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
15 static unsigned int vbibufs = 4;
16 module_param(vbibufs, int, 0644);
17 MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
18
19 static unsigned int vbi_debug;
20 module_param(vbi_debug, int, 0644);
21 MODULE_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
cx23885_vbi_fmt(struct file * file,void * priv,struct v4l2_format * f)36 int 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 */
cx23885_vbi_irq(struct cx23885_dev * dev,u32 status)69 int 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
cx23885_start_vbi_dma(struct cx23885_dev * dev,struct cx23885_dmaqueue * q,struct cx23885_buffer * buf)86 static 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
queue_setup(struct vb2_queue * q,unsigned int * num_buffers,unsigned int * num_planes,unsigned int sizes[],struct device * alloc_devs[])114 static 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
buffer_prepare(struct vb2_buffer * vb)128 static 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
buffer_finish(struct vb2_buffer * vb)152 static 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 */
buffer_queue(struct vb2_buffer * vb)182 static 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
cx23885_start_streaming(struct vb2_queue * q,unsigned int count)217 static 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
cx23885_stop_streaming(struct vb2_queue * q)228 static 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
247 const 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 .wait_prepare = vb2_ops_wait_prepare,
253 .wait_finish = vb2_ops_wait_finish,
254 .start_streaming = cx23885_start_streaming,
255 .stop_streaming = cx23885_stop_streaming,
256 };
257