diff options
| -rw-r--r-- | drivers/ata/ahci_da850.c | 91 |
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); |