// Copyright 2015-2016 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 "driver/spi_master.h"
#include "soc/gpio_sig_map.h"
#include "soc/spi_reg.h"
#include "soc/dport_reg.h"
#include "soc/spi_struct.h"
#include "soc/rtc_cntl_reg.h"
#include "rom/ets_sys.h"
#include "esp_types.h"
#include "esp_attr.h"
#include "esp_intr.h"
#include "esp_intr_alloc.h"
#include "esp_log.h"
#include "esp_err.h"
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "freertos/xtensa_api.h"
#include "freertos/task.h"
#include "freertos/ringbuf.h"
#include "soc/soc.h"
#include "soc/dport_reg.h"
#include "soc/uart_struct.h"
#include "rom/lldesc.h"
#include "driver/uart.h"
#include "driver/gpio.h"
#include "driver/periph_ctrl.h"
#include "esp_heap_alloc_caps.h"

#include "driver/spi_common.h"

static const char *SPI_TAG = "spi";

#define SPI_CHECK(a, str, ret_val) \
    if (!(a)) { \
        ESP_LOGE(SPI_TAG,"%s(%d): %s", __FUNCTION__, __LINE__, str); \
        return (ret_val); \
    }


typedef struct spi_device_t spi_device_t;

/*
 Stores a bunch of per-spi-peripheral data.
*/
typedef struct {
    const uint8_t spiclk_out;       //GPIO mux output signals
    const uint8_t spiclk_in;
    const uint8_t spid_out;
    const uint8_t spiq_out;
    const uint8_t spiwp_out;
    const uint8_t spihd_out;
    const uint8_t spid_in;          //GPIO mux input signals
    const uint8_t spiq_in;
    const uint8_t spiwp_in;
    const uint8_t spihd_in;
    const uint8_t spics_out[3];     // /CS GPIO output mux signals
    const uint8_t spics_in;
    const uint8_t spiclk_native;    //IO pins of IO_MUX muxed signals
    const uint8_t spid_native;
    const uint8_t spiq_native;
    const uint8_t spiwp_native;
    const uint8_t spihd_native;
    const uint8_t spics0_native;
    const uint8_t irq;              //irq source for interrupt mux
    const uint8_t irq_dma;          //dma irq source for interrupt mux
    const periph_module_t module;   //peripheral module, for enabling clock etc
    spi_dev_t *hw;              //Pointer to the hardware registers
} spi_signal_conn_t;

/*
 Bunch of constants for every SPI peripheral: GPIO signals, irqs, hw addr of registers etc
*/
static const spi_signal_conn_t io_signal[3]={
    {
        .spiclk_out=SPICLK_OUT_IDX,
        .spiclk_in=SPICLK_IN_IDX,
        .spid_out=SPID_OUT_IDX,
        .spiq_out=SPIQ_OUT_IDX,
        .spiwp_out=SPIWP_OUT_IDX,
        .spihd_out=SPIHD_OUT_IDX,
        .spid_in=SPID_IN_IDX,
        .spiq_in=SPIQ_IN_IDX,
        .spiwp_in=SPIWP_IN_IDX,
        .spihd_in=SPIHD_IN_IDX,
        .spics_out={SPICS0_OUT_IDX, SPICS1_OUT_IDX, SPICS2_OUT_IDX},
        .spics_in=SPICS0_IN_IDX,
        .spiclk_native=6,
        .spid_native=8,
        .spiq_native=7,
        .spiwp_native=10,
        .spihd_native=9,
        .spics0_native=11,
        .irq=ETS_SPI1_INTR_SOURCE,
        .irq_dma=ETS_SPI1_DMA_INTR_SOURCE,
        .module=PERIPH_SPI_MODULE,
        .hw=&SPI1
    }, {
        .spiclk_out=HSPICLK_OUT_IDX,
        .spiclk_in=HSPICLK_IN_IDX,
        .spid_out=HSPID_OUT_IDX,
        .spiq_out=HSPIQ_OUT_IDX,
        .spiwp_out=HSPIWP_OUT_IDX,
        .spihd_out=HSPIHD_OUT_IDX,
        .spid_in=HSPID_IN_IDX,
        .spiq_in=HSPIQ_IN_IDX,
        .spiwp_in=HSPIWP_IN_IDX,
        .spihd_in=HSPIHD_IN_IDX,
        .spics_out={HSPICS0_OUT_IDX, HSPICS1_OUT_IDX, HSPICS2_OUT_IDX},
        .spics_in=HSPICS0_IN_IDX,
        .spiclk_native=14,
        .spid_native=13,
        .spiq_native=12,
        .spiwp_native=2,
        .spihd_native=4,
        .spics0_native=15,
        .irq=ETS_SPI2_INTR_SOURCE,
        .irq_dma=ETS_SPI2_DMA_INTR_SOURCE,
        .module=PERIPH_HSPI_MODULE,
        .hw=&SPI2
    }, {
        .spiclk_out=VSPICLK_OUT_IDX,
        .spiclk_in=VSPICLK_IN_IDX,
        .spid_out=VSPID_OUT_IDX,
        .spiq_out=VSPIQ_OUT_IDX,
        .spiwp_out=VSPIWP_OUT_IDX,
        .spihd_out=VSPIHD_OUT_IDX,
        .spid_in=VSPID_IN_IDX,
        .spiq_in=VSPIQ_IN_IDX,
        .spiwp_in=VSPIWP_IN_IDX,
        .spihd_in=VSPIHD_IN_IDX,
        .spics_out={VSPICS0_OUT_IDX, VSPICS1_OUT_IDX, VSPICS2_OUT_IDX},
        .spics_in=VSPICS0_IN_IDX,
        .spiclk_native=18,
        .spid_native=23,
        .spiq_native=19,
        .spiwp_native=22,
        .spihd_native=21,
        .spics0_native=5,
        .irq=ETS_SPI3_INTR_SOURCE,
        .irq_dma=ETS_SPI3_DMA_INTR_SOURCE,
        .module=PERIPH_VSPI_MODULE,
        .hw=&SPI3
    }
};

