cx23885-vbi.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  Driver for the Conexant CX23885 PCIe bridge
  4 *
  5 *  Copyright (c) 2007 Steven Toth <stoth@linuxtv.org>
  6 */
  7
  8#include "cx23885.h"
  9
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/moduleparam.h>
 13#include <linux/init.h>
 14
 15static unsigned int vbibufs = 4;
 16module_param(vbibufs, int, 0644);
 17MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
 18
 19static unsigned int vbi_debug;
 20module_param(vbi_debug, int, 0644);
 21MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
 22
 23#define dprintk(level, fmt, arg...)\
 24	do { if (vbi_debug >= level)\
 25		printk(KERN_DEBUG pr_fmt("%s: vbi:" fmt), \
 26			__func__, ##arg); \
 27	} while (0)
 28
 29/* ------------------------------------------------------------------ */
 30
 31#define VBI_LINE_LENGTH 1440
 32#define VBI_NTSC_LINE_COUNT 12
 33#define VBI_PAL_LINE_COUNT 18
 34
 35
 36int cx23885_vbi_fmt(struct file *file, void *priv,
 37	struct v4l2_format *f)
 38{
 39	struct cx23885_dev *dev = video_drvdata(file);
 40
 41	f->fmt.vbi.sampling_rate = 27000000;
 42	f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
 43	f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
 44	f->fmt.vbi.offset = 0;
 45	f->fmt.vbi.flags = 0;
 46	if (dev->tvnorm & V4L2_STD_525_60) {
 47		/* ntsc */
 48		f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
 49		f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
 50		f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
 51		f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
 52	} else if (dev->tvnorm & V4L2_STD_625_50) {
 53		/* pal */
 54		f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
 55		f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
 56		f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
 57		f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
 58	}
 59
 60	return 0;
 61}
 62
 63/* We're given the Video Interrupt status register.
 64 * The cx23885_video_irq() func has already validated
 65 * the potential error bits, we just need to
 66 * deal with vbi payload and return indication if
 67 * we actually processed any payload.
 68 */
 69int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
 70{
 71	u32 count;
 72	int handled = 0;
 73
 74	if (status & VID_BC_MSK_VBI_RISCI1) {
 75		dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
 76		spin_lock(&dev->slock);
 77		count = cx_read(VBI_A_GPCNT);
 78		cx23885_video_wakeup(dev, &dev->vbiq, count);
 79		spin_unlock(&dev->slock);
 80		handled++;
 81	}
 82
 83	return handled;
 84}
 85
 86static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
 87			 struct cx23885_dmaqueue *q,
 88			 struct cx23885_buffer   *buf)
 89{
 90	dprintk(1, "%s()\n", __func__);
 91
 92	/* setup fifo + format */
 93	cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
 94				VBI_LINE_LENGTH, buf->risc.dma);
 95
 96	/* reset counter */
 97	cx_write(VID_A_VBI_CTRL, 3);
 98	cx_write(VBI_A_GPCNT_CTL, 3);
 99	q->count = 0;
100
101	/* enable irq */
102	cx23885_irq_add_enable(dev, 0x01);
103	cx_set(VID_A_INT_MSK, 0x000022);
104
105	/* start dma */
106	cx_set(DEV_CNTRL2, (1<<5));
107	cx_set(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
108
109	return 0;
110}
111
112/* ------------------------------------------------------------------ */
113
114static int queue_setup(struct vb2_queue *q,
115			   unsigned int *num_buffers, unsigned int *num_planes,
116			   unsigned int sizes[], struct device *alloc_devs[])
117{
118	struct cx23885_dev *dev = q->drv_priv;
119	unsigned lines = VBI_PAL_LINE_COUNT;
120
121	if (dev->tvnorm & V4L2_STD_525_60)
122		lines = VBI_NTSC_LINE_COUNT;
123	*num_planes = 1;
124	sizes[0] = lines * VBI_LINE_LENGTH * 2;
125	return 0;
126}
127
128static int buffer_prepare(struct vb2_buffer *vb)
129{
130	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
131	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
132	struct cx23885_buffer *buf = container_of(vbuf,
133		struct cx23885_buffer, vb);
134	struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
135	unsigned lines = VBI_PAL_LINE_COUNT;
136
137	if (dev->tvnorm & V4L2_STD_525_60)
138		lines = VBI_NTSC_LINE_COUNT;
139
140	if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
141		return -EINVAL;
142	vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
143
144	cx23885_risc_vbibuffer(dev->pci, &buf->risc,
145			 sgt->sgl,
146			 0, VBI_LINE_LENGTH * lines,
147			 VBI_LINE_LENGTH, 0,
148			 lines);
149	return 0;
150}
151
152static void buffer_finish(struct vb2_buffer *vb)
153{
154	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
155	struct cx23885_buffer *buf = container_of(vbuf,
156		struct cx23885_buffer, vb);
157
158	cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
159}
160
161/*
162 * The risc program for each buffer works as follows: it starts with a simple
163 * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
164 * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
165 * the initial JUMP).
