ENGR00125823-2 esdhc: add a interface to let clock always on

Implement platform independent clock always on function.
User would use clk_always_on flag in plat_data to decide whether
we should let the clock always on for their some specical use cases.
Host driver will not handle platform specific clock always on fucntion
any more.

However, we will reserve the clock always on function for SDIO cards

Signed-off-by: Aisheng.Dong <b29396@freescale.com>

1 files changed, 19 insertions, 19 deletions

diff --git a/drivers/mmc/host/mx_sdhci.c b/drivers/mmc/host/mx_sdhci.c
index 8ee825a9af9d..0a49b556dee9 100644
--- a/drivers/mmc/host/mx_sdhci.c
+++ b/drivers/mmc/host/mx_sdhci.c
@@ -813,6 +813,7 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 			host->plat_data->clk_flg = 1;
 		}
 	}
+
 	if (clock == host->clock && !(ios.bus_width & MMC_BUS_WIDTH_DDR))
 		return;
 
@@ -852,6 +853,14 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 	DBG("prescaler = 0x%x, divider = 0x%x\n", prescaler, div);
 	clk |= (prescaler << 8) | (div << 4);
 
+	if (host->plat_data->clk_always_on
+		| (host->mmc->card && mmc_card_sdio(host->mmc->card)))
+		clk |= SDHCI_CLOCK_PER_EN | SDHCI_CLOCK_HLK_EN
+			| SDHCI_CLOCK_IPG_EN;
+	else
+		clk &= ~(SDHCI_CLOCK_PER_EN | SDHCI_CLOCK_HLK_EN
+			| SDHCI_CLOCK_IPG_EN);
+
 	/* Configure the clock delay line */
 	if ((host->plat_data->vendor_ver >= ESDHC_VENDOR_V3)
 		&& host->plat_data->dll_override_en)
@@ -1083,7 +1092,7 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 {
 	struct sdhci_host *host;
 	unsigned long flags;
-	u32 ier, prot, clk, present;
+	u32 ier, prot, present;
 
 	host = mmc_priv(mmc);
 
@@ -1096,19 +1105,13 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 		if (--(host->sdio_enable))
 			goto exit_unlock;
 	}
-	/* Enable the clock */
-	if (!host->plat_data->clk_flg) {
-		clk_enable(host->clk);
-		host->plat_data->clk_flg = 1;
-	}
+
 	ier = readl(host->ioaddr + SDHCI_SIGNAL_ENABLE);
 	prot = readl(host->ioaddr + SDHCI_HOST_CONTROL);
-	clk = readl(host->ioaddr + SDHCI_CLOCK_CONTROL);
 
 	if (enable) {
 		ier |= SDHCI_INT_CARD_INT;
 		prot |= SDHCI_CTRL_D3CD;
-		clk |= SDHCI_CLOCK_PER_EN | SDHCI_CLOCK_IPG_EN;
 		present = readl(host->ioaddr + SDHCI_PRESENT_STATE);
 		if ((present & SDHCI_CARD_INT_MASK) != SDHCI_CARD_INT_ID)
 			writel(SDHCI_INT_CARD_INT,
@@ -1116,12 +1119,10 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 	} else {
 		ier &= ~SDHCI_INT_CARD_INT;
 		prot &= ~SDHCI_CTRL_D3CD;
-		clk &= ~(SDHCI_CLOCK_PER_EN | SDHCI_CLOCK_IPG_EN);
 	}
 
 	writel(prot, host->ioaddr + SDHCI_HOST_CONTROL);
 	writel(ier, host->ioaddr + SDHCI_SIGNAL_ENABLE);
-	writel(clk, host->ioaddr + SDHCI_CLOCK_CONTROL);
 
 	mmiowb();
       exit_unlock:
@@ -1231,17 +1232,13 @@ static void sdhci_tasklet_finish(unsigned long param)
 	/* Stop the clock when the req is done */
 	req_done = !(readl(host->ioaddr + SDHCI_PRESENT_STATE) &
 		(SDHCI_DATA_ACTIVE | SDHCI_DOING_WRITE | SDHCI_DOING_READ));
-	/* Do not disable the eSDHC clk on MX35 3DS board,
-	 * since SYSTEM can't boot up after the reset key
-	 * is pressed when the SD/MMC boot mode is used.
-	 * The root cause is that the ROM code don't ensure
-	 * the SD/MMC clk is running when boot system.
-	 * */
-	if (!machine_is_mx35_3ds() && req_done && host->plat_data->clk_flg &&
-	    !(host->mmc && host->mmc->card && mmc_card_sdio(host->mmc->card))) {
+	if (req_done && host->plat_data->clk_flg &&
+		!(host->plat_data->clk_always_on) &&
+		!(host->mmc->card && mmc_card_sdio(host->mmc->card))) {
 		clk_disable(host->clk);
 		host->plat_data->clk_flg = 0;
 	}
+
 	mmc_request_done(host->mmc, mrq);
 }
 
@@ -1803,8 +1800,11 @@ static int __devinit sdhci_probe_slot(struct platform_device
 
 	/* Get the SDHC clock from clock system APIs */
 	host->clk = clk_get(&pdev->dev, mmc_plat->clock_mmc);
-	if (NULL == host->clk)
+	if (NULL == host->clk) {
 		printk(KERN_ERR "MXC MMC can't get clock.\n");
+		goto out1;
+	} else
+		clk_enable(host->clk);
 	DBG("SDHC:%d clock:%lu\n", pdev->id, clk_get_rate(host->clk));
 
 	host->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);