// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* Driver for the NXP SAA7164 PCIe bridge
|
*
|
* Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
|
*/
|
|
#include "saa7164.h"
|
|
/* The message bus to/from the firmware is a ring buffer in PCI address
|
* space. Establish the defaults.
|
*/
|
int saa7164_bus_setup(struct saa7164_dev *dev)
|
{
|
struct tmComResBusInfo *b = &dev->bus;
|
|
mutex_init(&b->lock);
|
|
b->Type = TYPE_BUS_PCIe;
|
b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE;
|
|
b->m_pdwSetRing = (u8 __iomem *)(dev->bmmio +
|
((u32)dev->busdesc.CommandRing));
|
|
b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
|
|
b->m_pdwGetRing = (u8 __iomem *)(dev->bmmio +
|
((u32)dev->busdesc.ResponseRing));
|
|
b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
|
|
b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) +
|
(2 * sizeof(u64));
|
b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
|
|
b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
|
b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
|
|
return 0;
|
}
|
|
void saa7164_bus_dump(struct saa7164_dev *dev)
|
{
|
struct tmComResBusInfo *b = &dev->bus;
|
|
dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
|
dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
|
dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
|
dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
|
dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
|
dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
|
dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
|
dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
|
|
dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
|
b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
|
|
dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
|
b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
|
|
dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
|
b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
|
|
dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
|
b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
|
|
}
|
|
/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
|
static void saa7164_bus_verify(struct saa7164_dev *dev)
|
{
|
struct tmComResBusInfo *b = &dev->bus;
|
int bug = 0;
|
|
if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
|
bug++;
|
|
if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
|
bug++;
|
|
if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
|
bug++;
|
|
if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
|
bug++;
|
|
if (bug) {
|
saa_debug = 0xffff; /* Ensure we get the bus dump */
|
saa7164_bus_dump(dev);
|
saa_debug = 1024; /* Ensure we get the bus dump */
|
BUG();
|
}
|
}
|
|
static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m,
|
void *buf)
|
{
|
dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
|
dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
|
dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
|
dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
|
dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
|
dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
|
dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
|
if (buf)
|
dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
|
}
|
|
/*
|
* Places a command or a response on the bus. The implementation does not
|
* know if it is a command or a response it just places the data on the
|
* bus depending on the bus information given in the struct tmComResBusInfo
|
* structure. If the command or response does not fit into the bus ring
|
* buffer it will be refused.
|
*
|
* Return Value:
|
* SAA_OK The function executed successfully.
|
* < 0 One or more members are not initialized.
|
*/
|
int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
|
void *buf)
|
{
|
struct tmComResBusInfo *bus = &dev->bus;
|
u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
|
u32 new_swp, space_rem;
|
int ret = SAA_ERR_BAD_PARAMETER;
|
u16 size;
|
|
if (!msg) {
|
printk(KERN_ERR "%s() !msg\n", __func__);
|
return SAA_ERR_BAD_PARAMETER;
|
}
|
|
dprintk(DBGLVL_BUS, "%s()\n", __func__);
|
|
saa7164_bus_verify(dev);
|
|
if (msg->size > dev->bus.m_wMaxReqSize) {
|
printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
|
__func__);
|
return SAA_ERR_BAD_PARAMETER;
|
}
|
|
if ((msg->size > 0) && (buf == NULL)) {
|
printk(KERN_ERR "%s() Missing message buffer\n", __func__);
|
return SAA_ERR_BAD_PARAMETER;
|
}
|
|
/* Lock the bus from any other access */
|
mutex_lock(&bus->lock);
|
|
bytes_to_write = sizeof(*msg) + msg->size;
|
free_write_space = 0;
|
timeout = SAA_BUS_TIMEOUT;
|
curr_srp = saa7164_readl(bus->m_dwSetReadPos);
|
curr_swp = saa7164_readl(bus->m_dwSetWritePos);
|
|
/* Deal with ring wrapping issues */
|
if (curr_srp > curr_swp)
|
/* Deal with the wrapped ring */
|
free_write_space = curr_srp - curr_swp;
|
else
|
/* The ring has not wrapped yet */
|
free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
|
|
dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
|
bytes_to_write);
|
|
dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
|
free_write_space);
|
|
dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
|
dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
|
|
/* Process the msg and write the content onto the bus */
|
while (bytes_to_write >= free_write_space) {
|
|
if (timeout-- == 0) {
|
printk(KERN_ERR "%s() bus timeout\n", __func__);
|
ret = SAA_ERR_NO_RESOURCES;
|
goto out;
|
}
|
|
/* TODO: Review this delay, efficient? */
|
/* Wait, allowing the hardware fetch time */
|
mdelay(1);
|
|
/* Check the space usage again */
|
curr_srp = saa7164_readl(bus->m_dwSetReadPos);
|
|
/* Deal with ring wrapping issues */
|
if (curr_srp > curr_swp)
|
/* Deal with the wrapped ring */
|
free_write_space = curr_srp - curr_swp;
|
else
|
/* Read didn't wrap around the buffer */
|
free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
|
curr_swp;
|
|
}
|
|
/* Calculate the new write position */
|
new_swp = curr_swp + bytes_to_write;
|
|
dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
|
dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
|
bus->m_dwSizeSetRing);
|
|
/*
|
* Make a copy of msg->size before it is converted to le16 since it is
|
* used in the code below.
