/*
* Driver for the NXP SAA7164 PCIe bridge
*
* Copyright (c) 2010 Steven Toth <stoth@kernellabs.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
*
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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 *)(dev->bmmio +
((u32)dev->busdesc.CommandRing));
b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
b->m_pdwGetRing = (u8 *)(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;
if (!msg) {
printk(KERN_ERR "%s() !msg\n", __func__);
return SAA_ERR_BAD_PARAMETER;
}
dprintk(DBGLVL_BUS, "%s()\n", __func__);
saa7164_bus_verify(dev);
msg->size = cpu_to_le16(msg->size);
msg->command = cpu_to_le32(msg->command);
msg->controlselector = cpu_to_le16(msg->controlselector);
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 = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
curr_swp = le32_to_cpu(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 = le32_to_cpu(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);
/* 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(bus->m_pdwSetRing + curr_swp, msg, space_rem);
memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
sizeof(*msg) - space_rem);
memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
buf, msg->size);
} else if (space_rem == sizeof(*msg)) {
dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
/* Additional data at the beginning of the ring */
memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy(bus->m_pdwSetRing, buf, msg->size);
} else {
/* Additional data wraps around the ring */
memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
if (msg->size > 0) {
memcpy(bus->m_pdwSetRing + curr_swp +
sizeof(*msg), buf, space_rem -
sizeof(*msg));
memcpy(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(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
msg->size);
}
dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
/* Update the bus write position */
saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
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 = 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);
/* 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, 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)) {
/* 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 */
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;
}