_timer);
#else
		del_timer(&bluedroid_pm->bluedroid_pm_timer);
#endif
	}
	if (!IS_ERR(bluedroid_pm->gpio_reset) ||
		!IS_ERR(bluedroid_pm->gpio_shutdown) ||
		bluedroid_pm->vdd_1v8 || bluedroid_pm->vdd_3v3) {
		rfkill_unregister(bluedroid_pm->rfkill);
		rfkill_destroy(bluedroid_pm->rfkill);
	}
	if (bluedroid_pm->vdd_3v3)
		regulator_put(bluedroid_pm->vdd_3v3);
	if (bluedroid_pm->vdd_1v8)
		regulator_put(bluedroid_pm->vdd_1v8);

	return 0;
}

static int bluedroid_pm_suspend(struct platform_device *pdev,
						pm_message_t state)
{
	struct bluedroid_pm_data *bluedroid_pm = platform_get_drvdata(pdev);
	unsigned long flags;
	int ret = 0;

	if (!IS_ERR(bluedroid_pm->host_wake)) {
		if (!bluedroid_pm->is_blocked || !bluedroid_pm_blocked) {
			ret = enable_irq_wake(bluedroid_pm->host_wake_irq);
			if (ret < 0) {
				BDP_ERR("Failed to enable irq wake for irq %d, %d\n",
					bluedroid_pm->host_wake_irq, ret);
				return ret;
			}
		}
	}

	spin_lock_irqsave(&bluedroid_pm->lock, flags);
	bluedroid_pm->resumed = false;
	spin_unlock_irqrestore(&bluedroid_pm->lock, flags);
	cancel_work_sync(&bluedroid_pm->work);

	return 0;
}

static int bluedroid_pm_resume(struct platform_device *pdev)
{
	struct bluedroid_pm_data *bluedroid_pm = platform_get_drvdata(pdev);
	unsigned long flags;

	if (!IS_ERR(bluedroid_pm->host_wake))
		if (!bluedroid_pm->is_blocked || !bluedroid_pm_blocked)
			disable_irq_wake(bluedroid_pm->host_wake_irq);

	spin_lock_irqsave(&bluedroid_pm->lock, flags);
	bluedroid_pm->resumed = true;
	schedule_work(&bluedroid_pm->work);
	spin_unlock_irqrestore(&bluedroid_pm->lock, flags);

	return 0;
}

static void bluedroid_pm_shutdown(struct platform_device *pdev)
{
	struct bluedroid_pm_data *bluedroid_pm = platform_get_drvdata(pdev);

	cancel_work_sync(&bluedroid_pm->work);

	if (!IS_ERR(bluedroid_pm->gpio_shutdown))
		bluedroid_pm_gpio_set_value(
			bluedroid_pm->gpio_shutdown, 0);
	if (!IS_ERR(bluedroid_pm->gpio_reset))
		bluedroid_pm_gpio_set_value(
			bluedroid_pm->gpio_reset, 0);
	if (bluedroid_pm->vdd_3v3)
		regulator_disable(bluedroid_pm->vdd_3v3);
	if (bluedroid_pm->vdd_1v8)
		regulator_disable(bluedroid_pm->vdd_1v8);

}

static struct of_device_id bdroid_of_match[] = {
	{ .compatible = "nvidia,tegra-bluedroid_pm", },
	{ },
};
MODULE_DEVICE_TABLE(of, bdroid_of_match);

#if defined(NV_PLATFORM_DRIVER_STRUCT_REMOVE_RETURNS_VOID) /* Linux v6.11 */
static void bluedroid_pm_remove_wrapper(struct platform_device *pdev)
{
	bluedroid_pm_remove(pdev);
}
#else
static int bluedroid_pm_remove_wrapper(struct platform_device *pdev)
{
	return bluedroid_pm_remove(pdev);
}
#endif

static struct platform_driver bluedroid_pm_driver = {
	.probe = bluedroid_pm_probe,
	.remove = bluedroid_pm_remove_wrapper,
	.suspend = bluedroid_pm_suspend,
	.resume = bluedroid_pm_resume,
	.shutdown = bluedroid_pm_shutdown,
	.driver = {
		.name = "bluedroid_pm",
		.of_match_table = of_match_ptr(bdroid_of_match),
		.owner = THIS_MODULE,
	},
};

module_platform_driver(bluedroid_pm_driver);

MODULE_DESCRIPTION("bluedroid PM");
MODULE_AUTHOR("NVIDIA");
MODULE_LICENSE("GPL");