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49 lines
1.8 KiB
49 lines
1.8 KiB
From 3e9891e91d7dda096ab1cc2518830938ad69880d Mon Sep 17 00:00:00 2001
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From: popcornmix <popcornmix@gmail.com>
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Date: Sun, 12 May 2013 12:25:52 +0100
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Subject: [PATCH 021/174] sdhci-bcm2708: use extension FIFO to buffer DMA
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transfers
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The additional FIFO might speed up transfers in some cases.
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---
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drivers/mmc/host/sdhci-bcm2708.c | 11 +++++++++++
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1 file changed, 11 insertions(+)
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--- a/drivers/mmc/host/sdhci-bcm2708.c
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+++ b/drivers/mmc/host/sdhci-bcm2708.c
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@@ -74,6 +74,9 @@
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/* Mhz clock that the EMMC core is running at. Should match the platform clockman settings */
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#define BCM2708_EMMC_CLOCK_FREQ 50000000
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+#define REG_EXRDFIFO_EN 0x80
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+#define REG_EXRDFIFO_CFG 0x84
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+
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/*****************************************************************************\
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* *
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* Debug *
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@@ -957,10 +960,12 @@ static ssize_t attr_dma_store(struct dev
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int on = simple_strtol(buf, NULL, 0);
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if (on) {
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host->flags |= SDHCI_USE_PLATDMA;
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+ sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
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printk(KERN_INFO "%s: DMA enabled\n",
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mmc_hostname(host->mmc));
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} else {
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host->flags &= ~(SDHCI_USE_PLATDMA | SDHCI_REQ_USE_DMA);
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+ sdhci_bcm2708_writel(host, 0, REG_EXRDFIFO_EN);
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printk(KERN_INFO "%s: DMA disabled\n",
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mmc_hostname(host->mmc));
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}
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@@ -1272,6 +1277,12 @@ static int sdhci_bcm2708_probe(struct pl
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ret = device_create_file(&pdev->dev, &dev_attr_dma_wait);
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ret = device_create_file(&pdev->dev, &dev_attr_status);
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+#ifdef CONFIG_MMC_SDHCI_BCM2708_DMA
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+ /* enable extension fifo for paced DMA transfers */
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+ sdhci_bcm2708_writel(host, 1, REG_EXRDFIFO_EN);
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+ sdhci_bcm2708_writel(host, 4, REG_EXRDFIFO_CFG);
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+#endif
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+
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printk(KERN_INFO "%s: BCM2708 SDHC host at 0x%08llx DMA %d IRQ %d\n",
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mmc_hostname(host->mmc), (unsigned long long)iomem->start,
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host_priv->dma_chan, host_priv->dma_irq);
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