1*c942fddfSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
2b285192aSMauro Carvalho Chehab /*
3b285192aSMauro Carvalho Chehab * Driver for the NXP SAA7164 PCIe bridge
4b285192aSMauro Carvalho Chehab *
563a412ecSSteven Toth * Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
6b285192aSMauro Carvalho Chehab */
7b285192aSMauro Carvalho Chehab
8b285192aSMauro Carvalho Chehab #include "saa7164.h"
9b285192aSMauro Carvalho Chehab
10b285192aSMauro Carvalho Chehab /* The message bus to/from the firmware is a ring buffer in PCI address
11b285192aSMauro Carvalho Chehab * space. Establish the defaults.
12b285192aSMauro Carvalho Chehab */
saa7164_bus_setup(struct saa7164_dev * dev)13b285192aSMauro Carvalho Chehab int saa7164_bus_setup(struct saa7164_dev *dev)
14b285192aSMauro Carvalho Chehab {
15b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus;
16b285192aSMauro Carvalho Chehab
17b285192aSMauro Carvalho Chehab mutex_init(&b->lock);
18b285192aSMauro Carvalho Chehab
19b285192aSMauro Carvalho Chehab b->Type = TYPE_BUS_PCIe;
20b285192aSMauro Carvalho Chehab b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE;
21b285192aSMauro Carvalho Chehab
22065e1477SHans Verkuil b->m_pdwSetRing = (u8 __iomem *)(dev->bmmio +
23b285192aSMauro Carvalho Chehab ((u32)dev->busdesc.CommandRing));
24b285192aSMauro Carvalho Chehab
25b285192aSMauro Carvalho Chehab b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
26b285192aSMauro Carvalho Chehab
27065e1477SHans Verkuil b->m_pdwGetRing = (u8 __iomem *)(dev->bmmio +
28b285192aSMauro Carvalho Chehab ((u32)dev->busdesc.ResponseRing));
29b285192aSMauro Carvalho Chehab
30b285192aSMauro Carvalho Chehab b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
31b285192aSMauro Carvalho Chehab
32b285192aSMauro Carvalho Chehab b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) +
33b285192aSMauro Carvalho Chehab (2 * sizeof(u64));
34b285192aSMauro Carvalho Chehab b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
35b285192aSMauro Carvalho Chehab
36b285192aSMauro Carvalho Chehab b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
37b285192aSMauro Carvalho Chehab b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
38b285192aSMauro Carvalho Chehab
39b285192aSMauro Carvalho Chehab return 0;
40b285192aSMauro Carvalho Chehab }
41b285192aSMauro Carvalho Chehab
saa7164_bus_dump(struct saa7164_dev * dev)42b285192aSMauro Carvalho Chehab void saa7164_bus_dump(struct saa7164_dev *dev)
43b285192aSMauro Carvalho Chehab {
44b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus;
45b285192aSMauro Carvalho Chehab
46b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
47b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
48b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
49b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
50b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
51b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
52b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
53b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
54b285192aSMauro Carvalho Chehab
55b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
56b285192aSMauro Carvalho Chehab b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
57b285192aSMauro Carvalho Chehab
58b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
59b285192aSMauro Carvalho Chehab b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
60b285192aSMauro Carvalho Chehab
61b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
62b285192aSMauro Carvalho Chehab b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
63b285192aSMauro Carvalho Chehab
64b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
65b285192aSMauro Carvalho Chehab b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
66b285192aSMauro Carvalho Chehab
67b285192aSMauro Carvalho Chehab }
68b285192aSMauro Carvalho Chehab
69b285192aSMauro Carvalho Chehab /* Intensionally throw a BUG() if the state of the message bus looks corrupt */
saa7164_bus_verify(struct saa7164_dev * dev)705faf7db8SMauro Carvalho Chehab static void saa7164_bus_verify(struct saa7164_dev *dev)
