/*
 * Copyright 2018 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: AMD
 *
 */
#include "dce_i2c.h"
#include "dce_i2c_hw.h"
#include "reg_helper.h"
#include "include/gpio_service_interface.h"

#define CTX \
        dce_i2c_hw->ctx
#define REG(reg)\
        dce_i2c_hw->regs->reg

#undef FN
#define FN(reg_name, field_name) \
        dce_i2c_hw->shifts->field_name, dce_i2c_hw->masks->field_name

static void execute_transaction(
        struct dce_i2c_hw *dce_i2c_hw)
{
        REG_UPDATE_N(SETUP, 5,
                     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_EN), 0,
                     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_CLK_DRIVE_EN), 0,
                     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_SEL), 0,
                     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_TRANSACTION_DELAY), 0,
                     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_BYTE_DELAY), 0);


        REG_UPDATE_5(DC_I2C_CONTROL,
                     DC_I2C_SOFT_RESET, 0,
                     DC_I2C_SW_STATUS_RESET, 0,
                     DC_I2C_SEND_RESET, 0,
                     DC_I2C_GO, 0,
                     DC_I2C_TRANSACTION_COUNT, dce_i2c_hw->transaction_count - 1);

        /* start I2C transfer */
        REG_UPDATE(DC_I2C_CONTROL, DC_I2C_GO, 1);

        /* all transactions were executed and HW buffer became empty
         * (even though it actually happens when status becomes DONE)
         */
        dce_i2c_hw->transaction_count = 0;
        dce_i2c_hw->buffer_used_bytes = 0;
}

static enum i2c_channel_operation_result get_channel_status(
        struct dce_i2c_hw *dce_i2c_hw,
        uint8_t *returned_bytes)
{
        uint32_t i2c_sw_status = 0;
        uint32_t value =
                REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
        if (i2c_sw_status == DC_I2C_STATUS__DC_I2C_STATUS_USED_BY_SW)
                return I2C_CHANNEL_OPERATION_ENGINE_BUSY;
        else if (value & dce_i2c_hw->masks->DC_I2C_SW_STOPPED_ON_NACK)
                return I2C_CHANNEL_OPERATION_NO_RESPONSE;
        else if (value & dce_i2c_hw->masks->DC_I2C_SW_TIMEOUT)
                return I2C_CHANNEL_OPERATION_TIMEOUT;
        else if (value & dce_i2c_hw->masks->DC_I2C_SW_ABORTED)
                return I2C_CHANNEL_OPERATION_FAILED;
        else if (value & dce_i2c_hw->masks->DC_I2C_SW_DONE)
                return I2C_CHANNEL_OPERATION_SUCCEEDED;

        /*
         * this is the case when HW used for communication, I2C_SW_STATUS
         * could be zero
         */
        return I2C_CHANNEL_OPERATION_SUCCEEDED;
}

static uint32_t get_hw_buffer_available_size(
        const struct dce_i2c_hw *dce_i2c_hw)
{
        return dce_i2c_hw->buffer_size -
                        dce_i2c_hw->buffer_used_bytes;
}

static
uint32_t get_reference_clock(
                struct dc_bios *bios)
{
        struct dc_firmware_info info = { { 0 } };

        if (bios->funcs->get_firmware_info(bios, &info) != BP_RESULT_OK)
                return 0;

        return info.pll_info.crystal_frequency;
}

static uint32_t get_speed(
        const struct dce_i2c_hw *dce_i2c_hw)
{
        uint32_t pre_scale = 0;

        REG_GET(SPEED, DC_I2C_DDC1_PRESCALE, &pre_scale);

        /* [anaumov] it seems following is unnecessary */
        /*ASSERT(value.bits.DC_I2C_DDC1_PRESCALE);*/
        return pre_scale ?
                dce_i2c_hw->reference_frequency / pre_scale :
                dce_i2c_hw->default_speed;
}

static void process_channel_reply(
        struct dce_i2c_hw *dce_i2c_hw,
        struct i2c_payload *reply)
{
        uint32_t length = reply->length;
        uint8_t *buffer = reply->data;

        REG_SET_3(DC_I2C_DATA, 0,
                 DC_I2C_INDEX, dce_i2c_hw->buffer_used_write,
                 DC_I2C_DATA_RW, 1,
                 DC_I2C_INDEX_WRITE, 1);

        while (length) {
                /* after reading the status,
                 * if the I2C operation executed successfully
                 * (i.e. DC_I2C_STATUS_DONE = 1) then the I2C controller
                 * should read data bytes from I2C circular data buffer
                 */

                uint32_t i2c_data;

