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path: root/drivers/media/pci/saa7164/saa7164-bus.c
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Diffstat (limited to 'drivers/media/pci/saa7164/saa7164-bus.c')
-rw-r--r--drivers/media/pci/saa7164/saa7164-bus.c475
1 files changed, 475 insertions, 0 deletions
diff --git a/drivers/media/pci/saa7164/saa7164-bus.c b/drivers/media/pci/saa7164/saa7164-bus.c
new file mode 100644
index 000000000000..a7f58a998752
--- /dev/null
+++ b/drivers/media/pci/saa7164/saa7164-bus.c
@@ -0,0 +1,475 @@
+/*
+ * 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 */
+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();
+ }
+}
+
+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;
+}
+