drivers/media/pci/cx23885/cx23885-vbi.c

   1 /*
   2  *  Driver for the Conexant CX23885 PCIe bridge
   3  *
   4  *  Copyright (c) 2007 Steven Toth <stoth@linuxtv.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *
  15  *  GNU General Public License for more details.
  16  */
  17
  18 #include "cx23885.h"
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/init.h>
  24
  25 static unsigned int vbibufs = 4;
  26 module_param(vbibufs, int, 0644);
  27 MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
  28
  29 static unsigned int vbi_debug;
  30 module_param(vbi_debug, int, 0644);
  31 MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
  32
  33 #define dprintk(level, fmt, arg...)\
  34         do { if (vbi_debug >= level)\
  35                 printk(KERN_DEBUG pr_fmt("%s: vbi:" fmt), \
  36                         __func__, ##arg); \
  37         } while (0)
  38
  39 /* ------------------------------------------------------------------ */
  40
  41 #define VBI_LINE_LENGTH 1440
  42 #define VBI_NTSC_LINE_COUNT 12
  43 #define VBI_PAL_LINE_COUNT 18
  44
  45
  46 int cx23885_vbi_fmt(struct file *file, void *priv,
  47         struct v4l2_format *f)
  48 {
  49         struct cx23885_dev *dev = video_drvdata(file);
  50
  51         f->fmt.vbi.sampling_rate = 27000000;
  52         f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
  53         f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
  54         f->fmt.vbi.offset = 0;
  55         f->fmt.vbi.flags = 0;
  56         if (dev->tvnorm & V4L2_STD_525_60) {
  57                 /* ntsc */
  58                 f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
  59                 f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
  60                 f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
  61                 f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
  62         } else if (dev->tvnorm & V4L2_STD_625_50) {
  63                 /* pal */
  64                 f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
  65                 f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
  66                 f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
  67                 f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
  68         }
  69
  70         return 0;
  71 }
  72
  73 /* We're given the Video Interrupt status register.
  74  * The cx23885_video_irq() func has already validated
  75  * the potential error bits, we just need to
  76  * deal with vbi payload and return indication if
  77  * we actually processed any payload.
  78  */
  79 int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
  80 {
  81         u32 count;
  82         int handled = 0;
  83
  84         if (status & VID_BC_MSK_VBI_RISCI1) {
  85                 dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
  86                 spin_lock(&dev->slock);
  87                 count = cx_read(VBI_A_GPCNT);
  88                 cx23885_video_wakeup(dev, &dev->vbiq, count);
  89                 spin_unlock(&dev->slock);
  90                 handled++;
  91         }
  92
  93         return handled;
  94 }
  95
  96 static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
  97                          struct cx23885_dmaqueue *q,
  98                          struct cx23885_buffer   *buf)
  99 {
 100         dprintk(1, "%s()\n", __func__);
 101
 102         /* setup fifo + format */
 103         cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
 104                                 VBI_LINE_LENGTH, buf->risc.dma);
 105
 106         /* reset counter */
 107         cx_write(VID_A_VBI_CTRL, 3);
 108         cx_write(VBI_A_GPCNT_CTL, 3);
 109         q->count = 0;
 110
 111         /* enable irq */
 112         cx23885_irq_add_enable(dev, 0x01);
 113         cx_set(VID_A_INT_MSK, 0x000022);
 114
 115         /* start dma */
 116         cx_set(DEV_CNTRL2, (1<<5));
 117         cx_set(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
 118
 119         return 0;
 120 }
 121
 122 /* ------------------------------------------------------------------ */
 123
 124 static int queue_setup(struct vb2_queue *q,
 125                            unsigned int *num_buffers, unsigned int *num_planes,
 126                            unsigned int sizes[], struct device *alloc_devs[])
 127 {
 128         struct cx23885_dev *dev = q->drv_priv;
 129         unsigned lines = VBI_PAL_LINE_COUNT;
 130
 131         if (dev->tvnorm & V4L2_STD_525_60)
 132                 lines = VBI_NTSC_LINE_COUNT;
 133         *num_planes = 1;
 134         sizes[0] = lines * VBI_LINE_LENGTH * 2;
 135         return 0;
 136 }
 137
 138 static int buffer_prepare(struct vb2_buffer *vb)
 139 {
 140         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 141         struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
 142         struct cx23885_buffer *buf = container_of(vbuf,
 143                 struct cx23885_buffer, vb);
 144         struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
 145         unsigned lines = VBI_PAL_LINE_COUNT;
 146
 147         if (dev->tvnorm & V4L2_STD_525_60)
 148                 lines = VBI_NTSC_LINE_COUNT;
 149
 150         if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
 151                 return -EINVAL;
 152         vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
 153
 154         cx23885_risc_vbibuffer(dev->pci, &buf->risc,
 155                          sgt->sgl,
 156                          0, VBI_LINE_LENGTH * lines,
 157                          VBI_LINE_LENGTH, 0,
 158                          lines);
 159         return 0;
 160 }
 161
 162 static void buffer_finish(struct vb2_buffer *vb)
 163 {
 164         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 165         struct cx23885_buffer *buf = container_of(vbuf,
 166                 struct cx23885_buffer, vb);
 167
 168         cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
 169 }
 170
 171 /*
 172  * The risc program for each buffer works as follows: it starts with a simple
 173  * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
 174  * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
 175  * the initial JUMP).
