[linux-2.6-block.git] / drivers / media / pci / saa7164 / saa7164-bus.c

/*
 *  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;
}
Commit	Line	Data
443c1228 ST	1	/*
	2	* Driver for the NXP SAA7164 PCIe bridge
	3	*
9b8b0199	4	* Copyright (c) 2010 Steven Toth <stoth@kernellabs.com>
443c1228 ST	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	*
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	20	*/
	21
	22	#include "saa7164.h"
	23
	24	/* The message bus to/from the firmware is a ring buffer in PCI address
	25	* space. Establish the defaults.
	26	*/
	27	int saa7164_bus_setup(struct saa7164_dev *dev)
	28	{
4d270cfb	29	struct tmComResBusInfo *b = &dev->bus;
443c1228 ST	30
	31	mutex_init(&b->lock);
	32
	33	b->Type = TYPE_BUS_PCIe;
	34	b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE;
	35
	36	b->m_pdwSetRing = (u8 *)(dev->bmmio +
	37	((u32)dev->busdesc.CommandRing));
	38
	39	b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
	40
	41	b->m_pdwGetRing = (u8 *)(dev->bmmio +
	42	((u32)dev->busdesc.ResponseRing));
	43
	44	b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
	45
bc250684 ST	46	b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) +
bc250684 ST	47	(2 * sizeof(u64));
60665829	48	b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
443c1228	49
60665829 ST	50	b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
60665829 ST	51	b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
443c1228 ST	52
	53	return 0;
	54	}
	55
	56	void saa7164_bus_dump(struct saa7164_dev *dev)
	57	{
4d270cfb	58	struct tmComResBusInfo *b = &dev->bus;
443c1228 ST	59
	60	dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
	61	dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
	62	dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
	63	dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
	64	dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
	65	dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
	66	dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
	67	dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
	68
60665829 ST	69	dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
	70	b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
	71
	72	dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
	73	b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
443c1228	74
60665829 ST	75	dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
60665829 ST	76	b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
443c1228	77
60665829 ST	78	dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
60665829 ST	79	b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
443c1228	80
60665829 ST	81	}
	82
	83	/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
5faf7db8	84	static void saa7164_bus_verify(struct saa7164_dev *dev)
60665829	85	{
4d270cfb	86	struct tmComResBusInfo *b = &dev->bus;
99b73d38	87	int bug = 0;
60665829 ST	88
	89	if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
	90	bug++;
	91
	92	if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
	93	bug++;
	94
	95	if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
	96	bug++;
	97
	98	if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
	99	bug++;
	100
	101	if (bug) {
99b73d38	102	saa_debug = 0xffff; /* Ensure we get the bus dump */
60665829	103	saa7164_bus_dump(dev);
99b73d38	104	saa_debug = 1024; /* Ensure we get the bus dump */
60665829 ST	105	BUG();
60665829 ST	106	}
443c1228 ST	107	}
443c1228 ST	108
5faf7db8 MCC	109	static void saa7164_bus_dumpmsg(struct saa7164_dev dev, struct tmComResInfo m,
5faf7db8 MCC	110	void *buf)
443c1228 ST	111	{
	112	dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
	113	dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
	114	dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
	115	dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
	116	dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
	117	dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
	118	dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
	119	if (buf)
	120	dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
	121	}
	122
	123	/*
	124	* Places a command or a response on the bus. The implementation does not
	125	* know if it is a command or a response it just places the data on the
4d270cfb	126	* bus depending on the bus information given in the struct tmComResBusInfo
443c1228 ST	127	* structure. If the command or response does not fit into the bus ring
	128	* buffer it will be refused.
	129	*
	130	* Return Value:
	131	* SAA_OK The function executed successfully.
	132	* < 0 One or more members are not initialized.
