[PATCH 53/75] tty: Modem functions for the HSO driver

Alan Cox
2009-01-02T13:47:39Z

From: Denis Joseph Barrow <D.Barow@option.com>

Makes TIOCM ioctls for Data Carrier Detect & related functions
work like /drivers/serial/serial-core.c potentially needed
for pppd & similar user programs.

Signed-off-by: Denis Joseph Barrow <D.Barow@option.com>
Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/net/usb/hso.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 318 insertions(+), 13 deletions(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 7373fb6..d974d97 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -39,8 +39,11 @@
* port is opened, as this have a huge impact on the network port
* throughput.
*
- * Interface 2: Standard modem interface - circuit switched interface, should
- * not be used.
+ * Interface 2: Standard modem interface - circuit switched interface, this
+ * can be used to make a standard ppp connection however it
+ * should not be used in conjunction with the IP network interface
+ * enabled for USB performance reasons i.e. if using this set
+ * ideally disable_net=1.
*
*****************************************************************************/

@@ -63,6 +66,8 @@
#include <linux/usb/cdc.h>
#include <net/arp.h>
#include <asm/byteorder.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>

#define DRIVER_VERSION "1.2"
@@ -182,6 +187,41 @@ enum rx_ctrl_state{
RX_PENDING
};

+#define BM_REQUEST_TYPE (0xa1)
+#define B_NOTIFICATION (0x20)
+#define W_VALUE (0x0)
+#define W_INDEX (0x2)
+#define W_LENGTH (0x2)
+
+#define B_OVERRUN (0x1<<6)
+#define B_PARITY (0x1<<5)
+#define B_FRAMING (0x1<<4)
+#define B_RING_SIGNAL (0x1<<3)
+#define B_BREAK (0x1<<2)
+#define B_TX_CARRIER (0x1<<1)
+#define B_RX_CARRIER (0x1<<0)
+
+struct hso_serial_state_notification {
+ u8 bmRequestType;
+ u8 bNotification;
+ u16 wValue;
+ u16 wIndex;
+ u16 wLength;
+ u16 UART_state_bitmap;
+} __attribute__((packed));
+
+struct hso_tiocmget {
+ struct mutex mutex;
+ wait_queue_head_t waitq;
+ int intr_completed;
+ struct usb_endpoint_descriptor *endp;
+ struct urb *urb;
+ struct hso_serial_state_notification serial_state_notification;
+ u16 prev_UART_state_bitmap;
+ struct uart_icount icount;
+};
+
+
struct hso_serial {
struct hso_device *parent;
int magic;
@@ -219,6 +259,7 @@ struct hso_serial {
spinlock_t serial_lock;

int (*write_data) (struct hso_serial *serial);
+ struct hso_tiocmget *tiocmget;
/* Hacks required to get flow control
* working on the serial receive buffers
* so as not to drop characters on the floor.
@@ -305,7 +346,7 @@ static void async_get_intf(struct work_struct *data);
static void async_put_intf(struct work_struct *data);
static int hso_put_activity(struct hso_device *hso_dev);
static int hso_get_activity(struct hso_device *hso_dev);
-
+static void tiocmget_intr_callback(struct urb *urb);
/*****************************************************************************/
/* Helping functions */
/*****************************************************************************/
@@ -1419,25 +1460,217 @@ static int hso_serial_chars_in_buffer(struct tty_struct *tty)

