mmc: sdhci-s3c: Fix base clock source management

index 6debda9..52770d5 100644
@@ -144,7 +144,7 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 {
 	unsigned long rate;
 	struct clk *clksrc = ourhost->clk_bus[src];
-	int div;
+	int shift;
 
 	if (!clksrc)
 		return UINT_MAX;

@@ -160,15 +160,15 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 
 	rate = clk_get_rate(clksrc);
 
-	for (div = 1; div < 256; div *= 2) {
-		if ((rate / div) <= wanted)
+	for (shift = 0; shift < 8; ++shift) {
+		if ((rate >> shift) <= wanted)
 			break;
 	}
 
 	dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
-		src, rate, wanted, rate / div);
+		src, rate, wanted, rate >> shift);
 
-	return wanted - (rate / div);
+	return wanted - (rate >> shift);
 }
 
 /**

index 52770d5..9b78391 100644
@@ -57,6 +57,7 @@ struct sdhci_s3c {
 
 	struct clk		*clk_io;
 	struct clk		*clk_bus[MAX_BUS_CLK];
+	unsigned long		clk_rates[MAX_BUS_CLK];
 };
 
 /**

@@ -158,7 +159,7 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 		return wanted - rate;
 	}
 
-	rate = clk_get_rate(clksrc);
+	rate = ourhost->clk_rates[src];
 
 	for (shift = 0; shift < 8; ++shift) {
 		if ((rate >> shift) <= wanted)

@@ -215,7 +216,7 @@ static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
 		writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
 
 		ourhost->cur_clk = best_src;
-		host->max_clk = clk_get_rate(clk);
+		host->max_clk = ourhost->clk_rates[best_src];
 
 		ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
 		ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;

@@ -583,8 +584,10 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 		 */
 		sc->cur_clk = ptr;
 
+		sc->clk_rates[ptr] = clk_get_rate(sc->clk_bus[ptr]);
+
 		dev_info(dev, "clock source %d: %s (%ld Hz)\n",
-			 ptr, name, clk_get_rate(clk));
+				ptr, name, sc->clk_rates[ptr]);
 	}
 
 	if (clks == 0) {

index 9b78391..7fde938 100644
@@ -147,7 +147,7 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 	struct clk *clksrc = ourhost->clk_bus[src];
 	int shift;
 
-	if (!clksrc)
+	if (IS_ERR(clksrc))
 		return UINT_MAX;
 
 	/*

@@ -567,16 +567,14 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	clk_prepare_enable(sc->clk_io);
 
 	for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
-		struct clk *clk;
 		char name[14];
 
 		snprintf(name, 14, "mmc_busclk.%d", ptr);
-		clk = devm_clk_get(dev, name);
-		if (IS_ERR(clk))
+		sc->clk_bus[ptr] = devm_clk_get(dev, name);
+		if (IS_ERR(sc->clk_bus[ptr]))
 			continue;
 
 		clks++;
-		sc->clk_bus[ptr] = clk;
 
 		/*
 		 * save current clock index to know which clock bus

index 7fde938..7e14db0 100644
@@ -112,20 +112,16 @@ static void sdhci_s3c_check_sclk(struct sdhci_host *host)
 static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
 {
 	struct sdhci_s3c *ourhost = to_s3c(host);
-	struct clk *busclk;
-	unsigned int rate, max;
-	int clk;
+	unsigned long rate, max = 0;
+	int src;
 
 	/* note, a reset will reset the clock source */
 
 	sdhci_s3c_check_sclk(host);
 
-	for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
-		busclk = ourhost->clk_bus[clk];
-		if (!busclk)
-			continue;
 
-		rate = clk_get_rate(busclk);
+	for (src = 0; src < MAX_BUS_CLK; src++) {
+		rate = ourhost->clk_rates[src];
 		if (rate > max)
 			max = rate;
 	}

@@ -255,17 +251,17 @@ static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
 static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
 {
 	struct sdhci_s3c *ourhost = to_s3c(host);
-	unsigned int delta, min = UINT_MAX;
+	unsigned long rate, min = ULONG_MAX;
 	int src;
 
 	for (src = 0; src < MAX_BUS_CLK; src++) {
-		delta = sdhci_s3c_consider_clock(ourhost, src, 0);
-		if (delta == UINT_MAX)
+		rate = ourhost->clk_rates[src] / 256;
+		if (!rate)
 			continue;
-		/* delta is a negative value in this case */
-		if (-delta < min)
-			min = -delta;
+		if (rate < min)
+			min = rate;
 	}
+
 	return min;
 }
 

@@ -273,20 +269,44 @@ static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
 static unsigned int sdhci_cmu_get_max_clock(struct sdhci_host *host)
 {
 	struct sdhci_s3c *ourhost = to_s3c(host);
+	unsigned long rate, max = 0;
+	int src;
+
+	for (src = 0; src < MAX_BUS_CLK; src++) {
+		struct clk *clk;
+
+		clk = ourhost->clk_bus[src];
+		if (IS_ERR(clk))
+			continue;
+
+		rate = clk_round_rate(clk, ULONG_MAX);
+		if (rate > max)
+			max = rate;
+	}
 
-	return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], UINT_MAX);
+	return max;
 }
 
 /* sdhci_cmu_get_min_clock - callback to get minimal supported clock value. */
 static unsigned int sdhci_cmu_get_min_clock(struct sdhci_host *host)
 {
 	struct sdhci_s3c *ourhost = to_s3c(host);
+	unsigned long rate, min = ULONG_MAX;
+	int src;
 
