1// SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause 2 3/* MDIO support for Mellanox Gigabit Ethernet driver 4 * 5 * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES 6 */ 7 8#include <linux/acpi.h> 9#include <linux/bitfield.h> 10#include <linux/delay.h> 11#include <linux/device.h> 12#include <linux/err.h> 13#include <linux/io.h> 14#include <linux/iopoll.h> 15#include <linux/ioport.h> 16#include <linux/irqreturn.h> 17#include <linux/jiffies.h> 18#include <linux/module.h> 19#include <linux/mod_devicetable.h> 20#include <linux/phy.h> 21#include <linux/platform_device.h> 22#include <linux/property.h> 23 24#include "mlxbf_gige.h" 25#include "mlxbf_gige_regs.h" 26#include "mlxbf_gige_mdio_bf2.h" 27#include "mlxbf_gige_mdio_bf3.h" 28 29static struct mlxbf_gige_mdio_gw mlxbf_gige_mdio_gw_t[] = { 30 [MLXBF_GIGE_VERSION_BF2] = { 31 .gw_address = MLXBF2_GIGE_MDIO_GW_OFFSET, 32 .read_data_address = MLXBF2_GIGE_MDIO_GW_OFFSET, 33 .busy = { 34 .mask = MLXBF2_GIGE_MDIO_GW_BUSY_MASK, 35 .shift = MLXBF2_GIGE_MDIO_GW_BUSY_SHIFT, 36 }, 37 .read_data = { 38 .mask = MLXBF2_GIGE_MDIO_GW_AD_MASK, 39 .shift = MLXBF2_GIGE_MDIO_GW_AD_SHIFT, 40 }, 41 .write_data = { 42 .mask = MLXBF2_GIGE_MDIO_GW_AD_MASK, 43 .shift = MLXBF2_GIGE_MDIO_GW_AD_SHIFT, 44 }, 45 .devad = { 46 .mask = MLXBF2_GIGE_MDIO_GW_DEVAD_MASK, 47 .shift = MLXBF2_GIGE_MDIO_GW_DEVAD_SHIFT, 48 }, 49 .partad = { 50 .mask = MLXBF2_GIGE_MDIO_GW_PARTAD_MASK, 51 .shift = MLXBF2_GIGE_MDIO_GW_PARTAD_SHIFT, 52 }, 53 .opcode = { 54 .mask = MLXBF2_GIGE_MDIO_GW_OPCODE_MASK, 55 .shift = MLXBF2_GIGE_MDIO_GW_OPCODE_SHIFT, 56 }, 57 .st1 = { 58 .mask = MLXBF2_GIGE_MDIO_GW_ST1_MASK, 59 .shift = MLXBF2_GIGE_MDIO_GW_ST1_SHIFT, 60 }, 61 }, 62 [MLXBF_GIGE_VERSION_BF3] = { 63 .gw_address = MLXBF3_GIGE_MDIO_GW_OFFSET, 64 .read_data_address = MLXBF3_GIGE_MDIO_DATA_READ, 65 .busy = { 66 .mask = MLXBF3_GIGE_MDIO_GW_BUSY_MASK, 67 .shift = MLXBF3_GIGE_MDIO_GW_BUSY_SHIFT, 68 }, 69 .read_data = { 70 .mask = MLXBF3_GIGE_MDIO_GW_DATA_READ_MASK, 71 .shift = MLXBF3_GIGE_MDIO_GW_DATA_READ_SHIFT, 72 }, 73 .write_data = { 74 .mask = MLXBF3_GIGE_MDIO_GW_DATA_MASK, 75 .shift = MLXBF3_GIGE_MDIO_GW_DATA_SHIFT, 76 }, 77 .devad = { 78 .mask = MLXBF3_GIGE_MDIO_GW_DEVAD_MASK, 79 .shift = MLXBF3_GIGE_MDIO_GW_DEVAD_SHIFT, 80 }, 81 .partad = { 82 .mask = MLXBF3_GIGE_MDIO_GW_PARTAD_MASK, 83 .shift = MLXBF3_GIGE_MDIO_GW_PARTAD_SHIFT, 84 }, 85 .opcode = { 86 .mask = MLXBF3_GIGE_MDIO_GW_OPCODE_MASK, 87 .shift = MLXBF3_GIGE_MDIO_GW_OPCODE_SHIFT, 88 }, 89 .st1 = { 90 .mask = MLXBF3_GIGE_MDIO_GW_ST1_MASK, 91 .shift = MLXBF3_GIGE_MDIO_GW_ST1_SHIFT, 92 }, 93 }, 94}; 95 96#define MLXBF_GIGE_MDIO_FREQ_REFERENCE 