+/* get the current DMA position with correction on VIA chips */
+static unsigned int azx_via_get_position(struct azx *chip,
+ struct azx_dev *azx_dev)
+{
+ unsigned int link_pos, mini_pos, bound_pos;
+ unsigned int mod_link_pos, mod_dma_pos, mod_mini_pos;
+ unsigned int fifo_size;
+
+ link_pos = azx_sd_readl(azx_dev, SD_LPIB);
+ if (azx_dev->index >= 4) {
+ /* Playback, no problem using link position */
+ return link_pos;
+ }
+
+ /* Capture */
+ /* For new chipset,
+ * use mod to get the DMA position just like old chipset
+ */
+ mod_dma_pos = le32_to_cpu(*azx_dev->posbuf);
+ mod_dma_pos %= azx_dev->period_bytes;
+
+ /* azx_dev->fifo_size can't get FIFO size of in stream.
+ * Get from base address + offset.
+ */
+ fifo_size = readw(chip->remap_addr + VIA_IN_STREAM0_FIFO_SIZE_OFFSET);
+
+ if (azx_dev->insufficient) {
+ /* Link position never gather than FIFO size */
+ if (link_pos <= fifo_size)
+ return 0;
+
+ azx_dev->insufficient = 0;
+ }
+
+ if (link_pos <= fifo_size)
+ mini_pos = azx_dev->bufsize + link_pos - fifo_size;
+ else
+ mini_pos = link_pos - fifo_size;
+
+ /* Find nearest previous boudary */
+ mod_mini_pos = mini_pos % azx_dev->period_bytes;
+ mod_link_pos = link_pos % azx_dev->period_bytes;
+ if (mod_link_pos >= fifo_size)
+ bound_pos = link_pos - mod_link_pos;
+ else if (mod_dma_pos >= mod_mini_pos)
+ bound_pos = mini_pos - mod_mini_pos;
+ else {
+ bound_pos = mini_pos - mod_mini_pos + azx_dev->period_bytes;
+ if (bound_pos >= azx_dev->bufsize)
+ bound_pos = 0;
+ }
+
+ /* Calculate real DMA position we want */
+ return bound_pos + mod_dma_pos;
+}
+