71b285192aSMauro Carvalho Chehab {
72b285192aSMauro Carvalho Chehab struct tmComResBusInfo *b = &dev->bus;
73b285192aSMauro Carvalho Chehab int bug = 0;
74b285192aSMauro Carvalho Chehab
75b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
76b285192aSMauro Carvalho Chehab bug++;
77b285192aSMauro Carvalho Chehab
78b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
79b285192aSMauro Carvalho Chehab bug++;
80b285192aSMauro Carvalho Chehab
81b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
82b285192aSMauro Carvalho Chehab bug++;
83b285192aSMauro Carvalho Chehab
84b285192aSMauro Carvalho Chehab if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
85b285192aSMauro Carvalho Chehab bug++;
86b285192aSMauro Carvalho Chehab
87b285192aSMauro Carvalho Chehab if (bug) {
88b285192aSMauro Carvalho Chehab saa_debug = 0xffff; /* Ensure we get the bus dump */
89b285192aSMauro Carvalho Chehab saa7164_bus_dump(dev);
90b285192aSMauro Carvalho Chehab saa_debug = 1024; /* Ensure we get the bus dump */
91b285192aSMauro Carvalho Chehab BUG();
92b285192aSMauro Carvalho Chehab }
93b285192aSMauro Carvalho Chehab }
94b285192aSMauro Carvalho Chehab
saa7164_bus_dumpmsg(struct saa7164_dev * dev,struct tmComResInfo * m,void * buf)955faf7db8SMauro Carvalho Chehab static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m,
96b285192aSMauro Carvalho Chehab void *buf)
97b285192aSMauro Carvalho Chehab {
98b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
99b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
100b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
101b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
102b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
103b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
104b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
105b285192aSMauro Carvalho Chehab if (buf)
106b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
107b285192aSMauro Carvalho Chehab }
108b285192aSMauro Carvalho Chehab
109b285192aSMauro Carvalho Chehab /*
110b285192aSMauro Carvalho Chehab * Places a command or a response on the bus. The implementation does not
111b285192aSMauro Carvalho Chehab * know if it is a command or a response it just places the data on the
112b285192aSMauro Carvalho Chehab * bus depending on the bus information given in the struct tmComResBusInfo
113b285192aSMauro Carvalho Chehab * structure. If the command or response does not fit into the bus ring
114b285192aSMauro Carvalho Chehab * buffer it will be refused.
115b285192aSMauro Carvalho Chehab *
116b285192aSMauro Carvalho Chehab * Return Value:
117b285192aSMauro Carvalho Chehab * SAA_OK The function executed successfully.
118b285192aSMauro Carvalho Chehab * < 0 One or more members are not initialized.
119b285192aSMauro Carvalho Chehab */
saa7164_bus_set(struct saa7164_dev * dev,struct tmComResInfo * msg,void * buf)120b285192aSMauro Carvalho Chehab int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
121b285192aSMauro Carvalho Chehab void *buf)
122b285192aSMauro Carvalho Chehab {
123b285192aSMauro Carvalho Chehab struct tmComResBusInfo *bus = &dev->bus;
124b285192aSMauro Carvalho Chehab u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
125b285192aSMauro Carvalho Chehab u32 new_swp, space_rem;
126b285192aSMauro Carvalho Chehab int ret = SAA_ERR_BAD_PARAMETER;
127065e1477SHans Verkuil u16 size;
128b285192aSMauro Carvalho Chehab
129b285192aSMauro Carvalho Chehab if (!msg) {
130b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() !msg\n", __func__);
131b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER;
132b285192aSMauro Carvalho Chehab }
133b285192aSMauro Carvalho Chehab
134b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s()\n", __func__);
135b285192aSMauro Carvalho Chehab
136b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev);
137b285192aSMauro Carvalho Chehab
138b285192aSMauro Carvalho Chehab if (msg->size > dev->bus.m_wMaxReqSize) {
139b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