                REG_GET(DC_I2C_DATA, DC_I2C_DATA, &i2c_data);
                *buffer++ = i2c_data;

                --length;
        }
}

static bool process_transaction(
        struct dce_i2c_hw *dce_i2c_hw,
        struct i2c_request_transaction_data *request)
{
        uint32_t length = request->length;
        uint8_t *buffer = request->data;

        bool last_transaction = false;
        uint32_t value = 0;

        last_transaction = ((dce_i2c_hw->transaction_count == 3) ||
                        (request->action == DCE_I2C_TRANSACTION_ACTION_I2C_WRITE) ||
                        (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ));


        switch (dce_i2c_hw->transaction_count) {
        case 0:
                REG_UPDATE_5(DC_I2C_TRANSACTION0,
                                 DC_I2C_STOP_ON_NACK0, 1,
                                 DC_I2C_START0, 1,
                                 DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
                                 DC_I2C_COUNT0, length,
                                 DC_I2C_STOP0, last_transaction ? 1 : 0);
                break;
        case 1:
                REG_UPDATE_5(DC_I2C_TRANSACTION1,
                                 DC_I2C_STOP_ON_NACK0, 1,
                                 DC_I2C_START0, 1,
                                 DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
                                 DC_I2C_COUNT0, length,
                                 DC_I2C_STOP0, last_transaction ? 1 : 0);
                break;
        case 2:
                REG_UPDATE_5(DC_I2C_TRANSACTION2,
                                 DC_I2C_STOP_ON_NACK0, 1,
                                 DC_I2C_START0, 1,
                                 DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
                                 DC_I2C_COUNT0, length,
                                 DC_I2C_STOP0, last_transaction ? 1 : 0);
                break;
        case 3:
                REG_UPDATE_5(DC_I2C_TRANSACTION3,
                                 DC_I2C_STOP_ON_NACK0, 1,
                                 DC_I2C_START0, 1,
                                 DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
                                 DC_I2C_COUNT0, length,
                                 DC_I2C_STOP0, last_transaction ? 1 : 0);
                break;
        default:
                /* TODO Warning ? */
                break;
        }

        /* Write the I2C address and I2C data
         * into the hardware circular buffer, one byte per entry.
         * As an example, the 7-bit I2C slave address for CRT monitor
         * for reading DDC/EDID information is 0b1010001.
         * For an I2C send operation, the LSB must be programmed to 0;
         * for I2C receive operation, the LSB must be programmed to 1.
         */
        if (dce_i2c_hw->transaction_count == 0) {
                value = REG_SET_4(DC_I2C_DATA, 0,
                                  DC_I2C_DATA_RW, false,
                                  DC_I2C_DATA, request->address,
                                  DC_I2C_INDEX, 0,
                                  DC_I2C_INDEX_WRITE, 1);
                dce_i2c_hw->buffer_used_write = 0;
        } else
                value = REG_SET_2(DC_I2C_DATA, 0,
                          DC_I2C_DATA_RW, false,
                          DC_I2C_DATA, request->address);

        dce_i2c_hw->buffer_used_write++;

        if (!(request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ)) {
                while (length) {
                        REG_SET_2(DC_I2C_DATA, value,
                                  DC_I2C_INDEX_WRITE, 0,
                                  DC_I2C_DATA, *buffer++);
                        dce_i2c_hw->buffer_used_write++;
                        --length;
                }
        }

        ++dce_i2c_hw->transaction_count;
        dce_i2c_hw->buffer_used_bytes += length + 1;

        return last_transaction;
}

static inline void reset_hw_engine(struct dce_i2c_hw *dce_i2c_hw)
{
        REG_UPDATE_2(DC_I2C_CONTROL,
                     DC_I2C_SW_STATUS_RESET, 1,
                     DC_I2C_SW_STATUS_RESET, 1);
}

static void set_speed(
        struct dce_i2c_hw *dce_i2c_hw,
        uint32_t speed)
{

        if (speed) {
                if (dce_i2c_hw->masks->DC_I2C_DDC1_START_STOP_TIMING_CNTL)
                        REG_UPDATE_N(SPEED, 3,
                                     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed,
                                     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2,
                                     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_START_STOP_TIMING_CNTL), speed > 50 ? 2:1);
                else
                        REG_UPDATE_N(SPEED, 2,
                                     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed,
                                     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2);
        }
}

