// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include <stdlib.h>
#include <sys/cdefs.h>
#include "esp_log.h"
#include "esp_eth.h"
#include "eth_phy_regs_struct.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

static const char *TAG = "lan8720";
#define PHY_CHECK(a, str, goto_tag, ...)                                          \
    do                                                                            \
    {                                                                             \
        if (!(a))                                                                 \
        {                                                                         \
            ESP_LOGE(TAG, "%s(%d): " str, __FUNCTION__, __LINE__, ##__VA_ARGS__); \
            goto goto_tag;                                                        \
        }                                                                         \
    } while (0)

/***************Vendor Specific Register***************/

/**
 * @brief MCSR(Mode Control Status Register)
 *
 */
typedef union {
    struct {
        uint32_t reserved1 : 1;                  /* Reserved */
        uint32_t energy_is_on : 1;               /* Energy is On */
        uint32_t reserved2 : 4;                  /* Reserved */
        uint32_t en_alternate_interrupt : 1;     /* Enable Alternate Interrupt Mode */
        uint32_t reserved3 : 2;                  /* Reserved */
        uint32_t en_far_loopback : 1;            /* Enable Far Loopback Mode */
        uint32_t reserved4 : 3;                  /* Reserved */
        uint32_t en_energy_detect_powerdown : 1; /* Enable Energy Detect Power Down */
        uint32_t reserved5 : 2;                  /* Reserved */
    };
    uint32_t val;
} mcsr_reg_t;
#define ETH_PHY_MCSR_REG_ADDR (0x11)

/**
 * @brief SMR(Special Modes Register)
 *
 */
typedef union {
    struct {
        uint32_t phy_addr : 5; /* PHY Address */
        uint32_t mode : 3;     /* Transceiver Mode of Operation */
        uint32_t reserved : 8; /* Reserved */
    };
    uint32_t val;
} smr_reg_t;
#define ETH_PHY_SMR_REG_ADDR (0x12)

/**
 * @brief SECR(Symbol Error Counter Register)
 *
 */
typedef union {
    struct {
        uint32_t symbol_err_count : 16; /* Symbol Error Counter */
    };
    uint32_t val;
} secr_reg_t;
#define EHT_PHY_SECR_REG_ADDR (0x1A)

/**
 * @brief CSIR(Control Status Indications Register)
 *
 */
typedef union {
    struct {
        uint32_t reserved1 : 4;         /* Reserved */
        uint32_t base10_t_polarity : 1; /* Polarity State of 10Base-T */
        uint32_t reserved2 : 6;         /* Reserved */
        uint32_t dis_sqe : 1;           /* Disable SQE test(Heartbeat) */
        uint32_t reserved3 : 1;         /* Reserved */
        uint32_t select_channel : 1;    /* Manual channel select:MDI(0) or MDIX(1) */
        uint32_t reserved4 : 1;         /* Reserved */
        uint32_t auto_mdix_ctrl : 1;    /* Auto-MDIX Control: EN(0) or DE(1) */
    };
    uint32_t val;
} scsir_reg_t;
#define ETH_PHY_CSIR_REG_ADDR (0x1B)

/**
 * @brief ISR(Interrupt Source Register)
 *
 */
typedef union {
    struct {
        uint32_t reserved1 : 1;                /* Reserved */
        uint32_t auto_nego_page_received : 1;  /* Auto-Negotiation Page Received */
        uint32_t parallel_detect_falut : 1;    /* Parallel Detection Fault */
        uint32_t auto_nego_lp_acknowledge : 1; /* Auto-Negotiation LP Acknowledge */
        uint32_t link_down : 1;                /* Link Down */
        uint32_t remote_fault_detect : 1;      /* Remote Fault Detect */
        uint32_t auto_nego_complete : 1;       /* Auto-Negotiation Complete */
        uint32_t energy_on_generate : 1;       /* ENERYON generated */
        uint32_t reserved2 : 8;                /* Reserved */
    };
    uint32_t val;
} isfr_reg_t;
#define ETH_PHY_ISR_REG_ADDR (0x1D)