140b285192aSMauro Carvalho Chehab __func__);
141b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER;
142b285192aSMauro Carvalho Chehab }
143b285192aSMauro Carvalho Chehab
144b285192aSMauro Carvalho Chehab if ((msg->size > 0) && (buf == NULL)) {
145b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Missing message buffer\n", __func__);
146b285192aSMauro Carvalho Chehab return SAA_ERR_BAD_PARAMETER;
147b285192aSMauro Carvalho Chehab }
148b285192aSMauro Carvalho Chehab
149b285192aSMauro Carvalho Chehab /* Lock the bus from any other access */
150b285192aSMauro Carvalho Chehab mutex_lock(&bus->lock);
151b285192aSMauro Carvalho Chehab
152b285192aSMauro Carvalho Chehab bytes_to_write = sizeof(*msg) + msg->size;
153b285192aSMauro Carvalho Chehab free_write_space = 0;
154b285192aSMauro Carvalho Chehab timeout = SAA_BUS_TIMEOUT;
155065e1477SHans Verkuil curr_srp = saa7164_readl(bus->m_dwSetReadPos);
156065e1477SHans Verkuil curr_swp = saa7164_readl(bus->m_dwSetWritePos);
157b285192aSMauro Carvalho Chehab
158b285192aSMauro Carvalho Chehab /* Deal with ring wrapping issues */
159b285192aSMauro Carvalho Chehab if (curr_srp > curr_swp)
160b285192aSMauro Carvalho Chehab /* Deal with the wrapped ring */
161b285192aSMauro Carvalho Chehab free_write_space = curr_srp - curr_swp;
162b285192aSMauro Carvalho Chehab else
163b285192aSMauro Carvalho Chehab /* The ring has not wrapped yet */
164b285192aSMauro Carvalho Chehab free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
165b285192aSMauro Carvalho Chehab
166b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
167b285192aSMauro Carvalho Chehab bytes_to_write);
168b285192aSMauro Carvalho Chehab
169b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
170b285192aSMauro Carvalho Chehab free_write_space);
171b285192aSMauro Carvalho Chehab
172b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
173b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
174b285192aSMauro Carvalho Chehab
175b285192aSMauro Carvalho Chehab /* Process the msg and write the content onto the bus */
176b285192aSMauro Carvalho Chehab while (bytes_to_write >= free_write_space) {
177b285192aSMauro Carvalho Chehab
178b285192aSMauro Carvalho Chehab if (timeout-- == 0) {
179b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() bus timeout\n", __func__);
180b285192aSMauro Carvalho Chehab ret = SAA_ERR_NO_RESOURCES;
181b285192aSMauro Carvalho Chehab goto out;
182b285192aSMauro Carvalho Chehab }
183b285192aSMauro Carvalho Chehab
184b285192aSMauro Carvalho Chehab /* TODO: Review this delay, efficient? */
185b285192aSMauro Carvalho Chehab /* Wait, allowing the hardware fetch time */
186b285192aSMauro Carvalho Chehab mdelay(1);
187b285192aSMauro Carvalho Chehab
188b285192aSMauro Carvalho Chehab /* Check the space usage again */
189065e1477SHans Verkuil curr_srp = saa7164_readl(bus->m_dwSetReadPos);
190b285192aSMauro Carvalho Chehab
191b285192aSMauro Carvalho Chehab /* Deal with ring wrapping issues */
192b285192aSMauro Carvalho Chehab if (curr_srp > curr_swp)
193b285192aSMauro Carvalho Chehab /* Deal with the wrapped ring */
194b285192aSMauro Carvalho Chehab free_write_space = curr_srp - curr_swp;
195b285192aSMauro Carvalho Chehab else
196b285192aSMauro Carvalho Chehab /* Read didn't wrap around the buffer */
197b285192aSMauro Carvalho Chehab free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
198b285192aSMauro Carvalho Chehab curr_swp;
199b285192aSMauro Carvalho Chehab
200b285192aSMauro Carvalho Chehab }
201b285192aSMauro Carvalho Chehab
202b285192aSMauro Carvalho Chehab /* Calculate the new write position */
203b285192aSMauro Carvalho Chehab new_swp = curr_swp + bytes_to_write;
204b285192aSMauro Carvalho Chehab
205b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
206b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
207b285192aSMauro Carvalho Chehab bus->m_dwSizeSetRing);
208b285192aSMauro Carvalho Chehab
209065e1477SHans Verkuil /*
210065e1477SHans Verkuil * Make a copy of msg->size before it is converted to le16 since it is
211065e1477SHans Verkuil * used in the code below.