156250000ULL 97#define MLXBF_GIGE_MDIO_COREPLL_CONST 16384ULL 98#define MLXBF_GIGE_MDC_CLK_NS 400 99#define MLXBF_GIGE_MDIO_PLL_I1CLK_REG1 0x4 100#define MLXBF_GIGE_MDIO_PLL_I1CLK_REG2 0x8 101#define MLXBF_GIGE_MDIO_CORE_F_SHIFT 0 102#define MLXBF_GIGE_MDIO_CORE_F_MASK GENMASK(25, 0) 103#define MLXBF_GIGE_MDIO_CORE_R_SHIFT 26 104#define MLXBF_GIGE_MDIO_CORE_R_MASK GENMASK(31, 26) 105#define MLXBF_GIGE_MDIO_CORE_OD_SHIFT 0 106#define MLXBF_GIGE_MDIO_CORE_OD_MASK GENMASK(3, 0) 107 108/* Support clause 22 */ 109#define MLXBF_GIGE_MDIO_CL22_ST1 0x1 110#define MLXBF_GIGE_MDIO_CL22_WRITE 0x1 111#define MLXBF_GIGE_MDIO_CL22_READ 0x2 112 113/* Busy bit is set by software and cleared by hardware */ 114#define MLXBF_GIGE_MDIO_SET_BUSY 0x1 115 116#define MLXBF_GIGE_BF2_COREPLL_ADDR 0x02800c30 117#define MLXBF_GIGE_BF2_COREPLL_SIZE 0x0000000c 118#define MLXBF_GIGE_BF3_COREPLL_ADDR 0x13409824 119#define MLXBF_GIGE_BF3_COREPLL_SIZE 0x00000010 120 121static struct resource corepll_params[] = { 122 [MLXBF_GIGE_VERSION_BF2] = { 123 .start = MLXBF_GIGE_BF2_COREPLL_ADDR, 124 .end = MLXBF_GIGE_BF2_COREPLL_ADDR + MLXBF_GIGE_BF2_COREPLL_SIZE - 1, 125 .name = "COREPLL_RES" 126 }, 127 [MLXBF_GIGE_VERSION_BF3] = { 128 .start = MLXBF_GIGE_BF3_COREPLL_ADDR, 129 .end = MLXBF_GIGE_BF3_COREPLL_ADDR + MLXBF_GIGE_BF3_COREPLL_SIZE - 1, 130 .name = "COREPLL_RES" 131 } 132}; 133 134/* Returns core clock i1clk in Hz */ 135static u64 calculate_i1clk(struct mlxbf_gige *priv) 136{ 137 u8 core_od, core_r; 138 u64 freq_output; 139 u32 reg1, reg2; 140 u32 core_f; 141 142 reg1 = readl(priv->clk_io + MLXBF_GIGE_MDIO_PLL_I1CLK_REG1); 143 reg2 = readl(priv->clk_io + MLXBF_GIGE_MDIO_PLL_I1CLK_REG2); 144 145 core_f = (reg1 & MLXBF_GIGE_MDIO_CORE_F_MASK) >> 146 MLXBF_GIGE_MDIO_CORE_F_SHIFT; 147 core_r = (reg1 & MLXBF_GIGE_MDIO_CORE_R_MASK) >> 148 MLXBF_GIGE_MDIO_CORE_R_SHIFT; 149 core_od = (reg2 & MLXBF_GIGE_MDIO_CORE_OD_MASK) >> 150 MLXBF_GIGE_MDIO_CORE_OD_SHIFT; 151 152 /* Compute PLL output frequency as follow: 153 * 154 * CORE_F / 16384 155 * freq_output = freq_reference * ---------------------------- 156 * (CORE_R + 1) * (CORE_OD + 1) 157 */ 158 freq_output = div_u64((MLXBF_GIGE_MDIO_FREQ_REFERENCE * core_f), 159 MLXBF_GIGE_MDIO_COREPLL_CONST); 160 freq_output = div_u64(freq_output, (core_r + 1) * (core_od + 1)); 161 162 return freq_output; 163} 164 165/* Formula for encoding the MDIO period. The encoded value is 166 * passed to the MDIO config register. 