478 lines
14 KiB
C
478 lines
14 KiB
C
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/*
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* Driver for the NXP SAA7164 PCIe bridge
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*
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* Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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*
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* GNU General Public License for more details.
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*/
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#include "saa7164.h"
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/* The message bus to/from the firmware is a ring buffer in PCI address
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* space. Establish the defaults.
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*/
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int saa7164_bus_setup(struct saa7164_dev *dev)
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{
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struct tmComResBusInfo *b = &dev->bus;
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mutex_init(&b->lock);
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b->Type = TYPE_BUS_PCIe;
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b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE;
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b->m_pdwSetRing = (u8 __iomem *)(dev->bmmio +
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((u32)dev->busdesc.CommandRing));
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b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
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b->m_pdwGetRing = (u8 __iomem *)(dev->bmmio +
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((u32)dev->busdesc.ResponseRing));
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b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
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b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) +
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(2 * sizeof(u64));
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b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
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b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
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b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
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return 0;
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}
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void saa7164_bus_dump(struct saa7164_dev *dev)
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{
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struct tmComResBusInfo *b = &dev->bus;
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dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
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dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
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dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
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dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
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dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
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dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
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dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
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dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
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dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
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b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
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dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
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b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
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dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
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b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
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dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
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b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
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}
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/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
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static void saa7164_bus_verify(struct saa7164_dev *dev)
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{
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struct tmComResBusInfo *b = &dev->bus;
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int bug = 0;
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if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
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bug++;
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if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
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bug++;
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if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
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bug++;
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if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
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bug++;
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if (bug) {
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saa_debug = 0xffff; /* Ensure we get the bus dump */
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saa7164_bus_dump(dev);
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saa_debug = 1024; /* Ensure we get the bus dump */
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BUG();
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}
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}
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static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m,
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void *buf)
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{
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dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
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dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
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dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
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dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
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dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
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dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
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dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
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if (buf)
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dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
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}
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/*
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* Places a command or a response on the bus. The implementation does not
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* know if it is a command or a response it just places the data on the
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* bus depending on the bus information given in the struct tmComResBusInfo
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* structure. If the command or response does not fit into the bus ring
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* buffer it will be refused.
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*
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* Return Value:
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* SAA_OK The function executed successfully.
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* < 0 One or more members are not initialized.
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*/
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int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
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void *buf)
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{
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struct tmComResBusInfo *bus = &dev->bus;
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u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
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u32 new_swp, space_rem;
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int ret = SAA_ERR_BAD_PARAMETER;
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u16 size;
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if (!msg) {
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printk(KERN_ERR "%s() !msg\n", __func__);
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return SAA_ERR_BAD_PARAMETER;
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}
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dprintk(DBGLVL_BUS, "%s()\n", __func__);
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saa7164_bus_verify(dev);
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if (msg->size > dev->bus.m_wMaxReqSize) {
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printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
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__func__);
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return SAA_ERR_BAD_PARAMETER;
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}
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if ((msg->size > 0) && (buf == NULL)) {
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printk(KERN_ERR "%s() Missing message buffer\n", __func__);
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return SAA_ERR_BAD_PARAMETER;
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}
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/* Lock the bus from any other access */
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mutex_lock(&bus->lock);
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bytes_to_write = sizeof(*msg) + msg->size;
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free_write_space = 0;
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timeout = SAA_BUS_TIMEOUT;
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curr_srp = saa7164_readl(bus->m_dwSetReadPos);
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curr_swp = saa7164_readl(bus->m_dwSetWritePos);
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/* Deal with ring wrapping issues */
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if (curr_srp > curr_swp)
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/* Deal with the wrapped ring */
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free_write_space = curr_srp - curr_swp;
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else
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/* The ring has not wrapped yet */
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free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
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dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
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bytes_to_write);
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dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
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free_write_space);
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dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
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dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
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/* Process the msg and write the content onto the bus */
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while (bytes_to_write >= free_write_space) {
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if (timeout-- == 0) {
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printk(KERN_ERR "%s() bus timeout\n", __func__);
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ret = SAA_ERR_NO_RESOURCES;
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goto out;
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}
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/* TODO: Review this delay, efficient? */
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/* Wait, allowing the hardware fetch time */
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mdelay(1);
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/* Check the space usage again */
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curr_srp = saa7164_readl(bus->m_dwSetReadPos);
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/* Deal with ring wrapping issues */
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if (curr_srp > curr_swp)
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/* Deal with the wrapped ring */
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free_write_space = curr_srp - curr_swp;
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else
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/* Read didn't wrap around the buffer */
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free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
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curr_swp;
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}
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/* Calculate the new write position */
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new_swp = curr_swp + bytes_to_write;
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dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
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dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
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bus->m_dwSizeSetRing);
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/*
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* Make a copy of msg->size before it is converted to le16 since it is
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* used in the code below.