//Periph 1 is 'claimed' by SPI flash code.
static bool spi_periph_claimed[3]={true, false, false};

//Returns true if this peripheral is successfully claimed, false if otherwise.
bool spicommon_periph_claim(spi_host_device_t host) {
    bool ret = __sync_bool_compare_and_swap(&spi_periph_claimed[host], false, true);
    if (ret) periph_module_enable(io_signal[host].module);
    return ret;
}

//Returns true if this peripheral is successfully freed, false if otherwise.
bool spicommon_periph_free(spi_host_device_t host) {
    bool ret = __sync_bool_compare_and_swap(&spi_periph_claimed[host], true, false);
    if (ret) periph_module_disable(io_signal[host].module);
    return ret;
}


int spicommon_irqsource_for_host(spi_host_device_t host) {
    return io_signal[host].irq;
}

spi_dev_t *spicommon_hw_for_host(spi_host_device_t host) {
    return io_signal[host].hw;
}

/*
Do the common stuff to hook up a SPI host to a bus defined by a bunch of GPIO pins. Feed it a host number and a
bus config struct and it'll set up the GPIO matrix and enable the device. It will set is_native to 1 if the bus 
config can be done using the IOMUX instead of using the GPIO matrix.
*/
esp_err_t spicommon_bus_initialize_io(spi_host_device_t host, spi_bus_config_t *bus_config, int dma_chan, int flags, bool *is_native)
{
    bool native=true;
    bool is_master=(flags&SPICOMMON_BUSFLAG_MASTER)?true:false;
    bool use_quad=(flags&SPICOMMON_BUSFLAG_QUAD)?true:false;

    SPI_CHECK(bus_config->mosi_io_num<0 || GPIO_IS_VALID_OUTPUT_GPIO(bus_config->mosi_io_num), "spid pin invalid", ESP_ERR_INVALID_ARG);
    SPI_CHECK(bus_config->sclk_io_num<0 || GPIO_IS_VALID_OUTPUT_GPIO(bus_config->sclk_io_num), "spiclk pin invalid", ESP_ERR_INVALID_ARG);
    SPI_CHECK(bus_config->miso_io_num<0 || GPIO_IS_VALID_GPIO(bus_config->miso_io_num), "spiq pin invalid", ESP_ERR_INVALID_ARG);
    if (use_quad) {
        SPI_CHECK(bus_config->quadwp_io_num<0 || GPIO_IS_VALID_OUTPUT_GPIO(bus_config->quadwp_io_num), "spiwp pin invalid", ESP_ERR_INVALID_ARG);
        SPI_CHECK(bus_config->quadhd_io_num<0 || GPIO_IS_VALID_OUTPUT_GPIO(bus_config->quadhd_io_num), "spihd pin invalid", ESP_ERR_INVALID_ARG);
    }

    //Check if the selected pins correspond to the native pins of the peripheral
    if (bus_config->mosi_io_num >= 0 && bus_config->mosi_io_num!=io_signal[host].spid_native) native=false;
    if (bus_config->miso_io_num >= 0 && bus_config->miso_io_num!=io_signal[host].spiq_native) native=false;
    if (bus_config->sclk_io_num >= 0 && bus_config->sclk_io_num!=io_signal[host].spiclk_native) native=false;
    if (use_quad) {
        if (bus_config->quadwp_io_num >= 0 && bus_config->quadwp_io_num!=io_signal[host].spiwp_native) native=false;
        if (bus_config->quadhd_io_num >= 0 && bus_config->quadhd_io_num!=io_signal[host].spihd_native) native=false;
    }

