diff options
Diffstat (limited to 'drivers/misc/bt-host.c')
| -rw-r--r-- | drivers/misc/bt-host.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/drivers/misc/bt-host.c b/drivers/misc/bt-host.c new file mode 100644 index 000000000000..105d3fc664a4 --- /dev/null +++ b/drivers/misc/bt-host.c @@ -0,0 +1,420 @@ +#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"); |