path: root/drivers/bluetooth/hci_bcm.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 *  Bluetooth HCI UART driver for Broadcom devices
 *
 *  Copyright (C) 2015  Intel Corporation
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/property.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#include <linux/tty.h>
#include <linux/interrupt.h>
#include <linux/dmi.h>
#include <linux/pm_runtime.h>
#include <linux/serdev.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "btbcm.h"
#include "hci_uart.h"

#define BCM_NULL_PKT 0x00
#define BCM_NULL_SIZE 0

#define BCM_LM_DIAG_PKT 0x07
#define BCM_LM_DIAG_SIZE 63

#define BCM_TYPE49_PKT 0x31
#define BCM_TYPE49_SIZE 0

#define BCM_TYPE52_PKT 0x34
#define BCM_TYPE52_SIZE 0

#define BCM_AUTOSUSPEND_DELAY	5000 /* default autosleep delay */

#define BCM_NUM_SUPPLIES 2

/**
 * struct bcm_device_data - device specific data
 * @no_early_set_baudrate: Disallow set baudrate before driver setup()
 */
struct bcm_device_data {
	bool	no_early_set_baudrate;
	bool	drive_rts_on_open;
};

/**
 * struct bcm_device - device driver resources
 * @serdev_hu: HCI UART controller struct
 * @list: bcm_device_list node
 * @dev: physical UART slave
 * @name: device name logged by bt_dev_*() functions
 * @device_wakeup: BT_WAKE pin,
 *	assert = Bluetooth device must wake up or remain awake,
 *	deassert = Bluetooth device may sleep when sleep criteria are met
 * @shutdown: BT_REG_ON pin,
 *	power up or power down Bluetooth device internal regulators
 * @set_device_wakeup: callback to toggle BT_WAKE pin
 *	either by accessing @device_wakeup or by calling @btlp
 * @set_shutdown: callback to toggle BT_REG_ON pin
 *	either by accessing @shutdown or by calling @btpu/@btpd
 * @btlp: Apple ACPI method to toggle BT_WAKE pin ("Bluetooth Low Power")
 * @btpu: Apple ACPI method to drive BT_REG_ON pin high ("Bluetooth Power Up")
 * @btpd: Apple ACPI method to drive BT_REG_ON pin low ("Bluetooth Power Down")
 * @txco_clk: external reference frequency clock used by Bluetooth device
 * @lpo_clk: external LPO clock used by Bluetooth device
 * @supplies: VBAT and VDDIO supplies used by Bluetooth device
 * @res_enabled: whether clocks and supplies are prepared and enabled
 * @init_speed: default baudrate of Bluetooth device;
 *	the host UART is initially set to this baudrate so that
 *	it can configure the Bluetooth device for @oper_speed
 * @oper_speed: preferred baudrate of Bluetooth device;
 *	set to 0 if @init_speed is already the preferred baudrate
 * @irq: interrupt triggered by HOST_WAKE_BT pin
 * @irq_active_low: whether @irq is active low
 * @hu: pointer to HCI UART controller struct,
 *	used to disable flow control during runtime suspend and system sleep
 * @is_suspended: whether flow control is currently disabled
 * @no_early_set_baudrate: don't set_baudrate before setup()
 */
struct bcm_device {
	/* Must be the first member, hci_serdev.c expects this. */
	struct hci_uart		serdev_hu;
	struct list_head	list;

	struct device		*dev;

	const char		*name;
	struct gpio_desc	*device_wakeup;
	struct gpio_desc	*shutdown;
	int			(*set_device_wakeup)(struct bcm_device *, bool);
	int			(*set_shutdown)(struct bcm_device *, bool);
#ifdef CONFIG_ACPI
	acpi_handle		btlp, btpu, btpd;
	int			gpio_count;
	int			gpio_int_idx;
#endif

	struct clk		*txco_clk;
	struct clk		*lpo_clk;
	struct regulator_bulk_data supplies[BCM_NUM_SUPPLIES];
	bool			res_enabled;

	u32			init_speed;
	u32			oper_speed;
	int			irq;
	bool			irq_active_low;
	bool			irq_acquired;

#ifdef CONFIG_PM
	struct hci_uart		*hu;
	bool			is_suspended;
#endif
	bool			no_early_set_baudrate;
	bool			drive_rts_on_open;
	u8			pcm_int_params[5];
};