    *is_native=native;

    if (native) {
        //All SPI native pin selections resolve to 1, so we put that here instead of trying to figure
        //out which FUNC_GPIOx_xSPIxx to grab; they all are defined to 1 anyway.
        if (bus_config->mosi_io_num > 0) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->mosi_io_num], 1);
        if (bus_config->miso_io_num > 0) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->miso_io_num], 1);
        if (use_quad && bus_config->quadwp_io_num > 0) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->quadwp_io_num], 1);
        if (use_quad && bus_config->quadhd_io_num > 0) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->quadhd_io_num], 1);
        if (bus_config->sclk_io_num > 0) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->sclk_io_num], 1);
    } else {
        //Use GPIO 
        if (bus_config->mosi_io_num>0) {
            PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->mosi_io_num], PIN_FUNC_GPIO);
            gpio_set_direction(bus_config->mosi_io_num, is_master?GPIO_MODE_OUTPUT:GPIO_MODE_INPUT);
            gpio_matrix_out(bus_config->mosi_io_num, io_signal[host].spid_out, false, false);
            gpio_matrix_in(bus_config->mosi_io_num, io_signal[host].spid_in, false);
        }
        if (bus_config->miso_io_num>0) {
            PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->miso_io_num], PIN_FUNC_GPIO);
            gpio_set_direction(bus_config->miso_io_num, is_master?GPIO_MODE_INPUT:GPIO_MODE_OUTPUT);
            gpio_matrix_out(bus_config->miso_io_num, io_signal[host].spiq_out, false, false);
            gpio_matrix_in(bus_config->miso_io_num, io_signal[host].spiq_in, false);
        }
        if (use_quad && bus_config->quadwp_io_num>0) {
            PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->quadwp_io_num], PIN_FUNC_GPIO);
            gpio_set_direction(bus_config->quadwp_io_num, is_master?GPIO_MODE_OUTPUT:GPIO_MODE_INPUT);
            gpio_matrix_out(bus_config->quadwp_io_num, io_signal[host].spiwp_out, false, false);
            gpio_matrix_in(bus_config->quadwp_io_num, io_signal[host].spiwp_in, false);
        }
        if (use_quad && bus_config->quadhd_io_num>0) {
            PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->quadhd_io_num], PIN_FUNC_GPIO);
            gpio_set_direction(bus_config->quadhd_io_num, is_master?GPIO_MODE_OUTPUT:GPIO_MODE_INPUT);
            gpio_matrix_out(bus_config->quadhd_io_num, io_signal[host].spihd_out, false, false);
            gpio_matrix_in(bus_config->quadhd_io_num, io_signal[host].spihd_in, false);
        }
        if (bus_config->sclk_io_num>0) {
            PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[bus_config->sclk_io_num], PIN_FUNC_GPIO);
            gpio_set_direction(bus_config->sclk_io_num, is_master?GPIO_MODE_OUTPUT:GPIO_MODE_INPUT);
            gpio_matrix_out(bus_config->sclk_io_num, io_signal[host].spiclk_out, false, false);
            gpio_matrix_in(bus_config->sclk_io_num, io_signal[host].spiclk_in, false);
        }
    }

    //Select DMA channel.
    SET_PERI_REG_BITS(DPORT_SPI_DMA_CHAN_SEL_REG, 3, dma_chan, (host * 2));

    return ESP_OK;
}


//Find any pin with output muxed to ``func`` and reset it to GPIO
static void reset_func_to_gpio(int func) {
    for (int x=0; x<GPIO_PIN_COUNT; x++) {
        if (GPIO_IS_VALID_GPIO(x) && (READ_PERI_REG(GPIO_FUNC0_OUT_SEL_CFG_REG+(x*4))&GPIO_FUNC0_OUT_SEL_M)==func)  {
            gpio_matrix_out(x, SIG_GPIO_OUT_IDX, false, false);
        }
    }
}


esp_err_t spicommon_bus_free_io(spi_host_device_t host)
{
    if (REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spid_native], MCU_SEL)==1) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spid_native], PIN_FUNC_GPIO);
    if (REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spiq_native], MCU_SEL)==1) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spiq_native], PIN_FUNC_GPIO);
    if (REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spiclk_native], MCU_SEL)==1) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spiclk_native], PIN_FUNC_GPIO);
    if (REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spiwp_native], MCU_SEL)==1) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spiwp_native], PIN_FUNC_GPIO);
    if (REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spihd_native], MCU_SEL)==1) PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spihd_native], PIN_FUNC_GPIO);
    reset_func_to_gpio(io_signal[host].spid_out);
    reset_func_to_gpio(io_signal[host].spiq_out);
    reset_func_to_gpio(io_signal[host].spiclk_out);
    reset_func_to_gpio(io_signal[host].spiwp_out);
    reset_func_to_gpio(io_signal[host].spihd_out);
    return ESP_OK;
}

