i2c_master.c

/*
Copyright 2019 Massdrop Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "arm_atsam_protocol.h"

#ifndef MD_BOOTLOADER

#include <string.h>

//From keyboard
#include "config.h"
#include "config_led.h"
#include "matrix.h"

#define I2C_LED_USE_DMA 1               //Set 1 to use background DMA transfers for leds, Set 0 to use inline software transfers

static uint8_t i2c_led_q[I2C_Q_SIZE];   //I2C queue circular buffer
static uint8_t i2c_led_q_s;             //Start of circular buffer
static uint8_t i2c_led_q_e;             //End of circular buffer
static uint8_t i2c_led_q_full;          //Queue full counter for reset

static uint8_t dma_sendbuf[I2C_DMA_MAX_SEND]; //Data being written to I2C

volatile uint8_t i2c_led_q_running;

#endif //MD_BOOTLOADER

void i2c0_init(void)
{
    DBGC(DC_I2C0_INIT_BEGIN);

    CLK_set_i2c0_freq(CHAN_SERCOM_I2C0, FREQ_I2C0_DEFAULT);

    //MCU
    PORT->Group[0].PMUX[4].bit.PMUXE = 2;
    PORT->Group[0].PMUX[4].bit.PMUXO = 2;
    PORT->Group[0].PINCFG[8].bit.PMUXEN = 1;
    PORT->Group[0].PINCFG[9].bit.PMUXEN = 1;

    //I2C
    //Note: SW Reset handled in CLK_set_i2c0_freq clks.c

    SERCOM0->I2CM.CTRLA.bit.MODE = 5;                           //Set master mode

    SERCOM0->I2CM.CTRLA.bit.SPEED = 0;                          //Set to 1 for Fast-mode Plus (FM+) up to 1 MHz
    SERCOM0->I2CM.CTRLA.bit.RUNSTDBY = 1;                       //Enabled

    SERCOM0->I2CM.CTRLA.bit.ENABLE = 1;                         //Enable the device
    while (SERCOM0->I2CM.SYNCBUSY.bit.ENABLE) { DBGC(DC_I2C0_INIT_SYNC_ENABLING); }                //Wait for SYNCBUSY.ENABLE to clear

    SERCOM0->I2CM.STATUS.bit.BUSSTATE = 1;                      //Force into IDLE state
    while (SERCOM0->I2CM.SYNCBUSY.bit.SYSOP) { DBGC(DC_I2C0_INIT_SYNC_SYSOP); }
    while (SERCOM0->I2CM.STATUS.bit.BUSSTATE != 1) { DBGC(DC_I2C0_INIT_WAIT_IDLE); }           //Wait while not idle

    DBGC(DC_I2C0_INIT_COMPLETE);
}

uint8_t i2c0_start(uint8_t address)
{
    SERCOM0->I2CM.ADDR.bit.ADDR = address;
    while (SERCOM0->I2CM.SYNCBUSY.bit.SYSOP) {}
    while (SERCOM0->I2CM.INTFLAG.bit.MB == 0) {}
    while (SERCOM0->I2CM.STATUS.bit.RXNACK) {}

    return 1;
}

uint8_t i2c0_transmit(uint8_t address, uint8_t *data, uint16_t length, uint16_t timeout)
{
    if (!length) return 0;

    i2c0_start(address);

    while (length)
    {
        SERCOM0->I2CM.DATA.bit.DATA = *data;
        while (SERCOM0->I2CM.INTFLAG.bit.MB == 0) {}
        while (SERCOM0->I2CM.STATUS.bit.RXNACK) {}

        data++;
        length--;
    }

    i2c0_stop();

    return 1;
}

void i2c0_stop(void)
{
    if (SERCOM0->I2CM.STATUS.bit.CLKHOLD || SERCOM0->I2CM.INTFLAG.bit.MB == 1 || SERCOM0->I2CM.STATUS.bit.BUSSTATE != 1)
    {
        SERCOM0->I2CM.CTRLB.bit.CMD = 3;
        while (SERCOM0->I2CM.SYNCBUSY.bit.SYSOP);
        while (SERCOM0->I2CM.STATUS.bit.CLKHOLD);
        while (SERCOM0->I2CM.INTFLAG.bit.MB);
        while (SERCOM0->I2CM.STATUS.bit.BUSSTATE != 1);
    }
}

