diff options
Diffstat (limited to 'drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c')
| -rw-r--r-- | drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c | 154 |
1 files changed, 111 insertions, 43 deletions
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c index 435ed308d990..9ca2643c921e 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c @@ -17,10 +17,17 @@ #include "xilinx_axienet.h" -#define MAX_MDIO_FREQ 2500000 /* 2.5 MHz */ +#define DEFAULT_MDIO_FREQ 2500000 /* 2.5 MHz */ #define DEFAULT_HOST_CLOCK 150000000 /* 150 MHz */ -/* Wait till MDIO interface is ready to accept a new transaction.*/ +/** + * axienet_mdio_wait_until_ready - MDIO wait function + * @lp: Pointer to axienet local data structure. + * + * Return : 0 on success, Negative value on errors + * + * Wait till MDIO interface is ready to accept a new transaction. + */ static int axienet_mdio_wait_until_ready(struct axienet_local *lp) { u32 val; @@ -31,6 +38,33 @@ static int axienet_mdio_wait_until_ready(struct axienet_local *lp) } /** + * axienet_mdio_mdc_enable - MDIO MDC enable function + * @lp: Pointer to axienet local data structure. + * + * Enable the MDIO MDC. Called prior to a read/write operation + */ +static void axienet_mdio_mdc_enable(struct axienet_local *lp) +{ + axienet_iow(lp, XAE_MDIO_MC_OFFSET, + ((u32)lp->mii_clk_div | XAE_MDIO_MC_MDIOEN_MASK)); +} + +/** + * axienet_mdio_mdc_disable - MDIO MDC disable function + * @lp: Pointer to axienet local data structure. + * + * Disable the MDIO MDC. Called after a read/write operation + */ +static void axienet_mdio_mdc_disable(struct axienet_local *lp) +{ + u32 mc_reg; + + mc_reg = axienet_ior(lp, XAE_MDIO_MC_OFFSET); + axienet_iow(lp, XAE_MDIO_MC_OFFSET, + (mc_reg & ~XAE_MDIO_MC_MDIOEN_MASK)); +} + +/** * axienet_mdio_read - MDIO interface read function * @bus: Pointer to mii bus structure * @phy_id: Address of the PHY device @@ -48,9 +82,13 @@ static int axienet_mdio_read(struct mii_bus *bus, int phy_id, int reg) int ret; struct axienet_local *lp = bus->priv; + axienet_mdio_mdc_enable(lp); + ret = axienet_mdio_wait_until_ready(lp); - if (ret < 0) + if (ret < 0) { + axienet_mdio_mdc_disable(lp); return ret; + } axienet_iow(lp, XAE_MDIO_MCR_OFFSET, (((phy_id << XAE_MDIO_MCR_PHYAD_SHIFT) & @@ -61,14 +99,17 @@ static int axienet_mdio_read(struct mii_bus *bus, int phy_id, int reg) XAE_MDIO_MCR_OP_READ_MASK)); ret = axienet_mdio_wait_until_ready(lp); - if (ret < 0) + if (ret < 0) { + axienet_mdio_mdc_disable(lp); return ret; + } rc = axienet_ior(lp, XAE_MDIO_MRD_OFFSET) & 0x0000FFFF; dev_dbg(lp->dev, "axienet_mdio_read(phy_id=%i, reg=%x) == %x\n", phy_id, reg, rc); + axienet_mdio_mdc_disable(lp); return rc; } @@ -82,7 +123,7 @@ static int axienet_mdio_read(struct mii_bus *bus, int phy_id, int reg) * Return: 0 on success, -ETIMEDOUT on a timeout * * Writes the value to the requested register by first writing the value - * into MWD register. The the MCR register is then appropriately setup + * into MWD register. The MCR register is then appropriately setup * to finish the write operation. */ static int axienet_mdio_write(struct mii_bus *bus, int phy_id, int reg, @@ -94,11 +135,15 @@ static int axienet_mdio_write(struct mii_bus *bus, int phy_id, int reg, dev_dbg(lp->dev, "axienet_mdio_write(phy_id=%i, reg=%x, val=%x)\n", phy_id, reg, val); + axienet_mdio_mdc_enable(lp); + ret = axienet_mdio_wait_until_ready(lp); - if (ret < 0) + if (ret < 0) { + axienet_mdio_mdc_disable(lp); return ret; + } - axienet_iow(lp, XAE_MDIO_MWD_OFFSET, (u32) val); + axienet_iow(lp, XAE_MDIO_MWD_OFFSET, (u32)val); axienet_iow(lp, XAE_MDIO_MCR_OFFSET, (((phy_id << XAE_MDIO_MCR_PHYAD_SHIFT) & XAE_MDIO_MCR_PHYAD_MASK) | @@ -108,26 +153,36 @@ static int axienet_mdio_write(struct mii_bus *bus, int phy_id, int reg, XAE_MDIO_MCR_OP_WRITE_MASK)); ret = axienet_mdio_wait_until_ready(lp); - if (ret < 0) + if (ret < 0) { + axienet_mdio_mdc_disable(lp); return ret; + } + axienet_mdio_mdc_disable(lp); return 0; } /** * axienet_mdio_enable - MDIO hardware setup function * @lp: Pointer to axienet local data structure. + * @np: Pointer to mdio device tree node. * - * Return: 0 on success, -ETIMEDOUT on a timeout. + * Return: 0 on success, -ETIMEDOUT on a timeout, -EOVERFLOW on a clock + * divisor overflow. * * Sets up the MDIO interface by initializing the MDIO clock and enabling the * MDIO interface in hardware. **/ -int axienet_mdio_enable(struct axienet_local *lp) +static int axienet_mdio_enable(struct axienet_local *lp, struct device_node *np) { - u32 clk_div, host_clock; + u32 mdio_freq = DEFAULT_MDIO_FREQ; + u32 host_clock; + u32 clk_div; + int ret; - if (lp->clk) { - host_clock = clk_get_rate(lp->clk); + lp->mii_clk_div = 0; + + if (lp->axi_clk) { + host_clock = clk_get_rate(lp->axi_clk); } else { struct device_node *np1; @@ -151,6 +206,12 @@ int axienet_mdio_enable(struct axienet_local *lp) host_clock); } + if (np) + of_property_read_u32(np, "clock-frequency", &mdio_freq); + if (mdio_freq != DEFAULT_MDIO_FREQ) + netdev_info(lp->ndev, "Setting non-standard mdio bus frequency to %u Hz\n", + mdio_freq); + /* clk_div can be calculated by deriving it from the equation: * fMDIO = fHOST / ((1 + clk_div) * 2) * @@ -176,43 +237,45 @@ int axienet_mdio_enable(struct axienet_local *lp) * "clock-frequency" from the CPU */ - clk_div = (host_clock / (MAX_MDIO_FREQ * 2)) - 1; + clk_div = (host_clock / (mdio_freq * 2)) - 1; /* If there is any remainder from the division of - * fHOST / (MAX_MDIO_FREQ * 2), then we need to add - * 1 to the clock divisor or we will surely be above 2.5 MHz + * fHOST / (mdio_freq * 2), then we need to add + * 1 to the clock divisor or we will surely be + * above the requested frequency */ - if (host_clock % (MAX_MDIO_FREQ * 2)) + if (host_clock % (mdio_freq * 2)) clk_div++; + /* Check for overflow of mii_clk_div */ + if (clk_div & ~XAE_MDIO_MC_CLOCK_DIVIDE_MAX) { + netdev_warn(lp->ndev, "MDIO clock divisor overflow\n"); + return -EOVERFLOW; + } + lp->mii_clk_div = (u8)clk_div; + netdev_dbg(lp->ndev, "Setting MDIO clock divisor to %u/%u Hz host clock.\n", - clk_div, host_clock); + lp->mii_clk_div, host_clock); - axienet_iow(lp, XAE_MDIO_MC_OFFSET, clk_div | XAE_MDIO_MC_MDIOEN_MASK); + axienet_mdio_mdc_enable(lp); - return axienet_mdio_wait_until_ready(lp); -} + ret = axienet_mdio_wait_until_ready(lp); + if (ret) + axienet_mdio_mdc_disable(lp); -/** - * axienet_mdio_disable - MDIO hardware disable function - * @lp: Pointer to axienet local data structure. - * - * Disable the MDIO interface in hardware. - **/ -void axienet_mdio_disable(struct axienet_local *lp) -{ - axienet_iow(lp, XAE_MDIO_MC_OFFSET, 0); + return ret; } /** * axienet_mdio_setup - MDIO setup function * @lp: Pointer to axienet local data structure. * - * Return: 0 on success, -ETIMEDOUT on a timeout, -ENOMEM when - * mdiobus_alloc (to allocate memory for mii bus structure) fails. + * Return: 0 on success, -ETIMEDOUT on a timeout, -EOVERFLOW on a clock + * divisor overflow, -ENOMEM when mdiobus_alloc (to allocate + * memory for mii bus structure) fails. * - * Sets up the MDIO interface by initializing the MDIO clock and enabling the - * MDIO interface in hardware. Register the MDIO interface. + * Sets up the MDIO interface by initializing the MDIO clock. + * Register the MDIO interface. **/ int axienet_mdio_setup(struct axienet_local *lp) { @@ -220,10 +283,6 @@ int axienet_mdio_setup(struct axienet_local *lp) struct mii_bus *bus; int ret; - ret = axienet_mdio_enable(lp); - if (ret < 0) - return ret; - bus = mdiobus_alloc(); if (!bus) return -ENOMEM; @@ -239,14 +298,23 @@ int axienet_mdio_setup(struct axienet_local *lp) lp->mii_bus = bus; mdio_node = of_get_child_by_name(lp->dev->of_node, "mdio"); + ret = axienet_mdio_enable(lp, mdio_node); + if (ret < 0) + goto unregister; ret = of_mdiobus_register(bus, mdio_node); + if (ret) + goto unregister_mdio_enabled; of_node_put(mdio_node); - if (ret) { - mdiobus_free(bus); - lp->mii_bus = NULL; - return ret; - } + axienet_mdio_mdc_disable(lp); return 0; + +unregister_mdio_enabled: + axienet_mdio_mdc_disable(lp); +unregister: + of_node_put(mdio_node); + mdiobus_free(bus); + lp->mii_bus = NULL; + return ret; } /** |