[linux-2.6-block.git] / drivers / media / video / 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)
{
	tmComResBusInfo_t *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)
{
	tmComResBusInfo_t *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)
{
	tmComResBusInfo_t *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, tmComResInfo_t* 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 tmComResBusInfo_t
 * 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, tmComResInfo_t* msg, void *buf)
{
	tmComResBusInfo_t *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_le16(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 == 0)) {
		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 tmComResBusInfo_t structure.
 *
 * Return Value:
 *  0          The function executed successfully.
 *  < 0        One or more members are not initialized.
 */
int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
	int peekonly)
{
	tmComResBusInfo_t *bus = &dev->bus;
	u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
		new_grp, buf_size, space_rem;
	tmComResInfo_t msg_tmp;
	int ret = SAA_ERR_BAD_PARAMETER;

	saa7164_bus_verify(dev);
	if (msg == 0)
		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 == 0)) {
		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, 0);
		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 = le16_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	{
	29	tmComResBusInfo_t *b = &dev->bus;
	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
60665829 ST	46	b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) + (2 * sizeof(u64));
60665829 ST	47	b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
443c1228	48
60665829 ST	49	b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
60665829 ST	50	b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
443c1228 ST	51
	52	return 0;
	53	}
	54
	55	void saa7164_bus_dump(struct saa7164_dev *dev)
	56	{
	57	tmComResBusInfo_t *b = &dev->bus;
	58
	59	dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
	60	dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
	61	dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
	62	dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
	63	dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
	64	dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
	65	dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
	66	dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
	67
60665829 ST	68	dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
	69	b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
	70
	71	dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
	72	b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
443c1228	73
60665829 ST	74	dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
60665829 ST	75	b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
443c1228	76
60665829 ST	77	dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
60665829 ST	78	b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
443c1228	79
60665829 ST	80	}
	81
	82	/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
	83	void saa7164_bus_verify(struct saa7164_dev *dev)
	84	{
	85	tmComResBusInfo_t *b = &dev->bus;
99b73d38	86	int bug = 0;
60665829 ST	87
	88	if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
	89	bug++;
	90
	91	if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
	92	bug++;
	93
	94	if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
	95	bug++;
	96
	97	if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
	98	bug++;
	99
	100	if (bug) {
99b73d38	101	saa_debug = 0xffff; /* Ensure we get the bus dump */
60665829	102	saa7164_bus_dump(dev);
99b73d38	103	saa_debug = 1024; /* Ensure we get the bus dump */
60665829 ST	104	BUG();
60665829 ST	105	}
443c1228 ST	106	}
	107
	108	void saa7164_bus_dumpmsg(struct saa7164_dev dev, tmComResInfo_t m, void *buf)
	109	{
	110	dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
	111	dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
	112	dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
	113	dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
	114	dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
	115	dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
	116	dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
	117	if (buf)
	118	dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
	119	}
	120
	121	/*
	122	* Places a command or a response on the bus. The implementation does not
	123	* know if it is a command or a response it just places the data on the
	124	* bus depending on the bus information given in the tmComResBusInfo_t
	125	* structure. If the command or response does not fit into the bus ring
	126	* buffer it will be refused.
	127	*
	128	* Return Value:
	129	* SAA_OK The function executed successfully.
	130	* < 0 One or more members are not initialized.
