rt-thread/bsp/efm32/drv_iic.c

/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date         Author      Notes
 * 2011-01-06   onelife     Initial creation for EFM32
 * 2011-06-17   onelife     Modify init function for EFM32 library v2.0.0 upgrading
 * 2011-07-11   onelife     Add lock (semaphore) to prevent simultaneously access
 * 2011-08-04   onelife     Change the usage of the second parameter of Read
 *                            and Write functions from (seldom used) "Offset" to "Slave address"
 * 2011-08-04   onelife     Add a timer to prevent from forever waiting
 * 2011-11-29   onelife     Modify init function for EFM32 library v2.2.2 upgrading
 * 2011-12-27   onelife     Utilize "I2C_PRESENT" and "I2C_COUNT"
 * 2011-12-27   onelife     Change IIC read format
 */

/***************************************************************************//**
 * @addtogroup efm32
 * @{
 ******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "board.h"
#include "hdl_interrupt.h"
#include "drv_iic.h"

#if (defined(RT_USING_IIC0) || defined(RT_USING_IIC1))
 #if !defined(I2C_PRESENT)
 #error "IIC module is not available"
 #endif
/* Private typedef -----------------------------------------------------------*/
struct efm32_iic_block
{
    struct rt_device            device;
    struct rt_semaphore         lock;
    struct rt_timer             timer;
};

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
#ifdef RT_IIC_DEBUG
#define iic_debug(format,args...)           rt_kprintf(format, ##args)
#else
#define iic_debug(format,args...)
#endif

/* Private variables ---------------------------------------------------------*/
#ifdef RT_USING_IIC0
 #if (RT_USING_IIC0 > EFM32_IIC_LOCATION_COUNT)
 #error "Wrong location number"
 #endif
static struct efm32_iic_block   iic0;
#endif

#ifdef RT_USING_IIC1
 #if (I2C_COUNT <= 1)
 #error "Wrong unit number"
 #endif
 #if (RT_USING_IIC1 > EFM32_IIC_LOCATION_COUNT)
 #error "Wrong location number"
 #endif
static struct efm32_iic_block   iic1;
#endif

/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/***************************************************************************//**
 * @brief
 *   Initialize IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_err_t rt_iic_init (rt_device_t dev)
{
    struct efm32_iic_device_t* iic;

    iic = (struct efm32_iic_device_t*)dev->user_data;

    if (!(dev->flag & RT_DEVICE_FLAG_ACTIVATED))
    {
        /* Enable IIC */
        I2C_Enable(iic->iic_device, true);
        iic->rx_buffer = RT_NULL;
        iic->state = 0;

        dev->flag |= RT_DEVICE_FLAG_ACTIVATED;
    }

    return RT_EOK;
}

/***************************************************************************//**
 * @brief
 *   Open IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @param[in] oflag
 *   Device open flag
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_err_t rt_iic_open(rt_device_t dev, rt_uint16_t oflag)
{
    RT_ASSERT(dev != RT_NULL);

    struct efm32_iic_device_t   *iic;

    iic = (struct efm32_iic_device_t *)(dev->user_data);
    iic->counter++;

    iic_debug("IIC: Open with flag %x\n", oflag);
    return RT_EOK;
}

/***************************************************************************//**
 * @brief
 *   Close IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_err_t rt_iic_close(rt_device_t dev)
{
    RT_ASSERT(dev != RT_NULL);

    struct efm32_iic_device_t   *iic;

    iic = (struct efm32_iic_device_t *)(dev->user_data);
    if (--iic->counter == 0)
    {
        rt_free(iic->rx_buffer->data_ptr);
        rt_free(iic->rx_buffer);
        iic->rx_buffer = RT_NULL;
    }
    return RT_EOK;
}