/**
 * @brief IMR(Interrupt Mask Register)
 *
 */
typedef union {
    struct {
        uint32_t reserved1 : 1;                /* Reserved */
        uint32_t auto_nego_page_received : 1;  /* Auto-Negotiation Page Received */
        uint32_t parallel_detect_falut : 1;    /* Parallel Detection Fault */
        uint32_t auto_nego_lp_acknowledge : 1; /* Auto-Negotiation LP Acknowledge */
        uint32_t link_down : 1;                /* Link Down */
        uint32_t remote_fault_detect : 1;      /* Remote Fault Detect */
        uint32_t auto_nego_complete : 1;       /* Auto-Negotiation Complete */
        uint32_t energy_on_generate : 1;       /* ENERYON generated */
        uint32_t reserved2 : 8;                /* Reserved */
    };
    uint32_t val;
} imr_reg_t;
#define ETH_PHY_IMR_REG_ADDR (0x1E)

/**
 * @brief PSCSR(PHY Special Control Status Register)
 *
 */
typedef union {
    struct {
        uint32_t reserved1 : 2;        /* Reserved */
        uint32_t speed_indication : 3; /* Speed Indication */
        uint32_t reserved2 : 7;        /* Reserved */
        uint32_t auto_nego_done : 1;   /* Auto Negotiation Done */
        uint32_t reserved3 : 3;        /* Reserved */
    };
    uint32_t val;
} pscsr_reg_t;
#define ETH_PHY_PSCSR_REG_ADDR (0x1F)

typedef struct {
    esp_eth_phy_t parent;
    esp_eth_mediator_t *eth;
    uint32_t addr;
    uint32_t reset_timeout_ms;
    uint32_t autonego_timeout_ms;
    eth_link_t link_status;
    int reset_gpio_num;
} phy_lan8720_t;

static esp_err_t lan8720_update_link_duplex_speed(phy_lan8720_t *lan8720)
{
    esp_eth_mediator_t *eth = lan8720->eth;
    eth_speed_t speed = ETH_SPEED_10M;
    eth_duplex_t duplex = ETH_DUPLEX_HALF;
    bmsr_reg_t bmsr;
    pscsr_reg_t pscsr;
    PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMSR_REG_ADDR, &(bmsr.val)) == ESP_OK,
              "read BMSR failed", err);
    eth_link_t link = bmsr.link_status ? ETH_LINK_UP : ETH_LINK_DOWN;
    /* check if link status changed */
    if (lan8720->link_status != link) {
        /* when link up, read negotiation result */
        if (link == ETH_LINK_UP) {
            PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_PSCSR_REG_ADDR, &(pscsr.val)) == ESP_OK,
                      "read PSCSR failed", err);
            switch (pscsr.speed_indication) {
            case 1: //10Base-T half-duplex
                speed = ETH_SPEED_10M;
                duplex = ETH_DUPLEX_HALF;
                break;
            case 2: //100Base-TX half-duplex
                speed = ETH_SPEED_100M;
                duplex = ETH_DUPLEX_HALF;
                break;
            case 5: //10Base-T full-duplex
                speed = ETH_SPEED_10M;
                duplex = ETH_DUPLEX_FULL;
                break;
            case 6: //100Base-TX full-duplex
                speed = ETH_SPEED_100M;
                duplex = ETH_DUPLEX_FULL;
                break;
            default:
                break;
            }
            PHY_CHECK(eth->on_state_changed(eth, ETH_STATE_SPEED, (void *)speed) == ESP_OK,
                      "change speed failed", err);
            PHY_CHECK(eth->on_state_changed(eth, ETH_STATE_DUPLEX, (void *)duplex) == ESP_OK,
                      "change duplex failed", err);
        }
        PHY_CHECK(eth->on_state_changed(eth, ETH_STATE_LINK, (void *)link) == ESP_OK,
                  "change link failed", err);
        lan8720->link_status = link;
    }
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_set_mediator(esp_eth_phy_t *phy, esp_eth_mediator_t *eth)
{
    PHY_CHECK(eth, "can't set mediator to null", err);
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    lan8720->eth = eth;
    return ESP_OK;
err:
    return ESP_ERR_INVALID_ARG;
}