-	/*
-	 * initial clock can be in the frequency range of
-	 * 100KHz-400KHz, so we set it as max value.
-	 */
-	return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], 400000);
+	for (src = 0; src < MAX_BUS_CLK; src++) {
+		struct clk *clk;
+
+		clk = ourhost->clk_bus[src];
+		if (IS_ERR(clk))
+			continue;
+
+		rate = clk_round_rate(clk, 0);
+		if (rate < min)
+			min = rate;
+	}
+
+	return min;
 }
 
 /* sdhci_cmu_set_clock - callback on clock change.*/

index 7e14db0..bad0e00 100644
@@ -51,7 +51,7 @@ struct sdhci_s3c {
 	struct platform_device	*pdev;
 	struct resource		*ioarea;
 	struct s3c_sdhci_platdata *pdata;
-	unsigned int		cur_clk;
+	int			cur_clk;
 	int			ext_cd_irq;
 	int			ext_cd_gpio;
 

@@ -78,32 +78,6 @@ static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
 }
 
 /**
- * get_curclk - convert ctrl2 register to clock source number
- * @ctrl2: Control2 register value.
- */
-static u32 get_curclk(u32 ctrl2)
-{
-	ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
-	ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
-
-	return ctrl2;
-}
-
-static void sdhci_s3c_check_sclk(struct sdhci_host *host)
-{
-	struct sdhci_s3c *ourhost = to_s3c(host);
-	u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
-
-	if (get_curclk(tmp) != ourhost->cur_clk) {
-		dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
-
-		tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
-		tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
-		writel(tmp, host->ioaddr + S3C_SDHCI_CONTROL2);
-	}
-}
-
-/**
  * sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
  * @host: The SDHCI host instance.
  *

@@ -115,11 +89,6 @@ static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
 	unsigned long rate, max = 0;
 	int src;
 
-	/* note, a reset will reset the clock source */
-
-	sdhci_s3c_check_sclk(host);
-
-
 	for (src = 0; src < MAX_BUS_CLK; src++) {
 		rate = ourhost->clk_rates[src];
 		if (rate > max)

@@ -206,20 +175,22 @@ static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
 		struct clk *clk = ourhost->clk_bus[best_src];
 
 		clk_prepare_enable(clk);
-		clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
-
-		/* turn clock off to card before changing clock source */
-		writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
+		if (ourhost->cur_clk >= 0)
+			clk_disable_unprepare(
+					ourhost->clk_bus[ourhost->cur_clk]);
 
 		ourhost->cur_clk = best_src;
 		host->max_clk = ourhost->clk_rates[best_src];
-
-		ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
-		ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
-		ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
-		writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
 	}
 
+	/* turn clock off to card before changing clock source */
+	writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
+
+	ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
+	ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+	ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+	writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
+
 	/* reprogram default hardware configuration */
 	writel(S3C64XX_SDHCI_CONTROL4_DRIVE_9mA,
 		host->ioaddr + S3C64XX_SDHCI_CONTROL4);

@@ -573,6 +544,7 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	sc->host = host;
 	sc->pdev = pdev;
 	sc->pdata = pdata;
+	sc->cur_clk = -1;
 
 	platform_set_drvdata(pdev, host);
 

@@ -595,13 +567,6 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 			continue;
 
 		clks++;
-
-		/*
-		 * save current clock index to know which clock bus
-		 * is used later in overriding functions.
-		 */
-		sc->cur_clk = ptr;
-
 		sc->clk_rates[ptr] = clk_get_rate(sc->clk_bus[ptr]);
 
 		dev_info(dev, "clock source %d: %s (%ld Hz)\n",

@@ -614,10 +579,6 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 		goto err_no_busclks;
 	}
 
-#ifndef CONFIG_PM_RUNTIME
-	clk_prepare_enable(sc->clk_bus[sc->cur_clk]);
-#endif
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	host->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(host->ioaddr)) {

@@ -730,10 +691,6 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	return 0;
 
  err_req_regs:
-#ifndef CONFIG_PM_RUNTIME
-	clk_disable_unprepare(sc->clk_bus[sc->cur_clk]);
-#endif
-
  err_no_busclks:
 	clk_disable_unprepare(sc->clk_io);
 

@@ -764,9 +721,6 @@ static int sdhci_s3c_remove(struct platform_device *pdev)
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
-#ifndef CONFIG_PM_RUNTIME
-	clk_disable_unprepare(sc->clk_bus[sc->cur_clk]);
-#endif
 	clk_disable_unprepare(sc->clk_io);
 
 	sdhci_free_host(host);

@@ -800,7 +754,8 @@ static int sdhci_s3c_runtime_suspend(struct device *dev)
 
 	ret = sdhci_runtime_suspend_host(host);
 
-	clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
+	if (ourhost->cur_clk >= 0)
+		clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
 	clk_disable_unprepare(busclk);
 	return ret;
 }

@@ -813,7 +768,8 @@ static int sdhci_s3c_runtime_resume(struct device *dev)
 	int ret;
 
 	clk_prepare_enable(busclk);
-	clk_prepare_enable(ourhost->clk_bus[ourhost->cur_clk]);
+	if (ourhost->cur_clk >= 0)
+		clk_prepare_enable(ourhost->clk_bus[ourhost->cur_clk]);
 	ret = sdhci_runtime_resume_host(host);
 	return ret;
 }

index bad0e00..d61eb5a 100644
@@ -126,11 +126,18 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 
 	rate = ourhost->clk_rates[src];
 
-	for (shift = 0; shift < 8; ++shift) {
+	for (shift = 0; shift <= 8; ++shift) {
 		if ((rate >> shift) <= wanted)
 			break;
 	}
 
+	if (shift > 8) {
+		dev_dbg(&ourhost->pdev->dev,
+			"clk %d: rate %ld, min rate %lu > wanted %u\n",
+			src, rate, rate / 256, wanted);
+		return UINT_MAX;
+	}
+
 	dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
 		src, rate, wanted, rate >> shift);