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; 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(*bus->m_pdwGetWritePos); curr_grp = le32_to_cpu(*bus->m_pdwGetReadPos); if (curr_gwp == curr_grp) { dprintk(DBGLVL_BUS, "%s() No message on the bus\n", __func__); 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 */ *bus->m_pdwGetReadPos = 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); return ret; }
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); 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); write_distance = 0; if (curr_gwp >= curr_grp) write_distance = curr_gwp - curr_grp; else 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; } new_grp = curr_grp + bytes_to_read; if (new_grp > bus->m_dwSizeGetRing) { 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 { memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read); } if (peekonly) { memcpy(msg, &msg_tmp, sizeof(*msg)); goto peekout; } 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; } buf_size = msg->size; bytes_to_read = sizeof(*msg) + msg->size; write_distance = 0; if (curr_gwp >= curr_grp) write_distance = curr_gwp - curr_grp; else 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; } new_grp = curr_grp + bytes_to_read; if (new_grp > bus->m_dwSizeGetRing) { new_grp -= bus->m_dwSizeGetRing; space_rem = bus->m_dwSizeGetRing - curr_grp; if (space_rem < sizeof(*msg)) { 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 { 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 { memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); if (buf) memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg), buf_size); } 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; }