// SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause /* MDIO support for Mellanox Gigabit Ethernet driver * * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mlxbf_gige.h" #include "mlxbf_gige_regs.h" #define MLXBF_GIGE_MDIO_GW_OFFSET 0x0 #define MLXBF_GIGE_MDIO_CFG_OFFSET 0x4 #define MLXBF_GIGE_MDIO_FREQ_REFERENCE 156250000ULL #define MLXBF_GIGE_MDIO_COREPLL_CONST 16384ULL #define MLXBF_GIGE_MDC_CLK_NS 400 #define MLXBF_GIGE_MDIO_PLL_I1CLK_REG1 0x4 #define MLXBF_GIGE_MDIO_PLL_I1CLK_REG2 0x8 #define MLXBF_GIGE_MDIO_CORE_F_SHIFT 0 #define MLXBF_GIGE_MDIO_CORE_F_MASK GENMASK(25, 0) #define MLXBF_GIGE_MDIO_CORE_R_SHIFT 26 #define MLXBF_GIGE_MDIO_CORE_R_MASK GENMASK(31, 26) #define MLXBF_GIGE_MDIO_CORE_OD_SHIFT 0 #define MLXBF_GIGE_MDIO_CORE_OD_MASK GENMASK(3, 0) /* Support clause 22 */ #define MLXBF_GIGE_MDIO_CL22_ST1 0x1 #define MLXBF_GIGE_MDIO_CL22_WRITE 0x1 #define MLXBF_GIGE_MDIO_CL22_READ 0x2 /* Busy bit is set by software and cleared by hardware */ #define MLXBF_GIGE_MDIO_SET_BUSY 0x1 /* MDIO GW register bits */ #define MLXBF_GIGE_MDIO_GW_AD_MASK GENMASK(15, 0) #define MLXBF_GIGE_MDIO_GW_DEVAD_MASK GENMASK(20, 16) #define MLXBF_GIGE_MDIO_GW_PARTAD_MASK GENMASK(25, 21) #define MLXBF_GIGE_MDIO_GW_OPCODE_MASK GENMASK(27, 26) #define MLXBF_GIGE_MDIO_GW_ST1_MASK GENMASK(28, 28) #define MLXBF_GIGE_MDIO_GW_BUSY_MASK GENMASK(30, 30) /* MDIO config register bits */ #define MLXBF_GIGE_MDIO_CFG_MDIO_MODE_MASK GENMASK(1, 0) #define MLXBF_GIGE_MDIO_CFG_MDIO3_3_MASK GENMASK(2, 2) #define MLXBF_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK GENMASK(4, 4) #define MLXBF_GIGE_MDIO_CFG_MDC_PERIOD_MASK GENMASK(15, 8) #define MLXBF_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK GENMASK(23, 16) #define MLXBF_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK GENMASK(31, 24) #define MLXBF_GIGE_MDIO_CFG_VAL (FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_MODE_MASK, 1) | \ FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO3_3_MASK, 1) | \ FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK, 1) | \ FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK, 6) | \ FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK, 13)) #define MLXBF_GIGE_BF2_COREPLL_ADDR 0x02800c30 #define MLXBF_GIGE_BF2_COREPLL_SIZE 0x0000000c static struct resource corepll_params[] = { [MLXBF_GIGE_VERSION_BF2] = { .start = MLXBF_GIGE_BF2_COREPLL_ADDR, .end = MLXBF_GIGE_BF2_COREPLL_ADDR + MLXBF_GIGE_BF2_COREPLL_SIZE - 1, .name = "COREPLL_RES" }, }; /* Returns core clock i1clk in Hz */ static u64 calculate_i1clk(struct mlxbf_gige *priv) { u8 core_od, core_r; u64 freq_output; u32 reg1, reg2; u32 core_f; reg1 = readl(priv->clk_io + MLXBF_GIGE_MDIO_PLL_I1CLK_REG1); reg2 = readl(priv->clk_io + MLXBF_GIGE_MDIO_PLL_I1CLK_REG2); core_f = (reg1 & MLXBF_GIGE_MDIO_CORE_F_MASK) >> MLXBF_GIGE_MDIO_CORE_F_SHIFT; core_r = (reg1 & MLXBF_GIGE_MDIO_CORE_R_MASK) >> MLXBF_GIGE_MDIO_CORE_R_SHIFT; core_od = (reg2 & MLXBF_GIGE_MDIO_CORE_OD_MASK) >> MLXBF_GIGE_MDIO_CORE_OD_SHIFT; /* Compute PLL output frequency as follow: * * CORE_F / 16384 * freq_output = freq_reference * ---------------------------- * (CORE_R + 1) * (CORE_OD + 1) */ freq_output = div_u64((MLXBF_GIGE_MDIO_FREQ_REFERENCE * core_f), MLXBF_GIGE_MDIO_COREPLL_CONST); freq_output = div_u64(freq_output, (core_r + 1) * (core_od + 1)); return freq_output; } /* Formula for encoding the MDIO period. The encoded value is * passed to the MDIO config register. * * mdc_clk = 2*(val + 1)*(core clock in sec) * * i1clk is in Hz: * 400 ns = 2*(val + 1)*(1/i1clk) * * val = (((400/10^9) / (1/i1clk) / 2) - 1) * val = (400/2 * i1clk)/10^9 - 1 */ static u8 mdio_period_map(struct mlxbf_gige *priv) { u8 mdio_period; u64 i1clk; i1clk = calculate_i1clk(priv); mdio_period = div_u64((MLXBF_GIGE_MDC_CLK_NS >> 