static bool setup_engine(
        struct dce_i2c_hw *dce_i2c_hw)
{
        uint32_t i2c_setup_limit = I2C_SETUP_TIME_LIMIT_DCE;

        if (dce_i2c_hw->setup_limit != 0)
                i2c_setup_limit = dce_i2c_hw->setup_limit;
        /* Program pin select */
        REG_UPDATE_6(DC_I2C_CONTROL,
                     DC_I2C_GO, 0,
                     DC_I2C_SOFT_RESET, 0,
                     DC_I2C_SEND_RESET, 0,
                     DC_I2C_SW_STATUS_RESET, 1,
                     DC_I2C_TRANSACTION_COUNT, 0,
                     DC_I2C_DDC_SELECT, dce_i2c_hw->engine_id);

        /* Program time limit */
        if (dce_i2c_hw->send_reset_length == 0) {
                /*pre-dcn*/
                REG_UPDATE_N(SETUP, 2,
                             FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_TIME_LIMIT), i2c_setup_limit,
                             FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_ENABLE), 1);
        }
        /* Program HW priority
         * set to High - interrupt software I2C at any time
         * Enable restart of SW I2C that was interrupted by HW
         * disable queuing of software while I2C is in use by HW
         */
        REG_UPDATE_2(DC_I2C_ARBITRATION,
                     DC_I2C_NO_QUEUED_SW_GO, 0,
                     DC_I2C_SW_PRIORITY, DC_I2C_ARBITRATION__DC_I2C_SW_PRIORITY_NORMAL);

        return true;
}

static bool is_hw_busy(struct dce_i2c_hw *dce_i2c_hw)
{
        uint32_t i2c_sw_status = 0;

        REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
        if (i2c_sw_status == DC_I2C_STATUS__DC_I2C_STATUS_IDLE)
                return false;

        reset_hw_engine(dce_i2c_hw);

        REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
        return i2c_sw_status != DC_I2C_STATUS__DC_I2C_STATUS_IDLE;
}

static void release_engine(
        struct dce_i2c_hw *dce_i2c_hw)
{
        bool safe_to_reset;

        /* Restore original HW engine speed */

        set_speed(dce_i2c_hw, dce_i2c_hw->original_speed);

        /* Release I2C */
        REG_UPDATE(DC_I2C_ARBITRATION, DC_I2C_SW_DONE_USING_I2C_REG, 1);

        /* Reset HW engine */
        {
                uint32_t i2c_sw_status = 0;

                REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
                /* if used by SW, safe to reset */
                safe_to_reset = (i2c_sw_status == 1);
        }

        if (safe_to_reset)
                REG_UPDATE_2(DC_I2C_CONTROL,
                             DC_I2C_SOFT_RESET, 1,
                             DC_I2C_SW_STATUS_RESET, 1);
        else
                REG_UPDATE(DC_I2C_CONTROL, DC_I2C_SW_STATUS_RESET, 1);
        /* HW I2c engine - clock gating feature */
        if (!dce_i2c_hw->engine_keep_power_up_count)
                REG_UPDATE_N(SETUP, 1, FN(SETUP, DC_I2C_DDC1_ENABLE), 0);

}

struct dce_i2c_hw *acquire_i2c_hw_engine(
        struct resource_pool *pool,
        struct ddc *ddc)
{
        uint32_t counter = 0;
        enum gpio_result result;
        uint32_t current_speed;
        struct dce_i2c_hw *dce_i2c_hw = NULL;

        if (!ddc)
                return NULL;

        if (ddc->hw_info.hw_supported) {
                enum gpio_ddc_line line = dal_ddc_get_line(ddc);

                if (line < pool->pipe_count)
                        dce_i2c_hw = pool->hw_i2cs[line];
        }

        if (!dce_i2c_hw)
                return NULL;

        if (pool->i2c_hw_buffer_in_use)
                return NULL;

        do {
                result = dal_ddc_open(ddc, GPIO_MODE_HARDWARE,
                        GPIO_DDC_CONFIG_TYPE_MODE_I2C);

                if (result == GPIO_RESULT_OK)
                        break;

                /* i2c_engine is busy by VBios, lets wait and retry */

                udelay(10);

