// SPDX-License-Identifier: GPL-2.0
/* Copyright (c)  2018 Intel Corporation */

#include <linux/delay.h>

#include "igc_hw.h"

/**
 * igc_get_hw_semaphore_i225 - Acquire hardware semaphore
 * @hw: pointer to the HW structure
 *
 * Acquire the necessary semaphores for exclusive access to the EEPROM.
 * Set the EEPROM access request bit and wait for EEPROM access grant bit.
 * Return successful if access grant bit set, else clear the request for
 * EEPROM access and return -IGC_ERR_NVM (-1).
 */
static s32 igc_acquire_nvm_i225(struct igc_hw *hw)
{
        return igc_acquire_swfw_sync_i225(hw, IGC_SWFW_EEP_SM);
}

/**
 * igc_release_nvm_i225 - Release exclusive access to EEPROM
 * @hw: pointer to the HW structure
 *
 * Stop any current commands to the EEPROM and clear the EEPROM request bit,
 * then release the semaphores acquired.
 */
static void igc_release_nvm_i225(struct igc_hw *hw)
{
        igc_release_swfw_sync_i225(hw, IGC_SWFW_EEP_SM);
}

/**
 * igc_get_hw_semaphore_i225 - Acquire hardware semaphore
 * @hw: pointer to the HW structure
 *
 * Acquire the HW semaphore to access the PHY or NVM
 */
static s32 igc_get_hw_semaphore_i225(struct igc_hw *hw)
{
        s32 timeout = hw->nvm.word_size + 1;
        s32 i = 0;
        u32 swsm;

        /* Get the SW semaphore */
        while (i < timeout) {
                swsm = rd32(IGC_SWSM);
                if (!(swsm & IGC_SWSM_SMBI))
                        break;

                usleep_range(500, 600);
                i++;
        }

        if (i == timeout) {
                /* In rare circumstances, the SW semaphore may already be held
                 * unintentionally. Clear the semaphore once before giving up.
                 */
                if (hw->dev_spec._base.clear_semaphore_once) {
                        hw->dev_spec._base.clear_semaphore_once = false;
                        igc_put_hw_semaphore(hw);
                        for (i = 0; i < timeout; i++) {
                                swsm = rd32(IGC_SWSM);
                                if (!(swsm & IGC_SWSM_SMBI))
                                        break;

                                usleep_range(500, 600);
                        }
                }

                /* If we do not have the semaphore here, we have to give up. */
                if (i == timeout) {
                        hw_dbg("Driver can't access device - SMBI bit is set.\n");
                        return -IGC_ERR_NVM;
                }
        }

        /* Get the FW semaphore. */
        for (i = 0; i < timeout; i++) {
                swsm = rd32(IGC_SWSM);
                wr32(IGC_SWSM, swsm | IGC_SWSM_SWESMBI);

                /* Semaphore acquired if bit latched */
                if (rd32(IGC_SWSM) & IGC_SWSM_SWESMBI)
                        break;

                usleep_range(500, 600);
        }

        if (i == timeout) {
                /* Release semaphores */
                igc_put_hw_semaphore(hw);
                hw_dbg("Driver can't access the NVM\n");
                return -IGC_ERR_NVM;
        }

        return 0;
}

/**
 * igc_acquire_swfw_sync_i225 - Acquire SW/FW semaphore
 * @hw: pointer to the HW structure
 * @mask: specifies which semaphore to acquire
 *
 * Acquire the SW/FW semaphore to access the PHY or NVM.  The mask
 * will also specify which port we're acquiring the lock for.
 */
s32 igc_acquire_swfw_sync_i225(struct igc_hw *hw, u16 mask)
{
        s32 i = 0, timeout = 200;
        u32 fwmask = mask << 16;
        u32 swmask = mask;
        s32 ret_val = 0;
        u32 swfw_sync;

        while (i < timeout) {
                if (igc_get_hw_semaphore_i225(hw)) {
                        ret_val = -IGC_ERR_SWFW_SYNC;
                        goto out;
                }

                swfw_sync = rd32(IGC_SW_FW_SYNC);
                if (!(swfw_sync & (fwmask | swmask)))
                        break;

