1b285192aSMauro Carvalho Chehab /* 2b285192aSMauro Carvalho Chehab * Driver for the NXP SAA7164 PCIe bridge 3b285192aSMauro Carvalho Chehab * 463a412ecSSteven Toth * Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com> 5b285192aSMauro Carvalho Chehab * 6b285192aSMauro Carvalho Chehab * This program is free software; you can redistribute it and/or modify 7b285192aSMauro Carvalho Chehab * it under the terms of the GNU General Public License as published by 8b285192aSMauro Carvalho Chehab * the Free Software Foundation; either version 2 of the License, or 9b285192aSMauro Carvalho Chehab * (at your option) any later version. 10b285192aSMauro Carvalho Chehab * 11b285192aSMauro Carvalho Chehab * This program is distributed in the hope that it will be useful, 12b285192aSMauro Carvalho Chehab * but WITHOUT ANY WARRANTY; without even the implied warranty of 13b285192aSMauro Carvalho Chehab * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14b285192aSMauro Carvalho Chehab * 15b285192aSMauro Carvalho Chehab * GNU General Public License for more details. 16b285192aSMauro Carvalho Chehab */ 17b285192aSMauro Carvalho Chehab 18b285192aSMauro Carvalho Chehab #include "saa7164.h" 19b285192aSMauro Carvalho Chehab 20b285192aSMauro Carvalho Chehab /* The message bus to/from the firmware is a ring buffer in PCI address 21b285192aSMauro Carvalho Chehab * space. Establish the defaults. 22b285192aSMauro Carvalho Chehab */ 23b285192aSMauro Carvalho Chehab int saa7164_bus_setup(struct saa7164_dev *dev) 24b285192aSMauro Carvalho Chehab { 25b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus; 26b285192aSMauro Carvalho Chehab 27b285192aSMauro Carvalho Chehab mutex_init(&b->lock); 28b285192aSMauro Carvalho Chehab 29b285192aSMauro Carvalho Chehab b->Type = TYPE_BUS_PCIe; 30b285192aSMauro Carvalho Chehab b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE; 31b285192aSMauro Carvalho Chehab 32065e1477SHans Verkuil b->m_pdwSetRing = (u8 __iomem *)(dev->bmmio + 33b285192aSMauro Carvalho Chehab ((u32)dev->busdesc.CommandRing)); 34b285192aSMauro Carvalho Chehab 35b285192aSMauro Carvalho Chehab b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE; 36b285192aSMauro Carvalho Chehab 37065e1477SHans Verkuil b->m_pdwGetRing = (u8 __iomem *)(dev->bmmio + 38b285192aSMauro Carvalho Chehab ((u32)dev->busdesc.ResponseRing)); 39b285192aSMauro Carvalho Chehab 40b285192aSMauro Carvalho Chehab b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE; 41b285192aSMauro Carvalho Chehab 42b285192aSMauro Carvalho Chehab b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) + 43b285192aSMauro Carvalho Chehab (2 * sizeof(u64)); 44b285192aSMauro Carvalho Chehab b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32)); 45b285192aSMauro Carvalho Chehab 46b285192aSMauro Carvalho Chehab b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32)); 47b285192aSMauro Carvalho Chehab b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32)); 48b285192aSMauro Carvalho Chehab 49b285192aSMauro Carvalho Chehab return 0; 50b285192aSMauro Carvalho Chehab } 51b285192aSMauro Carvalho Chehab 52b285192aSMauro Carvalho Chehab void saa7164_bus_dump(struct saa7164_dev *dev) 53b285192aSMauro Carvalho Chehab { 54b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus; 55b285192aSMauro Carvalho Chehab 56b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "Dumping the bus structure:\n"); 57b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .type = %d\n", b->Type); 58b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio); 59b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize); 60b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing); 61b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing); 62b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing); 63b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing); 64b285192aSMauro Carvalho Chehab 65b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n", 66b285192aSMauro