drivers/misc/bt-host.c - linux - Git at Google

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/errno.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/miscdevice.h>
 #include <linux/timer.h>
 #include <linux/jiffies.h>
 #include <linux/bt-host.h>

 #define DEVICE_NAME	"bt-host"

 #define BT_IO_BASE	0xe4
 #define BT_IRQ		10

 #define BT_CR0		0x0
 #define   BT_CR0_IO_BASE		16
 #define   BT_CR0_IRQ			12
 #define   BT_CR0_EN_CLR_SLV_RDP		0x8
 #define   BT_CR0_EN_CLR_SLV_WRP		0x4
 #define   BT_CR0_ENABLE_IBT		0x1
 #define BT_CR1		0x4
 #define   BT_CR1_IRQ_H2B	0x01
 #define   BT_CR1_IRQ_HBUSY	0x40
 #define BT_CR2		0x8
 #define   BT_CR2_IRQ_H2B	0x01
 #define   BT_CR2_IRQ_HBUSY	0x40
 #define BT_CR3		0xc
 #define BT_CTRL		0x10
 #define   BT_CTRL_B_BUSY		0x80
 #define   BT_CTRL_H_BUSY		0x40
 #define   BT_CTRL_OEM0			0x20
 #define   BT_CTRL_SMS_ATN		0x10
 #define   BT_CTRL_B2H_ATN		0x08
 #define   BT_CTRL_H2B_ATN		0x04
 #define   BT_CTRL_CLR_RD_PTR		0x02
 #define   BT_CTRL_CLR_WR_PTR		0x01
 #define BT_BMC2HOST	0x14
 #define BT_INTMASK	0x18
 #define   BT_INTMASK_B2H_IRQEN		0x01
 #define   BT_INTMASK_B2H_IRQ		0x02
 #define   BT_INTMASK_BMC_HWRST		0x80

 struct bt_host {
 	struct device		dev;
 	struct miscdevice	miscdev;
 	void			*base;
 	int			open_count;
 	int			irq;
 	wait_queue_head_t	queue;
 	struct timer_list	poll_timer;
 };

 static u8 bt_inb(struct bt_host *bt_host, int reg)
 {
 	return ioread8(bt_host->base + reg);
 }

 static void bt_outb(struct bt_host *bt_host, u8 data, int reg)
 {
 	iowrite8(data, bt_host->base + reg);
 }

 static void clr_rd_ptr(struct bt_host *bt_host)
 {
 	bt_outb(bt_host, BT_CTRL_CLR_RD_PTR, BT_CTRL);
 }

 static void clr_wr_ptr(struct bt_host *bt_host)
 {
 	bt_outb(bt_host, BT_CTRL_CLR_WR_PTR, BT_CTRL);
 }

 static void clr_h2b_atn(struct bt_host *bt_host)
 {
 	bt_outb(bt_host, BT_CTRL_H2B_ATN, BT_CTRL);
 }

 static void set_b_busy(struct bt_host *bt_host)
 {
 	if (!(bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY))
 		bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
 }

 static void clr_b_busy(struct bt_host *bt_host)
 {
 	if (bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY)
 		bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
 }

 static void set_b2h_atn(struct bt_host *bt_host)
 {
 	bt_outb(bt_host, BT_CTRL_B2H_ATN, BT_CTRL);
 }

 static u8 bt_read(struct bt_host *bt_host)
 {
 	return bt_inb(bt_host, BT_BMC2HOST);
 }

 static void bt_write(struct bt_host *bt_host, u8 c)
 {
 	bt_outb(bt_host, c, BT_BMC2HOST);
 }

 static void set_sms_atn(struct bt_host *bt_host)
 {
 	bt_outb(bt_host, BT_CTRL_SMS_ATN, BT_CTRL);
 }

 static struct bt_host *file_bt_host(struct file *file)
 {
 	return container_of(file->private_data, struct bt_host, miscdev);
 }

 static int bt_host_open(struct inode *inode, struct file *file)
 {
 	struct bt_host *bt_host = file_bt_host(file);

 	clr_b_busy(bt_host);

 	return 0;
 }

 static ssize_t bt_host_read(struct file *file, char __user *buf,
 				size_t count, loff_t *ppos)
 {
 	struct bt_host *bt_host = file_bt_host(file);
 	char __user *p = buf;
 	u8 len;

 	if (!access_ok(VERIFY_WRITE, buf, count))
 		return -EFAULT;