void spicommon_cs_initialize(spi_host_device_t host, int cs_io_num, int cs_num, int force_gpio_matrix) {
    if (!force_gpio_matrix && cs_io_num == io_signal[host].spics0_native && cs_num==0) {
        //The cs0s for all SPI peripherals map to pin mux source 1, so we use that instead of a define.
        PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[cs_io_num], 1);
    } else {
        //Use GPIO matrix
        PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[cs_io_num], PIN_FUNC_GPIO);
        gpio_matrix_out(cs_io_num, io_signal[host].spics_out[cs_num], false, false);
        if (cs_num==0) gpio_matrix_in(cs_io_num, io_signal[host].spics_in, false);
    }
}

void spicommon_cs_free(spi_host_device_t host, int cs_io_num) {
    if (cs_io_num==0 && REG_GET_FIELD(GPIO_PIN_MUX_REG[io_signal[host].spics0_native], MCU_SEL)==1) {
        PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[io_signal[host].spics0_native], PIN_FUNC_GPIO);
    }
    reset_func_to_gpio(io_signal[host].spics_out[cs_io_num]);
}

//Set up a list of dma descriptors. dmadesc is an array of descriptors. Data is the buffer to point to.
void spicommon_setup_dma_desc_links(lldesc_t *dmadesc, int len, const uint8_t *data, bool isrx) {
    int n=0;
    while (len) {
        int dmachunklen=len;
        if (dmachunklen > SPI_MAX_DMA_LEN) dmachunklen=SPI_MAX_DMA_LEN;
        if (isrx) {
            //Receive needs DMA length rounded to next 32-bit boundary
            dmadesc[n].size=(dmachunklen+3)&(~3);
            dmadesc[n].length=(dmachunklen+3)&(~3);
        } else {
            dmadesc[n].size=dmachunklen;
            dmadesc[n].length=dmachunklen;
        }
        dmadesc[n].buf=(uint8_t*)data;
        dmadesc[n].eof=0;
        dmadesc[n].sosf=0;
        dmadesc[n].owner=1;
        dmadesc[n].qe.stqe_next=&dmadesc[n+1];
        len-=dmachunklen;
        data+=dmachunklen;
        n++;
    }
    dmadesc[n-1].eof=1; //Mark last DMA desc as end of stream.
    dmadesc[n-1].qe.stqe_next=NULL;
}


/*
Code for workaround for DMA issue in ESP32 v0/v1 silicon
*/


static volatile int dmaworkaround_channels_busy[2]={0,0};
static dmaworkaround_cb_t dmaworkaround_cb;
static void *dmaworkaround_cb_arg;
static portMUX_TYPE dmaworkaround_mux=portMUX_INITIALIZER_UNLOCKED;
static int dmaworkaround_waiting_for_chan=0;

bool IRAM_ATTR spicommon_dmaworkaround_req_reset(int dmachan, dmaworkaround_cb_t cb, void *arg) 
{
    int otherchan=(dmachan==1)?2:1;
    bool ret;
    portENTER_CRITICAL(&dmaworkaround_mux);
    if (dmaworkaround_channels_busy[otherchan]) {
        //Other channel is busy. Call back when it's done.
        dmaworkaround_cb=cb;
        dmaworkaround_cb_arg=arg;
        dmaworkaround_waiting_for_chan=otherchan;
        ret=false;
    } else {
        //Reset DMA
        SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_SPI_DMA_RST);
        CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_SPI_DMA_RST);
        ret=true;
    }
    portEXIT_CRITICAL(&dmaworkaround_mux);
    return ret;
}

bool IRAM_ATTR spicommon_dmaworkaround_reset_in_progress()
{
    return (dmaworkaround_waiting_for_chan!=0);
}

void IRAM_ATTR spicommon_dmaworkaround_idle(int dmachan) {
    portENTER_CRITICAL(&dmaworkaround_mux);
    dmaworkaround_channels_busy[dmachan]=0;
    if (dmaworkaround_waiting_for_chan == dmachan) {
        //Reset DMA
        SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_SPI_DMA_RST);
        CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_SPI_DMA_RST);
        dmaworkaround_waiting_for_chan=0;
        //Call callback
        dmaworkaround_cb(dmaworkaround_cb_arg);

    }
    portEXIT_CRITICAL(&dmaworkaround_mux);
}

void IRAM_ATTR spicommon_dmaworkaround_transfer_active(int dmachan) {
    portENTER_CRITICAL(&dmaworkaround_mux);
    dmaworkaround_channels_busy[dmachan]=1;
    portEXIT_CRITICAL(&dmaworkaround_mux);
}