/***************************************************************************//**
 * @brief
 *   Read from IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @param[in] pos
 *   Slave address
 *
 * @param[in] buffer
 *   Poniter to the buffer
 *
 * @param[in] size
 *   Buffer size in byte
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_ssize_t rt_iic_read (
    rt_device_t     dev,
    rt_off_t        pos,
    void*           buffer,
    rt_size_t       size)
{
    rt_err_t                    err_code;
    rt_size_t                   read_size;
    struct efm32_iic_device_t*  iic;
    I2C_TransferSeq_TypeDef     seq;
    I2C_TransferReturn_TypeDef  ret;

    if (!size)
    {
        return 0;
    }

    err_code = RT_EOK;
    read_size = 0;
    iic = (struct efm32_iic_device_t*)dev->user_data;

    /* Lock device */
    if (rt_hw_interrupt_check())
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_NO);
    }
    else
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_FOREVER);
    }
    if (ret != RT_EOK)
    {
        return ret;
    }

    if (iic->state & IIC_STATE_MASTER)
    {
        seq.addr = (rt_uint16_t)pos << 1;
        if (*(rt_uint8_t *)buffer == IIC_OP_READ_ONLY)
        {
            seq.flags = I2C_FLAG_READ;
            /* Set read buffer pointer and size */
            seq.buf[0].data = (rt_uint8_t *)buffer;
            seq.buf[0].len = size;
        }
        else
        {
            seq.flags = I2C_FLAG_WRITE_READ;
            /* Set register to be read */
            seq.buf[0].data = (rt_uint8_t *)buffer;
            seq.buf[0].len = 1;
            /* Set read buffer pointer and size */
            seq.buf[1].data = (rt_uint8_t *)buffer;
            seq.buf[1].len = size;
        }

        /* Do a polled transfer */
        iic->timeout = false;
        rt_timer_stop(iic->timer);
        rt_timer_start(iic->timer);
        ret = I2C_TransferInit(iic->iic_device, &seq);
        while ((ret == i2cTransferInProgress) && !iic->timeout)
        {
          ret = I2C_Transfer(iic->iic_device);
        }

        if (ret != i2cTransferDone)
        {
            iic_debug("IIC: read error %x\n", ret);
            iic_debug("IIC: read address %x\n", seq.addr);
            iic_debug("IIC: read data0 %x -> %x\n", seq.buf[0].data, *seq.buf[0].data);
            iic_debug("IIC: read len0 %x\n", seq.buf[0].len);
            iic_debug("IIC: read data1 %x -> %x\n", seq.buf[1].data, *seq.buf[1].data);
            iic_debug("IIC: read len1 %x\n", seq.buf[1].len);
            err_code = (rt_err_t)ret;
        }
        else
        {
            read_size = size;
            iic_debug("IIC: read size %d\n", read_size);
        }
    }
    else
    {
        rt_uint8_t* ptr;

        ptr = buffer;

        /* interrupt mode Rx */
        while (size)
        {
            rt_base_t level;
            struct efm32_iic_int_mode_t *int_rx;

            int_rx = iic->rx_buffer;

            /* disable interrupt */
            level = rt_hw_interrupt_disable();

            if (int_rx->read_index != int_rx->save_index)
            {
                /* read a character */
                *ptr++ = int_rx->data_ptr[int_rx->read_index];
                size--;

                /* move to next position */
                int_rx->read_index ++;
                if (int_rx->read_index >= IIC_RX_BUFFER_SIZE)
                {
                    int_rx->read_index = 0;
                }
            }
            else
            {
                /* set error code */
                err_code = -RT_EEMPTY;

                /* enable interrupt */
                rt_hw_interrupt_enable(level);
                break;
            }

            /* enable interrupt */
            rt_hw_interrupt_enable(level);
        }

        read_size = (rt_uint32_t)ptr - (rt_uint32_t)buffer;
        iic_debug("IIC: slave read size %d\n", read_size);
    }

    /* Unlock device */
    rt_sem_release(iic->lock);