212065e1477SHans Verkuil */
213065e1477SHans Verkuil size = msg->size;
214065e1477SHans Verkuil /* Convert to le16/le32 */
215065e1477SHans Verkuil msg->size = (__force u16)cpu_to_le16(msg->size);
216065e1477SHans Verkuil msg->command = (__force u32)cpu_to_le32(msg->command);
217065e1477SHans Verkuil msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector);
218065e1477SHans Verkuil
219b285192aSMauro Carvalho Chehab /* Mental Note: line 462 tmmhComResBusPCIe.cpp */
220b285192aSMauro Carvalho Chehab
221b285192aSMauro Carvalho Chehab /* Check if we're going to wrap again */
222b285192aSMauro Carvalho Chehab if (new_swp > bus->m_dwSizeSetRing) {
223b285192aSMauro Carvalho Chehab
224b285192aSMauro Carvalho Chehab /* Ring wraps */
225b285192aSMauro Carvalho Chehab new_swp -= bus->m_dwSizeSetRing;
226b285192aSMauro Carvalho Chehab
227b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeSetRing - curr_swp;
228b285192aSMauro Carvalho Chehab
229b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
230b285192aSMauro Carvalho Chehab space_rem);
231b285192aSMauro Carvalho Chehab
232b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
233b285192aSMauro Carvalho Chehab (u32)sizeof(*msg));
234b285192aSMauro Carvalho Chehab
235b285192aSMauro Carvalho Chehab if (space_rem < sizeof(*msg)) {
236b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
237b285192aSMauro Carvalho Chehab
238b285192aSMauro Carvalho Chehab /* Split the msg into pieces as the ring wraps */
239065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem);
240065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem,
241b285192aSMauro Carvalho Chehab sizeof(*msg) - space_rem);
242b285192aSMauro Carvalho Chehab
243065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
244065e1477SHans Verkuil buf, size);
245b285192aSMauro Carvalho Chehab
246b285192aSMauro Carvalho Chehab } else if (space_rem == sizeof(*msg)) {
247b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
248b285192aSMauro Carvalho Chehab
249b285192aSMauro Carvalho Chehab /* Additional data at the beginning of the ring */
250065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
251065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, buf, size);
252b285192aSMauro Carvalho Chehab
253b285192aSMauro Carvalho Chehab } else {
254b285192aSMauro Carvalho Chehab /* Additional data wraps around the ring */
255065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
256065e1477SHans Verkuil if (size > 0) {
257065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp +
258b285192aSMauro Carvalho Chehab sizeof(*msg), buf, space_rem -
259b285192aSMauro Carvalho Chehab sizeof(*msg));
260065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing, (u8 *)buf +
261b285192aSMauro Carvalho Chehab space_rem - sizeof(*msg),
262b285192aSMauro Carvalho Chehab bytes_to_write - space_rem);
263b285192aSMauro Carvalho Chehab }
264b285192aSMauro Carvalho Chehab
265b285192aSMauro Carvalho Chehab }
266b285192aSMauro Carvalho Chehab
267b285192aSMauro Carvalho Chehab } /* (new_swp > bus->m_dwSizeSetRing) */
268b285192aSMauro Carvalho Chehab else {
269b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
270b285192aSMauro Carvalho Chehab
271b285192aSMauro Carvalho Chehab /* The ring buffer doesn't wrap, two simple copies */
272065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
273065e1477SHans Verkuil memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
274065e1477SHans Verkuil size);
275b285192aSMauro Carvalho Chehab }
276b285192aSMauro Carvalho Chehab
277b285192aSMauro Carvalho Chehab dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
278b285192aSMauro Carvalho Chehab
279b285192aSMauro Carvalho Chehab /* Update the bus write position */
280065e1477SHans Verkuil saa7164_writel(bus->m_dwSetWritePos, new_swp);
281065e1477SHans Verkuil
282065e1477SHans Verkuil /* Convert back to cpu after writing the msg to the ringbuffer. */
283065e1477SHans Verkuil msg->size = le16_to_cpu((__force __le16)msg->size);
284065e1477SHans Verkuil msg->command = le32_to_cpu((__force __le32)msg->command);
285065e1477SHans Verkuil msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector);
286b285192aSMauro Carvalho Chehab ret = SAA_OK;
287b285192aSMauro Carvalho Chehab
288b285192aSMauro Carvalho Chehab out:
289b285192aSMauro Carvalho Chehab saa7164_bus_dump(dev);
290b285192aSMauro Carvalho Chehab mutex_unlock(&bus->lock);
291b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev);
292b285192aSMauro Carvalho Chehab return ret;
293b285192aSMauro Carvalho Chehab }
294b285192aSMauro Carvalho Chehab
295b285192aSMauro Carvalho Chehab /*
296b285192aSMauro Carvalho Chehab * Receive a command or a response from the bus. The implementation does not
297b285192aSMauro Carvalho Chehab * know if it is a command or a response it simply dequeues the data,
298b285192aSMauro Carvalho Chehab * depending on the bus information given in the struct tmComResBusInfo
299b285192aSMauro Carvalho Chehab * structure.
