1 files changed, 76 insertions, 15 deletions

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index d65088a2fd5f..1a50cd3b4233 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -29,17 +29,8 @@
 #define SATA_PHY_TXSWING(x)	((x) << 19)
 #define SATA_PHY_ENPLL(x)	((x) << 31)
 
-/*
- * The multiplier needed for 1.5GHz PLL output.
- *
- * NOTE: This is currently hardcoded to be suitable for 100MHz crystal
- * frequency (which is used by DA850 EVM board) and may need to be changed
- * if you would like to use this driver on some other board.
- */
-#define DA850_SATA_CLK_MULTIPLIER	7
-
 static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
-			    void __iomem *ahci_base)
+			    void __iomem *ahci_base, u32 mpy)
 {
 	unsigned int val;
 
@@ -48,13 +39,61 @@ static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
 	val &= ~BIT(0);
 	writel(val, pwrdn_reg);
 
-	val = SATA_PHY_MPY(DA850_SATA_CLK_MULTIPLIER + 1) | SATA_PHY_LOS(1) |
-	      SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) |
-	      SATA_PHY_ENPLL(1);
+	val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |
+	      SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);
 
 	writel(val, ahci_base + SATA_P0PHYCR_REG);
 }
 
+static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
+{
+	u32 pll_output = 1500000000, needed;
+
+	/*
+	 * We need to determine the value of the multiplier (MPY) bits.
+	 * In order to include the 12.5 multiplier we need to first divide
+	 * the refclk rate by ten.
+	 *
+	 * __div64_32() turned out to be unreliable, sometimes returning
+	 * false results.
+	 */
+	WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
+	needed = pll_output / (refclk_rate / 10);
+
+	/*
+	 * What we have now is (multiplier * 10).
+	 *
+	 * Let's determine the actual register value we need to write.
+	 */
+
+	switch (needed) {
+	case 50:
+		return 0x1;
+	case 60:
+		return 0x2;
+	case 80:
+		return 0x4;
+	case 100:
+		return 0x5;
+	case 120:
+		return 0x6;
+	case 125:
+		return 0x7;
+	case 150:
+		return 0x8;
+	case 200:
+		return 0x9;
+	case 250:
+		return 0xa;
+	default:
+		/*
+		 * We should have divided evenly - if not, return an invalid
+		 * value.
+		 */
+		return 0;
+	}
+}
+
 static int ahci_da850_softreset(struct ata_link *link,
 				unsigned int *class, unsigned long deadline)
 {
@@ -126,9 +165,10 @@ static int ahci_da850_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
-	struct resource *res;
 	void __iomem *pwrdn_reg;
+	struct resource *res;
 	struct clk *clk;
+	u32 mpy;
 	int rc;
 
 	hpriv = ahci_platform_get_resources(pdev);
@@ -150,6 +190,27 @@ static int ahci_da850_probe(struct platform_device *pdev)
 		hpriv->clks[0] = clk;
 	}
 
+	/*
+	 * The second clock used by ahci-da850 is the external REFCLK. If we
+	 * didn't get it from ahci_platform_get_resources(), let's try to
+	 * specify the con_id in clk_get().
+	 */
+	if (!hpriv->clks[1]) {
+		clk = clk_get(dev, "refclk");
+		if (IS_ERR(clk)) {
+			dev_err(dev, "unable to obtain the reference clock");
+			return -ENODEV;
+		}
+
+		hpriv->clks[1] = clk;
+	}
+
+	mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
+	if (mpy == 0) {
+		dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
+		return -EINVAL;
+	}
+
 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		return rc;
@@ -162,7 +223,7 @@ static int ahci_da850_probe(struct platform_device *pdev)
 	if (!pwrdn_reg)
 		goto disable_resources;
 
-	da850_sata_init(dev, pwrdn_reg, hpriv->mmio);
+	da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);
 
 	rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
 				     &ahci_platform_sht);