return chars;
}
+int tiocmget_submit_urb(struct hso_serial *serial,
+ struct hso_tiocmget *tiocmget,
+ struct usb_device *usb)
+{
+ int result;
+
+ if (serial->parent->usb_gone)
+ return -ENODEV;
+ usb_fill_int_urb(tiocmget->urb, usb,
+ usb_rcvintpipe(usb,
+ tiocmget->endp->
+ bEndpointAddress & 0x7F),
+ &tiocmget->serial_state_notification,
+ sizeof(struct hso_serial_state_notification),
+ tiocmget_intr_callback, serial,
+ tiocmget->endp->bInterval);
+ result = usb_submit_urb(tiocmget->urb, GFP_ATOMIC);
+ if (result) {
+ dev_warn(&usb->dev, "%s usb_submit_urb failed %d\n", __func__,
+ result);
+ }
+ return result;
+
+}
+
+static void tiocmget_intr_callback(struct urb *urb)
+{
+ struct hso_serial *serial = urb->context;
+ struct hso_tiocmget *tiocmget;
+ int status = urb->status;
+ u16 UART_state_bitmap, prev_UART_state_bitmap;
+ struct uart_icount *icount;
+ struct hso_serial_state_notification *serial_state_notification;
+ struct usb_device *usb;
+
+ /* Sanity checks */
+ if (!serial)
+ return;
+ if (status) {
+ log_usb_status(status, __func__);
+ return;
+ }
+ tiocmget = serial->tiocmget;
+ if (!tiocmget)
+ return;
+ usb = serial->parent->usb;
+ serial_state_notification = &tiocmget->serial_state_notification;
+ if (serial_state_notification->bmRequestType != BM_REQUEST_TYPE ||
+ serial_state_notification->bNotification != B_NOTIFICATION ||
+ le16_to_cpu(serial_state_notification->wValue) != W_VALUE ||
+ le16_to_cpu(serial_state_notification->wIndex) != W_INDEX ||
+ le16_to_cpu(serial_state_notification->wLength) != W_LENGTH) {
+ dev_warn(&usb->dev,
+ "hso received invalid serial state notification\n");
+ DUMP(serial_state_notification,
+ sizeof(hso_serial_state_notifation))
+ } else {
+
+ UART_state_bitmap = le16_to_cpu(serial_state_notification->
+ UART_state_bitmap);
+ prev_UART_state_bitmap = tiocmget->prev_UART_state_bitmap;
+ icount = &tiocmget->icount;
+ spin_lock(&serial->serial_lock);
+ if ((UART_state_bitmap & B_OVERRUN) !=
+ (prev_UART_state_bitmap & B_OVERRUN))
+ icount->parity++;
+ if ((UART_state_bitmap & B_PARITY) !=
+ (prev_UART_state_bitmap & B_PARITY))
+ icount->parity++;
+ if ((UART_state_bitmap & B_FRAMING) !=
+ (prev_UART_state_bitmap & B_FRAMING))
+ icount->frame++;
+ if ((UART_state_bitmap & B_RING_SIGNAL) &&
+ !(prev_UART_state_bitmap & B_RING_SIGNAL))
+ icount->rng++;
+ if ((UART_state_bitmap & B_BREAK) !=
+ (prev_UART_state_bitmap & B_BREAK))
+ icount->brk++;
+ if ((UART_state_bitmap & B_TX_CARRIER) !=
+ (prev_UART_state_bitmap & B_TX_CARRIER))
+ icount->dsr++;
+ if ((UART_state_bitmap & B_RX_CARRIER) !=
+ (prev_UART_state_bitmap & B_RX_CARRIER))
+ icount->dcd++;
+ tiocmget->prev_UART_state_bitmap = UART_state_bitmap;
+ spin_unlock(&serial->serial_lock);
+ tiocmget->intr_completed = 1;
+ wake_up_interruptible(&tiocmget->waitq);
+ }
+ memset(serial_state_notification, 0,
+ sizeof(struct hso_serial_state_notification));
+ tiocmget_submit_urb(serial,
+ tiocmget,
+ serial->parent->usb);
+}
+
+/*
+ * next few functions largely stolen from drivers/serial/serial_core.c
+ */
+/* Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+ * - mask passed in arg for lines of interest
+ * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+ * Caller should use TIOCGICOUNT to see which one it was
+ */
+static int
+hso_wait_modem_status(struct hso_serial *serial, unsigned long arg)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ struct uart_icount cprev, cnow;
+ struct hso_tiocmget *tiocmget;
+ int ret;
+
+ tiocmget = serial->tiocmget;
+ if (!tiocmget)
+ return -ENOENT;
+ /*
+ * note the counters on entry
+ */
+ spin_lock_irq(&serial->serial_lock);
+ memcpy(&cprev, &tiocmget->icount, sizeof(struct uart_icount));
+ spin_unlock_irq(&serial->serial_lock);
+ add_wait_queue(&tiocmget->waitq, &wait);
+ for (;;) {
+ spin_lock_irq(&serial->serial_lock);
+ memcpy(&cnow, &tiocmget->icount, sizeof(struct uart_icount));
+ spin_unlock_irq(&serial->serial_lock);
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+ ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+ ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd))) {
+ ret = 0;
+ break;
+ }
+ schedule();
+ /* see if a signal did it */
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+ cprev = cnow;
+ }
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&tiocmget->waitq, &wait);
+
+ return ret;
+}
+
+/*
+ * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+ * Return: write counters to the user passed counter struct
+ * NB: both 1->0 and 0->1 transitions are counted except for
+ * RI where only 0->1 is counted.
+ */
+static int hso_get_count(struct hso_serial *serial,
+ struct serial_icounter_struct __user *icnt)
+{
+ struct serial_icounter_struct icount;
+ struct uart_icount cnow;
+ struct hso_tiocmget *tiocmget = serial->tiocmget;
+
+ if (!tiocmget)
+ return -ENOENT;
+ spin_lock_irq(&serial->serial_lock);
+ memcpy(&cnow, &tiocmget->icount, sizeof(struct uart_icount));
+ spin_unlock_irq(&serial->serial_lock);
+
+ icount.cts = cnow.cts;
+ icount.dsr = cnow.dsr;
+ icount.rng = cnow.rng;
+ icount.dcd = cnow.dcd;
+ icount.rx = cnow.rx;
+ icount.tx = cnow.tx;
+ icount.frame = cnow.frame;
+ icount.overrun = cnow.overrun;
+ icount.parity = cnow.parity;
+ icount.brk = cnow.brk;
+ icount.buf_overrun = cnow.buf_overrun;
+
+ return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
+}
+

