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Commit 0395ffc1 authored by Frederic Danis's avatar Frederic Danis Committed by Marcel Holtmann
Browse files

Bluetooth: hci_bcm: Add PM for BCM devices 



Retrieve "shutdown" and "device_wakeup" GPIOs from ACPI.
Set device off during platform device enumeration.
Set device on only when attached.
As driver can be unbound we need to check if the bcm_device still exists
before calling GPIO's functions, this is protected using device_list_lock.

Signed-off-by: default avatarFrederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 85998229

drivers/bluetooth/hci_bcm.c

+214 −2
Original line number Diff line number Diff line
@@ -25,6 +25,12 @@ 
#include <linux/errno.h>

#include <linux/skbuff.h>

#include <linux/firmware.h>

#include <linux/module.h>

#include <linux/acpi.h>

#include <linux/platform_device.h>

#include <linux/clk.h>

#include <linux/gpio/consumer.h>

#include <linux/tty.h>



#include <net/bluetooth/bluetooth.h>

#include <net/bluetooth/hci_core.h>
@@ -32,11 +38,30 @@ 
#include "btbcm.h"

#include "hci_uart.h"



struct bcm_device {

	struct list_head	list;



	struct platform_device	*pdev;



	const char		*name;

	struct gpio_desc	*device_wakeup;

	struct gpio_desc	*shutdown;



	struct clk		*clk;

	bool			clk_enabled;

};



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_SPINLOCK(bcm_device_list_lock);

static LIST_HEAD(bcm_device_list);



static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)

{

	struct hci_dev *hdev = hu->hdev;
@@ -86,9 +111,41 @@ static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed) 
	return 0;

}



/* bcm_device_exists should be protected by bcm_device_list_lock */

static bool bcm_device_exists(struct bcm_device *device)

{

	struct list_head *p;



	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)

{

	if (powered && !IS_ERR(dev->clk) && !dev->clk_enabled)

		clk_enable(dev->clk);



	gpiod_set_value_cansleep(dev->shutdown, powered);

	gpiod_set_value_cansleep(dev->device_wakeup, powered);



	if (!powered && !IS_ERR(dev->clk) && dev->clk_enabled)

		clk_disable(dev->clk);



	dev->clk_enabled = powered;



	return 0;

}



static int bcm_open(struct hci_uart *hu)

{

	struct bcm_data *bcm;

	struct list_head *p;



	BT_DBG("hu %p", hu);
@@ -99,6 +156,26 @@ static int bcm_open(struct hci_uart *hu) 
	skb_queue_head_init(&bcm->txq);



	hu->priv = bcm;



	spin_lock(&bcm_device_list_lock);

	list_for_each(p, &bcm_device_list) {

		struct bcm_device *dev = list_entry(p, struct bcm_device, list);



		/* Retrieve saved bcm_device based on parent of the

		 * platform device (saved during device probe) and

		 * parent of tty device used by hci_uart

		 */

		if (hu->tty->dev->parent == dev->pdev->dev.parent) {

			bcm->dev = dev;

			break;

		}

	}



	if (bcm->dev)

		bcm_gpio_set_power(bcm->dev, true);



	spin_unlock(&bcm_device_list_lock);



	return 0;

}
@@ -108,6 +185,12 @@ static int bcm_close(struct hci_uart *hu) 


	BT_DBG("hu %p", hu);



	/* Protect bcm->dev against removal of the device or driver */

	spin_lock(&bcm_device_list_lock);

	if (bcm_device_exists(bcm->dev))

		bcm_gpio_set_power(bcm->dev, false);

	spin_unlock(&bcm_device_list_lock);



	skb_queue_purge(&bcm->txq);

	kfree_skb(bcm->rx_skb);

	kfree(bcm);
@@ -232,6 +315,113 @@ static struct sk_buff *bcm_dequeue(struct hci_uart *hu) 
	return skb_dequeue(&bcm->txq);

