Add eMMC DDR mode support for Freescale SDHC adapter card.
The u-boot should provide device tree properties 'adapter-type'
and 'periperal-frequency' for this feature, if not, the card
would not use DDR mode.

Signed-off-by: Yangbo Lu <yangbo...@freescale.com>
---
 drivers/mmc/host/sdhci-esdhc.h    |  24 +++++++
 drivers/mmc/host/sdhci-of-esdhc.c | 132 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 152 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index 163ac99..015ec01 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -28,10 +28,32 @@
 #define ESDHC_CLOCK_MASK       0x0000fff0
 #define ESDHC_PREDIV_SHIFT     8
 #define ESDHC_DIVIDER_SHIFT    4
+#define ESDHC_CLOCK_CRDEN      0x00000008
 #define ESDHC_CLOCK_PEREN      0x00000004
 #define ESDHC_CLOCK_HCKEN      0x00000002
 #define ESDHC_CLOCK_IPGEN      0x00000001
 
+#define ESDHCI_PRESENT_STATE   0x24
+#define ESDHC_CLK_STABLE       0x00000008
+
+#define ESDHC_CAPABILITIES_1   0x114
+#define ESDHC_MODE_MASK                0x00000007
+#define ESDHC_MODE_DDR50_SEL   0xfffffffc
+#define ESDHC_MODE_DDR50       0x00000004
+
+#define ESDHC_CLOCK_CONTROL    0x144
+#define ESDHC_CLKLPBK_EXTPIN   0x80000000
+#define ESDHC_CMDCLK_SHIFTED   0x00008000
+
+/* SDHC Adapter Card Type */
+#define ESDHC_ADAPTER_TYPE_EMMC45       0x1    /* eMMC Card Rev4.5 */
+#define ESDHC_ADAPTER_TYPE_SDMMC_LEGACY 0x2    /* SD/MMC Legacy Card */
+#define ESDHC_ADAPTER_TYPE_EMMC44       0x3    /* eMMC Card Rev4.4 */
+#define ESDHC_ADAPTER_TYPE_RSV          0x4    /* Reserved */
+#define ESDHC_ADAPTER_TYPE_MMC          0x5    /* MMC Card */
+#define ESDHC_ADAPTER_TYPE_SD           0x6    /* SD Card Rev2.0 Rev3.0 */
+#define ESDHC_NO_ADAPTER                0x7    /* No Card is Present*/
+
 /* pltfm-specific */
 #define ESDHC_HOST_CONTROL_LE  0x20
 
@@ -45,6 +67,8 @@
 /* OF-specific */
 #define ESDHC_DMA_SYSCTL       0x40c
 #define ESDHC_DMA_SNOOP                0x00000040
+#define ESDHC_FLUSH_ASYNC_FIFO          0x00040000
+#define ESDHC_USE_PERIPHERAL_CLK        0x00080000
 
 #define ESDHC_HOST_CONTROL_RES 0x01
 
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c 
b/drivers/mmc/host/sdhci-of-esdhc.c
index f1021d8..6d7e3f9 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -24,11 +24,30 @@
 
 #define VENDOR_V_22    0x12
 #define VENDOR_V_23    0x13
+
+static u32 adapter_type;
+static bool peripheral_clk_available;
+
 static u32 esdhc_readl(struct sdhci_host *host, int reg)
 {
        u32 ret;
 
-       ret = sdhci_32bs_readl(host, reg);
+       if (reg == SDHCI_CAPABILITIES_1) {
+               ret = sdhci_32bs_readl(host, ESDHC_CAPABILITIES_1);
+               switch (adapter_type) {
+               case ESDHC_ADAPTER_TYPE_EMMC44:
+                       if (ret & ESDHC_MODE_DDR50) {
+                               ret &= ESDHC_MODE_DDR50_SEL;
+                               /* enable 1/8V DDR capable */
+                               host->mmc->caps |= MMC_CAP_1_8V_DDR;
+                       } else
+                               ret &= ~ESDHC_MODE_MASK;
+                       break;
+               default:
+                       ret &= ~ESDHC_MODE_MASK;
+               }
+       } else
+               ret = sdhci_32bs_readl(host, reg);
        /*
         * The bit of ADMA flag in eSDHC is not compatible with standard
         * SDHC register, so set fake flag SDHCI_CAN_DO_ADMA2 when ADMA is
@@ -159,8 +178,11 @@ static void esdhc_writeb(struct sdhci_host *host, u8 val, 
int reg)
        }
 
        /* Prevent SDHCI core from writing reserved bits (e.g. HISPD). */
-       if (reg == SDHCI_HOST_CONTROL)
+       if (reg == SDHCI_HOST_CONTROL) {
                val &= ~ESDHC_HOST_CONTROL_RES;
+               val &= ~SDHCI_CTRL_HISPD;
+               val |= (sdhci_32bs_readl(host, reg) & SDHCI_CTRL_HISPD);
+       }
        sdhci_clrsetbits(host, 0xff, val, reg);
 }
 