1) * i1clk, 1000000000) - 1; return mdio_period; } static u32 mlxbf_gige_mdio_create_cmd(u16 data, int phy_add, int phy_reg, u32 opcode) { u32 gw_reg = 0; gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_AD_MASK, data); gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_DEVAD_MASK, phy_reg); gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_PARTAD_MASK, phy_add); gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_OPCODE_MASK, opcode); gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_ST1_MASK, MLXBF_GIGE_MDIO_CL22_ST1); gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_BUSY_MASK, MLXBF_GIGE_MDIO_SET_BUSY); return gw_reg; } static int mlxbf_gige_mdio_read(struct mii_bus *bus, int phy_add, int phy_reg) { struct mlxbf_gige *priv = bus->priv; u32 cmd; int ret; u32 val; if (phy_reg & MII_ADDR_C45) return -EOPNOTSUPP; /* Send mdio read request */ cmd = mlxbf_gige_mdio_create_cmd(0, phy_add, phy_reg, MLXBF_GIGE_MDIO_CL22_READ); writel(cmd, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET, val, !(val & MLXBF_GIGE_MDIO_GW_BUSY_MASK), 100, 1000000); if (ret) { writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); return ret; } ret = readl(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); /* Only return ad bits of the gw register */ ret &= MLXBF_GIGE_MDIO_GW_AD_MASK; /* The MDIO lock is set on read. To release it, clear gw register */ writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); return ret; } static int mlxbf_gige_mdio_write(struct mii_bus *bus, int phy_add, int phy_reg, u16 val) { struct mlxbf_gige *priv = bus->priv; u32 temp; u32 cmd; int ret; if (phy_reg & MII_ADDR_C45) return -EOPNOTSUPP; /* Send mdio write request */ cmd = mlxbf_gige_mdio_create_cmd(val, phy_add, phy_reg, MLXBF_GIGE_MDIO_CL22_WRITE); writel(cmd, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); /* If the poll timed out, drop the request */ ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET, temp, !(temp & MLXBF_GIGE_MDIO_GW_BUSY_MASK), 100, 1000000); /* The MDIO lock is set on read. To release it, clear gw register */ writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); return ret; } static void mlxbf_gige_mdio_cfg(struct mlxbf_gige *priv) { u8 mdio_period; u32 val; mdio_period = mdio_period_map(priv); val = MLXBF_GIGE_MDIO_CFG_VAL; val |= FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDC_PERIOD_MASK, mdio_period); writel(val, priv->mdio_io + MLXBF_GIGE_MDIO_CFG_OFFSET); } int mlxbf_gige_mdio_probe(struct platform_device *pdev, struct mlxbf_gige *priv) { struct device *dev = &pdev->dev; struct resource *res; int ret; priv->mdio_io = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_MDIO9); if (IS_ERR(priv->mdio_io)) return PTR_ERR(priv->mdio_io); /* clk resource shared with other drivers so cannot use * devm_platform_ioremap_resource */ res = platform_get_resource(pdev, IORESOURCE_MEM, MLXBF_GIGE_RES_CLK); if (!res) { /* For backward compatibility with older ACPI tables, also keep * CLK resource internal to the driver. */ res = &corepll_params[MLXBF_GIGE_VERSION_BF2]; } priv->clk_io = devm_ioremap(dev, res->start, resource_size(res)); if (!priv->clk_io) return -ENOMEM; mlxbf_gige_mdio_cfg(priv); priv->mdiobus = devm_mdiobus_alloc(dev); if (!priv->mdiobus) { dev_err(dev, "Failed to alloc MDIO bus\n"); return -ENOMEM; } priv->mdiobus->name = "mlxbf-mdio"; priv->mdiobus->read = mlxbf_gige_mdio_read; priv->mdiobus->write = mlxbf_gige_mdio_write; priv->mdiobus->parent = dev; priv->mdiobus->priv = priv; snprintf(priv->mdiobus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev)); ret = mdiobus_register(priv->mdiobus); if (ret) dev_err(dev, "Failed to register MDIO bus\n"); return ret; } void mlxbf_gige_mdio_remove(struct mlxbf_gige *priv) { mdiobus_unregister(priv->mdiobus); }