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 };