	133	*/
bc250684 ST	134	int saa7164_bus_set(struct saa7164_dev dev, struct tmComResInfo msg,
bc250684 ST	135	void *buf)
443c1228	136	{
4d270cfb	137	struct tmComResBusInfo *bus = &dev->bus;
60665829	138	u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
443c1228 ST	139	u32 new_swp, space_rem;
	140	int ret = SAA_ERR_BAD_PARAMETER;
	141
	142	if (!msg) {
	143	printk(KERN_ERR "%s() !msg\n", __func__);
	144	return SAA_ERR_BAD_PARAMETER;
	145	}
	146
	147	dprintk(DBGLVL_BUS, "%s()\n", __func__);
2e732d64	148
60665829	149	saa7164_bus_verify(dev);
443c1228 ST	150
443c1228 ST	151	msg->size = cpu_to_le16(msg->size);
773ddbd2	152	msg->command = cpu_to_le32(msg->command);
443c1228 ST	153	msg->controlselector = cpu_to_le16(msg->controlselector);
	154
	155	if (msg->size > dev->bus.m_wMaxReqSize) {
	156	printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
	157	__func__);
	158	return SAA_ERR_BAD_PARAMETER;
	159	}
	160
61ca1500	161	if ((msg->size > 0) && (buf == NULL)) {
443c1228 ST	162	printk(KERN_ERR "%s() Missing message buffer\n", __func__);
	163	return SAA_ERR_BAD_PARAMETER;
	164	}
	165
	166	/* Lock the bus from any other access */
	167	mutex_lock(&bus->lock);
	168
	169	bytes_to_write = sizeof(*msg) + msg->size;
60665829	170	free_write_space = 0;
443c1228	171	timeout = SAA_BUS_TIMEOUT;
60665829 ST	172	curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
60665829 ST	173	curr_swp = le32_to_cpu(saa7164_readl(bus->m_dwSetWritePos));
443c1228 ST	174
	175	/* Deal with ring wrapping issues */
	176	if (curr_srp > curr_swp)
443c1228	177	/* Deal with the wrapped ring */
60665829 ST	178	free_write_space = curr_srp - curr_swp;
	179	else
	180	/* The ring has not wrapped yet */
	181	free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
443c1228 ST	182
	183	dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
	184	bytes_to_write);
	185
60665829 ST	186	dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
60665829 ST	187	free_write_space);
443c1228 ST	188
	189	dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
	190	dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
	191
	192	/* Process the msg and write the content onto the bus */
60665829	193	while (bytes_to_write >= free_write_space) {
443c1228 ST	194
	195	if (timeout-- == 0) {
	196	printk(KERN_ERR "%s() bus timeout\n", __func__);
	197	ret = SAA_ERR_NO_RESOURCES;
	198	goto out;
	199	}
	200
	201	/* TODO: Review this delay, efficient? */
	202	/* Wait, allowing the hardware fetch time */
	203	mdelay(1);
	204
	205	/* Check the space usage again */
60665829	206	curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
443c1228 ST	207
	208	/* Deal with ring wrapping issues */
	209	if (curr_srp > curr_swp)
443c1228	210	/* Deal with the wrapped ring */
60665829 ST	211	free_write_space = curr_srp - curr_swp;
	212	else
	213	/* Read didn't wrap around the buffer */
	214	free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
443c1228 ST	215	curr_swp;
	216
	217	}
	218
	219	/* Calculate the new write position */
	220	new_swp = curr_swp + bytes_to_write;
	221
	222	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
	223	dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
	224	bus->m_dwSizeSetRing);
	225
	226	/* Mental Note: line 462 tmmhComResBusPCIe.cpp */
	227
	228	/* Check if we're going to wrap again */
	229	if (new_swp > bus->m_dwSizeSetRing) {
	230
	231	/* Ring wraps */
	232	new_swp -= bus->m_dwSizeSetRing;
	233
	234	space_rem = bus->m_dwSizeSetRing - curr_swp;
	235
	236	dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
	237	space_rem);
	238