Carvalho Chehab b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos)); 67b285192aSMauro Carvalho Chehab 68b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n", 69b285192aSMauro Carvalho Chehab b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos)); 70b285192aSMauro Carvalho Chehab 71b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n", 72b285192aSMauro Carvalho Chehab b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos)); 73b285192aSMauro Carvalho Chehab 74b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n", 75b285192aSMauro Carvalho Chehab b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos)); 76b285192aSMauro Carvalho Chehab 77b285192aSMauro Carvalho Chehab } 78b285192aSMauro Carvalho Chehab 79b285192aSMauro Carvalho Chehab /* Intensionally throw a BUG() if the state of the message bus looks corrupt */ 805faf7db8SMauro Carvalho Chehab static void saa7164_bus_verify(struct saa7164_dev *dev) 81b285192aSMauro Carvalho Chehab { 82b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus; 83b285192aSMauro Carvalho Chehab int bug = 0; 84b285192aSMauro Carvalho Chehab 85b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing) 86b285192aSMauro Carvalho Chehab bug++; 87b285192aSMauro Carvalho Chehab 88b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing) 89b285192aSMauro Carvalho Chehab bug++; 90b285192aSMauro Carvalho Chehab 91b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing) 92b285192aSMauro Carvalho Chehab bug++; 93b285192aSMauro Carvalho Chehab 94b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing) 95b285192aSMauro Carvalho Chehab bug++; 96b285192aSMauro Carvalho Chehab 97b285192aSMauro Carvalho Chehab if (bug) { 98b285192aSMauro Carvalho Chehab saa_debug = 0xffff; /* Ensure we get the bus dump */ 99b285192aSMauro Carvalho Chehab saa7164_bus_dump(dev); 100b285192aSMauro Carvalho Chehab saa_debug = 1024; /* Ensure we get the bus dump */ 101b285192aSMauro Carvalho Chehab BUG(); 102b285192aSMauro Carvalho Chehab } 103b285192aSMauro Carvalho Chehab } 104b285192aSMauro Carvalho Chehab 1055faf7db8SMauro Carvalho Chehab static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m, 106b285192aSMauro Carvalho Chehab void *buf) 107b285192aSMauro Carvalho Chehab { 108b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "Dumping msg structure:\n"); 109b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .id = %d\n", m->id); 110b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags); 111b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size); 112b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command); 113b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector); 114b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno); 115b285192aSMauro Carvalho Chehab if (buf) 116b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .buffer (ignored)\n"); 117b285192aSMauro Carvalho Chehab } 118b285192aSMauro Carvalho Chehab 119b285192aSMauro Carvalho Chehab /* 120b285192aSMauro Carvalho Chehab * Places a command or a response on the bus. The implementation does not 121b285192aSMauro Carvalho Chehab * know if it is a command or a response it just places the data on the 122b285192aSMauro Carvalho Chehab * bus depending on the bus information given in the struct tmComResBusInfo 123b285192aSMauro Carvalho Chehab * structure. If the command or response does not fit into the bus ring 124b285192aSMauro Carvalho Chehab * buffer it will be refused. 125b285192aSMauro Carvalho Chehab * 126b285192aSMauro Carvalho Chehab * Return Value: 127b285192aSMauro Carvalho Chehab * SAA_OK The function executed successfully. 128b285192aSMauro Carvalho Chehab * < 0 One or more members are not initialized. 