167 * 168 * mdc_clk = 2*(val + 1)*(core clock in sec) 169 * 170 * i1clk is in Hz: 171 * 400 ns = 2*(val + 1)*(1/i1clk) 172 * 173 * val = (((400/10^9) / (1/i1clk) / 2) - 1) 174 * val = (400/2 * i1clk)/10^9 - 1 175 */ 176static u8 mdio_period_map(struct mlxbf_gige *priv) 177{ 178 u8 mdio_period; 179 u64 i1clk; 180 181 i1clk = calculate_i1clk(priv); 182 183 mdio_period = div_u64((MLXBF_GIGE_MDC_CLK_NS >> 1) * i1clk, 1000000000) - 1; 184 185 return mdio_period; 186} 187 188static u32 mlxbf_gige_mdio_create_cmd(struct mlxbf_gige_mdio_gw *mdio_gw, u16 data, int phy_add, 189 int phy_reg, u32 opcode) 190{ 191 u32 gw_reg = 0; 192 193 gw_reg |= ((data << mdio_gw->write_data.shift) & 194 mdio_gw->write_data.mask); 195 gw_reg |= ((phy_reg << mdio_gw->devad.shift) & 196 mdio_gw->devad.mask); 197 gw_reg |= ((phy_add << mdio_gw->partad.shift) & 198 mdio_gw->partad.mask); 199 gw_reg |= ((opcode << mdio_gw->opcode.shift) & 200 mdio_gw->opcode.mask); 201 gw_reg |= ((MLXBF_GIGE_MDIO_CL22_ST1 << mdio_gw->st1.shift) & 202 mdio_gw->st1.mask); 203 gw_reg |= ((MLXBF_GIGE_MDIO_SET_BUSY << mdio_gw->busy.shift) & 204 mdio_gw->busy.mask); 205 206 return gw_reg; 207} 208 209static int mlxbf_gige_mdio_read(struct mii_bus *bus, int phy_add, int phy_reg) 210{ 211 struct mlxbf_gige *priv = bus->priv; 212 u32 cmd; 213 int ret; 214 u32 val; 215 216 /* Send mdio read request */ 217 cmd = mlxbf_gige_mdio_create_cmd(priv->mdio_gw, 0, phy_add, phy_reg, 218 MLXBF_GIGE_MDIO_CL22_READ); 219 220 writel(cmd, priv->mdio_io + priv->mdio_gw->gw_address); 221 222 ret = readl_poll_timeout_atomic(priv->mdio_io + priv->mdio_gw->gw_address, 223 val, !(val & priv->mdio_gw->busy.mask), 224 5, 1000000); 225 226 if (ret) { 227 writel(0, priv->mdio_io + priv->mdio_gw->gw_address); 228 return ret; 229 } 230 231 ret = readl(priv->mdio_io + priv->mdio_gw->read_data_address); 232 /* Only return ad bits of the gw register */ 233 ret &= priv->mdio_gw->read_data.mask; 234 235 /* The MDIO lock is set on read. To release it, clear gw register */ 236 writel(0, priv->mdio_io + priv->mdio_gw->gw_address); 237 238 return ret; 239} 240 241static int mlxbf_gige_mdio_write(struct mii_bus *bus, int phy_add, 242 int phy_reg, u16 val) 243{ 244 struct mlxbf_gige *priv = bus->priv; 245 u32 temp; 246 u32 cmd; 247 int ret; 248 249 /* Send mdio write request */ 250 cmd = mlxbf_gige_mdio_create_cmd(priv->mdio_gw, val, phy_add, phy_reg, 251 MLXBF_GIGE_MDIO_CL22_WRITE); 252 writel(cmd, priv->mdio_io + priv->mdio_gw->gw_address); 253 254 /* If the poll timed out, drop the request */ 255 ret = readl_poll_timeout_atomic(priv->mdio_io + priv->mdio_gw->gw_address, 256 temp, !