207b42c4 ST	239	dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
207b42c4 ST	240	(u32)sizeof(*msg));
443c1228 ST	241
	242	if (space_rem < sizeof(*msg)) {
	243	dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
	244
	245	/* Split the msg into pieces as the ring wraps */
60665829 ST	246	memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem);
60665829 ST	247	memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
443c1228 ST	248	sizeof(*msg) - space_rem);
443c1228 ST	249
60665829	250	memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
443c1228 ST	251	buf, msg->size);
	252
	253	} else if (space_rem == sizeof(*msg)) {
	254	dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
	255
	256	/* Additional data at the beginning of the ring */
60665829 ST	257	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
60665829 ST	258	memcpy(bus->m_pdwSetRing, buf, msg->size);
443c1228 ST	259
	260	} else {
	261	/* Additional data wraps around the ring */
60665829	262	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
443c1228	263	if (msg->size > 0) {
60665829	264	memcpy(bus->m_pdwSetRing + curr_swp +
443c1228 ST	265	sizeof(*msg), buf, space_rem -
443c1228 ST	266	sizeof(*msg));
60665829	267	memcpy(bus->m_pdwSetRing, (u8 *)buf +
443c1228 ST	268	space_rem - sizeof(*msg),
	269	bytes_to_write - space_rem);
	270	}
	271
	272	}
	273
	274	} /* (new_swp > bus->m_dwSizeSetRing) */
	275	else {
	276	dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
	277
	278	/* The ring buffer doesn't wrap, two simple copies */
60665829 ST	279	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
60665829 ST	280	memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
443c1228 ST	281	msg->size);
	282	}
	283
	284	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
	285
443c1228	286	/* Update the bus write position */
60665829	287	saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
443c1228 ST	288	ret = SAA_OK;
	289
	290	out:
60665829	291	saa7164_bus_dump(dev);
443c1228	292	mutex_unlock(&bus->lock);
60665829	293	saa7164_bus_verify(dev);
443c1228 ST	294	return ret;
	295	}
	296
	297	/*
	298	* Receive a command or a response from the bus. The implementation does not
	299	* know if it is a command or a response it simply dequeues the data,
bc250684 ST	300	* depending on the bus information given in the struct tmComResBusInfo
bc250684 ST	301	* structure.
443c1228 ST	302	*
	303	* Return Value:
	304	* 0 The function executed successfully.
	305	* < 0 One or more members are not initialized.
	306	*/
bc250684 ST	307	int saa7164_bus_get(struct saa7164_dev dev, struct tmComResInfo msg,
bc250684 ST	308	void *buf, int peekonly)
443c1228	309	{
4d270cfb	310	struct tmComResBusInfo *bus = &dev->bus;
443c1228 ST	311	u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
443c1228 ST	312	new_grp, buf_size, space_rem;
4d270cfb	313	struct tmComResInfo msg_tmp;
443c1228 ST	314	int ret = SAA_ERR_BAD_PARAMETER;
443c1228 ST	315
60665829	316	saa7164_bus_verify(dev);
2e732d64	317
61ca1500	318	if (msg == NULL)
443c1228 ST	319	return ret;
	320
	321	if (msg->size > dev->bus.m_wMaxReqSize) {
	322	printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
	323	__func__);
	324	return ret;
	325	}
	326
61ca1500	327	if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
443c1228 ST	328	printk(KERN_ERR
	329	"%s() Missing msg buf, size should be %d bytes\n",
	330	__func__, msg->size);
	331	return ret;
	332	}
	333
	334	mutex_lock(&bus->lock);
	335
	336	/* Peek the bus to see if a msg exists, if it's not what we're expecting
	337	* then return cleanly else read the message from the bus.