static int hso_serial_tiocmget(struct tty_struct *tty, struct file *file)
{
- unsigned int value;
+ int retval;
struct hso_serial *serial = get_serial_by_tty(tty);
- unsigned long flags;
+ struct hso_tiocmget *tiocmget;
+ u16 UART_state_bitmap;

/* sanity check */
if (!serial) {
D1("no tty structures");
return -EINVAL;
}
-
- spin_lock_irqsave(&serial->serial_lock, flags);
- value = ((serial->rts_state) ? TIOCM_RTS : 0) |
+ spin_lock_irq(&serial->serial_lock);
+ retval = ((serial->rts_state) ? TIOCM_RTS : 0) |
((serial->dtr_state) ? TIOCM_DTR : 0);
- spin_unlock_irqrestore(&serial->serial_lock, flags);
-
- return value;
+ tiocmget = serial->tiocmget;
+ if (tiocmget) {
+
+ UART_state_bitmap = le16_to_cpu(
+ tiocmget->prev_UART_state_bitmap);
+ if (UART_state_bitmap & B_RING_SIGNAL)
+ retval |= TIOCM_RNG;
+ if (UART_state_bitmap & B_RX_CARRIER)
+ retval |= TIOCM_CD;
+ if (UART_state_bitmap & B_TX_CARRIER)
+ retval |= TIOCM_DSR;
+ }
+ spin_unlock_irq(&serial->serial_lock);
+ return retval;
}

static int hso_serial_tiocmset(struct tty_struct *tty, struct file *file,
@@ -1479,6 +1712,32 @@ static int hso_serial_tiocmset(struct tty_struct *tty, struct file *file,
USB_CTRL_SET_TIMEOUT);
}

+static int hso_serial_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct hso_serial *serial = get_serial_by_tty(tty);
+ void __user *uarg = (void __user *)arg;
+ int ret = 0;
+ D4("IOCTL cmd: %d, arg: %ld", cmd, arg);
+
+ if (!serial)
+ return -ENODEV;
+ switch (cmd) {
+ case TIOCMIWAIT:
+ ret = hso_wait_modem_status(serial, arg);
+ break;
+
+ case TIOCGICOUNT:
+ ret = hso_get_count(serial, uarg);
+ break;
+ default:
+ ret = -ENOIOCTLCMD;
+ break;
+ }
+ return ret;
+}
+
+
/* starts a transmit */
static void hso_kick_transmit(struct hso_serial *serial)
{
@@ -1956,7 +2215,10 @@ static int hso_start_serial_device(struct hso_device *hso_dev, gfp_t flags)
serial->shared_int->use_count++;
mutex_unlock(&serial->shared_int->shared_int_lock);
}
-
+ if (serial->tiocmget)
+ tiocmget_submit_urb(serial,
+ serial->tiocmget,
+ serial->parent->usb);
return result;
}