                /* Firmware currently using resource (fwmask) */
                igc_put_hw_semaphore(hw);
                mdelay(5);
                i++;
        }

        if (i == timeout) {
                hw_dbg("Driver can't access resource, SW_FW_SYNC timeout.\n");
                ret_val = -IGC_ERR_SWFW_SYNC;
                goto out;
        }

        swfw_sync |= swmask;
        wr32(IGC_SW_FW_SYNC, swfw_sync);

        igc_put_hw_semaphore(hw);
out:
        return ret_val;
}

/**
 * igc_release_swfw_sync_i225 - Release SW/FW semaphore
 * @hw: pointer to the HW structure
 * @mask: specifies which semaphore to acquire
 *
 * Release the SW/FW semaphore used to access the PHY or NVM.  The mask
 * will also specify which port we're releasing the lock for.
 */
void igc_release_swfw_sync_i225(struct igc_hw *hw, u16 mask)
{
        u32 swfw_sync;

        while (igc_get_hw_semaphore_i225(hw))
                ; /* Empty */

        swfw_sync = rd32(IGC_SW_FW_SYNC);
        swfw_sync &= ~mask;
        wr32(IGC_SW_FW_SYNC, swfw_sync);

        igc_put_hw_semaphore(hw);
}

/**
 * igc_read_nvm_srrd_i225 - Reads Shadow Ram using EERD register
 * @hw: pointer to the HW structure
 * @offset: offset of word in the Shadow Ram to read
 * @words: number of words to read
 * @data: word read from the Shadow Ram
 *
 * Reads a 16 bit word from the Shadow Ram using the EERD register.
 * Uses necessary synchronization semaphores.
 */
static s32 igc_read_nvm_srrd_i225(struct igc_hw *hw, u16 offset, u16 words,
                                  u16 *data)
{
        s32 status = 0;
        u16 i, count;

        /* We cannot hold synchronization semaphores for too long,
         * because of forceful takeover procedure. However it is more efficient
         * to read in bursts than synchronizing access for each word.
         */
        for (i = 0; i < words; i += IGC_EERD_EEWR_MAX_COUNT) {
                count = (words - i) / IGC_EERD_EEWR_MAX_COUNT > 0 ?
                        IGC_EERD_EEWR_MAX_COUNT : (words - i);

                status = hw->nvm.ops.acquire(hw);
                if (status)
                        break;

                status = igc_read_nvm_eerd(hw, offset, count, data + i);
                hw->nvm.ops.release(hw);
                if (status)
                        break;
        }

        return status;
}

/**
 * igc_write_nvm_srwr - Write to Shadow Ram using EEWR
 * @hw: pointer to the HW structure
 * @offset: offset within the Shadow Ram to be written to
 * @words: number of words to write
 * @data: 16 bit word(s) to be written to the Shadow Ram
 *
 * Writes data to Shadow Ram at offset using EEWR register.
 *
 * If igc_update_nvm_checksum is not called after this function , the
 * Shadow Ram will most likely contain an invalid checksum.
 */
static s32 igc_write_nvm_srwr(struct igc_hw *hw, u16 offset, u16 words,
                              u16 *data)
{
        struct igc_nvm_info *nvm = &hw->nvm;
        u32 attempts = 100000;
        u32 i, k, eewr = 0;
        s32 ret_val = 0;