300b285192aSMauro Carvalho Chehab *
301b285192aSMauro Carvalho Chehab * Return Value:
302b285192aSMauro Carvalho Chehab * 0 The function executed successfully.
303b285192aSMauro Carvalho Chehab * < 0 One or more members are not initialized.
304b285192aSMauro Carvalho Chehab */
saa7164_bus_get(struct saa7164_dev * dev,struct tmComResInfo * msg,void * buf,int peekonly)305b285192aSMauro Carvalho Chehab int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
306b285192aSMauro Carvalho Chehab void *buf, int peekonly)
307b285192aSMauro Carvalho Chehab {
308b285192aSMauro Carvalho Chehab struct tmComResBusInfo *bus = &dev->bus;
309b285192aSMauro Carvalho Chehab u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
310b285192aSMauro Carvalho Chehab new_grp, buf_size, space_rem;
311b285192aSMauro Carvalho Chehab struct tmComResInfo msg_tmp;
312b285192aSMauro Carvalho Chehab int ret = SAA_ERR_BAD_PARAMETER;
313b285192aSMauro Carvalho Chehab
314b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev);
315b285192aSMauro Carvalho Chehab
316b285192aSMauro Carvalho Chehab if (msg == NULL)
317b285192aSMauro Carvalho Chehab return ret;
318b285192aSMauro Carvalho Chehab
319b285192aSMauro Carvalho Chehab if (msg->size > dev->bus.m_wMaxReqSize) {
320b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
321b285192aSMauro Carvalho Chehab __func__);
322b285192aSMauro Carvalho Chehab return ret;
323b285192aSMauro Carvalho Chehab }
324b285192aSMauro Carvalho Chehab
325b285192aSMauro Carvalho Chehab if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
326b285192aSMauro Carvalho Chehab printk(KERN_ERR
327b285192aSMauro Carvalho Chehab "%s() Missing msg buf, size should be %d bytes\n",
328b285192aSMauro Carvalho Chehab __func__, msg->size);
329b285192aSMauro Carvalho Chehab return ret;
330b285192aSMauro Carvalho Chehab }
331b285192aSMauro Carvalho Chehab
332b285192aSMauro Carvalho Chehab mutex_lock(&bus->lock);
333b285192aSMauro Carvalho Chehab
334b285192aSMauro Carvalho Chehab /* Peek the bus to see if a msg exists, if it's not what we're expecting
335b285192aSMauro Carvalho Chehab * then return cleanly else read the message from the bus.
