tw5864-core.c

  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#define DRIVER_NAME "tw5864"
 28
 29MODULE_DESCRIPTION("V4L2 driver module for tw5864-based multimedia capture & encoding devices");
 30MODULE_AUTHOR("Bluecherry Maintainers <maintainers@bluecherrydvr.com>");
 31MODULE_AUTHOR("Andrey Utkin <andrey.utkin@corp.bluecherry.net>");
 32MODULE_LICENSE("GPL");
 33
 34/*
 35 * BEWARE OF KNOWN ISSUES WITH VIDEO QUALITY
 36 *
 37 * This driver was developed by Bluecherry LLC by deducing behaviour of
 38 * original manufacturer's driver, from both source code and execution traces.
 39 * It is known that there are some artifacts on output video with this driver:
 40 *  - on all known hardware samples: random pixels of wrong color (mostly
 41 *    white, red or blue) appearing and disappearing on sequences of P-frames;
 42 *  - on some hardware samples (known with H.264 core version e006:2800):
 43 *    total madness on P-frames: blocks of wrong luminance; blocks of wrong
 44 *    colors "creeping" across the picture.
 45 * There is a workaround for both issues: avoid P-frames by setting GOP size
 46 * to 1. To do that, run this command on device files created by this driver:
 47 *
 48 * v4l2-ctl --device /dev/videoX --set-ctrl=video_gop_size=1
 49 *
 50 * These issues are not decoding errors; all produced H.264 streams are decoded
 51 * properly. Streams without P-frames don't have these artifacts so it's not
 52 * analog-to-digital conversion issues nor internal memory errors; we conclude
 53 * it's internal H.264 encoder issues.
 54 * We cannot even check the original driver's behaviour because it has never
 55 * worked properly at all in our development environment. So these issues may
 56 * be actually related to firmware or hardware. However it may be that there's
 57 * just some more register settings missing in the driver which would please
 58 * the hardware.
 59 * Manufacturer didn't help much on our inquiries, but feel free to disturb
 60 * again the support of Intersil (owner of former Techwell).
 61 */
 62
 63/* take first free /dev/videoX indexes by default */
 64static unsigned int video_nr[] = {[0 ... (TW5864_INPUTS - 1)] = -1 };
 65
 66module_param_array(video_nr, int, NULL, 0444);
 67MODULE_PARM_DESC(video_nr, "video devices numbers array");
 68
 69/*
 70 * Please add any new PCI IDs to: https://pci-ids.ucw.cz.  This keeps
 71 * the PCI ID database up to date.  Note that the entries must be
 72 * added under vendor 0x1797 (Techwell Inc.) as subsystem IDs.
 73 */
 74static const struct pci_device_id tw5864_pci_tbl[] = {
 75	{PCI_DEVICE(PCI_VENDOR_ID_TECHWELL, PCI_DEVICE_ID_TECHWELL_5864)},
 76	{0,}
 77};
 78
 79void tw5864_irqmask_apply(struct tw5864_dev *dev)
 80{
 81	tw_writel(TW5864_INTR_ENABLE_L, dev->irqmask & 0xffff);
 82	tw_writel(TW5864_INTR_ENABLE_H, (dev->irqmask >> 16));
 83}
 84
 85static void tw5864_interrupts_disable(struct tw5864_dev *dev)
 86{
 87	unsigned long flags;
 88
 89	spin_lock_irqsave(&dev->slock, flags);
 90	dev->irqmask = 0;
 91	tw5864_irqmask_apply(dev);
 92	spin_unlock_irqrestore(&dev->slock, flags);
 93}
 94
 95static void tw5864_timer_isr(struct tw5864_dev *dev);
 96static void tw5864_h264_isr(struct tw5864_dev *dev);
 97
 98static irqreturn_t tw5864_isr(int irq, void *dev_id)
 99{
100	struct tw5864_dev *dev = dev_id;
101	u32 status;
102
103	status = tw_readl(TW5864_INTR_STATUS_L) |
