diff options
Diffstat (limited to 'drivers/media/pci/saa7164/saa7164-bus.c')
| -rw-r--r-- | drivers/media/pci/saa7164/saa7164-bus.c | 492 |
1 files changed, 492 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..6c73f5b15 --- /dev/null +++ b/drivers/media/pci/saa7164/saa7164-bus.c @@ -0,0 +1,492 @@ +/* + * 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 __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); + + /* 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_fromio(msg, bus->m_pdwGetRing + curr_grp, space_rem); + memcpy_fromio((u8 *)msg + space_rem, bus->m_pdwGetRing, + sizeof(*msg) - space_rem); + if (buf) + memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) - + space_rem, buf_size); + + } else if (space_rem == sizeof(*msg)) { + memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); + if (buf) + memcpy_fromio(buf, bus->m_pdwGetRing, buf_size); + } else { + /* Additional data wraps around the ring */ + memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); + 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 */ + memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); + if (buf) + memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg), + buf_size); + } + /* Convert from little endian to CPU */ + 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); + + /* 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; +} + |