129b285192aSMauro Carvalho Chehab */ 130b285192aSMauro Carvalho Chehab int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg, 131b285192aSMauro Carvalho Chehab void *buf) 132b285192aSMauro Carvalho Chehab { 133b285192aSMauro Carvalho Chehab struct tmComResBusInfo *bus = &dev->bus; 134b285192aSMauro Carvalho Chehab u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp; 135b285192aSMauro Carvalho Chehab u32 new_swp, space_rem; 136b285192aSMauro Carvalho Chehab int ret = SAA_ERR_BAD_PARAMETER; 137065e1477SHans Verkuil u16 size; 138b285192aSMauro Carvalho Chehab 139b285192aSMauro Carvalho Chehab if (!msg) { 140b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() !msg\n", __func__); 141b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER; 142b285192aSMauro Carvalho Chehab } 143b285192aSMauro Carvalho Chehab 144b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s()\n", __func__); 145b285192aSMauro Carvalho Chehab 146b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev); 147b285192aSMauro Carvalho Chehab 148b285192aSMauro Carvalho Chehab if (msg->size > dev->bus.m_wMaxReqSize) { 149b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n", 150b285192aSMauro Carvalho Chehab __func__); 151b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER; 152b285192aSMauro Carvalho Chehab } 153b285192aSMauro Carvalho Chehab 154b285192aSMauro Carvalho Chehab if ((msg->size > 0) && (buf == NULL)) { 155b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Missing message buffer\n", __func__); 156b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER; 157b285192aSMauro Carvalho Chehab } 158b285192aSMauro Carvalho Chehab 159b285192aSMauro Carvalho Chehab /* Lock the bus from any other access */ 160b285192aSMauro Carvalho Chehab mutex_lock(&bus->lock); 161b285192aSMauro Carvalho Chehab 162b285192aSMauro Carvalho Chehab bytes_to_write = sizeof(*msg) + msg->size; 163b285192aSMauro Carvalho Chehab free_write_space = 0; 164b285192aSMauro Carvalho Chehab timeout = SAA_BUS_TIMEOUT; 165065e1477SHans Verkuil curr_srp = saa7164_readl(bus->m_dwSetReadPos); 166065e1477SHans Verkuil curr_swp = saa7164_readl(bus->m_dwSetWritePos); 167b285192aSMauro Carvalho Chehab 168b285192aSMauro Carvalho Chehab /* Deal with ring wrapping issues */ 169b285192aSMauro Carvalho Chehab if (curr_srp > curr_swp) 170b285192aSMauro Carvalho Chehab /* Deal with the wrapped ring */ 171b285192aSMauro Carvalho Chehab free_write_space = curr_srp - curr_swp; 172b285192aSMauro Carvalho Chehab else 173b285192aSMauro Carvalho Chehab /* The ring has not wrapped yet */ 174b285192aSMauro Carvalho Chehab free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp; 175b285192aSMauro Carvalho Chehab 176b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__, 177b285192aSMauro Carvalho Chehab bytes_to_write); 178b285192aSMauro Carvalho Chehab 179b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__, 180b285192aSMauro Carvalho Chehab free_write_space); 181b285192aSMauro Carvalho Chehab 182b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp); 183b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp); 184b285192aSMauro Carvalho Chehab 185b285192aSMauro Carvalho Chehab /* Process the msg and write the content onto the bus */ 186b285192aSMauro Carvalho Chehab while (bytes_to_write >= free_write_space) { 187b285192aSMauro Carvalho Chehab 188b285192aSMauro Carvalho Chehab if (timeout-- == 0) { 189b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() bus timeout\n", __func__); 190b285192aSMauro Carvalho Chehab ret = SAA_ERR_NO_RESOURCES; 191b285192aSMauro Carvalho Chehab goto out; 192b285192aSMauro Carvalho Chehab } 193b285192aSMauro Carvalho Chehab 194b285192aSMauro Carvalho Chehab /* TODO: Review this delay, efficient? */ 195b285192aSMauro Carvalho Chehab /* Wait, allowing the hardware fetch time */ 196b285192aSMauro Carvalho Chehab mdelay(1); 197b285192aSMauro Carvalho Chehab 198b285192aSMauro Carvalho Chehab /* Check the space usage again */ 199065e1477SHans Verkuil curr_srp = saa7164_readl(bus->m_dwSetReadPos); 200b285192aSMauro Carvalho Chehab 201b285192aSMauro Carvalho Chehab /* Deal with ring wrapping issues */ 202b285192aSMauro Carvalho Chehab if (curr_srp > curr_swp) 203b285192aSMauro