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

   1 From b802bfd3bb337e92226bd521f8ebbbcfc6642333 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 021/196] 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 diff --git a/drivers/mmc/host/sdhci-bcm2708.c b/drivers/mmc/host/sdhci-bcm2708.c
  13 index 3792b9f..326b962 100644
  14 --- a/drivers/mmc/host/sdhci-bcm2708.c
  15 +++ b/drivers/mmc/host/sdhci-bcm2708.c
  16 @@ -74,6 +74,9 @@
  17  /* Mhz clock that the EMMC core is running at. Should match the platform clockman settings */
  18  #define BCM2708_EMMC_CLOCK_FREQ 50000000
  19
  20 +#define REG_EXRDFIFO_EN     0x80
  21 +#define REG_EXRDFIFO_CFG    0x84
  22 +
  23  /*****************************************************************************\
  24   *                                                                          *
  25   * Debug                                                                    *
  26 @@ -957,10 +960,12 @@ static ssize_t attr_dma_store(struct device *_dev,
  27                 int on = simple_strtol(buf, NULL, 0);
  28                 if (on) {
  29                         host->flags |= SDHCI_USE_PLATDMA;
  30 +                       sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
  31                         printk(KERN_INFO "%s: DMA enabled\n",
  32                                mmc_hostname(host->mmc));
  33                 } else {
  34                         host->flags &= ~(SDHCI_USE_PLATDMA | SDHCI_REQ_USE_DMA);
  35 +                       sdhci_bcm2708_writel(host, 0, REG_EXRDFIFO_EN);
  36                         printk(KERN_INFO "%s: DMA disabled\n",
  37                                mmc_hostname(host->mmc));
  38                 }
  39 @@ -1272,6 +1277,12 @@ static int sdhci_bcm2708_probe(struct platform_device *pdev)
  40         ret = device_create_file(&pdev->dev, &dev_attr_dma_wait);
  41         ret = device_create_file(&pdev->dev, &dev_attr_status);
  42
  43 +#ifdef CONFIG_MMC_SDHCI_BCM2708_DMA
  44 +       /* enable extension fifo for paced DMA transfers */
  45 +       sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
  46 +       sdhci_bcm2708_writel(host, 4, REG_EXRDFIFO_CFG);
  47 +#endif
  48 +
  49         printk(KERN_INFO "%s: BCM2708 SDHC host at 0x%08llx DMA %d IRQ %d\n",
  50                mmc_hostname(host->mmc), (unsigned long long)iomem->start,
  51                host_priv->dma_chan, host_priv->dma_irq);
  52 --
  53 1.9.1
  54