mmc: dw_mmc: fix suspend/resume operation

This patch is related to re-init processing on suspend/resume.

When card is resuming, some register is reset.  If card is removable,
maybe controller should be rescan for card.  But if assume card is
non-removable, need to restore the old value at registers.

We store the value of FIFOTH at probe time and then restore it in
dw_mci_resume().

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/dw_mmc.c

@@ -1639,8 +1639,9 @@ static int dw_mci_probe(struct platform_device *pdev)
 	 */
 	fifo_size = mci_readl(host, FIFOTH);
 	fifo_size = (fifo_size >> 16) & 0x7ff;
-	mci_writel(host, FIFOTH, ((0x2 << 28) | ((fifo_size/2 - 1) << 16) |
-				  ((fifo_size/2) << 0)));
+	host->fifoth_val = ((0x2 << 28) | ((fifo_size/2 - 1) << 16) |
+			((fifo_size/2) << 0));
+	mci_writel(host, FIFOTH, host->fifoth_val);
 
 	/* disable clock to CIU */
 	mci_writel(host, CLKENA, 0);
@@ -1772,6 +1773,23 @@ static int dw_mci_resume(struct platform_device *pdev)
 	int i, ret;
 	struct dw_mci *host = platform_get_drvdata(pdev);
 
+	if (host->dma_ops->init)
+		host->dma_ops->init(host);
+
+	if (!mci_wait_reset(&pdev->dev, host)) {
+		ret = -ENODEV;
+		return ret;
+	}
+
+	/* Restore the old value at FIFOTH register */
+	mci_writel(host, FIFOTH, host->fifoth_val);
+
+	mci_writel(host, RINTSTS, 0xFFFFFFFF);
+	mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
+		   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
+		   DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
+	mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
+
 	for (i = 0; i < host->num_slots; i++) {
 		struct dw_mci_slot *slot = host->slot[i];
 		if (!slot)

include/linux/mmc/dw_mmc.h

@@ -140,6 +140,7 @@ struct dw_mci {
 	u32			bus_hz;
 	u32			current_speed;
 	u32			num_slots;
+	u32			fifoth_val;
 	struct platform_device	*pdev;
 	struct dw_mci_board	*pdata;
 	struct dw_mci_slot	*slot[MAX_MCI_SLOTS];