        /* A check for invalid values:  offset too large, too many words,
         * too many words for the offset, and not enough words.
         */
        if (offset >= nvm->word_size || (words > (nvm->word_size - offset)) ||
            words == 0) {
                hw_dbg("nvm parameter(s) out of bounds\n");
                ret_val = -IGC_ERR_NVM;
                goto out;
        }

        for (i = 0; i < words; i++) {
                eewr = ((offset + i) << IGC_NVM_RW_ADDR_SHIFT) |
                        (data[i] << IGC_NVM_RW_REG_DATA) |
                        IGC_NVM_RW_REG_START;

                wr32(IGC_SRWR, eewr);

                for (k = 0; k < attempts; k++) {
                        if (IGC_NVM_RW_REG_DONE &
                            rd32(IGC_SRWR)) {
                                ret_val = 0;
                                break;
                        }
                        udelay(5);
                }

                if (ret_val) {
                        hw_dbg("Shadow RAM write EEWR timed out\n");
                        break;
                }
        }

out:
        return ret_val;
}

/**
 * igc_write_nvm_srwr_i225 - Write to Shadow RAM using EEWR
 * @hw: pointer to the HW structure
 * @offset: offset within the Shadow RAM to be written to
 * @words: number of words to write
 * @data: 16 bit word(s) to be written to the Shadow RAM
 *
 * Writes data to Shadow RAM at offset using EEWR register.
 *
 * If igc_update_nvm_checksum is not called after this function , the
 * data will not be committed to FLASH and also Shadow RAM will most likely
 * contain an invalid checksum.
 *
 * If error code is returned, data and Shadow RAM may be inconsistent - buffer
 * partially written.
 */
static s32 igc_write_nvm_srwr_i225(struct igc_hw *hw, u16 offset, u16 words,
                                   u16 *data)
{
        s32 status = 0;
        u16 i, count;

        /* We cannot hold synchronization semaphores for too long,
         * because of forceful takeover procedure. However it is more efficient
         * to write in bursts than synchronizing access for each word.
         */
        for (i = 0; i < words; i += IGC_EERD_EEWR_MAX_COUNT) {
                count = (words - i) / IGC_EERD_EEWR_MAX_COUNT > 0 ?
                        IGC_EERD_EEWR_MAX_COUNT : (words - i);

                status = hw->nvm.ops.acquire(hw);
                if (status)
                        break;

                status = igc_write_nvm_srwr(hw, offset, count, data + i);
                hw->nvm.ops.release(hw);
                if (status)
                        break;
        }

        return status;
}

/**
 * igc_validate_nvm_checksum_i225 - Validate EEPROM checksum
 * @hw: pointer to the HW structure
 *
 * Calculates the EEPROM checksum by reading/adding each word of the EEPROM
 * and then verifies that the sum of the EEPROM is equal to 0xBABA.
 */
static s32 igc_validate_nvm_checksum_i225(struct igc_hw *hw)
{
        s32 (*read_op_ptr)(struct igc_hw *hw, u16 offset, u16 count,
                           u16 *data);
        s32 status = 0;

        status = hw->nvm.ops.acquire(hw);
        if (status)
                goto out;

        /* Replace the read function with semaphore grabbing with
         * the one that skips this for a while.
         * We have semaphore taken already here.
         */
        read_op_ptr = hw->nvm.ops.read;
        hw->nvm.ops.read = igc_read_nvm_eerd;

        status = igc_validate_nvm_checksum(hw);

        /* Revert original read operation. */
        hw->nvm.ops.read = read_op_ptr;

        hw->nvm.ops.release(hw);

out:
        return status;
}

/**
 * igc_pool_flash_update_done_i225 - Pool FLUDONE status
 * @hw: pointer to the HW structure
 */
static s32 igc_pool_flash_update_done_i225(struct igc_hw *hw)
{
        s32 ret_val = -IGC_ERR_NVM;
        u32 i, reg;

        for (i = 0; i < IGC_FLUDONE_ATTEMPTS; i++) {
                reg = rd32(IGC_EECD);
                if (reg & IGC_EECD_FLUDONE_I225) {
                        ret_val = 0;
                        break;
                }
                udelay(5);
        }

        return ret_val;
}

/**
 * igc_update_flash_i225 - Commit EEPROM to the flash
 * @hw: pointer to the HW structure
 */
static s32 igc_update_flash_i225(struct igc_hw *hw)
{
        s32 ret_val = 0;
        u32 flup;