                ++counter;
        } while (counter < 2);

        if (result != GPIO_RESULT_OK)
                return NULL;

        dce_i2c_hw->ddc = ddc;

        current_speed = get_speed(dce_i2c_hw);

        if (current_speed)
                dce_i2c_hw->original_speed = current_speed;

        if (!setup_engine(dce_i2c_hw)) {
                release_engine(dce_i2c_hw);
                return NULL;
        }

        pool->i2c_hw_buffer_in_use = true;
        return dce_i2c_hw;
}

static
enum i2c_channel_operation_result dce_i2c_hw_engine_wait_on_operation_result(
        struct dce_i2c_hw *dce_i2c_hw,
        uint32_t timeout,
        enum i2c_channel_operation_result expected_result)
{
        enum i2c_channel_operation_result result;
        uint32_t i = 0;

        if (!timeout)
                return I2C_CHANNEL_OPERATION_SUCCEEDED;

        do {

                result = get_channel_status(
                                dce_i2c_hw, NULL);

                if (result != expected_result)
                        break;

                udelay(1);

                ++i;
        } while (i < timeout);
        return result;
}

static void submit_channel_request_hw(
        struct dce_i2c_hw *dce_i2c_hw,
        struct i2c_request_transaction_data *request)
{
        request->status = I2C_CHANNEL_OPERATION_SUCCEEDED;

        if (!process_transaction(dce_i2c_hw, request))
                return;

        if (is_hw_busy(dce_i2c_hw)) {
                request->status = I2C_CHANNEL_OPERATION_ENGINE_BUSY;
                return;
        }

        execute_transaction(dce_i2c_hw);


}

static uint32_t get_transaction_timeout_hw(
        const struct dce_i2c_hw *dce_i2c_hw,
        uint32_t length)
{

        uint32_t speed = get_speed(dce_i2c_hw);



        uint32_t period_timeout;
        uint32_t num_of_clock_stretches;

        if (!speed)
                return 0;

        period_timeout = (1000 * TRANSACTION_TIMEOUT_IN_I2C_CLOCKS) / speed;

        num_of_clock_stretches = 1 + (length << 3) + 1;
        num_of_clock_stretches +=
                (dce_i2c_hw->buffer_used_bytes << 3) +
                (dce_i2c_hw->transaction_count << 1);

        return period_timeout * num_of_clock_stretches;
}

static
bool dce_i2c_hw_engine_submit_payload(
        struct dce_i2c_hw *dce_i2c_hw,
        struct i2c_payload *payload,
        bool middle_of_transaction)
{

        struct i2c_request_transaction_data request;

        uint32_t transaction_timeout;

        enum i2c_channel_operation_result operation_result;

        bool result = false;

        /* We need following:
         * transaction length will not exceed
         * the number of free bytes in HW buffer (minus one for address)
         */

        if (payload->length >=
                        get_hw_buffer_available_size(dce_i2c_hw)) {
                return false;
        }

        if (!payload->write)
                request.action = middle_of_transaction ?
                        DCE_I2C_TRANSACTION_ACTION_I2C_READ_MOT :
                        DCE_I2C_TRANSACTION_ACTION_I2C_READ;
        else
                request.action = middle_of_transaction ?
                        DCE_I2C_TRANSACTION_ACTION_I2C_WRITE_MOT :
                        DCE_I2C_TRANSACTION_ACTION_I2C_WRITE;


        request.address = (uint8_t) ((payload->address << 1) | !payload->write);
        request.length = payload->length;
        request.data = payload->data;

        /* obtain timeout value before submitting request */

        transaction_timeout = get_transaction_timeout_hw(
                dce_i2c_hw, payload->length + 1);

        submit_channel_request_hw(
                dce_i2c_hw, &request);

        if ((request.status == I2C_CHANNEL_OPERATION_FAILED) ||
                (request.status == I2C_CHANNEL_OPERATION_ENGINE_BUSY))
                return false;

        /* wait until transaction proceed */

        operation_result = dce_i2c_hw_engine_wait_on_operation_result(
                dce_i2c_hw,
                transaction_timeout,
                I2C_CHANNEL_OPERATION_ENGINE_BUSY);