 	WARN_ON(*ppos);

 	if (wait_event_interruptible(bt_host->queue,
 				bt_inb(bt_host, BT_CTRL) & BT_CTRL_H2B_ATN))
 		return -ERESTARTSYS;

 	set_b_busy(bt_host);
 	clr_h2b_atn(bt_host);
 	clr_rd_ptr(bt_host);

 	len = bt_read(bt_host);
 	__put_user(len, p++);

 	/* We pass the length back as well */
 	if (len + 1 > count)
 		len = count - 1;

 	while(len) {
 		if (__put_user(bt_read(bt_host), p))
 			return -EFAULT;
 		len--; p++;
 	}

 	clr_b_busy(bt_host);

 	return p - buf;
 }

 static ssize_t bt_host_write(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
 	struct bt_host *bt_host = file_bt_host(file);
 	const char __user *p = buf;
 	u8 c;

 	if (!access_ok(VERIFY_READ, buf, count))
 		return -EFAULT;

 	WARN_ON(*ppos);

 	/* There's no interrupt for clearing host busy so we have to
 	 * poll */
 	if (wait_event_interruptible(bt_host->queue,
 				!(bt_inb(bt_host, BT_CTRL) &
 					(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))))
 		return -ERESTARTSYS;

 	clr_wr_ptr(bt_host);

 	while (count) {
 		if (__get_user(c, p))
 			return -EFAULT;

 		bt_write(bt_host, c);
 		count--; p++;
 	}

 	set_b2h_atn(bt_host);

 	return p - buf;
 }

 static long bt_host_ioctl(struct file *file, unsigned int cmd,
 		unsigned long param)
 {
 	struct bt_host *bt_host = file_bt_host(file);
 	switch (cmd) {
 	case BT_HOST_IOCTL_SMS_ATN:
 		set_sms_atn(bt_host);
 		return 0;
 	}
 	return -EINVAL;
 }

 static int bt_host_release(struct inode *inode, struct file *file)
 {
 	struct bt_host *bt_host = file_bt_host(file);
 	set_b_busy(bt_host);
 	return 0;
 }

 static unsigned int bt_host_poll(struct file *file, poll_table *wait)
 {
 	struct bt_host *bt_host = file_bt_host(file);
 	unsigned int mask = 0;
 	uint8_t ctrl;

 	poll_wait(file, &bt_host->queue, wait);

 	ctrl = bt_inb(bt_host, BT_CTRL);

 	if (ctrl & BT_CTRL_H2B_ATN)
 		mask |= POLLIN;

 	if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
 		mask |= POLLOUT;

 	return mask;
 }

 static const struct file_operations bt_host_fops = {
 	.owner		= THIS_MODULE,
 	.open		= bt_host_open,
 	.read		= bt_host_read,
 	.write		= bt_host_write,
 	.release	= bt_host_release,
 	.poll		= bt_host_poll,
 	.unlocked_ioctl	= bt_host_ioctl,
 };

 static void poll_timer(unsigned long data)
 {
 	struct bt_host *bt_host = (void *)data;
 	bt_host->poll_timer.expires += msecs_to_jiffies(500);
 	wake_up(&bt_host->queue);
 	add_timer(&bt_host->poll_timer);
 }

 irqreturn_t bt_host_irq(int irq, void *arg)
 {
 	struct bt_host *bt_host = arg;
 	uint32_t reg;

 	reg = ioread32(bt_host->base + BT_CR2);
 	reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
 	if (!reg)
 		return IRQ_NONE;

 	/* ack pending IRQs */
 	iowrite32(reg, bt_host->base + BT_CR2);

 	wake_up(&bt_host->queue);
 	return IRQ_HANDLED;
 }

 static int bt_host_config_irq(struct bt_host *bt_host,
 		struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	uint32_t reg;
 	int rc;

 	bt_host->irq = irq_of_parse_and_map(dev->of_node, 0);
 	if (!bt_host->irq)
 		return -ENODEV;

 	rc = devm_request_irq(dev, bt_host->irq, bt_host_irq, IRQF_SHARED,
 			DEVICE_NAME, bt_host);
 	if (rc < 0) {
 		dev_warn(dev, "Unable to request IRQ %d\n", bt_host->irq);
 		bt_host->irq = 0;
 		return rc;
 	}

