tty_hci driver exposes a /dev/hci_tty character device node, that intends
to emulate a generic /dev/ttyX device that would be used by the user-space
Bluetooth stacks to send/receive data to/from the WL combo-connectivity
chipsets.
The device driver has no internal logic of its own to intrepret data & all
such logic is handled by the user-space stack.
Signed-off-by: Pavan Savoy <pavan_sa...@ti.com>
[Fixed checkpatch warnings]
Signed-off-by: Vishal Mahaveer <vish...@ti.com>
[Fixed checkpatch --strict warnings]
Signed-off-by: Eyal Reizer <ey...@ti.com>
---
drivers/misc/ti-st/Kconfig | 8 +
drivers/misc/ti-st/Makefile | 1 +
drivers/misc/ti-st/tty_hci.c | 538 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 547 insertions(+)
create mode 100644 drivers/misc/ti-st/tty_hci.c
diff --git a/drivers/misc/ti-st/Kconfig b/drivers/misc/ti-st/Kconfig
index f34dcc5..f2df2c7 100644
--- a/drivers/misc/ti-st/Kconfig
+++ b/drivers/misc/ti-st/Kconfig
@@ -14,4 +14,12 @@ config TI_ST
are returned to relevant protocol drivers based on their
packet types.
+config ST_HCI
+ tristate "HCI TTY emulation driver for Bluetooth"
+ depends on TI_ST
+ help
+ This enables the TTY device like emulation for HCI used by
+ user-space Bluetooth stacks.
+ It will provide a character device for user space Bluetooth stack to
+ send/receive data over shared transport.
endmenu
diff --git a/drivers/misc/ti-st/Makefile b/drivers/misc/ti-st/Makefile
index 78d7ebb..4546219 100644
--- a/drivers/misc/ti-st/Makefile
+++ b/drivers/misc/ti-st/Makefile
@@ -4,3 +4,4 @@
#
obj-$(CONFIG_TI_ST) += st_drv.o
st_drv-objs := st_core.o st_kim.o st_ll.o
+obj-$(CONFIG_ST_HCI) += tty_hci.o
diff --git a/drivers/misc/ti-st/tty_hci.c b/drivers/misc/ti-st/tty_hci.c
new file mode 100644
index 0000000..7a6669f
--- /dev/null
+++ b/drivers/misc/ti-st/tty_hci.c
@@ -0,0 +1,538 @@
+/*
+ * TTY emulation for user-space Bluetooth stacks over HCI-H4
+ * Copyright (C) 2011-2012 Texas Instruments
+ * Author: Pavan Savoy <pavan_sa...@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+/** define one of the following for debugging
+#define DEBUG
+#define VERBOSE
+*/
+
+#define pr_fmt(fmt) "(hci_tty): " fmt
+#include <linux/module.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+
+#include <linux/uaccess.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/skbuff.h>
+#include <linux/interrupt.h>
+
+#include <linux/ti_wilink_st.h>
+
+/* Number of seconds to wait for registration completion
+ * when ST returns PENDING status.
+ */
+#define BT_REGISTER_TIMEOUT 6000 /* 6 sec */
+
+/**
+ * struct ti_st - driver operation structure
+ * @hdev: hci device pointer which binds to bt driver
+ * @reg_status: ST registration callback status
+ * @st_write: write function provided by the ST driver
+ * to be used by the driver during send_frame.
+ * @wait_reg_completion - completion sync between ti_st_open
+ * and st_reg_completion_cb.
+ */
+struct ti_st {
+ struct hci_dev *hdev;
+ char reg_status;
+ long (*st_write)(struct sk_buff *);
+ struct completion wait_reg_completion;
+ wait_queue_head_t data_q;
+ struct sk_buff_head rx_list;
+};
+
+#define DEVICE_NAME "hci_tty"
+
+/***********Functions called from ST driver**********************************/
+/* Called by Shared Transport layer when receive data is
+ * available */
+static long st_receive(void *priv_data, struct sk_buff *skb)
+{
+ struct ti_st *hst = (void *)priv_data;
+
+ pr_debug("@ %s", __func__);
+#ifdef VERBOSE
+ print_hex_dump(KERN_INFO, ">rx>", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, skb->len, 0);
+#endif
+ skb_queue_tail(&hst->rx_list, skb);
+ wake_up_interruptible(&hst->data_q);
+ return 0;
+}
+
+/* Called by ST layer to indicate protocol registration completion
+ * status.ti_st_open() function will wait for signal from this
+ * API when st_register() function returns ST_PENDING.
