int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
int peekonly)
{
tmComResBusInfo_t *bus = &dev->bus;
u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
new_grp, buf_size, space_rem;
tmComResInfo_t msg_tmp;
int ret = SAA_ERR_BAD_PARAMETER;
if (msg == 0)
return ret;
if (msg->size > dev->bus.m_wMaxReqSize) {
printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
__func__);
return ret;
}
if ((peekonly == 0) && (msg->size > 0) && (buf == 0)) {
printk(KERN_ERR
"%s() Missing msg buf, size should be %d bytes\n",
__func__, msg->size);
return ret;
}
mutex_lock(&bus->lock);
/* Peek the bus to see if a msg exists, if it's not what we're expecting
* then return cleanly else read the message from the bus.
*/
curr_gwp = le32_to_cpu(*bus->m_pdwGetWritePos);
curr_grp = le32_to_cpu(*bus->m_pdwGetReadPos);
if (curr_gwp == curr_grp) {
dprintk(DBGLVL_BUS, "%s() No message on the bus\n", __func__);
ret = SAA_ERR_EMPTY;
goto out;
}
bytes_to_read = sizeof(*msg);
/* Calculate write distance to current read position */
write_distance = 0;
if (curr_gwp >= curr_grp)
/* Write doesn't wrap around the ring */
write_distance = curr_gwp - curr_grp;
else
/* Write wraps around the ring */
write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
if (bytes_to_read > write_distance) {
printk(KERN_ERR "%s() No message/response found\n", __func__);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
/* Calculate the new read position */
new_grp = curr_grp + bytes_to_read;
if (new_grp > bus->m_dwSizeGetRing) {
/* Ring wraps */
new_grp -= bus->m_dwSizeGetRing;
space_rem = bus->m_dwSizeGetRing - curr_grp;
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
bytes_to_read - space_rem);
} else {
/* No wrapping */
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
}
/* No need to update the read positions, because this was a peek */
/* If the caller specifically want to peek, return */
if (peekonly) {
memcpy(msg, &msg_tmp, sizeof(*msg));
goto peekout;
}
/* Check if the command/response matches what is expected */
if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
(msg_tmp.controlselector != msg->controlselector) ||
(msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {
printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
saa7164_bus_dumpmsg(dev, msg, buf);
saa7164_bus_dumpmsg(dev, &msg_tmp, 0);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
/* Get the actual command and response from the bus */
buf_size = msg->size;
bytes_to_read = sizeof(*msg) + msg->size;
/* Calculate write distance to current read position */
write_distance = 0;
if (curr_gwp >= curr_grp)
/* Write doesn't wrap around the ring */
write_distance = curr_gwp - curr_grp;
else
/* Write wraps around the ring */
write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
if (bytes_to_read > write_distance) {
printk(KERN_ERR "%s() Invalid bus state, missing msg "
"or mangled ring, faulty H/W / bad code?\n", __func__);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
/* Calculate the new read position */
new_grp = curr_grp + bytes_to_read;
if (new_grp > bus->m_dwSizeGetRing) {
/* Ring wraps */
new_grp -= bus->m_dwSizeGetRing;
space_rem = bus->m_dwSizeGetRing - curr_grp;
if (space_rem < sizeof(*msg)) {
/* msg wraps around the ring */
memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
sizeof(*msg) - space_rem);
if (buf)
memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
space_rem, buf_size);
} else if (space_rem == sizeof(*msg)) {
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy(buf, bus->m_pdwGetRing, buf_size);
} else {
/* Additional data wraps around the ring */
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf) {
memcpy(buf, bus->m_pdwGetRing + curr_grp +
sizeof(*msg), space_rem - sizeof(*msg));
memcpy(buf + space_rem - sizeof(*msg),
bus->m_pdwGetRing, bytes_to_read -
space_rem);
}
}
} else {
/* No wrapping */
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
buf_size);
}
/* Update the read positions, adjusting the ring */
*bus->m_pdwGetReadPos = cpu_to_le32(new_grp);
peekout:
msg->size = le16_to_cpu(msg->size);
msg->command = le16_to_cpu(msg->command);
msg->controlselector = le16_to_cpu(msg->controlselector);
ret = SAA_OK;
out:
mutex_unlock(&bus->lock);
return ret;
}
int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
void *buf, int peekonly)
{
struct tmComResBusInfo *bus = &dev->bus;
u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
new_grp, buf_size, space_rem;
struct tmComResInfo msg_tmp;
int ret = SAA_ERR_BAD_PARAMETER;
saa7164_bus_verify(dev);
if (msg == NULL)
return ret;
if (msg->size > dev->bus.m_wMaxReqSize) {
printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
__func__);
return ret;
}
if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
printk(KERN_ERR
"%s() Missing msg buf, size should be %d bytes\n",
__func__, msg->size);
return ret;
}
mutex_lock(&bus->lock);
curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));
if (curr_gwp == curr_grp) {
ret = SAA_ERR_EMPTY;
goto out;
}
bytes_to_read = sizeof(*msg);
write_distance = 0;
if (curr_gwp >= curr_grp)
write_distance = curr_gwp - curr_grp;
else
write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
if (bytes_to_read > write_distance) {
printk(KERN_ERR "%s() No message/response found\n", __func__);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
new_grp = curr_grp + bytes_to_read;
if (new_grp > bus->m_dwSizeGetRing) {
new_grp -= bus->m_dwSizeGetRing;
space_rem = bus->m_dwSizeGetRing - curr_grp;
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
bytes_to_read - space_rem);
} else {
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
}
if (peekonly) {
memcpy(msg, &msg_tmp, sizeof(*msg));
goto peekout;
}
if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
(msg_tmp.controlselector != msg->controlselector) ||
(msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {
printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
saa7164_bus_dumpmsg(dev, msg, buf);
saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
buf_size = msg->size;
bytes_to_read = sizeof(*msg) + msg->size;
write_distance = 0;
if (curr_gwp >= curr_grp)
write_distance = curr_gwp - curr_grp;
else
write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
if (bytes_to_read > write_distance) {
printk(KERN_ERR "%s() Invalid bus state, missing msg "
"or mangled ring, faulty H/W / bad code?\n", __func__);
ret = SAA_ERR_INVALID_COMMAND;
goto out;
}
new_grp = curr_grp + bytes_to_read;
if (new_grp > bus->m_dwSizeGetRing) {
new_grp -= bus->m_dwSizeGetRing;
space_rem = bus->m_dwSizeGetRing - curr_grp;
if (space_rem < sizeof(*msg)) {
memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
sizeof(*msg) - space_rem);
if (buf)
memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
space_rem, buf_size);
} else if (space_rem == sizeof(*msg)) {
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy(buf, bus->m_pdwGetRing, buf_size);
} else {
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf) {
memcpy(buf, bus->m_pdwGetRing + curr_grp +
sizeof(*msg), space_rem - sizeof(*msg));
memcpy(buf + space_rem - sizeof(*msg),
bus->m_pdwGetRing, bytes_to_read -
space_rem);
}
}
} else {
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
buf_size);
}
saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));
peekout:
msg->size = le16_to_cpu(msg->size);
msg->command = le32_to_cpu(msg->command);
msg->controlselector = le16_to_cpu(msg->controlselector);
ret = SAA_OK;
out:
mutex_unlock(&bus->lock);
saa7164_bus_verify(dev);
return ret;
}