 	/* Configure IRQs on the host clearing the H2B and HBUSY bits;
 	 * H2B will be asserted when the host has data for us; HBUSY
 	 * will be cleared (along with B2H) when we can write the next
 	 * message to the BT buffer */
 	reg = ioread32(bt_host->base + BT_CR1);
 	reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
 	iowrite32(reg, bt_host->base + BT_CR1);

 	return 0;
 }

 static int bt_host_probe(struct platform_device *pdev)
 {
 	struct bt_host *bt_host;
 	struct device *dev;
 	struct resource *res;
 	int rc;

 	if (!pdev || !pdev->dev.of_node)
 		return -ENODEV;

 	dev = &pdev->dev;
 	dev_info(dev, "Found bt host device\n");

 	bt_host = devm_kzalloc(dev, sizeof(*bt_host), GFP_KERNEL);
 	if (!bt_host)
 		return -ENOMEM;

 	dev_set_drvdata(&pdev->dev, bt_host);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(dev, "Unable to find resources\n");
 		rc = -ENXIO;
 		goto out_free;
 	}

 	bt_host->base = devm_ioremap_resource(&pdev->dev, res);
 	if (!bt_host->base) {
 		rc = -ENOMEM;
 		goto out_free;
 	}

 	init_waitqueue_head(&bt_host->queue);

 	bt_host->miscdev.minor	= MISC_DYNAMIC_MINOR,
 	bt_host->miscdev.name	= DEVICE_NAME,
 	bt_host->miscdev.fops	= &bt_host_fops,
 	bt_host->miscdev.parent = dev;
 	rc = misc_register(&bt_host->miscdev);
 	if (rc) {
 		dev_err(dev, "Unable to register device\n");
 		goto out_unmap;
 	}

 	bt_host_config_irq(bt_host, pdev);

 	if (bt_host->irq) {
 		dev_info(dev, "Using IRQ %d\n", bt_host->irq);
 	} else {
 		dev_info(dev, "No IRQ; using timer\n");
 		init_timer(&bt_host->poll_timer);
 		bt_host->poll_timer.function = poll_timer;
 		bt_host->poll_timer.data = (unsigned long)bt_host;
 		bt_host->poll_timer.expires = jiffies + msecs_to_jiffies(10);
 		add_timer(&bt_host->poll_timer);
 	}

 	iowrite32((BT_IO_BASE << BT_CR0_IO_BASE) |
 		  (BT_IRQ << BT_CR0_IRQ) |
 		  BT_CR0_EN_CLR_SLV_RDP |
 		  BT_CR0_EN_CLR_SLV_WRP |
 		  BT_CR0_ENABLE_IBT,
 		  bt_host->base + BT_CR0);

 	clr_b_busy(bt_host);

 	return 0;

 out_unmap:
 	devm_iounmap(&pdev->dev, bt_host->base);

 out_free:
 	devm_kfree(dev, bt_host);
 	return rc;

 }

 static int bt_host_remove(struct platform_device *pdev)
 {
 	struct bt_host *bt_host = dev_get_drvdata(&pdev->dev);
 	misc_deregister(&bt_host->miscdev);
 	if (!bt_host->irq)
 		del_timer_sync(&bt_host->poll_timer);
 	devm_iounmap(&pdev->dev, bt_host->base);
 	devm_kfree(&pdev->dev, bt_host);
 	bt_host = NULL;

 	return 0;
 }

 static const struct of_device_id bt_host_match[] = {
 	{ .compatible = "aspeed,bt-host" },
 	{ },
 };

 static struct platform_driver bt_host_driver = {
 	.driver = {
 		.name		= DEVICE_NAME,
 		.owner		= THIS_MODULE,
 		.of_match_table = bt_host_match,
 	},
 	.probe = bt_host_probe,
 	.remove = bt_host_remove,
 };

 module_platform_driver(bt_host_driver);