#ifndef MD_BOOTLOADER
void i2c1_init(void)
{
    DBGC(DC_I2C1_INIT_BEGIN);

    CLK_set_i2c1_freq(CHAN_SERCOM_I2C1, FREQ_I2C1_DEFAULT);

    /* MCU */
    PORT->Group[0].PMUX[8].bit.PMUXE = 2;       //PA16 even
    PORT->Group[0].PMUX[8].bit.PMUXO = 2;       //PA17 odd
    PORT->Group[0].PINCFG[16].bit.PMUXEN = 1;   //PA16
    PORT->Group[0].PINCFG[17].bit.PMUXEN = 1;   //PA17

    /* I2C */
    //Note: SW Reset handled in CLK_set_i2c1_freq clks.c

    SERCOM1->I2CM.CTRLA.bit.MODE = 5;                   //MODE: Set master mode (No sync)
    SERCOM1->I2CM.CTRLA.bit.SPEED = 1;                  //SPEED: Fm+ up to 1MHz (No sync)
    SERCOM1->I2CM.CTRLA.bit.RUNSTDBY = 1;               //RUNSTBY: Enabled (No sync)

    SERCOM1->I2CM.CTRLB.bit.SMEN = 1;                   //SMEN: Smart mode enabled (For DMA)(No sync)

    NVIC_EnableIRQ(SERCOM1_0_IRQn);
    SERCOM1->I2CM.INTENSET.bit.ERROR = 1;

    SERCOM1->I2CM.CTRLA.bit.ENABLE = 1;                 //ENABLE: Enable the device (sync SYNCBUSY.ENABLE)
    while (SERCOM1->I2CM.SYNCBUSY.bit.ENABLE) { DBGC(DC_I2C1_INIT_SYNC_ENABLING); }        //Wait for SYNCBUSY.ENABLE to clear

    SERCOM1->I2CM.STATUS.bit.BUSSTATE = 1;              //BUSSTATE: Force into IDLE state (sync SYNCBUSY.SYSOP)
    while (SERCOM1->I2CM.SYNCBUSY.bit.SYSOP) { DBGC(DC_I2C1_INIT_SYNC_SYSOP); }
    while (SERCOM1->I2CM.STATUS.bit.BUSSTATE != 1) { DBGC(DC_I2C1_INIT_WAIT_IDLE); }  //Wait while not idle

    DBGC(DC_I2C1_INIT_COMPLETE);
}

uint8_t i2c1_start(uint8_t address)
{
    SERCOM1->I2CM.ADDR.bit.ADDR = address;
    while (SERCOM1->I2CM.SYNCBUSY.bit.SYSOP) {}
    while (SERCOM1->I2CM.INTFLAG.bit.MB == 0) {}
    while (SERCOM1->I2CM.STATUS.bit.RXNACK) {}

    return 1;
}

uint8_t i2c1_transmit(uint8_t address, uint8_t *data, uint16_t length, uint16_t timeout)
{
    if (!length) return 0;

    i2c1_start(address);

    while (length)
    {
        SERCOM1->I2CM.DATA.bit.DATA = *data;
        while (SERCOM1->I2CM.INTFLAG.bit.MB == 0) {}
        while (SERCOM1->I2CM.STATUS.bit.RXNACK) {}

        data++;
        length--;
    }

    i2c1_stop();

    return 1;
}

void i2c1_stop(void)
{
    if (SERCOM1->I2CM.STATUS.bit.CLKHOLD || SERCOM1->I2CM.INTFLAG.bit.MB == 1 || SERCOM1->I2CM.STATUS.bit.BUSSTATE != 1)
    {
        SERCOM1->I2CM.CTRLB.bit.CMD = 3;
        while (SERCOM1->I2CM.SYNCBUSY.bit.SYSOP);
        while (SERCOM1->I2CM.STATUS.bit.CLKHOLD);
        while (SERCOM1->I2CM.INTFLAG.bit.MB);
        while (SERCOM1->I2CM.STATUS.bit.BUSSTATE != 1);
    }
}