 176  *
 177  * This is the risc program of the first buffer to be queued if the active list
 178  * is empty and it just keeps DMAing this buffer without generating any
 179  * interrupts.
 180  *
 181  * If a new buffer is added then the initial JUMP in the code for that buffer
 182  * will generate an interrupt which signals that the previous buffer has been
 183  * DMAed successfully and that it can be returned to userspace.
 184  *
 185  * It also sets the final jump of the previous buffer to the start of the new
 186  * buffer, thus chaining the new buffer into the DMA chain. This is a single
 187  * atomic u32 write, so there is no race condition.
 188  *
 189  * The end-result of all this that you only get an interrupt when a buffer
 190  * is ready, so the control flow is very easy.
 191  */
 192 static void buffer_queue(struct vb2_buffer *vb)
 193 {
 194         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 195         struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
 196         struct cx23885_buffer *buf = container_of(vbuf,
 197                         struct cx23885_buffer, vb);
 198         struct cx23885_buffer *prev;
 199         struct cx23885_dmaqueue *q = &dev->vbiq;
 200         unsigned long flags;
 201
 202         buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
 203         buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
 204         buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
 205         buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
 206
 207         if (list_empty(&q->active)) {
 208                 spin_lock_irqsave(&dev->slock, flags);
 209                 list_add_tail(&buf->queue, &q->active);
 210                 spin_unlock_irqrestore(&dev->slock, flags);
 211                 dprintk(2, "[%p/%d] vbi_queue - first active\n",
 212                         buf, buf->vb.vb2_buf.index);
 213
 214         } else {
 215                 buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
 216                 prev = list_entry(q->active.prev, struct cx23885_buffer,
 217                         queue);
 218                 spin_lock_irqsave(&dev->slock, flags);
 219                 list_add_tail(&buf->queue, &q->active);
 220                 spin_unlock_irqrestore(&dev->slock, flags);
 221                 prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
 222                 dprintk(2, "[%p/%d] buffer_queue - append to active\n",
 223                         buf, buf->vb.vb2_buf.index);
 224         }
 225 }
 226
 227 static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
 228 {
 229         struct cx23885_dev *dev = q->drv_priv;
 230         struct cx23885_dmaqueue *dmaq = &dev->vbiq;
 231         struct cx23885_buffer *buf = list_entry(dmaq->active.next,
 232                         struct cx23885_buffer, queue);
 233
 234         cx23885_start_vbi_dma(dev, dmaq, buf);
 235         return 0;
 236 }
 237
 238 static void cx23885_stop_streaming(struct vb2_queue *q)
 239 {
 240         struct cx23885_dev *dev = q->drv_priv;
 241         struct cx23885_dmaqueue *dmaq = &dev->vbiq;
 242         unsigned long flags;
 243
 244         cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
 245         spin_lock_irqsave(&dev->slock, flags);
 246         while (!list_empty(&dmaq->active)) {
 247                 struct cx23885_buffer *buf = list_entry(dmaq->active.next,
 248                         struct cx23885_buffer, queue);
 249
 250                 list_del(&buf->queue);
 251                 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 252         }
 253         spin_unlock_irqrestore(&dev->slock, flags);
 254 }
 255
 256
 257 const struct vb2_ops cx23885_vbi_qops = {
 258         .queue_setup    = queue_setup,
 259         .buf_prepare  = buffer_prepare,
 260         .buf_finish = buffer_finish,
 261         .buf_queue    = buffer_queue,
 262         .wait_prepare = vb2_ops_wait_prepare,
 263         .wait_finish = vb2_ops_wait_finish,
 264         .start_streaming = cx23885_start_streaming,
 265         .stop_streaming = cx23885_stop_streaming,
 266 };