	131	*/
	132	int saa7164_bus_set(struct saa7164_dev dev, tmComResInfo_t msg, void *buf)
	133	{
	134	tmComResBusInfo_t *bus = &dev->bus;
60665829	135	u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
443c1228 ST	136	u32 new_swp, space_rem;
	137	int ret = SAA_ERR_BAD_PARAMETER;
	138
	139	if (!msg) {
	140	printk(KERN_ERR "%s() !msg\n", __func__);
	141	return SAA_ERR_BAD_PARAMETER;
	142	}
	143
	144	dprintk(DBGLVL_BUS, "%s()\n", __func__);
60665829	145	saa7164_bus_verify(dev);
443c1228 ST	146
	147	msg->size = cpu_to_le16(msg->size);
	148	msg->command = cpu_to_le16(msg->command);
	149	msg->controlselector = cpu_to_le16(msg->controlselector);
	150
	151	if (msg->size > dev->bus.m_wMaxReqSize) {
	152	printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
	153	__func__);
	154	return SAA_ERR_BAD_PARAMETER;
	155	}
	156
	157	if ((msg->size > 0) && (buf == 0)) {
	158	printk(KERN_ERR "%s() Missing message buffer\n", __func__);
	159	return SAA_ERR_BAD_PARAMETER;
	160	}
	161
	162	/* Lock the bus from any other access */
	163	mutex_lock(&bus->lock);
	164
	165	bytes_to_write = sizeof(*msg) + msg->size;
60665829	166	free_write_space = 0;
443c1228	167	timeout = SAA_BUS_TIMEOUT;
60665829 ST	168	curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
60665829 ST	169	curr_swp = le32_to_cpu(saa7164_readl(bus->m_dwSetWritePos));
443c1228 ST	170
	171	/* Deal with ring wrapping issues */
	172	if (curr_srp > curr_swp)
443c1228	173	/* Deal with the wrapped ring */
60665829 ST	174	free_write_space = curr_srp - curr_swp;
	175	else
	176	/* The ring has not wrapped yet */
	177	free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
443c1228 ST	178
	179	dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
	180	bytes_to_write);
	181
60665829 ST	182	dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
60665829 ST	183	free_write_space);
443c1228 ST	184
	185	dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
	186	dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
	187
	188	/* Process the msg and write the content onto the bus */
60665829	189	while (bytes_to_write >= free_write_space) {
443c1228 ST	190
	191	if (timeout-- == 0) {
	192	printk(KERN_ERR "%s() bus timeout\n", __func__);
	193	ret = SAA_ERR_NO_RESOURCES;
	194	goto out;
	195	}
	196
	197	/* TODO: Review this delay, efficient? */
	198	/* Wait, allowing the hardware fetch time */
	199	mdelay(1);
	200
	201	/* Check the space usage again */
60665829	202	curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
443c1228 ST	203
	204	/* Deal with ring wrapping issues */
	205	if (curr_srp > curr_swp)
443c1228	206	/* Deal with the wrapped ring */
60665829 ST	207	free_write_space = curr_srp - curr_swp;
	208	else
	209	/* Read didn't wrap around the buffer */
	210	free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
443c1228 ST	211	curr_swp;
	212
	213	}
	214
	215	/* Calculate the new write position */
	216	new_swp = curr_swp + bytes_to_write;
	217
	218	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
	219	dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
	220	bus->m_dwSizeSetRing);
	221
	222	/* Mental Note: line 462 tmmhComResBusPCIe.cpp */
	223
	224	/* Check if we're going to wrap again */
	225	if (new_swp > bus->m_dwSizeSetRing) {
	226
	227	/* Ring wraps */
	228	new_swp -= bus->m_dwSizeSetRing;
	229
	230	space_rem = bus->m_dwSizeSetRing - curr_swp;
	231
	232	dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
	233	space_rem);
	234
207b42c4 ST	235	dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
207b42c4 ST	236	(u32)sizeof(*msg));
443c1228 ST	237
	238	if (space_rem < sizeof(*msg)) {
	239	dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
	240
	241	/* Split the msg into pieces as the ring wraps */
60665829 ST	242	memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem);
60665829 ST	243	memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