void i2c_led_send_CRWL(uint8_t drvid)
{
    uint8_t i2cdata[] = { ISSI3733_CMDRWL, ISSI3733_CMDRWL_WRITE_ENABLE_ONCE };
    i2c1_transmit(issidrv[drvid].addr, i2cdata, sizeof(i2cdata), 0);
}

void i2c_led_select_page(uint8_t drvid, uint8_t pageno)
{
    uint8_t i2cdata[] = { ISSI3733_CMDR, pageno };
    i2c1_transmit(issidrv[drvid].addr, i2cdata, sizeof(i2cdata), 0);
}

void i2c_led_send_GCR(uint8_t drvid)
{
    uint8_t i2cdata[] = { ISSI3733_GCCR, 0x00 };

    if (gcr_actual > LED_GCR_MAX) gcr_actual = LED_GCR_MAX;
    i2cdata[1] = gcr_actual;
    i2c1_transmit(issidrv[drvid].addr, i2cdata, sizeof(i2cdata), 0);
}

void i2c_led_send_onoff(uint8_t drvid)
{
    if (!i2c_led_q_running)
    {
        i2c_led_send_CRWL(drvid);
        i2c_led_select_page(drvid, 0);
    }

    *issidrv[drvid].onoff = 0; //Force start location offset to zero
    i2c1_transmit(issidrv[drvid].addr, issidrv[drvid].onoff, ISSI3733_PG0_BYTES, 0);
}

void i2c_led_send_mode_op_gcr(uint8_t drvid, uint8_t mode, uint8_t operation)
{
    uint8_t i2cdata[] = { ISSI3733_CR, mode | operation, gcr_actual};
    i2c1_transmit(issidrv[drvid].addr, i2cdata, sizeof(i2cdata), 0);
}

void i2c_led_send_pur_pdr(uint8_t drvid, uint8_t pur, uint8_t pdr)
{
    uint8_t i2cdata[] = { ISSI3733_SWYR_PUR, pur, pdr };

    i2c1_transmit(issidrv[drvid].addr, i2cdata, sizeof(i2cdata), 0);
}

void i2c_led_send_pwm(uint8_t drvid)
{
    if (!i2c_led_q_running)
    {
        i2c_led_send_CRWL(drvid);
        i2c_led_select_page(drvid, 1);
    }

    *issidrv[drvid].pwm_rdy = 0; //Force start location offset to zero
    i2c1_transmit(issidrv[drvid].addr, issidrv[drvid].pwm, ISSI3733_PG1_BYTES, 0);
}

uint8_t I2C3733_Init_Control(void)
{
    DBGC(DC_I2C3733_INIT_CONTROL_BEGIN);

    //Hardware state shutdown on boot
    //USB state machine will enable driver when communication is ready
    I2C3733_Control_Set(0);

    wait_ms(1);

    sr_exp_data.bit.IRST = 0;
    SR_EXP_WriteData();

    wait_ms(1);

    DBGC(DC_I2C3733_INIT_CONTROL_COMPLETE);

    return 1;
}

uint8_t I2C3733_Init_Drivers(void)
{
    DBGC(DC_I2C3733_INIT_DRIVERS_BEGIN);

    gcr_actual = ISSI3733_GCR_DEFAULT;
    gcr_actual_last = gcr_actual;

    if (gcr_actual > LED_GCR_MAX) gcr_actual = LED_GCR_MAX;
    gcr_desired = gcr_actual;

    //Set up master device
    i2c_led_send_CRWL(0);
    i2c_led_select_page(0, 3);
    i2c_led_send_mode_op_gcr(0, 0, ISSI3733_CR_SSD_NORMAL); //No SYNC due to brightness mismatch with second driver

    i2c_led_send_CRWL(0);
    i2c_led_select_page(0, 3);
    i2c_led_send_pur_pdr(0, ISSI3733_SWYR_PUR_8000, ISSI3733_CSXR_PDR_8000);