 MODULE_DEVICE_TABLE(of, bt_host_match);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Alistair Popple <alistair@popple.id.au>");
 MODULE_DESCRIPTION("Linux device interface to the BT interface");
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/errno.h>
	#include <linux/poll.h>
	#include <linux/sched.h>
	#include <linux/spinlock.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/of.h>
	#include <linux/of_irq.h>
	#include <linux/platform_device.h>
	#include <linux/io.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>
	#include <linux/miscdevice.h>
	#include <linux/timer.h>
	#include <linux/jiffies.h>
	#include <linux/bt-host.h>

	#define DEVICE_NAME "bt-host"

	#define BT_IO_BASE 0xe4
	#define BT_IRQ 10

	#define BT_CR0 0x0
	#define BT_CR0_IO_BASE 16
	#define BT_CR0_IRQ 12
	#define BT_CR0_EN_CLR_SLV_RDP 0x8
	#define BT_CR0_EN_CLR_SLV_WRP 0x4
	#define BT_CR0_ENABLE_IBT 0x1
	#define BT_CR1 0x4
	#define BT_CR1_IRQ_H2B 0x01
	#define BT_CR1_IRQ_HBUSY 0x40
	#define BT_CR2 0x8
	#define BT_CR2_IRQ_H2B 0x01
	#define BT_CR2_IRQ_HBUSY 0x40
	#define BT_CR3 0xc
	#define BT_CTRL 0x10
	#define BT_CTRL_B_BUSY 0x80
	#define BT_CTRL_H_BUSY 0x40
	#define BT_CTRL_OEM0 0x20
	#define BT_CTRL_SMS_ATN 0x10
	#define BT_CTRL_B2H_ATN 0x08
	#define BT_CTRL_H2B_ATN 0x04
	#define BT_CTRL_CLR_RD_PTR 0x02
	#define BT_CTRL_CLR_WR_PTR 0x01
	#define BT_BMC2HOST 0x14
	#define BT_INTMASK 0x18
	#define BT_INTMASK_B2H_IRQEN 0x01
	#define BT_INTMASK_B2H_IRQ 0x02
	#define BT_INTMASK_BMC_HWRST 0x80

	struct bt_host {
	struct device dev;
	struct miscdevice miscdev;
	void *base;
	int open_count;
	int irq;
	wait_queue_head_t queue;
	struct timer_list poll_timer;
	};

	static u8 bt_inb(struct bt_host *bt_host, int reg)
	{
	return ioread8(bt_host->base + reg);
	}

	static void bt_outb(struct bt_host *bt_host, u8 data, int reg)
	{
	iowrite8(data, bt_host->base + reg);
	}

	static void clr_rd_ptr(struct bt_host *bt_host)
	{
	bt_outb(bt_host, BT_CTRL_CLR_RD_PTR, BT_CTRL);
	}

	static void clr_wr_ptr(struct bt_host *bt_host)
	{
	bt_outb(bt_host, BT_CTRL_CLR_WR_PTR, BT_CTRL);
	}

	static void clr_h2b_atn(struct bt_host *bt_host)
	{
	bt_outb(bt_host, BT_CTRL_H2B_ATN, BT_CTRL);
	}

	static void set_b_busy(struct bt_host *bt_host)
	{
	if (!(bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY))
	bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
	}

	static void clr_b_busy(struct bt_host *bt_host)
	{
	if (bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY)
	bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
	}

	static void set_b2h_atn(struct bt_host *bt_host)
	{
	bt_outb(bt_host, BT_CTRL_B2H_ATN, BT_CTRL);
	}

	static u8 bt_read(struct bt_host *bt_host)
	{
	return bt_inb(bt_host, BT_BMC2HOST);
	}

	static void bt_write(struct bt_host *bt_host, u8 c)
	{
	bt_outb(bt_host, c, BT_BMC2HOST);
	}

	static void set_sms_atn(struct bt_host *bt_host)
	{
	bt_outb(bt_host, BT_CTRL_SMS_ATN, BT_CTRL);
	}

	static struct bt_host file_bt_host(struct file file)
	{
	return container_of(file->private_data, struct bt_host, miscdev);
	}

	static int bt_host_open(struct inode inode, struct file file)
	{
	struct bt_host *bt_host = file_bt_host(file);

	clr_b_busy(bt_host);

	return 0;
	}

	static ssize_t bt_host_read(struct file file, char __user buf,
	size_t count, loff_t *ppos)
	{
	struct bt_host *bt_host = file_bt_host(file);
	char __user *p = buf;
	u8 len;

	if (!access_ok(VERIFY_WRITE, buf, count))
	return -EFAULT;