336b285192aSMauro Carvalho Chehab */
337065e1477SHans Verkuil curr_gwp = saa7164_readl(bus->m_dwGetWritePos);
338065e1477SHans Verkuil curr_grp = saa7164_readl(bus->m_dwGetReadPos);
339b285192aSMauro Carvalho Chehab
340b285192aSMauro Carvalho Chehab if (curr_gwp == curr_grp) {
341b285192aSMauro Carvalho Chehab ret = SAA_ERR_EMPTY;
342b285192aSMauro Carvalho Chehab goto out;
343b285192aSMauro Carvalho Chehab }
344b285192aSMauro Carvalho Chehab
345b285192aSMauro Carvalho Chehab bytes_to_read = sizeof(*msg);
346b285192aSMauro Carvalho Chehab
347b285192aSMauro Carvalho Chehab /* Calculate write distance to current read position */
348b285192aSMauro Carvalho Chehab write_distance = 0;
349b285192aSMauro Carvalho Chehab if (curr_gwp >= curr_grp)
350b285192aSMauro Carvalho Chehab /* Write doesn't wrap around the ring */
351b285192aSMauro Carvalho Chehab write_distance = curr_gwp - curr_grp;
352b285192aSMauro Carvalho Chehab else
353b285192aSMauro Carvalho Chehab /* Write wraps around the ring */
354b285192aSMauro Carvalho Chehab write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
355b285192aSMauro Carvalho Chehab
356b285192aSMauro Carvalho Chehab if (bytes_to_read > write_distance) {
357b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() No message/response found\n", __func__);
358b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND;
359b285192aSMauro Carvalho Chehab goto out;
360b285192aSMauro Carvalho Chehab }
361b285192aSMauro Carvalho Chehab
362b285192aSMauro Carvalho Chehab /* Calculate the new read position */
363b285192aSMauro Carvalho Chehab new_grp = curr_grp + bytes_to_read;
364b285192aSMauro Carvalho Chehab if (new_grp > bus->m_dwSizeGetRing) {
365b285192aSMauro Carvalho Chehab
366b285192aSMauro Carvalho Chehab /* Ring wraps */
367b285192aSMauro Carvalho Chehab new_grp -= bus->m_dwSizeGetRing;
368b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeGetRing - curr_grp;
369b285192aSMauro Carvalho Chehab
370065e1477SHans Verkuil memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
371065e1477SHans Verkuil memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
372b285192aSMauro Carvalho Chehab bytes_to_read - space_rem);
373b285192aSMauro Carvalho Chehab
374b285192aSMauro Carvalho Chehab } else {
375b285192aSMauro Carvalho Chehab /* No wrapping */
376065e1477SHans Verkuil memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
377b285192aSMauro Carvalho Chehab }
378065e1477SHans Verkuil /* Convert from little endian to CPU */
379065e1477SHans Verkuil msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size);
380065e1477SHans Verkuil msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command);
381065e1477SHans Verkuil msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector);
3826fb05e0dSSteven Toth memcpy(msg, &msg_tmp, sizeof(*msg));
383b285192aSMauro Carvalho Chehab
384b285192aSMauro Carvalho Chehab /* No need to update the read positions, because this was a peek */
385b285192aSMauro Carvalho Chehab /* If the caller specifically want to peek, return */
386b285192aSMauro Carvalho Chehab if (peekonly) {
387b285192aSMauro Carvalho Chehab goto peekout;
388b285192aSMauro Carvalho Chehab }
389b285192aSMauro Carvalho Chehab
390b285192aSMauro Carvalho Chehab /* Check if the command/response matches what is expected */
391b285192aSMauro Carvalho Chehab if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
392b285192aSMauro Carvalho Chehab (msg_tmp.controlselector != msg->controlselector) ||
393b285192aSMauro Carvalho Chehab (msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {
394b285192aSMauro Carvalho Chehab
395b285192aSMauro Carvalho Chehab printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
396b285192aSMauro Carvalho Chehab saa7164_bus_dumpmsg(dev, msg, buf);
397b285192aSMauro Carvalho Chehab saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