Carvalho Chehab /* Deal with the wrapped ring */ 204b285192aSMauro Carvalho Chehab free_write_space = curr_srp - curr_swp; 205b285192aSMauro Carvalho Chehab else 206b285192aSMauro Carvalho Chehab /* Read didn't wrap around the buffer */ 207b285192aSMauro Carvalho Chehab free_write_space = (curr_srp + bus->m_dwSizeSetRing) - 208b285192aSMauro Carvalho Chehab curr_swp; 209b285192aSMauro Carvalho Chehab 210b285192aSMauro Carvalho Chehab } 211b285192aSMauro Carvalho Chehab 212b285192aSMauro Carvalho Chehab /* Calculate the new write position */ 213b285192aSMauro Carvalho Chehab new_swp = curr_swp + bytes_to_write; 214b285192aSMauro Carvalho Chehab 215b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp); 216b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__, 217b285192aSMauro Carvalho Chehab bus->m_dwSizeSetRing); 218b285192aSMauro Carvalho Chehab 219065e1477SHans Verkuil /* 220065e1477SHans Verkuil * Make a copy of msg->size before it is converted to le16 since it is 221065e1477SHans Verkuil * used in the code below. 222065e1477SHans Verkuil */ 223065e1477SHans Verkuil size = msg->size; 224065e1477SHans Verkuil /* Convert to le16/le32 */ 225065e1477SHans Verkuil msg->size = (__force u16)cpu_to_le16(msg->size); 226065e1477SHans Verkuil msg->command = (__force u32)cpu_to_le32(msg->command); 227065e1477SHans Verkuil msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector); 228065e1477SHans Verkuil 229b285192aSMauro Carvalho Chehab /* Mental Note: line 462 tmmhComResBusPCIe.cpp */ 230b285192aSMauro Carvalho Chehab 231b285192aSMauro Carvalho Chehab /* Check if we're going to wrap again */ 232b285192aSMauro Carvalho Chehab if (new_swp > bus->m_dwSizeSetRing) { 233b285192aSMauro Carvalho Chehab 234b285192aSMauro Carvalho Chehab /* Ring wraps */ 235b285192aSMauro Carvalho Chehab new_swp -= bus->m_dwSizeSetRing; 236b285192aSMauro Carvalho Chehab 237b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeSetRing - curr_swp; 238b285192aSMauro Carvalho Chehab 239b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__, 240b285192aSMauro Carvalho Chehab space_rem); 241b285192aSMauro Carvalho Chehab 242b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__, 243b285192aSMauro Carvalho Chehab (u32)sizeof(*msg)); 244b285192aSMauro Carvalho Chehab 245b285192aSMauro Carvalho Chehab if (space_rem < sizeof(*msg)) { 246b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr4\n", __func__); 247b285192aSMauro Carvalho Chehab 248b285192aSMauro Carvalho Chehab /* Split the msg into pieces as the ring wraps */ 249065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem); 250065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem, 251b285192aSMauro Carvalho Chehab sizeof(*msg) - space_rem); 252b285192aSMauro Carvalho Chehab 253065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem, 254065e1477SHans Verkuil buf, size); 255b285192aSMauro Carvalho Chehab 256b285192aSMauro Carvalho Chehab } else if (space_rem == sizeof(*msg)) { 257b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr5\n", __func__); 258b285192aSMauro Carvalho Chehab 259b285192aSMauro Carvalho Chehab /* Additional data at the beginning of the ring */ 260065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 261065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, buf, size); 262b285192aSMauro Carvalho Chehab 263b285192aSMauro Carvalho Chehab } else { 264b285192aSMauro Carvalho Chehab /* Additional data wraps around the ring */ 265065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 266065e1477SHans Verkuil if (size > 0) { 267065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp + 268b285192aSMauro Carvalho Chehab sizeof(*msg), buf, space_rem - 269b285192aSMauro Carvalho Chehab sizeof(*msg)); 270065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, (u8 *)buf + 271b285192aSMauro Carvalho Chehab space_rem - sizeof(*msg), 272b285192aSMauro Carvalho Chehab bytes_to_write - space_rem); 273b285192aSMauro Carvalho