	338	*/
60665829 ST	339	curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
60665829 ST	340	curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));
443c1228 ST	341
443c1228 ST	342	if (curr_gwp == curr_grp) {
443c1228 ST	343	ret = SAA_ERR_EMPTY;
	344	goto out;
	345	}
	346
	347	bytes_to_read = sizeof(*msg);
	348
	349	/* Calculate write distance to current read position */
	350	write_distance = 0;
	351	if (curr_gwp >= curr_grp)
	352	/* Write doesn't wrap around the ring */
	353	write_distance = curr_gwp - curr_grp;
	354	else
	355	/* Write wraps around the ring */
	356	write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
	357
	358	if (bytes_to_read > write_distance) {
	359	printk(KERN_ERR "%s() No message/response found\n", __func__);
	360	ret = SAA_ERR_INVALID_COMMAND;
	361	goto out;
	362	}
	363
	364	/* Calculate the new read position */
	365	new_grp = curr_grp + bytes_to_read;
	366	if (new_grp > bus->m_dwSizeGetRing) {
	367
	368	/* Ring wraps */
	369	new_grp -= bus->m_dwSizeGetRing;
	370	space_rem = bus->m_dwSizeGetRing - curr_grp;
	371
60665829 ST	372	memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
60665829 ST	373	memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
443c1228 ST	374	bytes_to_read - space_rem);
	375
	376	} else {
	377	/* No wrapping */
60665829	378	memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
443c1228 ST	379	}
	380
	381	/* No need to update the read positions, because this was a peek */
	382	/* If the caller specifically want to peek, return */
	383	if (peekonly) {
60665829	384	memcpy(msg, &msg_tmp, sizeof(*msg));
443c1228 ST	385	goto peekout;
	386	}
	387
	388	/* Check if the command/response matches what is expected */
	389	if ((msg_tmp.id != msg->id) \|\| (msg_tmp.command != msg->command) \|\|
	390	(msg_tmp.controlselector != msg->controlselector) \|\|
	391	(msg_tmp.seqno != msg->seqno) \|\| (msg_tmp.size != msg->size)) {
	392
	393	printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
	394	saa7164_bus_dumpmsg(dev, msg, buf);
61ca1500	395	saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
443c1228 ST	396	ret = SAA_ERR_INVALID_COMMAND;
	397	goto out;
	398	}
	399
	400	/* Get the actual command and response from the bus */
	401	buf_size = msg->size;
	402
	403	bytes_to_read = sizeof(*msg) + msg->size;
	404	/* Calculate write distance to current read position */
	405	write_distance = 0;
	406	if (curr_gwp >= curr_grp)
	407	/* Write doesn't wrap around the ring */
	408	write_distance = curr_gwp - curr_grp;
	409	else
	410	/* Write wraps around the ring */
	411	write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
	412
	413	if (bytes_to_read > write_distance) {
	414	printk(KERN_ERR "%s() Invalid bus state, missing msg "
	415	"or mangled ring, faulty H/W / bad code?\n", __func__);
	416	ret = SAA_ERR_INVALID_COMMAND;
	417	goto out;
	418	}
	419
	420	/* Calculate the new read position */
	421	new_grp = curr_grp + bytes_to_read;
	422	if (new_grp > bus->m_dwSizeGetRing) {
	423
	424	/* Ring wraps */
	425	new_grp -= bus->m_dwSizeGetRing;
	426	space_rem = bus->m_dwSizeGetRing - curr_grp;
	427
	428	if (space_rem < sizeof(*msg)) {
	429	/* msg wraps around the ring */
60665829 ST	430	memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
60665829 ST	431	memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
443c1228 ST	432	sizeof(*msg) - space_rem);
443c1228 ST	433	if (buf)
60665829	434	memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
443c1228 ST	435	space_rem, buf_size);
	436
	437	} else if (space_rem == sizeof(*msg)) {
60665829	438	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228 ST	439	if (buf)
	440	memcpy(buf, bus->m_pdwGetRing, buf_size);
	441	} else {
	442	/* Additional data wraps around the ring */
60665829	443	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228	444	if (buf) {
60665829	445	memcpy(buf, bus->m_pdwGetRing + curr_grp +
443c1228	446	sizeof(msg), space_rem - sizeof(msg));
60665829	447	memcpy(buf + space_rem - sizeof(*msg),
443c1228 ST	448	bus->m_pdwGetRing, bytes_to_read -
	449	space_rem);
	450	}
	451
	452	}
	453
	454	} else {
	455	/* No wrapping */
60665829	456	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228	457	if (buf)
60665829	458	memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
443c1228 ST	459	buf_size);
	460	}
	461
	462	/* Update the read positions, adjusting the ring */
60665829	463	saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));
443c1228 ST	464
	465	peekout:
	466	msg->size = le16_to_cpu(msg->size);
773ddbd2	467	msg->command = le32_to_cpu(msg->command);
443c1228 ST	468	msg->controlselector = le16_to_cpu(msg->controlselector);
	469	ret = SAA_OK;
	470	out:
	471	mutex_unlock(&bus->lock);
60665829	472	saa7164_bus_verify(dev);
443c1228 ST	473	return ret;
	474	}
	475