398b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND;
399b285192aSMauro Carvalho Chehab goto out;
400b285192aSMauro Carvalho Chehab }
401b285192aSMauro Carvalho Chehab
402b285192aSMauro Carvalho Chehab /* Get the actual command and response from the bus */
403b285192aSMauro Carvalho Chehab buf_size = msg->size;
404b285192aSMauro Carvalho Chehab
405b285192aSMauro Carvalho Chehab bytes_to_read = sizeof(*msg) + msg->size;
406b285192aSMauro Carvalho Chehab /* Calculate write distance to current read position */
407b285192aSMauro Carvalho Chehab write_distance = 0;
408b285192aSMauro Carvalho Chehab if (curr_gwp >= curr_grp)
409b285192aSMauro Carvalho Chehab /* Write doesn't wrap around the ring */
410b285192aSMauro Carvalho Chehab write_distance = curr_gwp - curr_grp;
411b285192aSMauro Carvalho Chehab else
412b285192aSMauro Carvalho Chehab /* Write wraps around the ring */
413b285192aSMauro Carvalho Chehab write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
414b285192aSMauro Carvalho Chehab
415b285192aSMauro Carvalho Chehab if (bytes_to_read > write_distance) {
41624f711c1SMauro Carvalho Chehab printk(KERN_ERR "%s() Invalid bus state, missing msg or mangled ring, faulty H/W / bad code?\n",
41724f711c1SMauro Carvalho Chehab __func__);
418b285192aSMauro Carvalho Chehab ret = SAA_ERR_INVALID_COMMAND;
419b285192aSMauro Carvalho Chehab goto out;
420b285192aSMauro Carvalho Chehab }
421b285192aSMauro Carvalho Chehab
422b285192aSMauro Carvalho Chehab /* Calculate the new read position */
423b285192aSMauro Carvalho Chehab new_grp = curr_grp + bytes_to_read;
424b285192aSMauro Carvalho Chehab if (new_grp > bus->m_dwSizeGetRing) {
425b285192aSMauro Carvalho Chehab
426b285192aSMauro Carvalho Chehab /* Ring wraps */
427b285192aSMauro Carvalho Chehab new_grp -= bus->m_dwSizeGetRing;
428b285192aSMauro Carvalho Chehab space_rem = bus->m_dwSizeGetRing - curr_grp;
429b285192aSMauro Carvalho Chehab
430b285192aSMauro Carvalho Chehab if (space_rem < sizeof(*msg)) {
431b285192aSMauro Carvalho Chehab if (buf)
432065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) -
433b285192aSMauro Carvalho Chehab space_rem, buf_size);
434b285192aSMauro Carvalho Chehab
435b285192aSMauro Carvalho Chehab } else if (space_rem == sizeof(*msg)) {
436b285192aSMauro Carvalho Chehab if (buf)
437065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing, buf_size);
438b285192aSMauro Carvalho Chehab } else {
439b285192aSMauro Carvalho Chehab /* Additional data wraps around the ring */
440b285192aSMauro Carvalho Chehab if (buf) {
441065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp +
442b285192aSMauro Carvalho Chehab sizeof(*msg), space_rem - sizeof(*msg));
443065e1477SHans Verkuil memcpy_fromio(buf + space_rem - sizeof(*msg),
444b285192aSMauro Carvalho Chehab bus->m_pdwGetRing, bytes_to_read -
445b285192aSMauro Carvalho Chehab space_rem);
446b285192aSMauro Carvalho Chehab }
447b285192aSMauro Carvalho Chehab
448b285192aSMauro Carvalho Chehab }
449b285192aSMauro Carvalho Chehab
450b285192aSMauro Carvalho Chehab } else {
451b285192aSMauro Carvalho Chehab /* No wrapping */
452b285192aSMauro Carvalho Chehab if (buf)
453065e1477SHans Verkuil memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
454b285192aSMauro Carvalho Chehab buf_size);
455b285192aSMauro Carvalho Chehab }
456b285192aSMauro Carvalho Chehab
457b285192aSMauro Carvalho Chehab /* Update the read positions, adjusting the ring */
458065e1477SHans Verkuil saa7164_writel(bus->m_dwGetReadPos, new_grp);
459b285192aSMauro Carvalho Chehab
460b285192aSMauro Carvalho Chehab peekout:
461b285192aSMauro Carvalho Chehab ret = SAA_OK;
462b285192aSMauro Carvalho Chehab out:
463b285192aSMauro Carvalho Chehab mutex_unlock(&bus->lock);
464b285192aSMauro Carvalho Chehab saa7164_bus_verify(dev);
465b285192aSMauro Carvalho Chehab return ret;
466b285192aSMauro Carvalho Chehab }
467b285192aSMauro Carvalho Chehab
468