Chehab } 274b285192aSMauro Carvalho Chehab 275b285192aSMauro Carvalho Chehab } 276b285192aSMauro Carvalho Chehab 277b285192aSMauro Carvalho Chehab } /* (new_swp > bus->m_dwSizeSetRing) */ 278b285192aSMauro Carvalho Chehab else { 279b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr6\n", __func__); 280b285192aSMauro Carvalho Chehab 281b285192aSMauro Carvalho Chehab /* The ring buffer doesn't wrap, two simple copies */ 282065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 283065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf, 284065e1477SHans Verkuil size); 285b285192aSMauro Carvalho Chehab } 286b285192aSMauro Carvalho Chehab 287b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp); 288b285192aSMauro Carvalho Chehab 289b285192aSMauro Carvalho Chehab /* Update the bus write position */ 290065e1477SHans Verkuil saa7164_writel(bus->m_dwSetWritePos, new_swp); 291065e1477SHans Verkuil 292065e1477SHans Verkuil /* Convert back to cpu after writing the msg to the ringbuffer. */ 293065e1477SHans Verkuil msg->size = le16_to_cpu((__force __le16)msg->size); 294065e1477SHans Verkuil msg->command = le32_to_cpu((__force __le32)msg->command); 295065e1477SHans Verkuil msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector); 296b285192aSMauro Carvalho Chehab ret = SAA_OK; 297b285192aSMauro Carvalho Chehab 298b285192aSMauro Carvalho Chehab out: 299b285192aSMauro Carvalho Chehab saa7164_bus_dump(dev); 300b285192aSMauro Carvalho Chehab mutex_unlock(&bus->lock); 301b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev); 302b285192aSMauro Carvalho Chehab return ret; 303b285192aSMauro Carvalho Chehab } 304b285192aSMauro Carvalho Chehab 305b285192aSMauro Carvalho Chehab /* 306b285192aSMauro Carvalho Chehab * Receive a command or a response from the bus. The implementation does not 307b285192aSMauro Carvalho Chehab * know if it is a command or a response it simply dequeues the data, 308b285192aSMauro Carvalho Chehab * depending on the bus information given in the struct tmComResBusInfo 309b285192aSMauro Carvalho Chehab * structure. 310b285192aSMauro Carvalho Chehab * 311b285192aSMauro Carvalho Chehab * Return Value: 312b285192aSMauro Carvalho Chehab * 0 The function executed successfully. 313b285192aSMauro Carvalho Chehab * < 0 One or more members are not initialized. 314b285192aSMauro Carvalho Chehab */ 315b285192aSMauro Carvalho Chehab int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg, 316b285192aSMauro Carvalho Chehab void *buf, int peekonly) 317b285192aSMauro Carvalho Chehab { 318b285192aSMauro Carvalho Chehab struct tmComResBusInfo *bus = &dev->bus; 319b285192aSMauro Carvalho Chehab u32 bytes_to_read, write_distance, curr_grp, curr_gwp, 320b285192aSMauro Carvalho Chehab new_grp, buf_size, space_rem; 321b285192aSMauro Carvalho Chehab struct tmComResInfo msg_tmp; 322b285192aSMauro Carvalho Chehab int ret = SAA_ERR_BAD_PARAMETER; 323b285192aSMauro Carvalho Chehab 324b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev); 325b285192aSMauro Carvalho Chehab 326b285192aSMauro Carvalho Chehab if (msg == NULL) 327b285192aSMauro Carvalho Chehab return ret; 328b285192aSMauro Carvalho Chehab 329b285192aSMauro Carvalho Chehab if (msg->size > dev->bus.m_wMaxReqSize) { 330b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n", 331b285192aSMauro Carvalho Chehab __func__); 332b285192aSMauro Carvalho Chehab return ret; 333b285192aSMauro Carvalho Chehab } 334b285192aSMauro Carvalho Chehab 335b285192aSMauro Carvalho Chehab if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) { 336b285192aSMauro Carvalho Chehab printk(KERN_ERR 337b285192aSMauro Carvalho Chehab "%s() Missing msg buf, size should be %d bytes\n", 338b285192aSMauro Carvalho Chehab __func__, msg->size); 339b285192aSMauro Carvalho Chehab return ret; 340b285192aSMauro Carvalho Chehab } 341b285192aSMauro Carvalho Chehab 342b285192aSMauro Carvalho Chehab mutex_lock(&bus->lock); 343b285192aSMauro Carvalho Chehab 