static esp_err_t lan8720_get_link(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    /* Updata information about link, speed, duplex */
    PHY_CHECK(lan8720_update_link_duplex_speed(lan8720) == ESP_OK, "update link duplex speed failed", err);
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_reset(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    lan8720->link_status = ETH_LINK_DOWN;
    esp_eth_mediator_t *eth = lan8720->eth;
    bmcr_reg_t bmcr = {.reset = 1};
    PHY_CHECK(eth->phy_reg_write(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, bmcr.val) == ESP_OK,
              "write BMCR failed", err);
    /* wait for reset complete */
    uint32_t to = 0;
    for (to = 0; to < lan8720->reset_timeout_ms / 10; to++) {
        vTaskDelay(pdMS_TO_TICKS(10));
        PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, &(bmcr.val)) == ESP_OK,
                  "read BMCR failed", err);
        if (!bmcr.reset) {
            break;
        }
    }
    PHY_CHECK(to < lan8720->reset_timeout_ms / 10, "reset timeout", err);
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_reset_hw(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    if (lan8720->reset_gpio_num >= 0) {
        gpio_pad_select_gpio(lan8720->reset_gpio_num);
        gpio_set_direction(lan8720->reset_gpio_num, GPIO_MODE_OUTPUT);
        gpio_set_level(lan8720->reset_gpio_num, 0);
        /* assert nRST signal on LAN8720 a little longer than the minimum specified in datasheet */
        ets_delay_us(150);
        gpio_set_level(lan8720->reset_gpio_num, 1);
    }
    return ESP_OK;
}

/**
 * @note This function is responsible for restarting a new auto-negotiation,
 *       the result of negotiation won't be relected to uppler layers.
 *       Instead, the negotiation result is fetched by linker timer, see `lan8720_get_link()`
 */
static esp_err_t lan8720_negotiate(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    esp_eth_mediator_t *eth = lan8720->eth;
    /* in case any link status has changed, let's assume we're in link down status */
    lan8720->link_status = ETH_LINK_DOWN;
    /* Restart auto negotiation */
    bmcr_reg_t bmcr = {
        .speed_select = 1,     /* 100Mbps */
        .duplex_mode = 1,      /* Full Duplex */
        .en_auto_nego = 1,     /* Auto Negotiation */
        .restart_auto_nego = 1 /* Restart Auto Negotiation */
    };
    PHY_CHECK(eth->phy_reg_write(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, bmcr.val) == ESP_OK, "write BMCR failed", err);
    /* Wait for auto negotiation complete */
    bmsr_reg_t bmsr;
    pscsr_reg_t pscsr;
    uint32_t to = 0;
    for (to = 0; to < lan8720->autonego_timeout_ms / 100; to++) {
        vTaskDelay(pdMS_TO_TICKS(100));
        PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMSR_REG_ADDR, &(bmsr.val)) == ESP_OK,
                  "read BMSR failed", err);
        PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_PSCSR_REG_ADDR, &(pscsr.val)) == ESP_OK,
                  "read PSCSR failed", err);
        if (bmsr.auto_nego_complete && pscsr.auto_nego_done) {
            break;
        }
    }
    /* Auto negotiation failed, maybe no network cable plugged in, so output a warning */
    if (to >= lan8720->autonego_timeout_ms / 100 && (lan8720->link_status == ETH_LINK_UP)) {
        ESP_LOGW(TAG, "auto negotiation timeout");
    }
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_pwrctl(esp_eth_phy_t *phy, bool enable)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    esp_eth_mediator_t *eth = lan8720->eth;
    bmcr_reg_t bmcr;
    PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, &(bmcr.val)) == ESP_OK,
              "read BMCR failed", err);
    if (!enable) {
        /* General Power Down Mode */
        bmcr.power_down = 1;
    } else {
        /* Normal operation Mode */
        bmcr.power_down = 0;
    }
    PHY_CHECK(eth->phy_reg_write(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, bmcr.val) == ESP_OK,
              "write BMCR failed", err);
    if (!enable) {
        PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, &(bmcr.val)) == ESP_OK,
                  "read BMCR failed", err);
        PHY_CHECK(bmcr.power_down == 1, "power down failed", err);
    } else {
        /* wait for power up complete */
        uint32_t to = 0;
        for (to = 0; to < lan8720->reset_timeout_ms / 10; to++) {
            vTaskDelay(pdMS_TO_TICKS(10));
            PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_BMCR_REG_ADDR, &(bmcr.val)) == ESP_OK,
                      "read BMCR failed", err);
            if (bmcr.power_down == 0) {
                break;
            }
        }
        PHY_CHECK(to < lan8720->reset_timeout_ms / 10, "power up timeout", err);
    }
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_set_addr(esp_eth_phy_t *phy, uint32_t addr)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    lan8720->addr = addr;
    return ESP_OK;
}

