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 <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/init.h>
  22
  23 #include "cx23885.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 "%s/0: " fmt, dev->name, ## arg);\
  36         } while (0)
  37
  38 /* ------------------------------------------------------------------ */
  39
  40 #define VBI_LINE_LENGTH 1440
  41 #define VBI_NTSC_LINE_COUNT 12
  42 #define VBI_PAL_LINE_COUNT 18
  43
  44
  45 int cx23885_vbi_fmt(struct file *file, void *priv,
  46         struct v4l2_format *f)
  47 {
  48         struct cx23885_dev *dev = video_drvdata(file);
  49
  50         f->fmt.vbi.sampling_rate = 27000000;
  51         f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
  52         f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
  53         f->fmt.vbi.offset = 0;
  54         f->fmt.vbi.flags = 0;
  55         if (dev->tvnorm & V4L2_STD_525_60) {
  56                 /* ntsc */
  57                 f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
  58                 f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
  59                 f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
  60                 f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
  61         } else if (dev->tvnorm & V4L2_STD_625_50) {
  62                 /* pal */
  63                 f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
  64                 f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
  65                 f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
  66                 f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
  67         }
  68
  69         return 0;
  70 }
  71
  72 /* We're given the Video Interrupt status register.
  73  * The cx23885_video_irq() func has already validated
  74  * the potential error bits, we just need to
  75  * deal with vbi payload and return indication if
  76  * we actually processed any payload.
  77  */
  78 int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
  79 {
  80         u32 count;
  81         int handled = 0;
  82
  83         if (status & VID_BC_MSK_VBI_RISCI1) {
  84                 dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
  85                 spin_lock(&dev->slock);
  86                 count = cx_read(VID_A_GPCNT);
  87                 cx23885_video_wakeup(dev, &dev->vbiq, count);
  88                 spin_unlock(&dev->slock);
  89                 handled++;
  90         }
  91
  92         return handled;
  93 }
  94
  95 static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
  96                          struct cx23885_dmaqueue *q,
  97                          struct cx23885_buffer   *buf)
  98 {
  99         dprintk(1, "%s()\n", __func__);
 100
 101         /* setup fifo + format */
 102         cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
 103                                 VBI_LINE_LENGTH, buf->risc.dma);
 104
 105         /* reset counter */
 106         cx_write(VID_A_GPCNT_CTL, 3);
 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, const void *parg,
 125                            unsigned int *num_buffers, unsigned int *num_planes,
 126                            unsigned int sizes[], void *alloc_ctxs[])
 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         alloc_ctxs[0] = dev->alloc_ctx;
 136         return 0;
 137 }
 138
 139 static int buffer_prepare(struct vb2_buffer *vb)
 140 {
 141         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 142         struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
 143         struct cx23885_buffer *buf = container_of(vbuf,
 144                 struct cx23885_buffer, vb);
 145         struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
 146         unsigned lines = VBI_PAL_LINE_COUNT;
 147
 148         if (dev->tvnorm & V4L2_STD_525_60)
 149                 lines = VBI_NTSC_LINE_COUNT;
 150
 151         if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
 152                 return -EINVAL;
 153         vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
 154
 155         cx23885_risc_vbibuffer(dev->pci, &buf->risc,
 156                          sgt->sgl,
 157                          0, VBI_LINE_LENGTH * lines,
 158                          VBI_LINE_LENGTH, 0,
 159                          lines);
 160         return 0;
 161 }
 162
 163 static void buffer_finish(struct vb2_buffer *vb)
 164 {
 165         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 166         struct cx23885_buffer *buf = container_of(vbuf,
 167                 struct cx23885_buffer, vb);
 168
 169         cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
 170 }
 171
 172 /*
 173  * The risc program for each buffer works as follows: it starts with a simple
 174  * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
 175  * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
 176  * the initial JUMP).
 177  *
 178  * This is the risc program of the first buffer to be queued if the active list
 179  * is empty and it just keeps DMAing this buffer without generating any
 180  * interrupts.
 181  *
 182  * If a new buffer is added then the initial JUMP in the code for that buffer
 183  * will generate an interrupt which signals that the previous buffer has been
 184  * DMAed successfully and that it can be returned to userspace.
 185  *
 186  * It also sets the final jump of the previous buffer to the start of the new
 187  * buffer, thus chaining the new buffer into the DMA chain. This is a single
 188  * atomic u32 write, so there is no race condition.
 189  *
 190  * The end-result of all this that you only get an interrupt when a buffer
 191  * is ready, so the control flow is very easy.
 192  */
 193 static void buffer_queue(struct vb2_buffer *vb)
 194 {
 195         struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 196         struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
 197         struct cx23885_buffer *buf = container_of(vbuf,
 198                         struct cx23885_buffer, vb);
 199         struct cx23885_buffer *prev;
 200         struct cx23885_dmaqueue *q = &dev->vbiq;
 201         unsigned long flags;
 202
 203         buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
 204         buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
 205         buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
 206         buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
 207
 208         if (list_empty(&q->active)) {
 209                 spin_lock_irqsave(&dev->slock, flags);
 210                 list_add_tail(&buf->queue, &q->active);
 211                 spin_unlock_irqrestore(&dev->slock, flags);
 212                 dprintk(2, "[%p/%d] vbi_queue - first active\n",
 213                         buf, buf->vb.vb2_buf.index);
 214
 215         } else {
 216                 buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
 217                 prev = list_entry(q->active.prev, struct cx23885_buffer,
 218                         queue);
 219                 spin_lock_irqsave(&dev->slock, flags);
 220                 list_add_tail(&buf->queue, &q->active);
 221                 spin_unlock_irqrestore(&dev->slock, flags);
 222                 prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
 223                 dprintk(2, "[%p/%d] buffer_queue - append to active\n",
 224                         buf, buf->vb.vb2_buf.index);
 225         }
 226 }
 227
 228 static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
 229 {
 230         struct cx23885_dev *dev = q->drv_priv;
 231         struct cx23885_dmaqueue *dmaq = &dev->vbiq;
 232         struct cx23885_buffer *buf = list_entry(dmaq->active.next,
 233                         struct cx23885_buffer, queue);
 234
 235         cx23885_start_vbi_dma(dev, dmaq, buf);
 236         return 0;
 237 }
 238
 239 static void cx23885_stop_streaming(struct vb2_queue *q)
 240 {
 241         struct cx23885_dev *dev = q->drv_priv;
 242         struct cx23885_dmaqueue *dmaq = &dev->vbiq;
 243         unsigned long flags;
 244
 245         cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
 246         spin_lock_irqsave(&dev->slock, flags);
 247         while (!list_empty(&dmaq->active)) {
 248                 struct cx23885_buffer *buf = list_entry(dmaq->active.next,
 249                         struct cx23885_buffer, queue);
 250
 251                 list_del(&buf->queue);
 252                 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 253         }
 254         spin_unlock_irqrestore(&dev->slock, flags);
 255 }
 256
 257
 258 struct vb2_ops cx23885_vbi_qops = {
 259         .queue_setup    = queue_setup,
 260         .buf_prepare  = buffer_prepare,
 261         .buf_finish = buffer_finish,
 262         .buf_queue    = buffer_queue,
 263         .wait_prepare = vb2_ops_wait_prepare,
 264         .wait_finish = vb2_ops_wait_finish,
 265         .start_streaming = cx23885_start_streaming,
 266         .stop_streaming = cx23885_stop_streaming,
 267 };