+ */
+static void st_reg_completion_cb(void *priv_data, char data)
+{
+ struct ti_st *lhst = (void *)priv_data;
+
+ pr_info("@ %s\n", __func__);
+ /* Save registration status for use in ti_st_open() */
+ lhst->reg_status = data;
+ /* complete the wait in ti_st_open() */
+ complete(&lhst->wait_reg_completion);
+}
+
+/* protocol structure registered with shared transport */
+#define MAX_BT_CHNL_IDS 3
+static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
+ {
+ .chnl_id = 0x04, /* HCI Events */
+ .hdr_len = 2,
+ .offset_len_in_hdr = 1,
+ .len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
+ .reserve = 8,
+ },
+ {
+ .chnl_id = 0x02, /* ACL */
+ .hdr_len = 4,
+ .offset_len_in_hdr = 2,
+ .len_size = 2, /* sizeof(dlen) in struct hci_acl_hdr */
+ .reserve = 8,
+ },
+ {
+ .chnl_id = 0x03, /* SCO */
+ .hdr_len = 3,
+ .offset_len_in_hdr = 2,
+ .len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
+ .reserve = 8,
+ },
+};
+
+/** hci_tty_open Function
+ * This function will perform an register on ST driver.
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @inod :
+ * Returns 0 - on success
+ * else suitable error code
+ */
+int hci_tty_open(struct inode *inod, struct file *file)
+{
+ int i = 0, err = 0;
+ unsigned long timeleft;
+ struct ti_st *hst;
+
+ pr_info("inside %s (%p, %p)\n", __func__, inod, file);
+
+ hst = kzalloc(sizeof(*hst), GFP_KERNEL);
+ file->private_data = hst;
+ hst = file->private_data;
+
+ for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
+ ti_st_proto[i].priv_data = hst;
+ ti_st_proto[i].max_frame_size = 1026;
+ ti_st_proto[i].recv = st_receive;
+ ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
+
+ /* Prepare wait-for-completion handler */
+ init_completion(&hst->wait_reg_completion);
+ /* Reset ST registration callback status flag,
+ * this value will be updated in
+ * st_reg_completion_cb()
+ * function whenever it called from ST driver.
+ */
+ hst->reg_status = -EINPROGRESS;
+
+ err = st_register(&ti_st_proto[i]);
+ if (!err)
+ goto done;
+
+ if (err != -EINPROGRESS) {
+ pr_err("st_register failed %d", err);
+ goto error;
+ }
+
+ /* ST is busy with either protocol
+ * registration or firmware download.
+ */
+ pr_debug("waiting for registration completion signal from ST");
+ timeleft = wait_for_completion_timeout
+ (&hst->wait_reg_completion,
+ msecs_to_jiffies(BT_REGISTER_TIMEOUT));
+ if (!timeleft) {
+ pr_err("Timeout(%d sec),didn't get reg completion
signal from ST",
+ BT_REGISTER_TIMEOUT / 1000);
+ err = -ETIMEDOUT;
+ goto error;
+ }
+
+ /* Is ST registration callback
+ * called with ERROR status? */
+ if (hst->reg_status != 0) {
+ pr_err("ST registration completed with invalid status
%d",
+ hst->reg_status);
+ err = -EAGAIN;
+ goto error;
+ }
+
+done:
+ hst->st_write = ti_st_proto[i].write;
+ if (!hst->st_write) {
+ pr_err("undefined ST write function");
+ for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
+ /* Undo registration with ST */
+ err = st_unregister(&ti_st_proto[i]);
+ if (err)
+ pr_err("st_unregister() failed with
error %d",
+ err);
+ hst->st_write = NULL;
+ }
+ return -EIO;
+ }
+ }
+
+ skb_queue_head_init(&hst->rx_list);
+ init_waitqueue_head(&hst->data_q);
+
+ return 0;
+
+error:
+ kfree(hst);
+ return err;
+}
+
+/** hci_tty_release Function
+ * This function will un-registers from the ST driver.