(temp & priv->mdio_gw->busy.mask), 257 5, 1000000); 258 259 /* The MDIO lock is set on read. To release it, clear gw register */ 260 writel(0, priv->mdio_io + priv->mdio_gw->gw_address); 261 262 return ret; 263} 264 265static void mlxbf_gige_mdio_cfg(struct mlxbf_gige *priv) 266{ 267 u8 mdio_period; 268 u32 val; 269 270 mdio_period = mdio_period_map(priv); 271 272 if (priv->hw_version == MLXBF_GIGE_VERSION_BF2) { 273 val = MLXBF2_GIGE_MDIO_CFG_VAL; 274 val |= FIELD_PREP(MLXBF2_GIGE_MDIO_CFG_MDC_PERIOD_MASK, mdio_period); 275 writel(val, priv->mdio_io + MLXBF2_GIGE_MDIO_CFG_OFFSET); 276 } else { 277 val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_MODE_MASK, 1) | 278 FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK, 1); 279 writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG0); 280 val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDC_PERIOD_MASK, mdio_period); 281 writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG1); 282 val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK, 6) | 283 FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK, 13); 284 writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG2); 285 } 286} 287 288int mlxbf_gige_mdio_probe(struct platform_device *pdev, struct mlxbf_gige *priv) 289{ 290 struct device *dev = &pdev->dev; 291 struct resource *res; 292 int ret; 293 294 if (priv->hw_version > MLXBF_GIGE_VERSION_BF3) 295 return -ENODEV; 296 297 priv->mdio_io = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_MDIO9); 298 if (IS_ERR(priv->mdio_io)) 299 return PTR_ERR(priv->mdio_io); 300 301 /* clk resource shared with other drivers so cannot use 302 * devm_platform_ioremap_resource 303 */ 304 res = platform_get_resource(pdev, IORESOURCE_MEM, MLXBF_GIGE_RES_CLK); 305 if (!res) { 306 /* For backward compatibility with older ACPI tables, also keep 307 * CLK resource internal to the driver. 308 */ 309 res = &corepll_params[priv->hw_version]; 310 } 311 312 priv->clk_io = devm_ioremap(dev, res->start, resource_size(res)); 313 if (!priv->clk_io) 314 return -ENOMEM; 315 316 priv->mdio_gw = &mlxbf_gige_mdio_gw_t[priv->hw_version]; 317 318 mlxbf_gige_mdio_cfg(priv); 319 320 priv->mdiobus = devm_mdiobus_alloc(dev); 321 if (!priv->mdiobus) { 322 dev_err(dev, "Failed to alloc MDIO bus\n"); 323 return -ENOMEM; 324 } 325 326 priv->mdiobus->name = "mlxbf-mdio"; 327 priv->mdiobus->read = mlxbf_gige_mdio_read; 328 priv->mdiobus->write = mlxbf_gige_mdio_write; 329 priv->mdiobus->parent = dev; 330 priv->mdiobus->priv = priv; 331 snprintf(priv->mdiobus->id, MII_BUS_ID_SIZE, "%s", 332 dev_name(dev)); 333 334 ret = mdiobus_register(priv->mdiobus); 335 if (ret) 336 dev_err(dev, "Failed to register MDIO bus\n"); 337 338 return ret; 339} 340 341void mlxbf_gige_mdio_remove(struct mlxbf_gige *priv) 342{ 343 mdiobus_unregister(priv->mdiobus); 344} 345