static esp_err_t lan8720_get_addr(esp_eth_phy_t *phy, uint32_t *addr)
{
    PHY_CHECK(addr, "addr can't be null", err);
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    *addr = lan8720->addr;
    return ESP_OK;
err:
    return ESP_ERR_INVALID_ARG;
}

static esp_err_t lan8720_del(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    free(lan8720);
    return ESP_OK;
}

static esp_err_t lan8720_init(esp_eth_phy_t *phy)
{
    phy_lan8720_t *lan8720 = __containerof(phy, phy_lan8720_t, parent);
    esp_eth_mediator_t *eth = lan8720->eth;
    // Detect PHY address
    if (lan8720->addr == ESP_ETH_PHY_ADDR_AUTO) {
        PHY_CHECK(esp_eth_detect_phy_addr(eth, &lan8720->addr) == ESP_OK, "Detect PHY address failed", err);
    }
    /* Power on Ethernet PHY */
    PHY_CHECK(lan8720_pwrctl(phy, true) == ESP_OK, "power control failed", err);
    /* Reset Ethernet PHY */
    PHY_CHECK(lan8720_reset(phy) == ESP_OK, "reset failed", err);
    /* Check PHY ID */
    phyidr1_reg_t id1;
    phyidr2_reg_t id2;
    PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_IDR1_REG_ADDR, &(id1.val)) == ESP_OK,
              "read ID1 failed", err);
    PHY_CHECK(eth->phy_reg_read(eth, lan8720->addr, ETH_PHY_IDR2_REG_ADDR, &(id2.val)) == ESP_OK,
              "read ID2 failed", err);
    PHY_CHECK(id1.oui_msb == 0x7 && id2.oui_lsb == 0x30 && id2.vendor_model == 0xF, "wrong chip ID", err);
    return ESP_OK;
err:
    return ESP_FAIL;
}

static esp_err_t lan8720_deinit(esp_eth_phy_t *phy)
{
    /* Power off Ethernet PHY */
    PHY_CHECK(lan8720_pwrctl(phy, false) == ESP_OK, "power control failed", err);
    return ESP_OK;
err:
    return ESP_FAIL;
}

esp_eth_phy_t *esp_eth_phy_new_lan8720(const eth_phy_config_t *config)
{
    PHY_CHECK(config, "can't set phy config to null", err);
    phy_lan8720_t *lan8720 = calloc(1, sizeof(phy_lan8720_t));
    PHY_CHECK(lan8720, "calloc lan8720 failed", err);
    lan8720->addr = config->phy_addr;
    lan8720->reset_gpio_num = config->reset_gpio_num;
    lan8720->reset_timeout_ms = config->reset_timeout_ms;
    lan8720->link_status = ETH_LINK_DOWN;
    lan8720->autonego_timeout_ms = config->autonego_timeout_ms;
    lan8720->parent.reset = lan8720_reset;
    lan8720->parent.reset_hw = lan8720_reset_hw;
    lan8720->parent.init = lan8720_init;
    lan8720->parent.deinit = lan8720_deinit;
    lan8720->parent.set_mediator = lan8720_set_mediator;
    lan8720->parent.negotiate = lan8720_negotiate;
    lan8720->parent.get_link = lan8720_get_link;
    lan8720->parent.pwrctl = lan8720_pwrctl;
    lan8720->parent.get_addr = lan8720_get_addr;
    lan8720->parent.set_addr = lan8720_set_addr;
    lan8720->parent.del = lan8720_del;

    return &(lan8720->parent);
err:
    return NULL;
}