344b285192aSMauro Carvalho Chehab /* Peek the bus to see if a msg exists, if it's not what we're expecting 345b285192aSMauro Carvalho Chehab * then return cleanly else read the message from the bus. 346b285192aSMauro Carvalho Chehab */ 347065e1477SHans Verkuil curr_gwp = saa7164_readl(bus->m_dwGetWritePos); 348065e1477SHans Verkuil curr_grp = saa7164_readl(bus->m_dwGetReadPos); 349b285192aSMauro Carvalho Chehab 350b285192aSMauro Carvalho Chehab if (curr_gwp == curr_grp) { 351b285192aSMauro Carvalho Chehab ret = SAA_ERR_EMPTY; 352b285192aSMauro Carvalho Chehab goto out; 353b285192aSMauro Carvalho Chehab } 354b285192aSMauro Carvalho Chehab 355b285192aSMauro Carvalho Chehab bytes_to_read = sizeof(*msg); 356b285192aSMauro Carvalho Chehab 357b285192aSMauro Carvalho Chehab /* Calculate write distance to current read position */ 358b285192aSMauro Carvalho Chehab write_distance = 0; 359b285192aSMauro Carvalho Chehab if (curr_gwp >= curr_grp) 360b285192aSMauro Carvalho Chehab /* Write doesn't wrap around the ring */ 361b285192aSMauro Carvalho Chehab write_distance = curr_gwp - curr_grp; 362b285192aSMauro Carvalho Chehab else 363b285192aSMauro Carvalho Chehab /* Write wraps around the ring */ 364b285192aSMauro Carvalho Chehab write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; 365b285192aSMauro Carvalho Chehab 366b285192aSMauro Carvalho Chehab if (bytes_to_read > write_distance) { 367b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() No message/response found\n", __func__); 368b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND; 369b285192aSMauro Carvalho Chehab goto out; 370b285192aSMauro Carvalho Chehab } 371b285192aSMauro Carvalho Chehab 372b285192aSMauro Carvalho Chehab /* Calculate the new read position */ 373b285192aSMauro Carvalho Chehab new_grp = curr_grp + bytes_to_read; 374b285192aSMauro Carvalho Chehab if (new_grp > bus->m_dwSizeGetRing) { 375b285192aSMauro Carvalho Chehab 376b285192aSMauro Carvalho Chehab /* Ring wraps */ 377b285192aSMauro Carvalho Chehab new_grp -= bus->m_dwSizeGetRing; 378b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeGetRing - curr_grp; 379b285192aSMauro Carvalho Chehab 380065e1477SHans Verkuil memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem); 381065e1477SHans Verkuil memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing, 382b285192aSMauro Carvalho Chehab bytes_to_read - space_rem); 383b285192aSMauro Carvalho Chehab 384b285192aSMauro Carvalho Chehab } else { 385b285192aSMauro Carvalho Chehab /* No wrapping */ 386065e1477SHans Verkuil memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read); 387b285192aSMauro Carvalho Chehab } 388065e1477SHans Verkuil /* Convert from little endian to CPU */ 389065e1477SHans Verkuil msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size); 390065e1477SHans Verkuil msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command); 391065e1477SHans Verkuil msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector); 392*6fb05e0dSSteven Toth memcpy(msg, &msg_tmp, sizeof(*msg)); 393b285192aSMauro Carvalho Chehab 394b285192aSMauro Carvalho Chehab /* No need to update the read positions, because this was a peek */ 395b285192aSMauro Carvalho Chehab /* If the caller specifically want to peek, return */ 396b285192aSMauro Carvalho Chehab if (peekonly) { 397b285192aSMauro Carvalho Chehab goto peekout; 398b285192aSMauro Carvalho Chehab } 399b285192aSMauro Carvalho Chehab 400b285192aSMauro Carvalho Chehab /* Check if the command/response matches what is expected */ 401b285192aSMauro Carvalho Chehab if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) || 402b285192aSMauro Carvalho Chehab (msg_tmp.controlselector != msg->controlselector) || 403b285192aSMauro Carvalho Chehab (msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) { 404b285192aSMauro Carvalho Chehab 405b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__); 406b285192aSMauro Carvalho Chehab saa7164_bus_dumpmsg(dev, msg, buf); 