mmc: jz4740: Add support for Low Power Mode (LPM)

Add support for low power mode to the Ingenic's MMC/SD Controller.

Signed-off-by: Zhou Yanjie <zhouyanjie@zoho.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
index 0f69ba60f37c2e1663c64b087be163e70f85acf1..78383f60a3dce60c7ff03faa51f615495557204a 100644 (file)
--- a/drivers/mmc/host/jz4740_mmc.c
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -41,6 +41,7 @@
 #define JZ_REG_MMC_RESP_FIFO   0x34
 #define JZ_REG_MMC_RXFIFO      0x38
 #define JZ_REG_MMC_TXFIFO      0x3C
+#define JZ_REG_MMC_LPM         0x40
 #define JZ_REG_MMC_DMAC                0x44
 
 #define JZ_MMC_STRPCL_EXIT_MULTIPLE BIT(7)
@@ -100,6 +101,12 @@
 #define JZ_MMC_DMAC_DMA_SEL BIT(1)
 #define JZ_MMC_DMAC_DMA_EN BIT(0)
 
+#define        JZ_MMC_LPM_DRV_RISING BIT(31)
+#define        JZ_MMC_LPM_DRV_RISING_QTR_PHASE_DLY BIT(31)
+#define        JZ_MMC_LPM_DRV_RISING_1NS_DLY BIT(30)
+#define        JZ_MMC_LPM_SMP_RISING_QTR_OR_HALF_PHASE_DLY BIT(29)
+#define        JZ_MMC_LPM_LOW_POWER_MODE_EN BIT(0)
+
 #define JZ_MMC_CLK_RATE 24000000
 
 enum jz4740_mmc_version {
@@ -856,6 +863,22 @@ static int jz4740_mmc_set_clock_rate(struct jz4740_mmc_host *host, int rate)
        }
 
        writew(div, host->base + JZ_REG_MMC_CLKRT);
+
+       if (real_rate > 25000000) {
+               if (host->version >= JZ_MMC_X1000) {
+                       writel(JZ_MMC_LPM_DRV_RISING_QTR_PHASE_DLY |
+                                  JZ_MMC_LPM_SMP_RISING_QTR_OR_HALF_PHASE_DLY |
+                                  JZ_MMC_LPM_LOW_POWER_MODE_EN,
+                                  host->base + JZ_REG_MMC_LPM);
+               } else if (host->version >= JZ_MMC_JZ4760) {
+                       writel(JZ_MMC_LPM_DRV_RISING |
+                                  JZ_MMC_LPM_LOW_POWER_MODE_EN,
+                                  host->base + JZ_REG_MMC_LPM);
+               } else if (host->version >= JZ_MMC_JZ4725B)
+                       writel(JZ_MMC_LPM_LOW_POWER_MODE_EN,
+                                  host->base + JZ_REG_MMC_LPM);
+       }
+
        return real_rate;
 }