    //Set up slave devices
    for (uint8_t drvid = 1; drvid < ISSI3733_DRIVER_COUNT; drvid++)
    {
        i2c_led_send_CRWL(drvid);
        i2c_led_select_page(drvid, 3);
        i2c_led_send_mode_op_gcr(drvid, 0, ISSI3733_CR_SSD_NORMAL); //No SYNC due to brightness mismatch with master driver and slight flicker at rgb values 1,2

        i2c_led_send_CRWL(drvid);
        i2c_led_select_page(drvid, 3);
        i2c_led_send_pur_pdr(drvid, ISSI3733_SWYR_PUR_8000, ISSI3733_CSXR_PDR_8000);
    }

    DBGC(DC_I2C3733_INIT_DRIVERS_COMPLETE);

    return 1;
}

void I2C_DMAC_LED_Init(void)
{
    Dmac *dmac = DMAC;

    DBGC(DC_I2C_DMAC_LED_INIT_BEGIN);

    //Disable device
    dmac->CTRL.bit.DMAENABLE = 0;                   //Disable DMAC
    while (dmac->CTRL.bit.DMAENABLE) {}             //Wait for disabled state in case of ongoing transfers
    dmac->CTRL.bit.SWRST = 1;                       //Software Reset DMAC
    while (dmac->CTRL.bit.SWRST) {}                 //Wait for software reset to complete

    //Configure device
    dmac->BASEADDR.reg = (uint32_t)&dmac_desc;      //Set descriptor base address
    dmac->WRBADDR.reg = (uint32_t)&dmac_desc_wb;    //Set descriptor write back address
    dmac->CTRL.reg |= 0x0f00;                       //Handle all priorities (LVL0-3)

    //Disable channel
    dmac->Channel[0].CHCTRLA.bit.ENABLE = 0;        //Disable the channel
    while (dmac->Channel[0].CHCTRLA.bit.ENABLE) {}  //Wait for disabled state in case of ongoing transfers
    dmac->Channel[0].CHCTRLA.bit.SWRST = 1;         //Software Reset the channel
    while (dmac->Channel[0].CHCTRLA.bit.SWRST) {}   //Wait for software reset to complete

    //Configure channel
    dmac->Channel[0].CHCTRLA.bit.THRESHOLD = 0;     //1BEAT
    dmac->Channel[0].CHCTRLA.bit.BURSTLEN = 0;      //SINGLE
    dmac->Channel[0].CHCTRLA.bit.TRIGACT = 2;       //BURST
    dmac->Channel[0].CHCTRLA.bit.TRIGSRC = SERCOM1_DMAC_ID_TX;  //Trigger source
    dmac->Channel[0].CHCTRLA.bit.RUNSTDBY = 1;      //Run in standby

    NVIC_EnableIRQ(DMAC_0_IRQn);
    dmac->Channel[0].CHINTENSET.bit.TCMPL = 1;
    dmac->Channel[0].CHINTENSET.bit.TERR = 1;

    //Enable device
    dmac->CTRL.bit.DMAENABLE = 1;                   //Enable DMAC
    while (dmac->CTRL.bit.DMAENABLE == 0) {}        //Wait for enable state

    DBGC(DC_I2C_DMAC_LED_INIT_COMPLETE);
}

//state = 1 enable
//state = 0 disable
void I2C3733_Control_Set(uint8_t state)
{
    DBGC(DC_I2C3733_CONTROL_SET_BEGIN);

    if (sr_exp_data.bit.SDB_N == 0 && state == 1)
    {
        gcr_actual = 0; //Set low GCR when turning on to prevent instant overload conditions
    }

    sr_exp_data.bit.SDB_N = (state == 1 ? 1 : 0);
    SR_EXP_WriteData();