104		tw_readl(TW5864_INTR_STATUS_H) << 16;
105	if (!status)
106		return IRQ_NONE;
107
108	tw_writel(TW5864_INTR_CLR_L, 0xffff);
109	tw_writel(TW5864_INTR_CLR_H, 0xffff);
110
111	if (status & TW5864_INTR_VLC_DONE)
112		tw5864_h264_isr(dev);
113
114	if (status & TW5864_INTR_TIMER)
115		tw5864_timer_isr(dev);
116
117	if (!(status & (TW5864_INTR_TIMER | TW5864_INTR_VLC_DONE))) {
118		dev_dbg(&dev->pci->dev, "Unknown interrupt, status 0x%08X\n",
119			status);
120	}
121
122	return IRQ_HANDLED;
123}
124
125static void tw5864_h264_isr(struct tw5864_dev *dev)
126{
127	int channel = tw_readl(TW5864_DSP) & TW5864_DSP_ENC_CHN;
128	struct tw5864_input *input = &dev->inputs[channel];
129	int cur_frame_index, next_frame_index;
130	struct tw5864_h264_frame *cur_frame, *next_frame;
131	unsigned long flags;
132
133	spin_lock_irqsave(&dev->slock, flags);
134
135	cur_frame_index = dev->h264_buf_w_index;
136	next_frame_index = (cur_frame_index + 1) % H264_BUF_CNT;
137	cur_frame = &dev->h264_buf[cur_frame_index];
138	next_frame = &dev->h264_buf[next_frame_index];
139
140	if (next_frame_index != dev->h264_buf_r_index) {
141		cur_frame->vlc_len = tw_readl(TW5864_VLC_LENGTH) << 2;
142		cur_frame->checksum = tw_readl(TW5864_VLC_CRC_REG);
143		cur_frame->input = input;
144		cur_frame->timestamp = ktime_get_ns();
145		cur_frame->seqno = input->frame_seqno;
146		cur_frame->gop_seqno = input->frame_gop_seqno;
147
148		dev->h264_buf_w_index = next_frame_index;
149		queue_work(system_bh_wq, &dev->bh_work);
150
151		cur_frame = next_frame;
152
153		spin_lock(&input->slock);
154		input->frame_seqno++;
155		input->frame_gop_seqno++;
156		if (input->frame_gop_seqno >= input->gop)
157			input->frame_gop_seqno = 0;
158		spin_unlock(&input->slock);
159	} else {
160		dev_err(&dev->pci->dev,
161			"Skipped frame on input %d because all buffers busy\n",
162			channel);
163	}
164
165	dev->encoder_busy = 0;
166
167	spin_unlock_irqrestore(&dev->slock, flags);
168
169	tw_writel(TW5864_VLC_STREAM_BASE_ADDR, cur_frame->vlc.dma_addr);
170	tw_writel(TW5864_MV_STREAM_BASE_ADDR, cur_frame->mv.dma_addr);
171
172	/* Additional ack for this interrupt */
173	tw_writel(TW5864_VLC_DSP_INTR, 0x00000001);
174	tw_writel(TW5864_PCI_INTR_STATUS, TW5864_VLC_DONE_INTR);
175}
176
177static void tw5864_input_deadline_update(struct tw5864_input *input)
178{
179	input->new_frame_deadline = jiffies + msecs_to_jiffies(1000);
180}
181
182static void tw5864_timer_isr(struct tw5864_dev *dev)
183{
184	unsigned long flags;
185	int i;
186	int encoder_busy;
187
188	/* Additional ack for this interrupt */
189	tw_writel(TW5864_PCI_INTR_STATUS, TW5864_TIMER_INTR);
190
191	spin_lock_irqsave(&dev->slock, flags);
192	encoder_busy = dev->encoder_busy;
193	spin_unlock_irqrestore(&dev->slock, flags);
194
195	if (encoder_busy)
196		return;
197
198	/*
199	 * Traversing inputs in round-robin fashion, starting from next to the
200	 * last processed one
201	 */
202	for (i = 0; i < TW5864_INPUTS; i++) {
203		int next_input = (i + dev->next_input) % TW5864_INPUTS;
204		struct tw5864_input *input = &dev->inputs[next_input];
205		int raw_buf_id; /* id of internal buf with last raw frame */
206
207		spin_lock_irqsave(&input->slock, flags);
208		if (!input->enabled)
209			goto next;
210
211		/* Check if new raw frame is available */
212		raw_buf_id = tw_mask_shift_readl(TW5864_SENIF_ORG_FRM_PTR1, 0x3,
213						 2 * input->nr);
214
215		if (input->buf_id != raw_buf_id) {
