diff options
Diffstat (limited to 'drivers/net/mdio/mdio-mscc-miim.c')
-rw-r--r-- | drivers/net/mdio/mdio-mscc-miim.c | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c index 582969751b4c..85b4b097da05 100644 --- a/drivers/net/mdio/mdio-mscc-miim.c +++ b/drivers/net/mdio/mdio-mscc-miim.c @@ -7,6 +7,7 @@ */ #include <linux/bitops.h> +#include <linux/clk.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/kernel.h> @@ -30,6 +31,8 @@ #define MSCC_MIIM_CMD_VLD BIT(31) #define MSCC_MIIM_REG_DATA 0xC #define MSCC_MIIM_DATA_ERROR (BIT(16) | BIT(17)) +#define MSCC_MIIM_REG_CFG 0x10 +#define MSCC_MIIM_CFG_PRESCALE_MASK GENMASK(7, 0) #define MSCC_PHY_REG_PHY_CFG 0x0 #define PHY_CFG_PHY_ENA (BIT(0) | BIT(1) | BIT(2) | BIT(3)) @@ -50,6 +53,8 @@ struct mscc_miim_dev { int mii_status_offset; struct regmap *phy_regs; const struct mscc_miim_info *info; + struct clk *clk; + u32 bus_freq; }; /* When high resolution timers aren't built-in: we can't use usleep_range() as @@ -241,9 +246,32 @@ int mscc_miim_setup(struct device *dev, struct mii_bus **pbus, const char *name, } EXPORT_SYMBOL(mscc_miim_setup); +static int mscc_miim_clk_set(struct mii_bus *bus) +{ + struct mscc_miim_dev *miim = bus->priv; + unsigned long rate; + u32 div; + + /* Keep the current settings */ + if (!miim->bus_freq) + return 0; + + rate = clk_get_rate(miim->clk); + + div = DIV_ROUND_UP(rate, 2 * miim->bus_freq) - 1; + if (div == 0 || div & ~MSCC_MIIM_CFG_PRESCALE_MASK) { + dev_err(&bus->dev, "Incorrect MDIO clock frequency\n"); + return -EINVAL; + } + + return regmap_update_bits(miim->regs, MSCC_MIIM_REG_CFG, + MSCC_MIIM_CFG_PRESCALE_MASK, div); +} + static int mscc_miim_probe(struct platform_device *pdev) { struct regmap *mii_regmap, *phy_regmap = NULL; + struct device_node *np = pdev->dev.of_node; void __iomem *regs, *phy_regs; struct mscc_miim_dev *miim; struct resource *res; @@ -294,21 +322,47 @@ static int mscc_miim_probe(struct platform_device *pdev) if (!miim->info) return -EINVAL; - ret = of_mdiobus_register(bus, pdev->dev.of_node); + miim->clk = devm_clk_get_optional(&pdev->dev, NULL); + if (IS_ERR(miim->clk)) + return PTR_ERR(miim->clk); + + of_property_read_u32(np, "clock-frequency", &miim->bus_freq); + + if (miim->bus_freq && !miim->clk) { + dev_err(&pdev->dev, + "cannot use clock-frequency without a clock\n"); + return -EINVAL; + } + + ret = clk_prepare_enable(miim->clk); + if (ret) + return ret; + + ret = mscc_miim_clk_set(bus); + if (ret) + goto out_disable_clk; + + ret = of_mdiobus_register(bus, np); if (ret < 0) { dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret); - return ret; + goto out_disable_clk; } platform_set_drvdata(pdev, bus); return 0; + +out_disable_clk: + clk_disable_unprepare(miim->clk); + return ret; } static int mscc_miim_remove(struct platform_device *pdev) { struct mii_bus *bus = platform_get_drvdata(pdev); + struct mscc_miim_dev *miim = bus->priv; + clk_disable_unprepare(miim->clk); mdiobus_unregister(bus); return 0; |