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*/
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size = msg->size;
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/* Convert to le16/le32 */
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msg->size = (__force u16)cpu_to_le16(msg->size);
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msg->command = (__force u32)cpu_to_le32(msg->command);
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msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector);
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/* Mental Note: line 462 tmmhComResBusPCIe.cpp */
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/* Check if we're going to wrap again */
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if (new_swp > bus->m_dwSizeSetRing) {
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/* Ring wraps */
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new_swp -= bus->m_dwSizeSetRing;
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space_rem = bus->m_dwSizeSetRing - curr_swp;
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dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
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space_rem);
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dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
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(u32)sizeof(*msg));
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if (space_rem < sizeof(*msg)) {
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dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
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/* Split the msg into pieces as the ring wraps */
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memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem);
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memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem,
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sizeof(*msg) - space_rem);
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memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
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buf, size);
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} else if (space_rem == sizeof(*msg)) {
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dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
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/* Additional data at the beginning of the ring */
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memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
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memcpy_toio(bus->m_pdwSetRing, buf, size);
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} else {
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/* Additional data wraps around the ring */
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memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
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if (size > 0) {
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memcpy_toio(bus->m_pdwSetRing + curr_swp +
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sizeof(*msg), buf, space_rem -
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sizeof(*msg));
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memcpy_toio(bus->m_pdwSetRing, (u8 *)buf +
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space_rem - sizeof(*msg),
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bytes_to_write - space_rem);
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}
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}
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} /* (new_swp > bus->m_dwSizeSetRing) */
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else {
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dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
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/* The ring buffer doesn't wrap, two simple copies */
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memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
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memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
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size);
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}
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dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
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/* Update the bus write position */
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saa7164_writel(bus->m_dwSetWritePos, new_swp);
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/* Convert back to cpu after writing the msg to the ringbuffer. */
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msg->size = le16_to_cpu((__force __le16)msg->size);
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msg->command = le32_to_cpu((__force __le32)msg->command);
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msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector);
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ret = SAA_OK;
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out:
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saa7164_bus_dump(dev);
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mutex_unlock(&bus->lock);
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saa7164_bus_verify(dev);
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return ret;
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}
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/*
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* Receive a command or a response from the bus. The implementation does not
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* know if it is a command or a response it simply dequeues the data,
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* depending on the bus information given in the struct tmComResBusInfo
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* structure.
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*
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* Return Value:
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* 0 The function executed successfully.
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* < 0 One or more members are not initialized.
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*/
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int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
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void *buf, int peekonly)
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{
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struct tmComResBusInfo *bus = &dev->bus;
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u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
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new_grp, buf_size, space_rem;
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struct tmComResInfo msg_tmp;
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int ret = SAA_ERR_BAD_PARAMETER;
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saa7164_bus_verify(dev);
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if (msg == NULL)
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return ret;
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if (msg->size > dev->bus.m_wMaxReqSize) {
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printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
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__func__);
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return ret;
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}
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if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
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printk(KERN_ERR
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"%s() Missing msg buf, size should be %d bytes\n",
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__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;
|
||
|
|
}
|
||
|
|
|