// 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"
#include "mlxbf_gige_mdio_bf2.h"
#include "mlxbf_gige_mdio_bf3.h"
static struct mlxbf_gige_mdio_gw mlxbf_gige_mdio_gw_t[] = {
[MLXBF_GIGE_VERSION_BF2] = {
.gw_address = MLXBF2_GIGE_MDIO_GW_OFFSET,
.read_data_address = MLXBF2_GIGE_MDIO_GW_OFFSET,
.busy = {
.mask = MLXBF2_GIGE_MDIO_GW_BUSY_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_BUSY_SHIFT,
},
.read_data = {
.mask = MLXBF2_GIGE_MDIO_GW_AD_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_AD_SHIFT,
},
.write_data = {
.mask = MLXBF2_GIGE_MDIO_GW_AD_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_AD_SHIFT,
},
.devad = {
.mask = MLXBF2_GIGE_MDIO_GW_DEVAD_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_DEVAD_SHIFT,
},
.partad = {
.mask = MLXBF2_GIGE_MDIO_GW_PARTAD_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_PARTAD_SHIFT,
},
.opcode = {
.mask = MLXBF2_GIGE_MDIO_GW_OPCODE_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_OPCODE_SHIFT,
},
.st1 = {
.mask = MLXBF2_GIGE_MDIO_GW_ST1_MASK,
.shift = MLXBF2_GIGE_MDIO_GW_ST1_SHIFT,
},
},
[MLXBF_GIGE_VERSION_BF3] = {
.gw_address = MLXBF3_GIGE_MDIO_GW_OFFSET,
.read_data_address = MLXBF3_GIGE_MDIO_DATA_READ,
.busy = {
.mask = MLXBF3_GIGE_MDIO_GW_BUSY_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_BUSY_SHIFT,
},
.read_data = {
.mask = MLXBF3_GIGE_MDIO_GW_DATA_READ_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_DATA_READ_SHIFT,
},
.write_data = {
.mask = MLXBF3_GIGE_MDIO_GW_DATA_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_DATA_SHIFT,
},
.devad = {
.mask = MLXBF3_GIGE_MDIO_GW_DEVAD_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_DEVAD_SHIFT,
},
.partad = {
.mask = MLXBF3_GIGE_MDIO_GW_PARTAD_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_PARTAD_SHIFT,
},
.opcode = {
.mask = MLXBF3_GIGE_MDIO_GW_OPCODE_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_OPCODE_SHIFT,
},
.st1 = {
.mask = MLXBF3_GIGE_MDIO_GW_ST1_MASK,
.shift = MLXBF3_GIGE_MDIO_GW_ST1_SHIFT,
},
},
};
#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
#define MLXBF_GIGE_BF2_COREPLL_ADDR 0x02800c30
#define MLXBF_GIGE_BF2_COREPLL_SIZE 0x0000000c
#define MLXBF_GIGE_BF3_COREPLL_ADDR 0x13409824
#define MLXBF_GIGE_BF3_COREPLL_SIZE 0x00000010
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"
},
[MLXBF_GIGE_VERSION_BF3] = {
.start = MLXBF_GIGE_BF3_COREPLL_ADDR,
.end = MLXBF_GIGE_BF3_COREPLL_ADDR + MLXBF_GIGE_BF3_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(struct mlxbf_gige_mdio_gw *mdio_gw, u16 data, int phy_add,
int phy_reg, u32 opcode)
{
u32 gw_reg = 0;
gw_reg |= ((data << mdio_gw->write_data.shift) &
mdio_gw->write_data.mask);
gw_reg |= ((phy_reg << mdio_gw->devad.shift) &
mdio_gw->devad.mask);
gw_reg |= ((phy_add << mdio_gw->partad.shift) &
mdio_gw->partad.mask);
gw_reg |= ((opcode << mdio_gw->opcode.shift) &
mdio_gw->opcode.mask);
gw_reg |= ((MLXBF_GIGE_MDIO_CL22_ST1 << mdio_gw->st1.shift) &
mdio_gw->st1.mask);
gw_reg |= ((MLXBF_GIGE_MDIO_SET_BUSY << mdio_gw->busy.shift) &
mdio_gw->busy.mask);
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;
/* Send mdio read request */
cmd = mlxbf_gige_mdio_create_cmd(priv->mdio_gw, 0, phy_add, phy_reg,
MLXBF_GIGE_MDIO_CL22_READ);
writel(cmd, priv->mdio_io + priv->mdio_gw->gw_address);
ret = readl_poll_timeout_atomic(priv->mdio_io + priv->mdio_gw->gw_address,
val, !(val & priv->mdio_gw->busy.mask),
5, 1000000);
if (ret) {
writel(0, priv->mdio_io + priv->mdio_gw->gw_address);
return ret;
}
ret = readl(priv->mdio_io + priv->mdio_gw->read_data_address);
/* Only return ad bits of the gw register */
ret &= priv->mdio_gw->read_data.mask;
/* The MDIO lock is set on read. To release it, clear gw register */
writel(0, priv->mdio_io + priv->mdio_gw->gw_address);
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;
/* Send mdio write request */
cmd = mlxbf_gige_mdio_create_cmd(priv->mdio_gw, val, phy_add, phy_reg,
MLXBF_GIGE_MDIO_CL22_WRITE);
writel(cmd, priv->mdio_io + priv->mdio_gw->gw_address);
/* If the poll timed out, drop the request */
ret = readl_poll_timeout_atomic(priv->mdio_io + priv->mdio_gw->gw_address,
temp, !(temp & priv->mdio_gw->busy.mask),
5, 1000000);
/* The MDIO lock is set on read. To release it, clear gw register */
writel(0, priv->mdio_io + priv->mdio_gw->gw_address);
return ret;
}
static void mlxbf_gige_mdio_cfg(struct mlxbf_gige *priv)
{
u8 mdio_period;
u32 val;
mdio_period = mdio_period_map(priv);
if (priv->hw_version == MLXBF_GIGE_VERSION_BF2) {
val = MLXBF2_GIGE_MDIO_CFG_VAL;
val |= FIELD_PREP(MLXBF2_GIGE_MDIO_CFG_MDC_PERIOD_MASK, mdio_period);
writel(val, priv->mdio_io + MLXBF2_GIGE_MDIO_CFG_OFFSET);
} else {
val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_MODE_MASK, 1) |
FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_FULL_DRIVE_MASK, 1);
writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG0);
val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDC_PERIOD_MASK, mdio_period);
writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG1);
val = FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_IN_SAMP_MASK, 6) |
FIELD_PREP(MLXBF3_GIGE_MDIO_CFG_MDIO_OUT_SAMP_MASK, 13);
writel(val, priv->mdio_io + MLXBF3_GIGE_MDIO_CFG_REG2);
}
}
int mlxbf_gige_mdio_probe(struct platform_device *pdev, struct mlxbf_gige *priv)
{
struct device *dev = &pdev->dev;
struct resource *res;
int ret;
if (priv->hw_version > MLXBF_GIGE_VERSION_BF3)
return -ENODEV;
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[priv->hw_version];
}
priv->clk_io = devm_ioremap(dev, res->start, resource_size(res));
if (!priv->clk_io)
return -ENOMEM;
priv->mdio_gw = &mlxbf_gige_mdio_gw_t[priv->hw_version];
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);
}
