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-rw-r--r--drivers/ata/ahci_da850.c91
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);