    DBGC(DC_I2C3733_CONTROL_SET_COMPLETE);
}

//Return 1 if enabled
//Return 0 if disabled
uint8_t I2C3733_Control_Get(void)
{
    return (sr_exp_data.bit.SDB_N == 1);
}

void i2c_led_desc_defaults(void)
{
    dmac_desc.BTCTRL.bit.STEPSIZE = 0;      //SRCINC used in favor for auto 1 inc
    dmac_desc.BTCTRL.bit.STEPSEL = 0;       //SRCINC used in favor for auto 1 inc
    dmac_desc.BTCTRL.bit.DSTINC = 0;        //The Destination Address Increment is disabled
    dmac_desc.BTCTRL.bit.SRCINC = 1;        //The Source Address Increment is enabled (Inc by 1)
    dmac_desc.BTCTRL.bit.BEATSIZE = 0;      //8-bit bus transfer
    dmac_desc.BTCTRL.bit.BLOCKACT = 0;      //Channel will be disabled if it is the last block transfer in the transaction
    dmac_desc.BTCTRL.bit.EVOSEL = 0;        //Event generation disabled
    dmac_desc.BTCTRL.bit.VALID = 1;         //Set dmac valid
}

void i2c_led_prepare_send_dma(uint8_t *data, uint8_t len)
{
    i2c_led_desc_defaults();

    dmac_desc.BTCNT.reg = len;
    dmac_desc.SRCADDR.reg = (uint32_t)data + len;
    dmac_desc.DSTADDR.reg = (uint32_t)&SERCOM1->I2CM.DATA.reg;
    dmac_desc.DESCADDR.reg = 0;
}

void i2c_led_begin_dma(uint8_t drvid)
{
    DMAC->Channel[0].CHCTRLA.bit.ENABLE = 1; //Enable the channel

    SERCOM1->I2CM.ADDR.reg = (dmac_desc.BTCNT.reg << 16) | 0x2000 | issidrv[drvid].addr; //Begin transfer
}

void i2c_led_send_CRWL_dma(uint8_t drvid)
{
    *(dma_sendbuf+0) = ISSI3733_CMDRWL;
    *(dma_sendbuf+1) = ISSI3733_CMDRWL_WRITE_ENABLE_ONCE;
    i2c_led_prepare_send_dma(dma_sendbuf, 2);

    i2c_led_begin_dma(drvid);
}

void i2c_led_select_page_dma(uint8_t drvid, uint8_t pageno)
{
    *(dma_sendbuf+0) = ISSI3733_CMDR;
    *(dma_sendbuf+1) = pageno;
    i2c_led_prepare_send_dma(dma_sendbuf, 2);

    i2c_led_begin_dma(drvid);
}

void i2c_led_send_GCR_dma(uint8_t drvid)
{
    *(dma_sendbuf+0) = ISSI3733_GCCR;
    *(dma_sendbuf+1) = gcr_actual;
    i2c_led_prepare_send_dma(dma_sendbuf, 2);

    i2c_led_begin_dma(drvid);
}

void i2c_led_send_pwm_dma(uint8_t drvid)
{
    memcpy(dma_sendbuf, issidrv[drvid].pwm_rdy, ISSI3733_PG1_BYTES);
    *dma_sendbuf = 0; //Force start location offset to zero
    i2c_led_prepare_send_dma(dma_sendbuf, ISSI3733_PG1_BYTES);

    i2c_led_begin_dma(drvid);
}

void i2c_led_send_onoff_dma(uint8_t drvid)
{
    //Note: This copies the CURRENT onoff buffer, which may be getting modified
    memcpy(dma_sendbuf, issidrv[drvid].onoff, ISSI3733_PG0_BYTES);
    *dma_sendbuf = 0; //Force start location offset to zero
    i2c_led_prepare_send_dma(dma_sendbuf, ISSI3733_PG0_BYTES);

    i2c_led_begin_dma(drvid);
}

void i2c_led_q_init(void)
{
    memset(i2c_led_q, 0, I2C_Q_SIZE);
    i2c_led_q_s = 0;
    i2c_led_q_e = 0;
    i2c_led_q_running = 0;
    i2c_led_q_full = 0;
}

uint8_t i2c_led_q_isempty(void)
{
    return i2c_led_q_s == i2c_led_q_e;
}

uint8_t i2c_led_q_size(void)
{
    return (i2c_led_q_e - i2c_led_q_s) % I2C_Q_SIZE;
}

uint8_t i2c_led_q_available(void)
{
    return I2C_Q_SIZE - i2c_led_q_size() - 1; //Never allow end to meet start
}

void i2c_led_q_add(uint8_t cmd)
{
    //WARNING: Always request room before adding commands!

