1 files changed, 467 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 000000000..16739895a
--- /dev/null
+++ b/drivers/media/pci/saa7164/saa7164-bus.c
@@ -0,0 +1,467 @@
+// 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;
+}
+