1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * TW5864 driver - core functions
4 *
5 * Copyright (C) 2016 Bluecherry, LLC <maintainers@bluecherrydvr.com>
6 */
7
8 #include <linux/init.h>
9 #include <linux/list.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/kmod.h>
14 #include <linux/sound.h>
15 #include <linux/interrupt.h>
16 #include <linux/delay.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/pm.h>
19 #include <linux/pci_ids.h>
20 #include <linux/jiffies.h>
21 #include <asm/dma.h>
22 #include <media/v4l2-dev.h>
23
24 #include "tw5864.h"
25 #include "tw5864-reg.h"
26
27 MODULE_DESCRIPTION("V4L2 driver module for tw5864-based multimedia capture & encoding devices");
28 MODULE_AUTHOR("Bluecherry Maintainers <maintainers@bluecherrydvr.com>");
29 MODULE_AUTHOR("Andrey Utkin <andrey.utkin@corp.bluecherry.net>");
30 MODULE_LICENSE("GPL");
31
32 /*
33 * BEWARE OF KNOWN ISSUES WITH VIDEO QUALITY
34 *
35 * This driver was developed by Bluecherry LLC by deducing behaviour of
36 * original manufacturer's driver, from both source code and execution traces.
37 * It is known that there are some artifacts on output video with this driver:
38 * - on all known hardware samples: random pixels of wrong color (mostly
39 * white, red or blue) appearing and disappearing on sequences of P-frames;
40 * - on some hardware samples (known with H.264 core version e006:2800):
41 * total madness on P-frames: blocks of wrong luminance; blocks of wrong
42 * colors "creeping" across the picture.
43 * There is a workaround for both issues: avoid P-frames by setting GOP size
44 * to 1. To do that, run this command on device files created by this driver:
45 *
46 * v4l2-ctl --device /dev/videoX --set-ctrl=video_gop_size=1
47 *
48 * These issues are not decoding errors; all produced H.264 streams are decoded
49 * properly. Streams without P-frames don't have these artifacts so it's not
50 * analog-to-digital conversion issues nor internal memory errors; we conclude
51 * it's internal H.264 encoder issues.
52 * We cannot even check the original driver's behaviour because it has never
53 * worked properly at all in our development environment. So these issues may
54 * be actually related to firmware or hardware. However it may be that there's
55 * just some more register settings missing in the driver which would please
56 * the hardware.
57 * Manufacturer didn't help much on our inquiries, but feel free to disturb
58 * again the support of Intersil (owner of former Techwell).
59 */
60
61 /* take first free /dev/videoX indexes by default */
62 static unsigned int video_nr[] = {[0 ... (TW5864_INPUTS - 1)] = -1 };
63
64 module_param_array(video_nr, int, NULL, 0444);
65 MODULE_PARM_DESC(video_nr, "video devices numbers array");
66
67 /*
68 * Please add any new PCI IDs to: https://pci-ids.ucw.cz. This keeps
69 * the PCI ID database up to date. Note that the entries must be
70 * added under vendor 0x1797 (Techwell Inc.) as subsystem IDs.
71 */
72 static const struct pci_device_id tw5864_pci_tbl[] = {
73 {PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, PCI_DEVICE_ID_TECHWELL_5864)},
74 {0,}
75 };
76
tw5864_irqmask_apply(struct tw5864_dev * dev)77 void tw5864_irqmask_apply(struct tw5864_dev *dev)
78 {
79 tw_writel(TW5864_INTR_ENABLE_L, dev->irqmask & 0xffff);
80 tw_writel(TW5864_INTR_ENABLE_H, (dev->irqmask >> 16));
81 }
82
tw5864_interrupts_disable(struct tw5864_dev * dev)83 static void tw5864_interrupts_disable(struct tw5864_dev *dev)
84 {
85 unsigned long flags;
86
87 spin_lock_irqsave(&dev->slock, flags);
88 dev->irqmask = 0;
89 tw5864_irqmask_apply(dev);
90 spin_unlock_irqrestore(&dev->slock, flags);
91 }