    //Assign command
    i2c_led_q[i2c_led_q_e] = cmd;

    i2c_led_q_e = (i2c_led_q_e + 1) % I2C_Q_SIZE; //Move end up one or wrap
}

void i2c_led_q_s_advance(void)
{
    i2c_led_q_s = (i2c_led_q_s + 1) % I2C_Q_SIZE; //Move start up one or wrap
}

//Always request room before adding commands
//PS: In case the queue somehow gets filled, it will reset if it can not clear up
//PS: Could only get this to happen through unrealistic timings to overload the I2C bus
uint8_t i2c_led_q_request_room(uint8_t request_size)
{
    if (request_size > i2c_led_q_available())
    {
        i2c_led_q_full++;

        if (i2c_led_q_full >= 100) //Give the queue a chance to clear up
        {
            DBG_LED_ON;
            I2C_DMAC_LED_Init();
            i2c_led_q_init();
            return 1;
        }

        return 0;
    }

    i2c_led_q_full = 0;

    return 1;
}

uint8_t i2c_led_q_run(void)
{
    if (i2c_led_q_isempty())
    {
        i2c_led_q_running = 0;
        return 0;
    }

    if (i2c_led_q_running) return 1;

    i2c_led_q_running = 1;

#if I2C_LED_USE_DMA != 1
    while (!i2c_led_q_isempty())
    {
#endif
        //run command
        if (i2c_led_q[i2c_led_q_s] == I2C_Q_CRWL)
        {
            i2c_led_q_s_advance();
            uint8_t drvid = i2c_led_q[i2c_led_q_s];
#if I2C_LED_USE_DMA == 1
            i2c_led_send_CRWL_dma(drvid);
#else
            i2c_led_send_CRWL(drvid);
#endif
        }
        else if (i2c_led_q[i2c_led_q_s] == I2C_Q_PAGE_SELECT)
        {
            i2c_led_q_s_advance();
            uint8_t drvid = i2c_led_q[i2c_led_q_s];
            i2c_led_q_s_advance();
            uint8_t page = i2c_led_q[i2c_led_q_s];
#if I2C_LED_USE_DMA == 1
            i2c_led_select_page_dma(drvid, page);
#else
            i2c_led_select_page(drvid, page);
#endif
        }
        else if (i2c_led_q[i2c_led_q_s] == I2C_Q_PWM)
        {
            i2c_led_q_s_advance();
            uint8_t drvid = i2c_led_q[i2c_led_q_s];
#if I2C_LED_USE_DMA == 1
            i2c_led_send_pwm_dma(drvid);
#else
            i2c_led_send_pwm(drvid);
#endif
        }
        else if (i2c_led_q[i2c_led_q_s] == I2C_Q_GCR)
        {
            i2c_led_q_s_advance();
            uint8_t drvid = i2c_led_q[i2c_led_q_s];
#if I2C_LED_USE_DMA == 1
            i2c_led_send_GCR_dma(drvid);
#else
            i2c_led_send_GCR(drvid);
#endif
        }
        else if (i2c_led_q[i2c_led_q_s] == I2C_Q_ONOFF)
        {
            i2c_led_q_s_advance();
            uint8_t drvid = i2c_led_q[i2c_led_q_s];
#if I2C_LED_USE_DMA == 1
            i2c_led_send_onoff_dma(drvid);
#else
            i2c_led_send_onoff(drvid);
#endif
        }

        i2c_led_q_s_advance(); //Advance last run command or if the command byte was not serviced

#if I2C_LED_USE_DMA != 1
    }

    i2c_led_q_running = 0;
#endif

    return 1;
}
#endif //MD_BOOTLOADER