	WARN_ON(*ppos);

	if (wait_event_interruptible(bt_host->queue,
	bt_inb(bt_host, BT_CTRL) & BT_CTRL_H2B_ATN))
	return -ERESTARTSYS;

	set_b_busy(bt_host);
	clr_h2b_atn(bt_host);
	clr_rd_ptr(bt_host);

	len = bt_read(bt_host);
	__put_user(len, p++);

	/* We pass the length back as well */
	if (len + 1 > count)
	len = count - 1;

	while(len) {
	if (__put_user(bt_read(bt_host), p))
	return -EFAULT;
	len--; p++;
	}

	clr_b_busy(bt_host);

	return p - buf;
	}

	static ssize_t bt_host_write(struct file file, const char __user buf,
	size_t count, loff_t *ppos)
	{
	struct bt_host *bt_host = file_bt_host(file);
	const char __user *p = buf;
	u8 c;

	if (!access_ok(VERIFY_READ, buf, count))
	return -EFAULT;

	WARN_ON(*ppos);

	/* There's no interrupt for clearing host busy so we have to
	* poll */
	if (wait_event_interruptible(bt_host->queue,
	!(bt_inb(bt_host, BT_CTRL) &
	(BT_CTRL_H_BUSY \| BT_CTRL_B2H_ATN))))
	return -ERESTARTSYS;

	clr_wr_ptr(bt_host);

	while (count) {
	if (__get_user(c, p))
	return -EFAULT;

	bt_write(bt_host, c);
	count--; p++;
	}

	set_b2h_atn(bt_host);

	return p - buf;
	}

	static long bt_host_ioctl(struct file *file, unsigned int cmd,
	unsigned long param)
	{
	struct bt_host *bt_host = file_bt_host(file);
	switch (cmd) {
	case BT_HOST_IOCTL_SMS_ATN:
	set_sms_atn(bt_host);
	return 0;
	}
	return -EINVAL;
	}

	static int bt_host_release(struct inode inode, struct file file)
	{
	struct bt_host *bt_host = file_bt_host(file);
	set_b_busy(bt_host);
	return 0;
	}

	static unsigned int bt_host_poll(struct file file, poll_table wait)
	{
	struct bt_host *bt_host = file_bt_host(file);
	unsigned int mask = 0;
	uint8_t ctrl;

	poll_wait(file, &bt_host->queue, wait);

	ctrl = bt_inb(bt_host, BT_CTRL);

	if (ctrl & BT_CTRL_H2B_ATN)
	mask \|= POLLIN;

	if (!(ctrl & (BT_CTRL_H_BUSY \| BT_CTRL_B2H_ATN)))
	mask \|= POLLOUT;

	return mask;
	}

	static const struct file_operations bt_host_fops = {
	.owner = THIS_MODULE,
	.open = bt_host_open,
	.read = bt_host_read,
	.write = bt_host_write,
	.release = bt_host_release,
	.poll = bt_host_poll,
	.unlocked_ioctl = bt_host_ioctl,
	};

	static void poll_timer(unsigned long data)
	{
	struct bt_host bt_host = (void )data;
	bt_host->poll_timer.expires += msecs_to_jiffies(500);
	wake_up(&bt_host->queue);
	add_timer(&bt_host->poll_timer);
	}

	irqreturn_t bt_host_irq(int irq, void *arg)
	{
	struct bt_host *bt_host = arg;
	uint32_t reg;

	reg = ioread32(bt_host->base + BT_CR2);
	reg &= BT_CR2_IRQ_H2B \| BT_CR2_IRQ_HBUSY;
	if (!reg)
	return IRQ_NONE;

	/* ack pending IRQs */
	iowrite32(reg, bt_host->base + BT_CR2);

	wake_up(&bt_host->queue);
	return IRQ_HANDLED;
	}

	static int bt_host_config_irq(struct bt_host *bt_host,
	struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	uint32_t reg;
	int rc;

	bt_host->irq = irq_of_parse_and_map(dev->of_node, 0);
	if (!bt_host->irq)
	return -ENODEV;

	rc = devm_request_irq(dev, bt_host->irq, bt_host_irq, IRQF_SHARED,
	DEVICE_NAME, bt_host);
	if (rc < 0) {
	dev_warn(dev, "Unable to request IRQ %d\n", bt_host->irq);
	bt_host->irq = 0;
	return rc;
	}

