Linux 5.6-rc2
[sfrench/cifs-2.6.git] / drivers / media / pci / cx23885 / 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
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
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  */
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
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
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
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
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  */
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
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
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 };