@@ -1964,6 +2226,7 @@ static int hso_stop_serial_device(struct hso_device *hso_dev)
{
int i;
struct hso_serial *serial = dev2ser(hso_dev);
+ struct hso_tiocmget *tiocmget;

if (!serial)
return -ENODEV;
@@ -1992,6 +2255,11 @@ static int hso_stop_serial_device(struct hso_device *hso_dev)
}
mutex_unlock(&serial->shared_int->shared_int_lock);
}
+ tiocmget = serial->tiocmget;
+ if (tiocmget) {
+ wake_up_interruptible(&tiocmget->waitq);
+ usb_kill_urb(tiocmget->urb);
+ }

return 0;
}
@@ -2338,6 +2606,20 @@ exit:
return NULL;
}

+static void hso_free_tiomget(struct hso_serial *serial)
+{
+ struct hso_tiocmget *tiocmget = serial->tiocmget;
+ if (tiocmget) {
+ kfree(tiocmget);
+ if (tiocmget->urb) {
+ usb_free_urb(tiocmget->urb);
+ tiocmget->urb = NULL;
+ }
+ serial->tiocmget = NULL;
+
+ }
+}
+
/* Frees an AT channel ( goes for both mux and non-mux ) */
static void hso_free_serial_device(struct hso_device *hso_dev)
{
@@ -2356,6 +2638,7 @@ static void hso_free_serial_device(struct hso_device *hso_dev)
else
mutex_unlock(&serial->shared_int->shared_int_lock);
}
+ hso_free_tiomget(serial);
kfree(serial);
hso_free_device(hso_dev);
}
@@ -2367,6 +2650,7 @@ static struct hso_device *hso_create_bulk_serial_device(
struct hso_device *hso_dev;
struct hso_serial *serial;
int num_urbs;
+ struct hso_tiocmget *tiocmget;

hso_dev = hso_create_device(interface, port);
if (!hso_dev)
@@ -2379,8 +2663,27 @@ static struct hso_device *hso_create_bulk_serial_device(
serial->parent = hso_dev;
hso_dev->port_data.dev_serial = serial;

- if (port & HSO_PORT_MODEM)
+ if (port & HSO_PORT_MODEM) {
num_urbs = 2;
+ serial->tiocmget = kzalloc(sizeof(struct hso_tiocmget),
+ GFP_KERNEL);
+ /* it isn't going to break our heart if serial->tiocmget
+ * allocation fails don't bother checking this.
+ */
+ if (serial->tiocmget) {
+ tiocmget = serial->tiocmget;
+ tiocmget->urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (tiocmget->urb) {
+ mutex_init(&tiocmget->mutex);
+ init_waitqueue_head(&tiocmget->waitq);
+ tiocmget->endp = hso_get_ep(
+ interface,
+ USB_ENDPOINT_XFER_INT,
+ USB_DIR_IN);
+ } else
+ hso_free_tiomget(serial);
+ }
+ }
else
num_urbs = 1;

@@ -2416,6 +2719,7 @@ static struct hso_device *hso_create_bulk_serial_device(
exit2:
hso_serial_common_free(serial);
exit:
+ hso_free_tiomget(serial);
kfree(serial);
hso_free_device(hso_dev);
return NULL;
@@ -2926,6 +3230,7 @@ static const struct tty_operations hso_serial_ops = {
.close = hso_serial_close,
.write = hso_serial_write,
.write_room = hso_serial_write_room,
+ .ioctl = hso_serial_ioctl,
.set_termios = hso_serial_set_termios,
.chars_in_buffer = hso_serial_chars_in_buffer,
.tiocmget = hso_serial_tiocmget,