92
93 static void tw5864_timer_isr(struct tw5864_dev *dev);
94 static void tw5864_h264_isr(struct tw5864_dev *dev);
95
tw5864_isr(int irq,void * dev_id)96 static irqreturn_t tw5864_isr(int irq, void *dev_id)
97 {
98 struct tw5864_dev *dev = dev_id;
99 u32 status;
100
101 status = tw_readl(TW5864_INTR_STATUS_L) |
102 tw_readl(TW5864_INTR_STATUS_H) << 16;
103 if (!status)
104 return IRQ_NONE;
105
106 tw_writel(TW5864_INTR_CLR_L, 0xffff);
107 tw_writel(TW5864_INTR_CLR_H, 0xffff);
108
109 if (status & TW5864_INTR_VLC_DONE)
110 tw5864_h264_isr(dev);
111
112 if (status & TW5864_INTR_TIMER)
113 tw5864_timer_isr(dev);
114
115 if (!(status & (TW5864_INTR_TIMER | TW5864_INTR_VLC_DONE))) {
116 dev_dbg(&dev->pci->dev, "Unknown interrupt, status 0x%08X\n",
117 status);
118 }
119
120 return IRQ_HANDLED;
121 }
122
tw5864_h264_isr(struct tw5864_dev * dev)123 static void tw5864_h264_isr(struct tw5864_dev *dev)
124 {
125 int channel = tw_readl(TW5864_DSP) & TW5864_DSP_ENC_CHN;
126 struct tw5864_input *input = &dev->inputs[channel];
127 int cur_frame_index, next_frame_index;
128 struct tw5864_h264_frame *cur_frame, *next_frame;
129 unsigned long flags;
130
131 spin_lock_irqsave(&dev->slock, flags);
132
133 cur_frame_index = dev->h264_buf_w_index;
134 next_frame_index = (cur_frame_index + 1) % H264_BUF_CNT;
135 cur_frame = &dev->h264_buf[cur_frame_index];
136 next_frame = &dev->h264_buf[next_frame_index];
137
138 if (next_frame_index != dev->h264_buf_r_index) {
139 cur_frame->vlc_len = tw_readl(TW5864_VLC_LENGTH) << 2;
140 cur_frame->checksum = tw_readl(TW5864_VLC_CRC_REG);
141 cur_frame->input = input;
142 cur_frame->timestamp = ktime_get_ns();
143 cur_frame->seqno = input->frame_seqno;
144 cur_frame->gop_seqno = input->frame_gop_seqno;
145
146 dev->h264_buf_w_index = next_frame_index;
147 queue_work(system_bh_wq, &dev->bh_work);
148
149 cur_frame = next_frame;
150
151 spin_lock(&input->slock);
152 input->frame_seqno++;
153 input->frame_gop_seqno++;
154 if (input->frame_gop_seqno >= input->gop)
155 input->frame_gop_seqno = 0;
156 spin_unlock(&input->slock);
157 } else {
158 dev_err(&dev->pci->dev,
159 "Skipped frame on input %d because all buffers busy\n",
160 channel);
161 }
162
163 dev->encoder_busy = 0;
164
165 spin_unlock_irqrestore(&dev->slock, flags);
166
167 tw_writel(TW5864_VLC_STREAM_BASE_ADDR, cur_frame->vlc.dma_addr);
168 tw_writel(TW5864_MV_STREAM_BASE_ADDR, cur_frame->mv.dma_addr);
169
170 /* Additional ack for this interrupt */
171 tw_writel(TW5864_VLC_DSP_INTR, 0x00000001);
172 tw_writel(TW5864_PCI_INTR_STATUS, TW5864_VLC_DONE_INTR);
173 }
174
tw5864_input_deadline_update(struct tw5864_input * input)175 static void tw5864_input_deadline_update(struct tw5864_input *input)
176 {
177 input->new_frame_deadline = jiffies + msecs_to_jiffies(1000);
178 }
179
tw5864_timer_isr(struct tw5864_dev * dev)180 static void tw5864_timer_isr(struct tw5864_dev *dev)
181 {
182 unsigned long flags;
183 int i;
184 int encoder_busy;
185
186 /* Additional ack for this interrupt */
187 tw_writel(TW5864_PCI_INTR_STATUS, TW5864_TIMER_INTR);
188
189 spin_lock_irqsave(&dev->slock, flags);
190 encoder_busy = dev->encoder_busy;
191 spin_unlock_irqrestore(&dev->slock, flags);
192
193 if (encoder_busy)
194 return;
195
196 /*
197 * Traversing inputs in round-robin fashion, starting from next to the
198 * last processed one
199 */
200 for (i = 0; i < TW5864_INPUTS; i++) {
201 int next_input = (i + dev->next_input) % TW5864_INPUTS;
202 struct tw5864_input *input = &dev->inputs[next_input];
203 int raw_buf_id; /* id of internal buf with last raw frame */
204
205 spin_lock_irqsave(&input->slock, flags);
206 if (!input->enabled)