216			input->buf_id = raw_buf_id;
217			tw5864_input_deadline_update(input);
218			spin_unlock_irqrestore(&input->slock, flags);
219
220			spin_lock_irqsave(&dev->slock, flags);
221			dev->encoder_busy = 1;
222			dev->next_input = (next_input + 1) % TW5864_INPUTS;
223			spin_unlock_irqrestore(&dev->slock, flags);
224
225			tw5864_request_encoded_frame(input);
226			break;
227		}
228
229		/* No new raw frame; check if channel is stuck */
230		if (time_is_after_jiffies(input->new_frame_deadline)) {
231			/* If stuck, request new raw frames again */
232			tw_mask_shift_writel(TW5864_ENC_BUF_PTR_REC1, 0x3,
233					     2 * input->nr, input->buf_id + 3);
234			tw5864_input_deadline_update(input);
235		}
236next:
237		spin_unlock_irqrestore(&input->slock, flags);
238	}
239}
240
241static int tw5864_initdev(struct pci_dev *pci_dev,
242			  const struct pci_device_id *pci_id)
243{
244	struct tw5864_dev *dev;
245	int err;
246
247	dev = devm_kzalloc(&pci_dev->dev, sizeof(*dev), GFP_KERNEL);
248	if (!dev)
249		return -ENOMEM;
250
251	snprintf(dev->name, sizeof(dev->name), "%s:%s", DRIVER_NAME,
252		 pci_name(pci_dev));
253
254	err = v4l2_device_register(&pci_dev->dev, &dev->v4l2_dev);
255	if (err)
256		return err;
257
258	/* pci init */
259	dev->pci = pci_dev;
260	err = pcim_enable_device(pci_dev);
261	if (err) {
262		dev_err(&dev->pci->dev, "pcim_enable_device() failed\n");
263		goto unreg_v4l2;
264	}
265
266	pci_set_master(pci_dev);
267
268	err = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
269	if (err) {
270		dev_err(&dev->pci->dev, "32 bit PCI DMA is not supported\n");
271		goto unreg_v4l2;
272	}
273
274	/* get mmio */
275	dev->mmio = pcim_iomap_region(pci_dev, 0, DRIVER_NAME);
276	err = PTR_ERR_OR_ZERO(dev->mmio);
277	if (err) {
278		dev_err(&dev->pci->dev, "Cannot request regions for MMIO\n");
279		goto unreg_v4l2;
280	}
281
282	spin_lock_init(&dev->slock);
283
284	dev_info(&pci_dev->dev, "TW5864 hardware version: %04x\n",
285		 tw_readl(TW5864_HW_VERSION));
286	dev_info(&pci_dev->dev, "TW5864 H.264 core version: %04x:%04x\n",
287		 tw_readl(TW5864_H264REV),
288		 tw_readl(TW5864_UNDECLARED_H264REV_PART2));
289
290	err = tw5864_video_init(dev, video_nr);
291	if (err)
292		goto unreg_v4l2;
293
294	/* get irq */
295	err = devm_request_irq(&pci_dev->dev, pci_dev->irq, tw5864_isr,
296			       IRQF_SHARED, DRIVER_NAME, dev);
297	if (err < 0) {
298		dev_err(&dev->pci->dev, "can't get IRQ %d\n", pci_dev->irq);
299		goto fini_video;
300	}
301
302	dev_info(&pci_dev->dev, "Note: there are known video quality issues. For details\n");
303	dev_info(&pci_dev->dev, "see the comment in drivers/media/pci/tw5864/tw5864-core.c.\n");
304
305	return 0;
306
307fini_video:
308	tw5864_video_fini(dev);
309unreg_v4l2:
310	v4l2_device_unregister(&dev->v4l2_dev);
311	return err;
312}
313
314static void tw5864_finidev(struct pci_dev *pci_dev)
315{
316	struct v4l2_device *v4l2_dev = pci_get_drvdata(pci_dev);
317	struct tw5864_dev *dev =
318		container_of(v4l2_dev, struct tw5864_dev, v4l2_dev);
319
320	/* shutdown subsystems */
321	tw5864_interrupts_disable(dev);
322
323	/* unregister */
324	tw5864_video_fini(dev);
325
326	v4l2_device_unregister(&dev->v4l2_dev);
327}
328
329static struct pci_driver tw5864_pci_driver = {
330	.name = DRIVER_NAME,
331	.id_table = tw5864_pci_tbl,
332	.probe = tw5864_initdev,
333	.remove = tw5864_finidev,
334};
335
336module_pci_driver(tw5864_pci_driver);