1 // SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause
3 /* MDIO support for Mellanox Gigabit Ethernet driver
5 * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES
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>
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>
24 #include "mlxbf_gige.h"
26 #define MLXBF_GIGE_MDIO_GW_OFFSET 0x0
27 #define MLXBF_GIGE_MDIO_CFG_OFFSET 0x4
29 /* Support clause 22 */
30 #define MLXBF_GIGE_MDIO_CL22_ST1 0x1
31 #define MLXBF_GIGE_MDIO_CL22_WRITE 0x1
32 #define MLXBF_GIGE_MDIO_CL22_READ 0x2
34 /* Busy bit is set by software and cleared by hardware */
35 #define MLXBF_GIGE_MDIO_SET_BUSY 0x1
37 /* MDIO GW register bits */
38 #define MLXBF_GIGE_MDIO_GW_AD_MASK GENMASK(15, 0)
39 #define MLXBF_GIGE_MDIO_GW_DEVAD_MASK GENMASK(20, 16)
40 #define MLXBF_GIGE_MDIO_GW_PARTAD_MASK GENMASK(25, 21)
41 #define MLXBF_GIGE_MDIO_GW_OPCODE_MASK GENMASK(27, 26)
42 #define MLXBF_GIGE_MDIO_GW_ST1_MASK GENMASK(28, 28)
43 #define MLXBF_GIGE_MDIO_GW_BUSY_MASK GENMASK(30, 30)
45 /* MDIO config register bits */
46 #define MLXBF_GIGE_MDIO_CFG_MDIO_MODE_MASK GENMASK(1, 0)
47 #define MLXBF_GIGE_MDIO_CFG_MDIO3_3_MASK GENMASK(2, 2)
48 #define MLXBF_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK GENMASK(4, 4)
49 #define MLXBF_GIGE_MDIO_CFG_MDC_PERIOD_MASK GENMASK(15, 8)
50 #define MLXBF_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK GENMASK(23, 16)
51 #define MLXBF_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK GENMASK(31, 24)
53 /* Formula for encoding the MDIO period. The encoded value is
54 * passed to the MDIO config register.
56 * mdc_clk = 2*(val + 1)*i1clk
58 * 400 ns = 2*(val + 1)*(((1/430)*1000) ns)
60 * val = (((400 * 430 / 1000) / 2) - 1)
62 #define MLXBF_GIGE_I1CLK_MHZ 430
63 #define MLXBF_GIGE_MDC_CLK_NS 400
65 #define MLXBF_GIGE_MDIO_PERIOD (((MLXBF_GIGE_MDC_CLK_NS * MLXBF_GIGE_I1CLK_MHZ / 1000) / 2) - 1)
67 #define MLXBF_GIGE_MDIO_CFG_VAL (FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_MODE_MASK, 1) | \
68 FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO3_3_MASK, 1) | \
69 FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK, 1) | \
70 FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDC_PERIOD_MASK, \
71 MLXBF_GIGE_MDIO_PERIOD) | \
72 FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK, 6) | \
73 FIELD_PREP(MLXBF_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK, 13))
75 static u32 mlxbf_gige_mdio_create_cmd(u16 data, int phy_add,
76 int phy_reg, u32 opcode)
80 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_AD_MASK, data);
81 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_DEVAD_MASK, phy_reg);
82 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_PARTAD_MASK, phy_add);
83 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_OPCODE_MASK, opcode);
84 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_ST1_MASK,
85 MLXBF_GIGE_MDIO_CL22_ST1);
86 gw_reg |= FIELD_PREP(MLXBF_GIGE_MDIO_GW_BUSY_MASK,
87 MLXBF_GIGE_MDIO_SET_BUSY);
92 static int mlxbf_gige_mdio_read(struct mii_bus *bus, int phy_add, int phy_reg)
94 struct mlxbf_gige *priv = bus->priv;
99 if (phy_reg & MII_ADDR_C45)
102 /* Send mdio read request */
103 cmd = mlxbf_gige_mdio_create_cmd(0, phy_add, phy_reg, MLXBF_GIGE_MDIO_CL22_READ);
105 writel(cmd, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
107 ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET,
108 val, !(val & MLXBF_GIGE_MDIO_GW_BUSY_MASK),
112 writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
116 ret = readl(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
117 /* Only return ad bits of the gw register */
118 ret &= MLXBF_GIGE_MDIO_GW_AD_MASK;
123 static int mlxbf_gige_mdio_write(struct mii_bus *bus, int phy_add,
124 int phy_reg, u16 val)
126 struct mlxbf_gige *priv = bus->priv;
131 if (phy_reg & MII_ADDR_C45)
134 /* Send mdio write request */
135 cmd = mlxbf_gige_mdio_create_cmd(val, phy_add, phy_reg,
136 MLXBF_GIGE_MDIO_CL22_WRITE);
137 writel(cmd, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
139 /* If the poll timed out, drop the request */
140 ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET,
141 temp, !(temp & MLXBF_GIGE_MDIO_GW_BUSY_MASK),
147 int mlxbf_gige_mdio_probe(struct platform_device *pdev, struct mlxbf_gige *priv)
149 struct device *dev = &pdev->dev;
152 priv->mdio_io = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_MDIO9);
153 if (IS_ERR(priv->mdio_io))
154 return PTR_ERR(priv->mdio_io);
156 /* Configure mdio parameters */
157 writel(MLXBF_GIGE_MDIO_CFG_VAL,
158 priv->mdio_io + MLXBF_GIGE_MDIO_CFG_OFFSET);
160 priv->mdiobus = devm_mdiobus_alloc(dev);
161 if (!priv->mdiobus) {
162 dev_err(dev, "Failed to alloc MDIO bus\n");
166 priv->mdiobus->name = "mlxbf-mdio";
167 priv->mdiobus->read = mlxbf_gige_mdio_read;
168 priv->mdiobus->write = mlxbf_gige_mdio_write;
169 priv->mdiobus->parent = dev;
170 priv->mdiobus->priv = priv;
171 snprintf(priv->mdiobus->id, MII_BUS_ID_SIZE, "%s",
174 ret = mdiobus_register(priv->mdiobus);
176 dev_err(dev, "Failed to register MDIO bus\n");
181 void mlxbf_gige_mdio_remove(struct mlxbf_gige *priv)
183 mdiobus_unregister(priv->mdiobus);