207 goto next;
208
209 /* Check if new raw frame is available */
210 raw_buf_id = tw_mask_shift_readl(TW5864_SENIF_ORG_FRM_PTR1, 0x3,
211 2 * input->nr);
212
213 if (input->buf_id != raw_buf_id) {
214 input->buf_id = raw_buf_id;
215 tw5864_input_deadline_update(input);
216 spin_unlock_irqrestore(&input->slock, flags);
217
218 spin_lock_irqsave(&dev->slock, flags);
219 dev->encoder_busy = 1;
220 dev->next_input = (next_input + 1) % TW5864_INPUTS;
221 spin_unlock_irqrestore(&dev->slock, flags);
222
223 tw5864_request_encoded_frame(input);
224 break;
225 }
226
227 /* No new raw frame; check if channel is stuck */
228 if (time_is_after_jiffies(input->new_frame_deadline)) {
229 /* If stuck, request new raw frames again */
230 tw_mask_shift_writel(TW5864_ENC_BUF_PTR_REC1, 0x3,
231 2 * input->nr, input->buf_id + 3);
232 tw5864_input_deadline_update(input);
233 }
234 next:
235 spin_unlock_irqrestore(&input->slock, flags);
236 }
237 }
238
tw5864_initdev(struct pci_dev * pci_dev,const struct pci_device_id * pci_id)239 static int tw5864_initdev(struct pci_dev *pci_dev,
240 const struct pci_device_id *pci_id)
241 {
242 struct tw5864_dev *dev;
243 int err;
244
245 dev = devm_kzalloc(&pci_dev->dev, sizeof(*dev), GFP_KERNEL);
246 if (!dev)
247 return -ENOMEM;
248
249 snprintf(dev->name, sizeof(dev->name), "tw5864:%s", pci_name(pci_dev));
250
251 err = v4l2_device_register(&pci_dev->dev, &dev->v4l2_dev);
252 if (err)
253 return err;
254
255 /* pci init */
256 dev->pci = pci_dev;
257 err = pcim_enable_device(pci_dev);
258 if (err) {
259 dev_err(&dev->pci->dev, "pcim_enable_device() failed\n");
260 goto unreg_v4l2;
261 }
262
263 pci_set_master(pci_dev);
264
265 err = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
266 if (err) {
267 dev_err(&dev->pci->dev, "32 bit PCI DMA is not supported\n");
268 goto unreg_v4l2;
269 }
270
271 /* get mmio */
272 err = pcim_iomap_regions(pci_dev, BIT(0), dev->name);
273 if (err) {
274 dev_err(&dev->pci->dev, "Cannot request regions for MMIO\n");
275 goto unreg_v4l2;
276 }
277 dev->mmio = pcim_iomap_table(pci_dev)[0];
278
279 spin_lock_init(&dev->slock);
280
281 dev_info(&pci_dev->dev, "TW5864 hardware version: %04x\n",
282 tw_readl(TW5864_HW_VERSION));
283 dev_info(&pci_dev->dev, "TW5864 H.264 core version: %04x:%04x\n",
284 tw_readl(TW5864_H264REV),
285 tw_readl(TW5864_UNDECLARED_H264REV_PART2));
286
287 err = tw5864_video_init(dev, video_nr);
288 if (err)
289 goto unreg_v4l2;
290
291 /* get irq */
292 err = devm_request_irq(&pci_dev->dev, pci_dev->irq, tw5864_isr,
293 IRQF_SHARED, "tw5864", dev);
294 if (err < 0) {
295 dev_err(&dev->pci->dev, "can't get IRQ %d\n", pci_dev->irq);
296 goto fini_video;
297 }
298
299 dev_info(&pci_dev->dev, "Note: there are known video quality issues. For details\n");
300 dev_info(&pci_dev->dev, "see the comment in drivers/media/pci/tw5864/tw5864-core.c.\n");
301
302 return 0;
303
304 fini_video:
305 tw5864_video_fini(dev);
306 unreg_v4l2:
307 v4l2_device_unregister(&dev->v4l2_dev);
308 return err;
309 }
310
tw5864_finidev(struct pci_dev * pci_dev)311 static void tw5864_finidev(struct pci_dev *pci_dev)
312 {
313 struct v4l2_device *v4l2_dev = pci_get_drvdata(pci_dev);
314 struct tw5864_dev *dev =
315 container_of(v4l2_dev, struct tw5864_dev, v4l2_dev);
316
317 /* shutdown subsystems */
318 tw5864_interrupts_disable(dev);
319
320 /* unregister */
321 tw5864_video_fini(dev);
322
323 v4l2_device_unregister(&dev->v4l2_dev);
324 }
325
326 static struct pci_driver tw5864_pci_driver = {
327 .name = "tw5864",
328 .id_table = tw5864_pci_tbl,
329 .probe = tw5864_initdev,
330 .remove = tw5864_finidev,
331 };
332
333 module_pci_driver(tw5864_pci_driver);
334