        /* update transaction status */

        if (operation_result == I2C_CHANNEL_OPERATION_SUCCEEDED)
                result = true;

        if (result && (!payload->write))
                process_channel_reply(dce_i2c_hw, payload);

        return result;
}

bool dce_i2c_submit_command_hw(
        struct resource_pool *pool,
        struct ddc *ddc,
        struct i2c_command *cmd,
        struct dce_i2c_hw *dce_i2c_hw)
{
        uint8_t index_of_payload = 0;
        bool result;

        set_speed(dce_i2c_hw, cmd->speed);

        result = true;

        while (index_of_payload < cmd->number_of_payloads) {
                bool mot = (index_of_payload != cmd->number_of_payloads - 1);

                struct i2c_payload *payload = cmd->payloads + index_of_payload;

                if (!dce_i2c_hw_engine_submit_payload(
                                dce_i2c_hw, payload, mot)) {
                        result = false;
                        break;
                }



                ++index_of_payload;
        }

        pool->i2c_hw_buffer_in_use = false;

        release_engine(dce_i2c_hw);
        dal_ddc_close(dce_i2c_hw->ddc);

        dce_i2c_hw->ddc = NULL;

        return result;
}

void dce_i2c_hw_construct(
        struct dce_i2c_hw *dce_i2c_hw,
        struct dc_context *ctx,
        uint32_t engine_id,
        const struct dce_i2c_registers *regs,
        const struct dce_i2c_shift *shifts,
        const struct dce_i2c_mask *masks)
{
        dce_i2c_hw->ctx = ctx;
        dce_i2c_hw->engine_id = engine_id;
        dce_i2c_hw->reference_frequency = get_reference_clock(ctx->dc_bios) >> 1;
        dce_i2c_hw->regs = regs;
        dce_i2c_hw->shifts = shifts;
        dce_i2c_hw->masks = masks;
        dce_i2c_hw->buffer_used_bytes = 0;
        dce_i2c_hw->transaction_count = 0;
        dce_i2c_hw->engine_keep_power_up_count = 1;
        dce_i2c_hw->original_speed = DEFAULT_I2C_HW_SPEED;
        dce_i2c_hw->default_speed = DEFAULT_I2C_HW_SPEED;
        dce_i2c_hw->send_reset_length = 0;
        dce_i2c_hw->setup_limit = I2C_SETUP_TIME_LIMIT_DCE;
        dce_i2c_hw->buffer_size = I2C_HW_BUFFER_SIZE_DCE;
}

void dce100_i2c_hw_construct(
        struct dce_i2c_hw *dce_i2c_hw,
        struct dc_context *ctx,
        uint32_t engine_id,
        const struct dce_i2c_registers *regs,
        const struct dce_i2c_shift *shifts,
        const struct dce_i2c_mask *masks)
{

        uint32_t xtal_ref_div = 0;

        dce_i2c_hw_construct(dce_i2c_hw,
                        ctx,
                        engine_id,
                        regs,
                        shifts,
                        masks);
        dce_i2c_hw->buffer_size = I2C_HW_BUFFER_SIZE_DCE100;

        REG_GET(MICROSECOND_TIME_BASE_DIV, XTAL_REF_DIV, &xtal_ref_div);

        if (xtal_ref_div == 0)
                xtal_ref_div = 2;

        /*Calculating Reference Clock by divding original frequency by
         * XTAL_REF_DIV.
         * At upper level, uint32_t reference_frequency =
         *  dal_dce_i2c_get_reference_clock(as) >> 1
         *  which already divided by 2. So we need x2 to get original
         *  reference clock from ppll_info
         */
        dce_i2c_hw->reference_frequency =
                (dce_i2c_hw->reference_frequency * 2) / xtal_ref_div;
}

void dce112_i2c_hw_construct(
        struct dce_i2c_hw *dce_i2c_hw,
        struct dc_context *ctx,
        uint32_t engine_id,
        const struct dce_i2c_registers *regs,
        const struct dce_i2c_shift *shifts,
        const struct dce_i2c_mask *masks)
{
        dce100_i2c_hw_construct(dce_i2c_hw,
                        ctx,
                        engine_id,
                        regs,
                        shifts,
                        masks);
        dce_i2c_hw->default_speed = DEFAULT_I2C_HW_SPEED_100KHZ;
}

void dcn1_i2c_hw_construct(
        struct dce_i2c_hw *dce_i2c_hw,
        struct dc_context *ctx,
        uint32_t engine_id,
        const struct dce_i2c_registers *regs,
        const struct dce_i2c_shift *shifts,
        const struct dce_i2c_mask *masks)
{
        dce112_i2c_hw_construct(dce_i2c_hw,
                        ctx,
                        engine_id,
                        regs,
                        shifts,
                        masks);
        dce_i2c_hw->setup_limit = I2C_SETUP_TIME_LIMIT_DCN;
}