target/linux/brcm2708/patches-3.10/0021-sdhci-bcm2708-use-extension-FIFO-to-buffer-DMA-trans.patch

   1 From 3e9891e91d7dda096ab1cc2518830938ad69880d Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Sun, 12 May 2013 12:25:52 +0100
   4 Subject: [PATCH 021/174] sdhci-bcm2708: use extension FIFO to buffer DMA
   5  transfers
   6
   7 The additional FIFO might speed up transfers in some cases.
   8 ---
   9  drivers/mmc/host/sdhci-bcm2708.c | 11 +++++++++++
  10  1 file changed, 11 insertions(+)
  11
  12 --- a/drivers/mmc/host/sdhci-bcm2708.c
  13 +++ b/drivers/mmc/host/sdhci-bcm2708.c
  14 @@ -74,6 +74,9 @@
  15  /* Mhz clock that the EMMC core is running at. Should match the platform clockman settings */
  16  #define BCM2708_EMMC_CLOCK_FREQ 50000000
  17
  18 +#define REG_EXRDFIFO_EN     0x80
  19 +#define REG_EXRDFIFO_CFG    0x84
  20 +
  21  /*****************************************************************************\
  22   *                                                                          *
  23   * Debug                                                                    *
  24 @@ -957,10 +960,12 @@ static ssize_t attr_dma_store(struct dev
  25                 int on = simple_strtol(buf, NULL, 0);
  26                 if (on) {
  27                         host->flags |= SDHCI_USE_PLATDMA;
  28 +                       sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
  29                         printk(KERN_INFO "%s: DMA enabled\n",
  30                                mmc_hostname(host->mmc));
  31                 } else {
  32                         host->flags &= ~(SDHCI_USE_PLATDMA | SDHCI_REQ_USE_DMA);
  33 +                       sdhci_bcm2708_writel(host, 0, REG_EXRDFIFO_EN);
  34                         printk(KERN_INFO "%s: DMA disabled\n",
  35                                mmc_hostname(host->mmc));
  36                 }
  37 @@ -1272,6 +1277,12 @@ static int sdhci_bcm2708_probe(struct pl
  38         ret = device_create_file(&pdev->dev, &dev_attr_dma_wait);
  39         ret = device_create_file(&pdev->dev, &dev_attr_status);
  40
  41 +#ifdef CONFIG_MMC_SDHCI_BCM2708_DMA
  42 +       /* enable extension fifo for paced DMA transfers */
  43 +       sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
  44 +       sdhci_bcm2708_writel(host, 4, REG_EXRDFIFO_CFG);
  45 +#endif
  46 +
  47         printk(KERN_INFO "%s: BCM2708 SDHC host at 0x%08llx DMA %d IRQ %d\n",
  48                mmc_hostname(host->mmc), (unsigned long long)iomem->start,
  49                host_priv->dma_chan, host_priv->dma_irq);