|
*/
|
size = msg->size;
|
/* Convert to le16/le32 */
|
msg->size = (__force u16)cpu_to_le16(msg->size);
|
msg->command = (__force u32)cpu_to_le32(msg->command);
|
msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector);
|
|
/* Mental Note: line 462 tmmhComResBusPCIe.cpp */
|
|
/* Check if we're going to wrap again */
|
if (new_swp > bus->m_dwSizeSetRing) {
|
|
/* Ring wraps */
|
new_swp -= bus->m_dwSizeSetRing;
|
|
space_rem = bus->m_dwSizeSetRing - curr_swp;
|
|
dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
|
space_rem);
|
|
dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
|
(u32)sizeof(*msg));
|
|
if (space_rem < sizeof(*msg)) {
|
dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
|
|
/* Split the msg into pieces as the ring wraps */
|
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem);
|
memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem,
|
sizeof(*msg) - space_rem);
|
|
memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
|
buf, size);
|
|
} else if (space_rem == sizeof(*msg)) {
|
dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
|
|
/* Additional data at the beginning of the ring */
|
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
|
memcpy_toio(bus->m_pdwSetRing, buf, size);
|
|
} else {
|
/* Additional data wraps around the ring */
|
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
|
if (size > 0) {
|
memcpy_toio(bus->m_pdwSetRing + curr_swp +
|
sizeof(*msg), buf, space_rem -
|
sizeof(*msg));
|
memcpy_toio(bus->m_pdwSetRing, (u8 *)buf +
|
space_rem - sizeof(*msg),
|
bytes_to_write - space_rem);
|
}
|
|
}
|
|
} /* (new_swp > bus->m_dwSizeSetRing) */
|
else {
|
dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
|
|
/* The ring buffer doesn't wrap, two simple copies */
|
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
|
memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
|
size);
|
}
|
|
dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
|
|
/* Update the bus write position */
|
saa7164_writel(bus->m_dwSetWritePos, new_swp);
|
|
/* Convert back to cpu after writing the msg to the ringbuffer. */
|
msg->size = le16_to_cpu((__force __le16)msg->size);
|
msg->command = le32_to_cpu((__force __le32)msg->command);
|
msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector);
|
ret = SAA_OK;
|
|
out:
|
saa7164_bus_dump(dev);
|
mutex_unlock(&bus->lock);
|
saa7164_bus_verify(dev);
|
return ret;
|
}
|
|
/*
|
* Receive a command or a response from the bus. The implementation does not
|
* know if it is a command or a response it simply dequeues the data,
|
* depending on the bus information given in the struct tmComResBusInfo
|
* structure.
|
*
|
* Return Value:
|
* 0 The function executed successfully.
|
* < 0 One or more members are not initialized.
|
*/
|
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);
|
|
/* 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 = saa7164_readl(bus->m_dwGetWritePos);
|
curr_grp = saa7164_readl(bus->m_dwGetReadPos);
|
|
if (curr_gwp == curr_grp) {
|
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_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
|
memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
|
bytes_to_read - space_rem);
|
|
} else {
|
/* No wrapping */
|
memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
|
}
|
/* Convert from little endian to CPU */
|
msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size);
|
msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command);
|
msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector);
|
memcpy(msg, &msg_tmp, sizeof(*msg));
|
|
/* No need to update the read positions, because this was a peek */
|
/* If the caller specifically want to peek, return */
|
if (peekonly) {
|
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, NULL);
|
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)) {
|
if (buf)
|
memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) -
|
space_rem, buf_size);
|
|
} else if (space_rem == sizeof(*msg)) {
|
if (buf)
|
memcpy_fromio(buf, bus->m_pdwGetRing, buf_size);
|
} else {
|
/* Additional data wraps around the ring */
|
if (buf) {
|
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp +
|
sizeof(*msg), space_rem - sizeof(*msg));
|
memcpy_fromio(buf + space_rem - sizeof(*msg),
|
bus->m_pdwGetRing, bytes_to_read -
|
space_rem);
|
}
|
|
}
|
|
} else {
|
/* No wrapping */
|
if (buf)
|
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
|
buf_size);
|
}
|
|
/* Update the read positions, adjusting the ring */
|
saa7164_writel(bus->m_dwGetReadPos, new_grp);
|
|
peekout:
|
ret = SAA_OK;
|
out:
|
mutex_unlock(&bus->lock);
|
saa7164_bus_verify(dev);
|
return ret;
|
}
|