@@ -307,6 +329,84 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
 
+static void esdhc_clock_control(struct sdhci_host *host, bool enable)
+{
+       u32 value;
+       u32 time_out;
+
+       value = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
+
+       if (enable)
+               value |= ESDHC_CLOCK_CRDEN;
+       else
+               value &= ~ESDHC_CLOCK_CRDEN;
+
+       sdhci_writel(host, value, ESDHC_SYSTEM_CONTROL);
+
+       time_out = 20;
+       value = ESDHC_CLK_STABLE;
+       while (!(sdhci_readl(host, ESDHCI_PRESENT_STATE) & value)) {
+               if (time_out == 0) {
+                       pr_err("%s: Internal clock never stabilised.\n",
+                               mmc_hostname(host->mmc));
+                       break;
+               }
+               time_out--;
+               mdelay(1);
+       }
+}
+
+static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
+{
+       u16 ctrl_2;
+       u32 time_out;
+       u32 value;
+
+       ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+       /* Select Bus Speed Mode for host */
+       ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
+       if ((uhs == MMC_TIMING_MMC_HS200) ||
+               (uhs == MMC_TIMING_UHS_SDR104))
+               ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
+       else if (uhs == MMC_TIMING_UHS_SDR12)
+               ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
+       else if (uhs == MMC_TIMING_UHS_SDR25)
+               ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
+       else if (uhs == MMC_TIMING_UHS_SDR50)
+               ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
+       else if (uhs == MMC_TIMING_UHS_DDR50)
+               ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
+
+       if (uhs == MMC_TIMING_UHS_DDR50) {
+               esdhc_clock_control(host, false);
+               sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+               value = sdhci_readl(host, ESDHC_CLOCK_CONTROL);
+               value |= (ESDHC_CLKLPBK_EXTPIN | ESDHC_CMDCLK_SHIFTED);
+               sdhci_writel(host, value, ESDHC_CLOCK_CONTROL);
+               esdhc_clock_control(host, true);
+
+               esdhc_clock_control(host, false);
+               value = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+               value |= ESDHC_FLUSH_ASYNC_FIFO;
+               sdhci_writel(host, value, ESDHC_DMA_SYSCTL);
+               /* Wait max 20 ms */
+               time_out = 20;
+               value = ESDHC_FLUSH_ASYNC_FIFO;
+               while (sdhci_readl(host, ESDHC_DMA_SYSCTL) & value) {
+                       if (time_out == 0) {
+                               pr_err("%s: FAF bit is auto cleaned failed.\n",
+                                       mmc_hostname(host->mmc));
+
+                               break;
+                       }
+                       time_out--;
+                       mdelay(1);
+               }
+               esdhc_clock_control(host, true);
+       } else
+               sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+}
+
 static const struct sdhci_ops sdhci_esdhc_ops = {
        .read_l = esdhc_readl,
        .read_w = esdhc_readw,
@@ -322,7 +422,7 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
        .adma_workaround = esdhci_of_adma_workaround,
        .set_bus_width = esdhc_pltfm_set_bus_width,
        .reset = esdhc_reset,
-       .set_uhs_signaling = sdhci_set_uhs_signaling,
+       .set_uhs_signaling = esdhc_set_uhs_signaling,
 };
 
 #ifdef CONFIG_PM
@@ -376,6 +476,8 @@ static void esdhc_get_property(struct platform_device *pdev)
        struct device_node *np = pdev->dev.of_node;
        struct sdhci_host *host = platform_get_drvdata(pdev);
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+       const __be32 *value;
+       int size;
 
        sdhci_get_of_property(pdev);
 
@@ -383,6 +485,18 @@ static void esdhc_get_property(struct platform_device 
*pdev)
        mmc_of_parse(host->mmc);
        mmc_of_parse_voltage(np, &host->ocr_mask);
 
+       value = of_get_property(np, "adapter-type", &size);
+       if (value && size == sizeof(*value) && *value)
+               adapter_type = be32_to_cpup(value);
+
+       /* If getting a peripheral-frequency, use it instead */
+       value = of_get_property(np, "peripheral-frequency", &size);
+       if (value && size == sizeof(*value) && *value) {
+               pltfm_host->clock = be32_to_cpup(value);
+               peripheral_clk_available = true;
+       } else
+               peripheral_clk_available = false;
+
        if (of_device_is_compatible(np, "fsl,p5040-esdhc") ||
            of_device_is_compatible(np, "fsl,p5020-esdhc") ||
            of_device_is_compatible(np, "fsl,p4080-esdhc") ||
@@ -409,13 +523,23 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)
 {
        struct sdhci_host *host;
        int ret;
-
+       u32 value;
 
        host = sdhci_pltfm_init(pdev, &sdhci_esdhc_pdata, 0);
        if (IS_ERR(host))
                return PTR_ERR(host);
 
        esdhc_get_property(pdev);
+
+       /* Select peripheral clock as the eSDHC clock */
+       if (peripheral_clk_available) {
+               esdhc_clock_control(host, false);
+               value = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+               value |= ESDHC_USE_PERIPHERAL_CLK;
+               sdhci_writel(host, value, ESDHC_DMA_SYSCTL);
+               esdhc_clock_control(host, true);
+       }
+
        ret = sdhci_add_host(host);
        if (ret)
                goto err;
-- 
2.1.0.27.g96db324

--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to