443c1228 ST	244	sizeof(*msg) - space_rem);
443c1228 ST	245
60665829	246	memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
443c1228 ST	247	buf, msg->size);
	248
	249	} else if (space_rem == sizeof(*msg)) {
	250	dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
	251
	252	/* Additional data at the beginning of the ring */
60665829 ST	253	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
60665829 ST	254	memcpy(bus->m_pdwSetRing, buf, msg->size);
443c1228 ST	255
	256	} else {
	257	/* Additional data wraps around the ring */
60665829	258	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
443c1228	259	if (msg->size > 0) {
60665829	260	memcpy(bus->m_pdwSetRing + curr_swp +
443c1228 ST	261	sizeof(*msg), buf, space_rem -
443c1228 ST	262	sizeof(*msg));
60665829	263	memcpy(bus->m_pdwSetRing, (u8 *)buf +
443c1228 ST	264	space_rem - sizeof(*msg),
	265	bytes_to_write - space_rem);
	266	}
	267
	268	}
	269
	270	} /* (new_swp > bus->m_dwSizeSetRing) */
	271	else {
	272	dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
	273
	274	/* The ring buffer doesn't wrap, two simple copies */
60665829 ST	275	memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
60665829 ST	276	memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
443c1228 ST	277	msg->size);
	278	}
	279
	280	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
	281
443c1228	282	/* Update the bus write position */
60665829	283	saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
443c1228 ST	284	ret = SAA_OK;
	285
	286	out:
60665829	287	saa7164_bus_dump(dev);
443c1228	288	mutex_unlock(&bus->lock);
60665829	289	saa7164_bus_verify(dev);
443c1228 ST	290	return ret;
	291	}
	292
	293	/*
	294	* Receive a command or a response from the bus. The implementation does not
	295	* know if it is a command or a response it simply dequeues the data,
	296	* depending on the bus information given in the tmComResBusInfo_t structure.
	297	*
	298	* Return Value:
	299	* 0 The function executed successfully.
	300	* < 0 One or more members are not initialized.
	301	*/
	302	int saa7164_bus_get(struct saa7164_dev dev, tmComResInfo_t msg, void *buf,
	303	int peekonly)
	304	{
	305	tmComResBusInfo_t *bus = &dev->bus;
	306	u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
	307	new_grp, buf_size, space_rem;
	308	tmComResInfo_t msg_tmp;
	309	int ret = SAA_ERR_BAD_PARAMETER;
	310
60665829	311	saa7164_bus_verify(dev);
443c1228 ST	312	if (msg == 0)
	313	return ret;
	314
	315	if (msg->size > dev->bus.m_wMaxReqSize) {
	316	printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
	317	__func__);
	318	return ret;
	319	}
	320
	321	if ((peekonly == 0) && (msg->size > 0) && (buf == 0)) {
	322	printk(KERN_ERR
	323	"%s() Missing msg buf, size should be %d bytes\n",
	324	__func__, msg->size);
	325	return ret;
	326	}
	327
	328	mutex_lock(&bus->lock);
	329
	330	/* Peek the bus to see if a msg exists, if it's not what we're expecting
	331	* then return cleanly else read the message from the bus.
	332	*/
60665829 ST	333	curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
60665829 ST	334	curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));
443c1228 ST	335
443c1228 ST	336	if (curr_gwp == curr_grp) {
443c1228 ST	337	ret = SAA_ERR_EMPTY;
	338	goto out;
	339	}
	340
	341	bytes_to_read = sizeof(*msg);
	342
	343	/* Calculate write distance to current read position */
	344	write_distance = 0;
	345	if (curr_gwp >= curr_grp)
	346	/* Write doesn't wrap around the ring */
	347	write_distance = curr_gwp - curr_grp;
	348	else
	349	/* Write wraps around the ring */
	350	write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
	351
	352	if (bytes_to_read > write_distance) {
	353	printk(KERN_ERR "%s() No message/response found\n", __func__);
	354	ret = SAA_ERR_INVALID_COMMAND;
	355	goto out;
	356	}
	357
	358	/* Calculate the new read position */
