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cdc_vcom: reset the vcom state in proper cases 

Reset the vcom state in class_{run,stop} and when the PC is not
receiving data from me.
This commit is contained in:
Grissiom 2013-05-25 15:25:32 +08:00
parent d0d1861d81
commit 046182be94
1 changed files with 44 additions and 5 deletions
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49
components/drivers/usb/usbdevice/class/cdc_vcom.c
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@ -36,8 +36,8 @@ static rt_uint8_t rx_buf[CDC_RX_BUFSIZE];
ALIGN(RT_ALIGN_SIZE)
static rt_uint8_t tx_buf[CDC_TX_BUFSIZE];
static rt_bool_t vcom_connected = RT_FALSE;
static rt_bool_t vcom_in_sending = RT_FALSE;
volatile static rt_bool_t vcom_connected = RT_FALSE;
volatile static rt_bool_t vcom_in_sending = RT_FALSE;
static struct udevice_descriptor dev_desc =
{
@ -151,6 +151,17 @@ const static char* _ustring[] =
"Interface",
};
static void _vcom_reset_state(void)
{
int lvl = rt_hw_interrupt_disable();
tx_ringbuffer.read_mirror = tx_ringbuffer.read_index = 0;
tx_ringbuffer.write_mirror = tx_ringbuffer.write_index = 0;
vcom_connected = RT_FALSE;
vcom_in_sending = RT_FALSE;
/*rt_kprintf("reset USB serial\n", cnt);*/
rt_hw_interrupt_enable(lvl);
}
/**
* This function will handle cdc bulk in endpoint request.
*
@ -170,7 +181,21 @@ static rt_err_t _ep_in_handler(udevice_t device, uclass_t cls, rt_size_t size)
remain = RT_RINGBUFFER_SIZE(&tx_ringbuffer);
if (remain != 0)
{
/* although vcom_in_sending is set in SOF handler in the very
* beginning, we have to guarantee the state is right when start
* sending. There is at least one extreme case where we have finished the
* last IN transaction but the vcom_in_sending is RT_FALSE.
*
* Ok, what the extreme case is: pour data into vcom in loop. Open
* terminal on the PC, you will see the data. Then close it. So the
* data will be sent to the PC in the back. When the buffer of the PC
* driver is full. It will not send IN packet to the board and you will
* have no chance to clear vcom_in_sending in this function. The data
* will fill into the ringbuffer until it is full, and we will reset
* the state machine and clear vcom_in_sending. When you open the
* terminal on the PC again. The IN packet will appear on the line and
* we will, eventually, reach here with vcom_in_sending is clear.
*/
vcom_in_sending = RT_TRUE;
rt_ringbuffer_get(&tx_ringbuffer, eps->ep_in->buffer, remain);
rt_hw_interrupt_enable(level);
@ -369,6 +394,8 @@ static rt_err_t _class_run(udevice_t device, uclass_t cls)
eps->ep_in->buffer = tx_buf;
eps->ep_out->buffer = rx_buf;
_vcom_reset_state();
dcd_ep_read(device->dcd, eps->ep_out, eps->ep_out->buffer,
eps->ep_out->ep_desc->wMaxPacketSize);
@ -388,6 +415,8 @@ static rt_err_t _class_stop(udevice_t device, uclass_t cls)
RT_DEBUG_LOG(RT_DEBUG_USB, ("cdc class stop\n"));
_vcom_reset_state();
return RT_EOK;
}
@ -408,7 +437,9 @@ static rt_err_t _class_sof_handler(udevice_t device, uclass_t cls)
return -RT_ERROR;
if (vcom_in_sending)
{
return RT_EOK;
}
eps = (cdc_eps_t)cls->eps;
@ -559,10 +590,12 @@ static rt_err_t _vcom_control(struct rt_serial_device *serial,
static int _vcom_putc(struct rt_serial_device *serial, char c)
{
rt_uint32_t level;
int cnt = 500;
int cnt;
if (vcom_connected != RT_TRUE)
{
return 0;
}
/* if the buffer is full, there is a chance that the host would pull some
* data out soon. But we cannot rely on that and if we wait to long, just
@ -571,12 +604,18 @@ static int _vcom_putc(struct rt_serial_device *serial, char c)
RT_RINGBUFFER_EMPTY(&tx_ringbuffer) == 0 && cnt;
cnt--)
{
rt_kprintf("wait for %d\n", cnt);
/*rt_kprintf("wait for %d\n", cnt);*/
if (vcom_connected != RT_TRUE)
return 0;
}
if (cnt == 0)
{
/* OK, we believe that the connection is lost. So don't send any more
* data and act as the USB cable is not plugged in. Reset the VCOM
* state machine */
_vcom_reset_state();
return 0;
}
level = rt_hw_interrupt_disable();
if (RT_RINGBUFFER_EMPTY(&tx_ringbuffer))