From: Minda Chen <[email protected]>

8bit-width enable bit of CSR MMC hosts is 3, while stardard hosts use
bit 5. this patch fixes the functionality of 8bit transfer in CSR mmc
controllers and improve performance for mmc0 a lot.

Signed-off-by: Minda Chen <[email protected]>
Signed-off-by: Barry Song <[email protected]>
---
 drivers/mmc/host/sdhci-sirf.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-sirf.c b/drivers/mmc/host/sdhci-sirf.c
index 1700453..376f45f 100644
--- a/drivers/mmc/host/sdhci-sirf.c
+++ b/drivers/mmc/host/sdhci-sirf.c
@@ -15,6 +15,8 @@
 #include <linux/mmc/slot-gpio.h>
 #include "sdhci-pltfm.h"
 
+#define SDHCI_SIRF_8BITBUS BIT(3)
+
 struct sdhci_sirf_priv {
        struct clk *clk;
        int gpio_cd;
@@ -27,10 +29,33 @@ static unsigned int sdhci_sirf_get_max_clk(struct 
sdhci_host *host)
        return clk_get_rate(priv->clk);
 }
 
+static void sdhci_sirf_set_bus_width(struct sdhci_host *host, int width)
+{
+        u8 ctrl;
+
+        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+        if (width == MMC_BUS_WIDTH_8) {
+                ctrl &= ~SDHCI_CTRL_4BITBUS;
+                /*
+                 * 8bit-width enable bit of CSR MMC hosts is 3,
+                 * while stardard hosts use bit 5
+                 */
+                ctrl |= SDHCI_SIRF_8BITBUS;
+        } else {
+                if (host->version >= SDHCI_SPEC_300)
+                        ctrl &= ~SDHCI_SIRF_8BITBUS;
+                if (width == MMC_BUS_WIDTH_4)
+                        ctrl |= SDHCI_CTRL_4BITBUS;
+                else
+                        ctrl &= ~SDHCI_CTRL_4BITBUS;
+        }
+        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+}
+
 static struct sdhci_ops sdhci_sirf_ops = {
        .set_clock = sdhci_set_clock,
        .get_max_clock  = sdhci_sirf_get_max_clk,
-       .set_bus_width = sdhci_set_bus_width,
+       .set_bus_width = sdhci_sirf_set_bus_width,
        .reset = sdhci_reset,
        .set_uhs_signaling = sdhci_set_uhs_signaling,
 };
-- 
2.0.4



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