166 *
167 * This is the risc program of the first buffer to be queued if the active list
168 * is empty and it just keeps DMAing this buffer without generating any
169 * interrupts.
170 *
171 * If a new buffer is added then the initial JUMP in the code for that buffer
172 * will generate an interrupt which signals that the previous buffer has been
173 * DMAed successfully and that it can be returned to userspace.
174 *
175 * It also sets the final jump of the previous buffer to the start of the new
176 * buffer, thus chaining the new buffer into the DMA chain. This is a single
177 * atomic u32 write, so there is no race condition.
178 *
179 * The end-result of all this that you only get an interrupt when a buffer
180 * is ready, so the control flow is very easy.
181 */
182static void buffer_queue(struct vb2_buffer *vb)
183{
184	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
185	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
186	struct cx23885_buffer *buf = container_of(vbuf,
187			struct cx23885_buffer, vb);
188	struct cx23885_buffer *prev;
189	struct cx23885_dmaqueue *q = &dev->vbiq;
190	unsigned long flags;
191
192	buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
193	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
194	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
195	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
196
197	if (list_empty(&q->active)) {
198		spin_lock_irqsave(&dev->slock, flags);
199		list_add_tail(&buf->queue, &q->active);
200		spin_unlock_irqrestore(&dev->slock, flags);
201		dprintk(2, "[%p/%d] vbi_queue - first active\n",
202			buf, buf->vb.vb2_buf.index);
203
204	} else {
205		buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
206		prev = list_entry(q->active.prev, struct cx23885_buffer,
207			queue);
208		spin_lock_irqsave(&dev->slock, flags);
209		list_add_tail(&buf->queue, &q->active);
210		spin_unlock_irqrestore(&dev->slock, flags);
211		prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
212		dprintk(2, "[%p/%d] buffer_queue - append to active\n",
213			buf, buf->vb.vb2_buf.index);
214	}
215}
216
217static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
218{
219	struct cx23885_dev *dev = q->drv_priv;
220	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
221	struct cx23885_buffer *buf = list_entry(dmaq->active.next,
222			struct cx23885_buffer, queue);
223
224	cx23885_start_vbi_dma(dev, dmaq, buf);
225	return 0;
226}
227
228static void cx23885_stop_streaming(struct vb2_queue *q)
229{
230	struct cx23885_dev *dev = q->drv_priv;
231	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
232	unsigned long flags;
233
234	cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
235	spin_lock_irqsave(&dev->slock, flags);
236	while (!list_empty(&dmaq->active)) {
237		struct cx23885_buffer *buf = list_entry(dmaq->active.next,
238			struct cx23885_buffer, queue);
239
240		list_del(&buf->queue);
241		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
242	}
243	spin_unlock_irqrestore(&dev->slock, flags);
244}
245
246
247const struct vb2_ops cx23885_vbi_qops = {
248	.queue_setup    = queue_setup,
249	.buf_prepare  = buffer_prepare,
250	.buf_finish = buffer_finish,
251	.buf_queue    = buffer_queue,
252	.start_streaming = cx23885_start_streaming,
253	.stop_streaming = cx23885_stop_streaming,
254};