drivers/mdio/mdio_intel_igc.c

/*
 * Copyright (c) 2025 Intel Corporation.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT intel_igc_mdio

#include <zephyr/kernel.h>
#include <zephyr/net/mdio.h>
#include <zephyr/drivers/mdio.h>
#include <zephyr/drivers/pcie/pcie.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(intel_igc_mdio, CONFIG_MDIO_LOG_LEVEL);

#define INTEL_IGC_MDIC_OFFSET         0x00020
#define INTEL_IGC_MDIC_DATA_MASK      GENMASK(15, 0)
#define INTEL_IGC_MDIC_REG_MASK       GENMASK(20, 16)
#define INTEL_IGC_MDIC_PHY_MASK       GENMASK(25, 21)
#define INTEL_IGC_MDIC_OP_MASK        GENMASK(27, 26)
#define INTEL_IGC_MDIC_READY          BIT(28)
#define INTEL_IGC_MMDCTRL             0xD
#define INTEL_IGC_MMDCTRL_ACTYPE_MASK GENMASK(15, 14)
#define INTEL_IGC_MMDCTRL_DEVAD_MASK  GENMASK(4, 0)
#define INTEL_IGC_MMDDATA             0xE
#define INTEL_IGC_DEFAULT_DEVNUM      0

struct intel_igc_mdio_cfg {
	const struct device *const platform;
};

struct intel_igc_mdio_data {
	struct k_mutex mutex;
};

static int intel_igc_mdio(const struct device *dev, uint32_t command)
{
	const struct intel_igc_mdio_cfg *cfg = dev->config;
	struct intel_igc_mdio_data *data = dev->data;
	mm_reg_t mdic;
	int ret;

	mdic = DEVICE_MMIO_GET(cfg->platform) + INTEL_IGC_MDIC_OFFSET;

	k_mutex_lock(&data->mutex, K_FOREVER);
	sys_write32(command, mdic);
	/* Wait for the read or write transaction to complete */
	if (!WAIT_FOR((sys_read32(mdic) & INTEL_IGC_MDIC_READY),
		      CONFIG_MDIO_INTEL_BUSY_CHECK_TIMEOUT, k_usleep(1))) {
		LOG_ERR("MDIC operation timed out");
		k_mutex_unlock(&data->mutex);
		return -ETIMEDOUT;
	}
	ret = sys_read32(mdic);
	k_mutex_unlock(&data->mutex);

	return ret;
}

static int intel_igc_mdio_read(const struct device *dev, uint8_t prtad, uint8_t regad,
			       uint16_t *user_data)
{
	int ret = 0;
	uint32_t command = FIELD_PREP(INTEL_IGC_MDIC_PHY_MASK, prtad) |
			   FIELD_PREP(INTEL_IGC_MDIC_REG_MASK, regad) |
			   FIELD_PREP(INTEL_IGC_MDIC_OP_MASK, MDIO_OP_C22_READ);

	ret = intel_igc_mdio(dev, command);
	if (ret < 0) {
		return ret;
	}

	*user_data = FIELD_GET(INTEL_IGC_MDIC_DATA_MASK, ret);

	return 0;
}

static int intel_igc_mdio_write(const struct device *dev, uint8_t prtad, uint8_t regad,
				uint16_t user_data)
{
	int ret;

	uint32_t command = FIELD_PREP(INTEL_IGC_MDIC_PHY_MASK, prtad) |
			   FIELD_PREP(INTEL_IGC_MDIC_REG_MASK, regad) |
			   FIELD_PREP(INTEL_IGC_MDIC_OP_MASK, MDIO_OP_C22_WRITE) |
			   FIELD_PREP(INTEL_IGC_MDIC_DATA_MASK, user_data);

	ret = intel_igc_mdio(dev, command);

	return ret < 0 ? ret : 0;
}

static int intel_igc_mdio_pre_handle_c45(const struct device *dev, uint8_t prtad, uint8_t devnum,
					 uint16_t regad)
{
	int ret;

	/* Set device number using MMDCTRL */
	ret = intel_igc_mdio_write(dev, prtad, INTEL_IGC_MMDCTRL,
				   (uint16_t)(FIELD_PREP(INTEL_IGC_MMDCTRL_DEVAD_MASK, devnum)));
	if (ret < 0) {
		return ret;
	}

	/* Set register address using MMDDATA */
	ret = intel_igc_mdio_write(dev, prtad, INTEL_IGC_MMDDATA, regad);
	if (ret < 0) {
		return ret;
	}

	/* Set device number and access type as data using MMDCTRL */
	return intel_igc_mdio_write(dev, prtad, INTEL_IGC_MMDCTRL,
				    (uint16_t)(FIELD_PREP(INTEL_IGC_MMDCTRL_ACTYPE_MASK, 1) |
					       FIELD_PREP(INTEL_IGC_MMDCTRL_DEVAD_MASK, devnum)));
}

static int intel_igc_mdio_post_handle_c45(const struct device *dev, uint8_t prtad)
{
	/* Restore default device number using MMDCTRL */
	return intel_igc_mdio_write(dev, prtad, INTEL_IGC_MMDCTRL, INTEL_IGC_DEFAULT_DEVNUM);
}

static int intel_igc_mdio_read_c45(const struct device *dev, uint8_t prtad, uint8_t devnum,
				   uint16_t regad, uint16_t *user_data)
{
	int ret = intel_igc_mdio_pre_handle_c45(dev, prtad, devnum, regad);

	if (ret < 0) {
		return ret;
	}

	/* Read user data using MMDDATA */
	ret = intel_igc_mdio_read(dev, prtad, INTEL_IGC_MMDDATA, user_data);
	if (ret < 0) {
		return ret;
	}

	return intel_igc_mdio_post_handle_c45(dev, prtad);
}

static int intel_igc_mdio_write_c45(const struct device *dev, uint8_t prtad, uint8_t devnum,
				    uint16_t regad, uint16_t user_data)
{
	int ret = intel_igc_mdio_pre_handle_c45(dev, prtad, devnum, regad);

	if (ret < 0) {
		return ret;
	}

	/* Write the user_data using MMDDATA */
	ret = intel_igc_mdio_write(dev, prtad, INTEL_IGC_MMDDATA, user_data);
	if (ret < 0) {
		return ret;
	}

	return intel_igc_mdio_post_handle_c45(dev, prtad);
}

static DEVICE_API(mdio, mdio_api) = {
	.read = intel_igc_mdio_read,
	.write = intel_igc_mdio_write,
	.read_c45 = intel_igc_mdio_read_c45,
	.write_c45 = intel_igc_mdio_write_c45,
};

#define INTEL_IGC_MDIO_INIT(n)                                                                     \
	static struct intel_igc_mdio_data mdio_data_##n = {                                        \
		.mutex = Z_MUTEX_INITIALIZER(mdio_data_##n.mutex),                                 \
	};                                                                                         \
	static struct intel_igc_mdio_cfg mdio_cfg_##n = {                                          \
		.platform = DEVICE_DT_GET(DT_INST_PARENT(n)),                                      \
	};                                                                                         \
	DEVICE_DT_INST_DEFINE(n, NULL, NULL, &mdio_data_##n, &mdio_cfg_##n, POST_KERNEL,           \
			      CONFIG_MDIO_INIT_PRIORITY, &mdio_api);

DT_INST_FOREACH_STATUS_OKAY(INTEL_IGC_MDIO_INIT)