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @inod :
+ * Returns 0 - on success
+ * else suitable error code
+ */
+int hci_tty_release(struct inode *inod, struct file *file)
+{
+ int err, i;
+ struct ti_st *hst = file->private_data;
+
+ pr_info("inside %s (%p, %p)\n", __func__, inod, file);
+
+ for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
+ err = st_unregister(&ti_st_proto[i]);
+ if (err)
+ pr_err("st_unregister(%d) failed with error %d",
+ ti_st_proto[i].chnl_id, err);
+ }
+
+ hst->st_write = NULL;
+ skb_queue_purge(&hst->rx_list);
+ kfree(hst);
+ return err;
+}
+
+/** hci_tty_read Function
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @data : Data which needs to be passed to APP
+ * @size : Length of the data passesd
+ * offset :
+ * Returns Size of packet received - on success
+ * else suitable error code
+ */
+ssize_t hci_tty_read(struct file *file, char __user *data, size_t size,
+ loff_t *offset)
+{
+ int len = 0, tout;
+ struct sk_buff *skb = NULL, *rskb = NULL;
+ struct ti_st *hst;
+
+ pr_debug("inside %s (%p, %p, %u, %p)\n",
+ __func__, file, data, size, offset);
+
+ /* Validate input parameters */
+ if ((NULL == file) || (((NULL == data) || (0 == size)))) {
+ pr_err("Invalid input params passed to %s", __func__);
+ return -EINVAL;
+ }
+
+ hst = file->private_data;
+
+ /* cannot come here if poll-ed before reading
+ * if not poll-ed wait on the same wait_q
+ */
+ tout = wait_event_interruptible_timeout(hst->data_q,
+ !skb_queue_empty(&hst->rx_list),
+ msecs_to_jiffies(1000));
+ /* Check for timed out condition */
+ if (0 == tout) {
+ pr_err("Device Read timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ /* hst->rx_list not empty skb already present */
+ skb = skb_dequeue(&hst->rx_list);
+ if (!skb) {
+ pr_err("dequed skb is null?\n");
+ return -EIO;
+ }
+
+#ifdef VERBOSE
+ print_hex_dump(KERN_INFO, ">in>", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, skb->len, 0);
+#endif
+
+ /* Forward the data to the user */
+ if (skb->len >= size) {
+ pr_err("FIONREAD not done before read\n");
+ return -ENOMEM;
+ }
+ /* returning skb */
+ rskb = alloc_skb(size, GFP_KERNEL);
+ if (!rskb)
+ return -ENOMEM;
+
+ /* cb[0] has the pkt_type 0x04 or 0x02 or 0x03 */
+ memcpy(skb_put(rskb, 1), &skb->cb[0], 1);
+ memcpy(skb_put(rskb, skb->len), skb->data, skb->len);
+
+ if (copy_to_user(data, rskb->data, rskb->len)) {
+ pr_err("unable to copy to user space\n");
+ /* Queue the skb back to head */
+ skb_queue_head(&hst->rx_list, skb);
+ kfree_skb(rskb);
+ return -EIO;
+ }
+
+ len = rskb->len; /* len of returning skb */
+ kfree_skb(skb);
+ kfree_skb(rskb);
+ pr_debug("total size read= %d\n", len);
+ return len;
+}
+
+/* hci_tty_write Function
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @data : packet data from BT application
+ * @size : Size of the packet data
+ * @offset :
+ * Returns Size of packet on success
+ * else suitable error code
+ */
+ssize_t hci_tty_write(struct file *file, const char __user *data,
+ size_t size, loff_t *offset)
+{
+ struct ti_st *hst = file->private_data;
+ struct sk_buff *skb;
+
+ pr_debug("inside %s (%p, %p, %u, %p)\n",
+ __func__, file, data, size, offset);
+
+ if (!hst->st_write) {
+ pr_err(" Can't write to ST, hhci_tty->st_write null ?");
+ return -EINVAL;
+ }
+
+ skb = alloc_skb(size, GFP_KERNEL);
+ /* Validate Created SKB */
+ if (NULL == skb)
+ return -ENOMEM;
+
+ /* Forward the data from the user space to ST core */
+ if (copy_from_user(skb_put(skb, size), data, size)) {
+ pr_err(" Unable to copy from user space");
+ kfree_skb(skb);
+ return -EIO;
+ }
+
+#ifdef VERBOSE
+ pr_debug("start data..");
+ print_hex_dump(KERN_INFO, "<out<", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, size, 0);
+ pr_debug("\n..end data");
+#endif
+
+ hst->st_write(skb);
+ return size;
+}
+
+/** hci_tty_ioctl Function
+ * This will peform the functions as directed by the command and command
+ * argument.
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @cmd : IOCTL Command
+ * @arg : Command argument for IOCTL command
+ * Returns 0 on success
+ * else suitable error code
+ */
+static long hci_tty_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct sk_buff *skb = NULL;
+ int retcode = 0;
+ struct ti_st *hst;
+
+ pr_debug("inside %s (%p, %u, %lx)", __func__, file, cmd, arg);
+
+ /* Validate input parameters */
+ if ((NULL == file) || (0 == cmd)) {
+ pr_err("invalid input parameters passed to %s", __func__);
+ return -EINVAL;
+ }
+
+ hst = file->private_data;
+
+ switch (cmd) {
+ case FIONREAD:
+ /* Deque the SKB from the head if rx_list is not empty
+ * update the argument with skb->len to provide amount of data
+ * available in the available SKB +1 for the PKT_TYPE
+ * field not provided in data by TI-ST.