	359	new_grp = curr_grp + bytes_to_read;
	360	if (new_grp > bus->m_dwSizeGetRing) {
	361
	362	/* Ring wraps */
	363	new_grp -= bus->m_dwSizeGetRing;
	364	space_rem = bus->m_dwSizeGetRing - curr_grp;
	365
60665829 ST	366	memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
60665829 ST	367	memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
443c1228 ST	368	bytes_to_read - space_rem);
	369
	370	} else {
	371	/* No wrapping */
60665829	372	memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
443c1228 ST	373	}
	374
	375	/* No need to update the read positions, because this was a peek */
	376	/* If the caller specifically want to peek, return */
	377	if (peekonly) {
60665829	378	memcpy(msg, &msg_tmp, sizeof(*msg));
443c1228 ST	379	goto peekout;
	380	}
	381
	382	/* Check if the command/response matches what is expected */
	383	if ((msg_tmp.id != msg->id) \|\| (msg_tmp.command != msg->command) \|\|
	384	(msg_tmp.controlselector != msg->controlselector) \|\|
	385	(msg_tmp.seqno != msg->seqno) \|\| (msg_tmp.size != msg->size)) {
	386
	387	printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
	388	saa7164_bus_dumpmsg(dev, msg, buf);
	389	saa7164_bus_dumpmsg(dev, &msg_tmp, 0);
	390	ret = SAA_ERR_INVALID_COMMAND;
	391	goto out;
	392	}
	393
	394	/* Get the actual command and response from the bus */
	395	buf_size = msg->size;
	396
	397	bytes_to_read = sizeof(*msg) + msg->size;
	398	/* Calculate write distance to current read position */
	399	write_distance = 0;
	400	if (curr_gwp >= curr_grp)
	401	/* Write doesn't wrap around the ring */
	402	write_distance = curr_gwp - curr_grp;
	403	else
	404	/* Write wraps around the ring */
	405	write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
	406
	407	if (bytes_to_read > write_distance) {
	408	printk(KERN_ERR "%s() Invalid bus state, missing msg "
	409	"or mangled ring, faulty H/W / bad code?\n", __func__);
	410	ret = SAA_ERR_INVALID_COMMAND;
	411	goto out;
	412	}
	413
	414	/* Calculate the new read position */
	415	new_grp = curr_grp + bytes_to_read;
	416	if (new_grp > bus->m_dwSizeGetRing) {
	417
	418	/* Ring wraps */
	419	new_grp -= bus->m_dwSizeGetRing;
	420	space_rem = bus->m_dwSizeGetRing - curr_grp;
	421
	422	if (space_rem < sizeof(*msg)) {
	423	/* msg wraps around the ring */
60665829 ST	424	memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
60665829 ST	425	memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
443c1228 ST	426	sizeof(*msg) - space_rem);
443c1228 ST	427	if (buf)
60665829	428	memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
443c1228 ST	429	space_rem, buf_size);
	430
	431	} else if (space_rem == sizeof(*msg)) {
60665829	432	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228 ST	433	if (buf)
	434	memcpy(buf, bus->m_pdwGetRing, buf_size);
	435	} else {
	436	/* Additional data wraps around the ring */
60665829	437	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228	438	if (buf) {
60665829	439	memcpy(buf, bus->m_pdwGetRing + curr_grp +
443c1228	440	sizeof(msg), space_rem - sizeof(msg));
60665829	441	memcpy(buf + space_rem - sizeof(*msg),
443c1228 ST	442	bus->m_pdwGetRing, bytes_to_read -
	443	space_rem);
	444	}
	445
	446	}
	447
	448	} else {
	449	/* No wrapping */
60665829	450	memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
443c1228	451	if (buf)
60665829	452	memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
443c1228 ST	453	buf_size);
	454	}
	455
	456	/* Update the read positions, adjusting the ring */
60665829	457	saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));
443c1228 ST	458
	459	peekout:
	460	msg->size = le16_to_cpu(msg->size);
	461	msg->command = le16_to_cpu(msg->command);
	462	msg->controlselector = le16_to_cpu(msg->controlselector);
	463	ret = SAA_OK;
	464	out:
	465	mutex_unlock(&bus->lock);
60665829	466	saa7164_bus_verify(dev);
443c1228 ST	467	return ret;
	468	}
	469