	/* Configure IRQs on the host clearing the H2B and HBUSY bits;
	* H2B will be asserted when the host has data for us; HBUSY
	* will be cleared (along with B2H) when we can write the next
	* message to the BT buffer */
	reg = ioread32(bt_host->base + BT_CR1);
	reg \|= BT_CR1_IRQ_H2B \| BT_CR1_IRQ_HBUSY;
	iowrite32(reg, bt_host->base + BT_CR1);

	return 0;
	}

	static int bt_host_probe(struct platform_device *pdev)
	{
	struct bt_host *bt_host;
	struct device *dev;
	struct resource *res;
	int rc;

	if (!pdev \|\| !pdev->dev.of_node)
	return -ENODEV;

	dev = &pdev->dev;
	dev_info(dev, "Found bt host device\n");

	bt_host = devm_kzalloc(dev, sizeof(*bt_host), GFP_KERNEL);
	if (!bt_host)
	return -ENOMEM;

	dev_set_drvdata(&pdev->dev, bt_host);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(dev, "Unable to find resources\n");
	rc = -ENXIO;
	goto out_free;
	}

	bt_host->base = devm_ioremap_resource(&pdev->dev, res);
	if (!bt_host->base) {
	rc = -ENOMEM;
	goto out_free;
	}

	init_waitqueue_head(&bt_host->queue);

	bt_host->miscdev.minor = MISC_DYNAMIC_MINOR,
	bt_host->miscdev.name = DEVICE_NAME,
	bt_host->miscdev.fops = &bt_host_fops,
	bt_host->miscdev.parent = dev;
	rc = misc_register(&bt_host->miscdev);
	if (rc) {
	dev_err(dev, "Unable to register device\n");
	goto out_unmap;
	}

	bt_host_config_irq(bt_host, pdev);

	if (bt_host->irq) {
	dev_info(dev, "Using IRQ %d\n", bt_host->irq);
	} else {
	dev_info(dev, "No IRQ; using timer\n");
	init_timer(&bt_host->poll_timer);
	bt_host->poll_timer.function = poll_timer;
	bt_host->poll_timer.data = (unsigned long)bt_host;
	bt_host->poll_timer.expires = jiffies + msecs_to_jiffies(10);
	add_timer(&bt_host->poll_timer);
	}

	iowrite32((BT_IO_BASE << BT_CR0_IO_BASE) \|
	(BT_IRQ << BT_CR0_IRQ) \|
	BT_CR0_EN_CLR_SLV_RDP \|
	BT_CR0_EN_CLR_SLV_WRP \|
	BT_CR0_ENABLE_IBT,
	bt_host->base + BT_CR0);

	clr_b_busy(bt_host);

	return 0;

	out_unmap:
	devm_iounmap(&pdev->dev, bt_host->base);

	out_free:
	devm_kfree(dev, bt_host);
	return rc;

	}

	static int bt_host_remove(struct platform_device *pdev)
	{
	struct bt_host *bt_host = dev_get_drvdata(&pdev->dev);
	misc_deregister(&bt_host->miscdev);
	if (!bt_host->irq)
	del_timer_sync(&bt_host->poll_timer);
	devm_iounmap(&pdev->dev, bt_host->base);
	devm_kfree(&pdev->dev, bt_host);
	bt_host = NULL;

	return 0;
	}

	static const struct of_device_id bt_host_match[] = {
	{ .compatible = "aspeed,bt-host" },
	{ },
	};

	static struct platform_driver bt_host_driver = {
	.driver = {
	.name = DEVICE_NAME,
	.owner = THIS_MODULE,
	.of_match_table = bt_host_match,
	},
	.probe = bt_host_probe,
	.remove = bt_host_remove,
	};

	module_platform_driver(bt_host_driver);

	MODULE_DEVICE_TABLE(of, bt_host_match);
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Alistair Popple <alistair@popple.id.au>");
	MODULE_DESCRIPTION("Linux device interface to the BT interface");