407b285192aSMauro Carvalho Chehab saa7164_bus_dumpmsg(dev, &msg_tmp, NULL); 408b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND; 409b285192aSMauro Carvalho Chehab goto out; 410b285192aSMauro Carvalho Chehab } 411b285192aSMauro Carvalho Chehab 412b285192aSMauro Carvalho Chehab /* Get the actual command and response from the bus */ 413b285192aSMauro Carvalho Chehab buf_size = msg->size; 414b285192aSMauro Carvalho Chehab 415b285192aSMauro Carvalho Chehab bytes_to_read = sizeof(*msg) + msg->size; 416b285192aSMauro Carvalho Chehab /* Calculate write distance to current read position */ 417b285192aSMauro Carvalho Chehab write_distance = 0; 418b285192aSMauro Carvalho Chehab if (curr_gwp >= curr_grp) 419b285192aSMauro Carvalho Chehab /* Write doesn't wrap around the ring */ 420b285192aSMauro Carvalho Chehab write_distance = curr_gwp - curr_grp; 421b285192aSMauro Carvalho Chehab else 422b285192aSMauro Carvalho Chehab /* Write wraps around the ring */ 423b285192aSMauro Carvalho Chehab write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; 424b285192aSMauro Carvalho Chehab 425b285192aSMauro Carvalho Chehab if (bytes_to_read > write_distance) { 42624f711c1SMauro Carvalho Chehab printk(KERN_ERR "%s() Invalid bus state, missing msg or mangled ring, faulty H/W / bad code?\n", 42724f711c1SMauro Carvalho Chehab __func__); 428b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND; 429b285192aSMauro Carvalho Chehab goto out; 430b285192aSMauro Carvalho Chehab } 431b285192aSMauro Carvalho Chehab 432b285192aSMauro Carvalho Chehab /* Calculate the new read position */ 433b285192aSMauro Carvalho Chehab new_grp = curr_grp + bytes_to_read; 434b285192aSMauro Carvalho Chehab if (new_grp > bus->m_dwSizeGetRing) { 435b285192aSMauro Carvalho Chehab 436b285192aSMauro Carvalho Chehab /* Ring wraps */ 437b285192aSMauro Carvalho Chehab new_grp -= bus->m_dwSizeGetRing; 438b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeGetRing - curr_grp; 439b285192aSMauro Carvalho Chehab 440b285192aSMauro Carvalho Chehab if (space_rem < sizeof(*msg)) { 441b285192aSMauro Carvalho Chehab if (buf) 442065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) - 443b285192aSMauro Carvalho Chehab space_rem, buf_size); 444b285192aSMauro Carvalho Chehab 445b285192aSMauro Carvalho Chehab } else if (space_rem == sizeof(*msg)) { 446b285192aSMauro Carvalho Chehab if (buf) 447065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing, buf_size); 448b285192aSMauro Carvalho Chehab } else { 449b285192aSMauro Carvalho Chehab /* Additional data wraps around the ring */ 450b285192aSMauro Carvalho Chehab if (buf) { 451065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + 452b285192aSMauro Carvalho Chehab sizeof(*msg), space_rem - sizeof(*msg)); 453065e1477SHans Verkuil memcpy_fromio(buf + space_rem - sizeof(*msg), 454b285192aSMauro Carvalho Chehab bus->m_pdwGetRing, bytes_to_read - 455b285192aSMauro Carvalho Chehab space_rem); 456b285192aSMauro Carvalho Chehab } 457b285192aSMauro Carvalho Chehab 458b285192aSMauro Carvalho Chehab } 459b285192aSMauro Carvalho Chehab 460b285192aSMauro Carvalho Chehab } else { 461b285192aSMauro Carvalho Chehab /* No wrapping */ 462b285192aSMauro Carvalho Chehab if (buf) 463065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg), 464b285192aSMauro Carvalho Chehab buf_size); 465b285192aSMauro Carvalho Chehab } 466b285192aSMauro Carvalho Chehab 467b285192aSMauro Carvalho Chehab /* Update the read positions, adjusting the ring */ 468065e1477SHans Verkuil saa7164_writel(bus->m_dwGetReadPos, new_grp); 469b285192aSMauro Carvalho Chehab 470b285192aSMauro Carvalho Chehab peekout: 471b285192aSMauro Carvalho Chehab ret = SAA_OK; 472b285192aSMauro Carvalho Chehab out: 473b285192aSMauro Carvalho Chehab mutex_unlock(&bus->lock); 474b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev); 475b285192aSMauro Carvalho Chehab return ret; 476b285192aSMauro Carvalho Chehab } 477b285192aSMauro Carvalho Chehab 478