From e882b3e27e72530ee3d173a6261d9a6a1a095362 Mon Sep 17 00:00:00 2001
From: Doug Anderson <dianders@chromium.org>
Date: Wed, 25 Jul 2012 08:33:17 -0700
Subject: [PATCH] --- yaml --- r: 322509 b: refs/heads/master c:
 9623b5b9192b349bcadb31cce159072a78ac6972 h: refs/heads/master i:   322507:
 a95d4671dcef259b9f70028d414e6627f768416b v: v3

---
 [refs]                          |  2 +-
 trunk/drivers/mmc/host/dw_mmc.c | 41 ++++++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 3225093c6dc1..d20379cf24be 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e74f3a9c993a088f0a067e13941075e4acb7300a
+refs/heads/master: 9623b5b9192b349bcadb31cce159072a78ac6972
diff --git a/trunk/drivers/mmc/host/dw_mmc.c b/trunk/drivers/mmc/host/dw_mmc.c
index cf8511b80782..af40d227bece 100644
--- a/trunk/drivers/mmc/host/dw_mmc.c
+++ b/trunk/drivers/mmc/host/dw_mmc.c
@@ -627,6 +627,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
 {
 	struct dw_mci *host = slot->host;
 	u32 div;
+	u32 clk_en_a;
 
 	if (slot->clock != host->current_speed) {
 		div = host->bus_hz / slot->clock;
@@ -659,9 +660,11 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
 		mci_send_cmd(slot,
 			     SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
 
-		/* enable clock */
-		mci_writel(host, CLKENA, ((SDMMC_CLKEN_ENABLE |
-			   SDMMC_CLKEN_LOW_PWR) << slot->id));
+		/* enable clock; only low power if no SDIO */
+		clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
+		if (!(mci_readl(host, INTMASK) & SDMMC_INT_SDIO(slot->id)))
+			clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id;
+		mci_writel(host, CLKENA, clk_en_a);
 
 		/* inform CIU */
 		mci_send_cmd(slot,
@@ -862,6 +865,30 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
 	return present;
 }
 
+/*
+ * Disable lower power mode.
+ *
+ * Low power mode will stop the card clock when idle.  According to the
+ * description of the CLKENA register we should disable low power mode
+ * for SDIO cards if we need SDIO interrupts to work.
+ *
+ * This function is fast if low power mode is already disabled.
+ */
+static void dw_mci_disable_low_power(struct dw_mci_slot *slot)
+{
+	struct dw_mci *host = slot->host;
+	u32 clk_en_a;
+	const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
+
+	clk_en_a = mci_readl(host, CLKENA);
+
+	if (clk_en_a & clken_low_pwr) {
+		mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr);
+		mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
+			     SDMMC_CMD_PRV_DAT_WAIT, 0);
+	}
+}
+
 static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 {
 	struct dw_mci_slot *slot = mmc_priv(mmc);
@@ -871,6 +898,14 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 	/* Enable/disable Slot Specific SDIO interrupt */
 	int_mask = mci_readl(host, INTMASK);
 	if (enb) {
+		/*
+		 * Turn off low power mode if it was enabled.  This is a bit of
+		 * a heavy operation and we disable / enable IRQs a lot, so
+		 * we'll leave low power mode disabled and it will get
+		 * re-enabled again in dw_mci_setup_bus().
+		 */
+		dw_mci_disable_low_power(slot);
+
 		mci_writel(host, INTMASK,
 			   (int_mask | SDMMC_INT_SDIO(slot->id)));
 	} else {