+ */
+ skb = skb_dequeue(&hst->rx_list);
+ if (skb) {
+ *(unsigned int *)arg = skb->len + 1;
+ /* Re-Store the SKB for furtur Read operations */
+ skb_queue_head(&hst->rx_list, skb);
+ } else {
+ *(unsigned int *)arg = 0;
+ }
+ pr_debug("returning %d\n", *(unsigned int *)arg);
+ break;
+ default:
+ pr_debug("Un-Identified IOCTL %d", cmd);
+ retcode = 0;
+ break;
+ }
+
+ return retcode;
+}
+
+/** hci_tty_poll Function
+ * This function will wait till some data is received to the hci_tty driver
from ST
+ *
+ * Parameters :
+ * @file : File pointer for BT char driver
+ * @wait : POLL wait information
+ * Returns status of POLL on success
+ * else suitable error code
+ */
+static unsigned int hci_tty_poll(struct file *file, poll_table *wait)
+{
+ struct ti_st *hst = file->private_data;
+ unsigned long mask = 0;
+
+ pr_debug("@ %s\n", __func__);
+
+ /* wait to be completed by st_receive */
+ poll_wait(file, &hst->data_q, wait);
+ pr_debug("poll broke\n");
+
+ if (!skb_queue_empty(&hst->rx_list)) {
+ pr_debug("rx list que !empty\n");
+ mask |= POLLIN; /* TODO: check app for mask */
+ }
+
+ return mask;
+}
+
+/* BT Char driver function pointers
+ * These functions are called from USER space by pefroming File Operations
+ * on /dev/hci_tty node exposed by this driver during init
+ */
+const struct file_operations hci_tty_chrdev_ops = {
+ .owner = THIS_MODULE,
+ .open = hci_tty_open,
+ .read = hci_tty_read,
+ .write = hci_tty_write,
+ .unlocked_ioctl = hci_tty_ioctl,
+ .poll = hci_tty_poll,
+ .release = hci_tty_release,
+};
+
+/*********Functions called during insmod and
delmod****************************/
+
+static int hci_tty_major; /* major number */
+static struct class *hci_tty_class; /* class during class_create */
+static struct device *hci_tty_dev; /* dev during device_create */
+/** hci_tty_init Function
+ * This function Initializes the hci_tty driver parameters and exposes
+ * /dev/hci_tty node to user space
+ *
+ * Parameters : NULL
+ * Returns 0 on success
+ * else suitable error code
+ */
+static int __init hci_tty_init(void)
+{
+ pr_info("inside %s\n", __func__);
+
+ /* Expose the device DEVICE_NAME to user space
+ * And obtain the major number for the device
+ */
+ hci_tty_major = register_chrdev(0, DEVICE_NAME, &hci_tty_chrdev_ops);
+
+ if (0 > hci_tty_major) {
+ pr_err("Error when registering to char dev");
+ return hci_tty_major;
+ }
+
+ /* udev */
+ hci_tty_class = class_create(THIS_MODULE, DEVICE_NAME);
+ if (IS_ERR(hci_tty_class)) {
+ pr_err("Something went wrong in class_create");
+ unregister_chrdev(hci_tty_major, DEVICE_NAME);
+ return -1;
+ }
+
+ hci_tty_dev =
+ device_create(hci_tty_class, NULL, MKDEV(hci_tty_major, 0),
+ NULL, DEVICE_NAME);
+ if (IS_ERR(hci_tty_dev)) {
+ pr_err("Error in device create");
+ unregister_chrdev(hci_tty_major, DEVICE_NAME);
+ class_destroy(hci_tty_class);
+ return -1;
+ }
+ pr_info("allocated %d, %d\n", hci_tty_major, 0);
+ return 0;
+}
+
+/** hci_tty_exit Function
+ * This function Destroys the hci_tty driver parameters and /dev/hci_tty node
+ *
+ * Parameters : NULL
+ * Returns NULL
+ */
+static void __exit hci_tty_exit(void)
+{
+ pr_info("inside %s\n", __func__);
+ pr_info("bye.. freeing up %d\n", hci_tty_major);
+
+ device_destroy(hci_tty_class, MKDEV(hci_tty_major, 0));
+ class_destroy(hci_tty_class);
+ unregister_chrdev(hci_tty_major, DEVICE_NAME);
+}
+
+module_init(hci_tty_init);
+module_exit(hci_tty_exit);
+
+MODULE_AUTHOR("Pavan Savoy <pavan_sa...@ti.com>");
+MODULE_LICENSE("GPL");
--
1.7.9.5
--
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