/* generic bcm uart resources */
struct bcm_data {
	struct sk_buff		*rx_skb;
	struct sk_buff_head	txq;

	struct bcm_device	*dev;
};

/* List of BCM BT UART devices */
static DEFINE_MUTEX(bcm_device_lock);
static LIST_HEAD(bcm_device_list);

static int irq_polarity = -1;
module_param(irq_polarity, int, 0444);
MODULE_PARM_DESC(irq_polarity, "IRQ polarity 0: active-high 1: active-low");

static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
	if (hu->serdev)
		serdev_device_set_baudrate(hu->serdev, speed);
	else
		hci_uart_set_baudrate(hu, speed);
}

static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
	struct hci_dev *hdev = hu->hdev;
	struct sk_buff *skb;
	struct bcm_update_uart_baud_rate param;

	if (speed > 3000000) {
		struct bcm_write_uart_clock_setting clock;

		clock.type = BCM_UART_CLOCK_48MHZ;

		bt_dev_dbg(hdev, "Set Controller clock (%d)", clock.type);

		/* This Broadcom specific command changes the UART's controller
		 * clock for baud rate > 3000000.
		 */
		skb = __hci_cmd_sync(hdev, 0xfc45, 1, &clock, HCI_INIT_TIMEOUT);
		if (IS_ERR(skb)) {
			int err = PTR_ERR(skb);
			bt_dev_err(hdev, "BCM: failed to write clock (%d)",
				   err);
			return err;
		}

		kfree_skb(skb);
	}

	bt_dev_dbg(hdev, "Set Controller UART speed to %d bit/s", speed);

	param.zero = cpu_to_le16(0);
	param.baud_rate = cpu_to_le32(speed);

	/* This Broadcom specific command changes the UART's controller baud
	 * rate.
	 */
	skb = __hci_cmd_sync(hdev, 0xfc18, sizeof(param), &param,
			     HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		int err = PTR_ERR(skb);
		bt_dev_err(hdev, "BCM: failed to write update baudrate (%d)",
			   err);
		return err;
	}

	kfree_skb(skb);

	return 0;
}

/* bcm_device_exists should be protected by bcm_device_lock */
static bool bcm_device_exists(struct bcm_device *device)
{
	struct list_head *p;

#ifdef CONFIG_PM
	/* Devices using serdev always exist */
	if (device && device->hu && device->hu->serdev)
		return true;
#endif

	list_for_each(p, &bcm_device_list) {
		struct bcm_device *dev = list_entry(p, struct bcm_device, list);

		if (device == dev)
			return true;
	}

	return false;
}

static int bcm_gpio_set_power(struct bcm_device *dev, bool powered)
{
	int err;

	if (powered && !dev->res_enabled) {
		/* Intel Macs use bcm_apple_get_resources() and don't
		 * have regulator supplies configured.
		 */
		if (dev->supplies[0].supply) {
			err = regulator_bulk_enable(BCM_NUM_SUPPLIES,
						    dev->supplies);
			if (err)
				return err;
		}

		/* LPO clock needs to be 32.768 kHz */
		err = clk_set_rate(dev->lpo_clk, 32768);
		if (err) {
			dev_err(dev->dev, "Could not set LPO clock rate\n");
			goto err_regulator_disable;
		}

		err = clk_prepare_enable(dev->lpo_clk);
		if (err)
			goto err_regulator_disable;

		err = clk_prepare_enable(dev->txco_clk);
		if (err)
			goto err_lpo_clk_disable;
	}

	err = dev->set_shutdown(dev, powered);
	if (err)
		goto err_txco_clk_disable;

	err = dev->set_device_wakeup(dev, powered);
	if (err)
		goto err_revert_shutdown;

	if (!powered && dev->res_enabled) {
		clk_disable_unprepare(dev->txco_clk);
		clk_disable_unprepare(dev->lpo_clk);

		/* Intel Macs use bcm_apple_get_resources() and don't
		 * have regulator supplies configured.
		 */
		if (dev->supplies[0].supply)
			regulator_bulk_disable(BCM_NUM_SUPPLIES,
					       dev->supplies);
	}

	/* wait for device to power on and come out of reset */
	usleep_range(100000, 120000);

	dev->res_enabled = powered;

	return 0;

err_revert_shutdown:
	dev->set_shutdown(dev, !powered);
err_txco_clk_disable:
	if (powered && !dev->res_enabled