/**
* hdm_add_padding - add padding bytes
* @mdev: most device
* @channel: channel ID
* @mbo: buffer object
*
* This inserts the INIC hardware specific padding bytes into a streaming
* channel's buffer
*/
static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
{
struct most_channel_config *conf = &mdev->conf[channel];
unsigned int frame_size = get_stream_frame_size(conf);
unsigned int j, num_frames;
u16 rd_addr, wr_addr;
if (!frame_size)
return -EIO;
num_frames = mbo->buffer_length / frame_size;
if (num_frames < 1) {
dev_err(&mdev->usb_device->dev,
"Missed minimal transfer unit.\n");
return -EIO;
}
for (j = 1; j < num_frames; j++) {
wr_addr = (num_frames - j) * USB_MTU;
rd_addr = (num_frames - j) * frame_size;
memmove(mbo->virt_address + wr_addr,
mbo->virt_address + rd_addr,
frame_size);
}
mbo->buffer_length = num_frames * USB_MTU;
return 0;
}
/**
* hdm_remove_padding - remove padding bytes
* @mdev: most device
* @channel: channel ID
* @mbo: buffer object
*
* This takes the INIC hardware specific padding bytes off a streaming
* channel's buffer.
*/
static int hdm_remove_padding(struct most_dev *mdev, int channel,
struct mbo *mbo)
{
struct most_channel_config *const conf = &mdev->conf[channel];
unsigned int frame_size = get_stream_frame_size(conf);
unsigned int j, num_frames;
if (!frame_size)
return -EIO;
num_frames = mbo->processed_length / USB_MTU;
for (j = 1; j < num_frames; j++)
memmove(mbo->virt_address + frame_size * j,
mbo->virt_address + USB_MTU * j,
frame_size);
mbo->processed_length = frame_size * num_frames;
return 0;
}
/**
* hdm_configure_channel - receive channel configuration from core
* @iface: interface
* @channel: channel ID
* @conf: structure that holds the configuration information
*/
static int hdm_configure_channel(struct most_interface *iface, int channel,
struct most_channel_config *conf)
{
unsigned int num_frames;
unsigned int frame_size;
unsigned int temp_size;
unsigned int tail_space;
struct most_dev *mdev = to_mdev(iface);
struct device *dev = &mdev->usb_device->dev;
mdev->is_channel_healthy[channel] = true;
mdev->clear_work[channel].channel = channel;
mdev->clear_work[channel].mdev = mdev;
INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
if (unlikely(!iface || !conf)) {
dev_err(dev, "Bad interface or config pointer.\n");
return -EINVAL;
}
if (unlikely(channel < 0 || channel >= iface->num_channels)) {
dev_err(dev, "Channel ID out of range.\n");
return -EINVAL;
}
if (!conf->num_buffers || !conf->buffer_size) {
dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
return -EINVAL;
}
if (conf->data_type != MOST_CH_SYNC &&
!(conf->data_type == MOST_CH_ISOC &&
conf->packets_per_xact != 0xFF)) {
mdev->padding_active[channel] = false;
goto exit;
}
mdev->padding_active[channel] = true;
temp_size = conf->buffer_size;
frame_size = get_stream_frame_size(conf);
if (frame_size == 0 || frame_size > USB_MTU) {
dev_warn(dev, "Misconfig: frame size wrong\n");
return -EINVAL;
}
if (conf->buffer_size % frame_size) {
u16 tmp_val;
tmp_val = conf->buffer_size / frame_size;
conf->buffer_size = tmp_val * frame_size;
dev_notice(dev,
"Channel %d - rounding buffer size to %d bytes, channel config says %d bytes\n",
channel,
conf->buffer_size,
temp_size);
}
num_frames = conf->buffer_size / frame_size;
tail_space = num_frames * (USB_MTU - frame_size);
temp_size += tail_space;
/* calculate extra length to comply w/ HW padding */
conf->extra_len = (DIV_ROUND_UP(temp_size, USB_MTU) * USB_MTU)
- conf->buffer_size;
exit:
mdev->conf[channel] = *conf;
return 0;
}
/**
* hdm_configure_channel - receive channel configuration from core
* @iface: interface
* @channel: channel ID
* @conf: structure that holds the configuration information
*
* The attached network interface controller (NIC) supports a padding mode
* to avoid short packets on USB, hence increasing the performance due to a
* lower interrupt load. This mode is default for synchronous data and can
* be switched on for isochronous data. In case padding is active the
* driver needs to know the frame size of the payload in order to calculate
* the number of bytes it needs to pad when transmitting or to cut off when
* receiving data.
*
*/
static int hdm_configure_channel(struct most_interface *iface, int channel,
struct most_channel_config *conf)
{
unsigned int num_frames;
unsigned int frame_size;
struct most_dev *mdev = to_mdev(iface);
struct device *dev = &mdev->usb_device->dev;
mdev->is_channel_healthy[channel] = true;
mdev->clear_work[channel].channel = channel;
mdev->clear_work[channel].mdev = mdev;
INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
if (unlikely(!iface || !conf)) {
dev_err(dev, "Bad interface or config pointer.\n");
return -EINVAL;
}
if (unlikely(channel < 0 || channel >= iface->num_channels)) {
dev_err(dev, "Channel ID out of range.\n");
return -EINVAL;
}
if (!conf->num_buffers || !conf->buffer_size) {
dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
return -EINVAL;
}
if (conf->data_type != MOST_CH_SYNC &&
!(conf->data_type == MOST_CH_ISOC &&
conf->packets_per_xact != 0xFF)) {
mdev->padding_active[channel] = false;
/*
* Since the NIC's padding mode is not going to be
* used, we can skip the frame size calculations and
* move directly on to exit.
*/
goto exit;
}
mdev->padding_active[channel] = true;
frame_size = get_stream_frame_size(conf);
if (frame_size == 0 || frame_size > USB_MTU) {
dev_warn(dev, "Misconfig: frame size wrong\n");
return -EINVAL;
}
num_frames = conf->buffer_size / frame_size;
if (conf->buffer_size % frame_size) {
u16 old_size = conf->buffer_size;
conf->buffer_size = num_frames * frame_size;
dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
mdev->suffix[channel], old_size, conf->buffer_size);
}
/* calculate extra length to comply w/ HW padding */
conf->extra_len = num_frames * (USB_MTU - frame_size);
exit:
mdev->conf[channel] = *conf;
if (conf->data_type == MOST_CH_ASYNC) {
u16 ep = mdev->ep_address[channel];
if (start_sync_ep(mdev->usb_device, ep) < 0)
dev_warn(dev, "sync for ep%02x failed", ep);
}
return 0;
}