        ret_val = igc_pool_flash_update_done_i225(hw);
        if (ret_val == -IGC_ERR_NVM) {
                hw_dbg("Flash update time out\n");
                goto out;
        }

        flup = rd32(IGC_EECD) | IGC_EECD_FLUPD_I225;
        wr32(IGC_EECD, flup);

        ret_val = igc_pool_flash_update_done_i225(hw);
        if (ret_val)
                hw_dbg("Flash update time out\n");
        else
                hw_dbg("Flash update complete\n");

out:
        return ret_val;
}

/**
 * igc_update_nvm_checksum_i225 - Update EEPROM checksum
 * @hw: pointer to the HW structure
 *
 * Updates the EEPROM checksum by reading/adding each word of the EEPROM
 * up to the checksum.  Then calculates the EEPROM checksum and writes the
 * value to the EEPROM. Next commit EEPROM data onto the Flash.
 */
static s32 igc_update_nvm_checksum_i225(struct igc_hw *hw)
{
        u16 checksum = 0;
        s32 ret_val = 0;
        u16 i, nvm_data;

        /* Read the first word from the EEPROM. If this times out or fails, do
         * not continue or we could be in for a very long wait while every
         * EEPROM read fails
         */
        ret_val = igc_read_nvm_eerd(hw, 0, 1, &nvm_data);
        if (ret_val) {
                hw_dbg("EEPROM read failed\n");
                goto out;
        }

        ret_val = hw->nvm.ops.acquire(hw);
        if (ret_val)
                goto out;

        /* Do not use hw->nvm.ops.write, hw->nvm.ops.read
         * because we do not want to take the synchronization
         * semaphores twice here.
         */

        for (i = 0; i < NVM_CHECKSUM_REG; i++) {
                ret_val = igc_read_nvm_eerd(hw, i, 1, &nvm_data);
                if (ret_val) {
                        hw->nvm.ops.release(hw);
                        hw_dbg("NVM Read Error while updating checksum.\n");
                        goto out;
                }
                checksum += nvm_data;
        }
        checksum = (u16)NVM_SUM - checksum;
        ret_val = igc_write_nvm_srwr(hw, NVM_CHECKSUM_REG, 1,
                                     &checksum);
        if (ret_val) {
                hw->nvm.ops.release(hw);
                hw_dbg("NVM Write Error while updating checksum.\n");
                goto out;
        }

        hw->nvm.ops.release(hw);

        ret_val = igc_update_flash_i225(hw);

out:
        return ret_val;
}

/**
 * igc_get_flash_presence_i225 - Check if flash device is detected
 * @hw: pointer to the HW structure
 */
bool igc_get_flash_presence_i225(struct igc_hw *hw)
{
        bool ret_val = false;
        u32 eec = 0;

        eec = rd32(IGC_EECD);
        if (eec & IGC_EECD_FLASH_DETECTED_I225)
                ret_val = true;

        return ret_val;
}

/**
 * igc_init_nvm_params_i225 - Init NVM func ptrs.
 * @hw: pointer to the HW structure
 */
s32 igc_init_nvm_params_i225(struct igc_hw *hw)
{
        struct igc_nvm_info *nvm = &hw->nvm;

        nvm->ops.acquire = igc_acquire_nvm_i225;
        nvm->ops.release = igc_release_nvm_i225;

        /* NVM Function Pointers */
        if (igc_get_flash_presence_i225(hw)) {
                hw->nvm.type = igc_nvm_flash_hw;
                nvm->ops.read = igc_read_nvm_srrd_i225;
                nvm->ops.write = igc_write_nvm_srwr_i225;
                nvm->ops.validate = igc_validate_nvm_checksum_i225;
                nvm->ops.update = igc_update_nvm_checksum_i225;
        } else {
                hw->nvm.type = igc_nvm_invm;
                nvm->ops.read = igc_read_nvm_eerd;
                nvm->ops.write = NULL;
                nvm->ops.validate = NULL;
                nvm->ops.update = NULL;
        }
        return 0;
}