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: http://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 
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 
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 
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 
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 		tasklet_schedule(&dev->tasklet);
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 
175 static void tw5864_input_deadline_update(struct tw5864_input *input)
176 {
177 	input->new_frame_deadline = jiffies + msecs_to_jiffies(1000);
178 }
179 
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 
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 = pci_enable_device(pci_dev);
258 	if (err) {
259 		dev_err(&dev->pci->dev, "pci_enable_device() failed\n");
260 		goto unreg_v4l2;
261 	}
262 
263 	pci_set_master(pci_dev);
264 
265 	err = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
266 	if (err) {
267 		dev_err(&dev->pci->dev, "32 bit PCI DMA is not supported\n");
268 		goto disable_pci;
269 	}
270 
271 	/* get mmio */
272 	err = pci_request_regions(pci_dev, dev->name);
273 	if (err) {
274 		dev_err(&dev->pci->dev, "Cannot request regions for MMIO\n");
275 		goto disable_pci;
276 	}
277 	dev->mmio = pci_ioremap_bar(pci_dev, 0);
278 	if (!dev->mmio) {
279 		err = -EIO;
280 		dev_err(&dev->pci->dev, "can't ioremap() MMIO memory\n");
281 		goto release_mmio;
282 	}
283 
284 	spin_lock_init(&dev->slock);
285 
286 	dev_info(&pci_dev->dev, "TW5864 hardware version: %04x\n",
287 		 tw_readl(TW5864_HW_VERSION));
288 	dev_info(&pci_dev->dev, "TW5864 H.264 core version: %04x:%04x\n",
289 		 tw_readl(TW5864_H264REV),
290 		 tw_readl(TW5864_UNDECLARED_H264REV_PART2));
291 
292 	err = tw5864_video_init(dev, video_nr);
293 	if (err)
294 		goto unmap_mmio;
295 
296 	/* get irq */
297 	err = devm_request_irq(&pci_dev->dev, pci_dev->irq, tw5864_isr,
298 			       IRQF_SHARED, "tw5864", dev);
299 	if (err < 0) {
300 		dev_err(&dev->pci->dev, "can't get IRQ %d\n", pci_dev->irq);
301 		goto fini_video;
302 	}
303 
304 	dev_info(&pci_dev->dev, "Note: there are known video quality issues. For details\n");
305 	dev_info(&pci_dev->dev, "see the comment in drivers/media/pci/tw5864/tw5864-core.c.\n");
306 
307 	return 0;
308 
309 fini_video:
310 	tw5864_video_fini(dev);
311 unmap_mmio:
312 	iounmap(dev->mmio);
313 release_mmio:
314 	pci_release_regions(pci_dev);
315 disable_pci:
316 	pci_disable_device(pci_dev);
317 unreg_v4l2:
318 	v4l2_device_unregister(&dev->v4l2_dev);
319 	return err;
320 }
321 
322 static void tw5864_finidev(struct pci_dev *pci_dev)
323 {
324 	struct v4l2_device *v4l2_dev = pci_get_drvdata(pci_dev);
325 	struct tw5864_dev *dev =
326 		container_of(v4l2_dev, struct tw5864_dev, v4l2_dev);
327 
328 	/* shutdown subsystems */
329 	tw5864_interrupts_disable(dev);
330 
331 	/* unregister */
332 	tw5864_video_fini(dev);
333 
334 	/* release resources */
335 	iounmap(dev->mmio);
336 	release_mem_region(pci_resource_start(pci_dev, 0),
337 			   pci_resource_len(pci_dev, 0));
338 
339 	v4l2_device_unregister(&dev->v4l2_dev);
340 	devm_kfree(&pci_dev->dev, dev);
341 }
342 
343 static struct pci_driver tw5864_pci_driver = {
344 	.name = "tw5864",
345 	.id_table = tw5864_pci_tbl,
346 	.probe = tw5864_initdev,
347 	.remove = tw5864_finidev,
348 };
349 
350 module_pci_driver(tw5864_pci_driver);
351