diff options
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c new file mode 100644 index 000000000..aa780b161 --- /dev/null +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c @@ -0,0 +1,278 @@ +// 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 <linux/acpi.h> +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/ioport.h> +#include <linux/irqreturn.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/phy.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +#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), + 5, 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), + 5, 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); +} |