}



static const struct acpi_gpio_params device_wakeup_gpios = { 0, 0, false };

static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };



static const struct acpi_gpio_mapping acpi_bcm_default_gpios[] = {

	{ "device-wakeup-gpios", &device_wakeup_gpios, 1 },

	{ "shutdown-gpios", &shutdown_gpios, 1 },

	{ },

};



static int bcm_acpi_probe(struct bcm_device *dev)

{

	struct platform_device *pdev = dev->pdev;

	const struct acpi_device_id *id;

	struct gpio_desc *gpio;

	int ret;



	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);

	if (!id)

		return -ENODEV;



	/* Retrieve GPIO data */

	dev->name = dev_name(&pdev->dev);

	ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(&pdev->dev),

					acpi_bcm_default_gpios);

	if (ret)

		return ret;



	dev->clk = devm_clk_get(&pdev->dev, NULL);



	gpio = devm_gpiod_get(&pdev->dev, "device-wakeup");

	if (!IS_ERR(gpio)) {

		ret = gpiod_direction_output(gpio, 0);

		if (ret)

			return ret;

		dev->device_wakeup = gpio;

	}



	gpio = devm_gpiod_get(&pdev->dev, "shutdown");

	if (!IS_ERR(gpio)) {

		ret = gpiod_direction_output(gpio, 0);

		if (ret)

			return ret;

		dev->shutdown = gpio;

	}



	/* Make sure at-least one of the GPIO is defined and that

	 * a name is specified for this instance

	 */

	if ((!dev->device_wakeup && !dev->shutdown) || !dev->name) {

		dev_err(&pdev->dev, "invalid platform data\n");

		return -EINVAL;

	}



	return 0;

}



static int bcm_probe(struct platform_device *pdev)

{

	struct bcm_device *dev;

	struct acpi_device_id *pdata = pdev->dev.platform_data;

	int ret;



	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);

	if (!dev)

		return -ENOMEM;



	dev->pdev = pdev;



	if (ACPI_HANDLE(&pdev->dev)) {

		ret = bcm_acpi_probe(dev);

		if (ret)

			return ret;

	} else if (pdata) {

		dev->name = pdata->id;

	} else {

		return -ENODEV;

	}



	platform_set_drvdata(pdev, dev);



	dev_info(&pdev->dev, "%s device registered.\n", dev->name);



	/* Place this instance on the device list */

	spin_lock(&bcm_device_list_lock);

	list_add_tail(&dev->list, &bcm_device_list);

	spin_unlock(&bcm_device_list_lock);



	bcm_gpio_set_power(dev, false);



	return 0;

}



static int bcm_remove(struct platform_device *pdev)

{

	struct bcm_device *dev = platform_get_drvdata(pdev);



	spin_lock(&bcm_device_list_lock);

	list_del(&dev->list);

	spin_unlock(&bcm_device_list_lock);



	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));



	dev_info(&pdev->dev, "%s device unregistered.\n", dev->name);



	return 0;

}



static const struct hci_uart_proto bcm_proto = {

	.id		= HCI_UART_BCM,

	.name		= "BCM",
@@ -247,12 +437,34 @@ static const struct hci_uart_proto bcm_proto = { 
	.dequeue	= bcm_dequeue,

};



#ifdef CONFIG_ACPI

static const struct acpi_device_id bcm_acpi_match[] = {

	{ "BCM2E39", 0 },

	{ "BCM2E67", 0 },

	{ },

};

MODULE_DEVICE_TABLE(acpi, bcm_acpi_match);

#endif



static struct platform_driver bcm_driver = {

	.probe = bcm_probe,

	.remove = bcm_remove,

	.driver = {

		.name = "hci_bcm",

		.acpi_match_table = ACPI_PTR(bcm_acpi_match),

	},

};



int __init bcm_init(void)

{

	platform_driver_register(&bcm_driver);



	return hci_uart_register_proto(&bcm_proto);

}



int __exit bcm_deinit(void)

{

	platform_driver_unregister(&bcm_driver);



	return hci_uart_unregister_proto(&bcm_proto);

}