    /* set error code */
    rt_set_errno(err_code);
    return read_size;
}

/***************************************************************************//**
 * @brief
 *   Write to IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @param[in] pos
 *   Slave address
 *
 * @param[in] buffer
 *   Poniter to the buffer
 *
 * @param[in] size
 *   Buffer size in byte
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_ssize_t rt_iic_write (
    rt_device_t     dev,
    rt_off_t        pos,
    const void*     buffer,
    rt_size_t       size)
{
    rt_err_t                    err_code;
    rt_size_t                   write_size;
    struct efm32_iic_device_t*  iic;
    I2C_TransferSeq_TypeDef     seq;
    I2C_TransferReturn_TypeDef  ret;

    if (!size)
    {
        return 0;
    }

    err_code = RT_EOK;
    write_size = 0;
    iic = (struct efm32_iic_device_t*)dev->user_data;

    /* Lock device */
    if (rt_hw_interrupt_check())
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_NO);
    }
    else
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_FOREVER);
    }
    if (ret != RT_EOK)
    {
        return ret;
    }

    if (iic->state & IIC_STATE_MASTER)
    {
        seq.addr = (rt_uint16_t)pos << 1;
        seq.flags = I2C_FLAG_WRITE;
        /* Set write buffer pointer and size */
        seq.buf[0].data = (rt_uint8_t *)buffer;
        seq.buf[0].len = size;
    }
    else
    {
        // TODO: Slave mode TX
    }

    /* Do a polled transfer */
    iic->timeout = false;
    rt_timer_stop(iic->timer);
    rt_timer_start(iic->timer);
    ret = I2C_TransferInit(iic->iic_device, &seq);
    while ((ret == i2cTransferInProgress) && !iic->timeout)
    {
        ret = I2C_Transfer(iic->iic_device);
    }

    if (ret != i2cTransferDone)
    {
        err_code = (rt_err_t)ret;
    }
    else
    {
        write_size = size;
    }

    /* Unlock device */
    rt_sem_release(iic->lock);

    /* set error code */
    rt_set_errno(err_code);
    return write_size;
}

 /***************************************************************************//**
 * @brief
 *   Configure IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *   Pointer to device descriptor
 *
 * @param[in] cmd
 *   IIC control command
 *
 * @param[in] args
 *   Arguments
 *
 * @return
 *   Error code
 ******************************************************************************/
static rt_err_t rt_iic_control (
    rt_device_t     dev,
    rt_uint8_t      cmd,
    void            *args)
{
     RT_ASSERT(dev != RT_NULL);

    rt_err_t ret;
    struct efm32_iic_device_t *iic;

    iic = (struct efm32_iic_device_t*)dev->user_data;

    /* Lock device */
    if (rt_hw_interrupt_check())
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_NO);
    }
    else
    {
        ret = rt_sem_take(iic->lock, RT_WAITING_FOREVER);
    }
    if (ret != RT_EOK)
    {
        return ret;
    }

    switch (cmd)
    {
    case RT_DEVICE_CTRL_SUSPEND:
        /* suspend device */
        dev->flag |= RT_DEVICE_FLAG_SUSPENDED;
        I2C_Enable(iic->iic_device, false);
        break;

    case RT_DEVICE_CTRL_RESUME:
        /* resume device */
        dev->flag &= ~RT_DEVICE_FLAG_SUSPENDED;
        I2C_Enable(iic->iic_device, true);
        break;

    case RT_DEVICE_CTRL_IIC_SETTING:
        {
            /* change device setting */
            struct efm32_iic_control_t *control;

            control = (struct efm32_iic_control_t *)args;
            iic->state = control->config & (IIC_STATE_MASTER | IIC_STATE_BROADCAST);
            iic->address = control->address << 1;

            if (!(iic->state & IIC_STATE_MASTER))
            {
                if (iic->rx_buffer == RT_NULL)
                {
                    iic->rx_buffer = rt_malloc(sizeof(struct efm32_iic_int_mode_t));
                    if (iic->rx_buffer == RT_NULL)
                    {
                        iic_debug("IIC err: no MEM for IIC RX structure\n");
                        return -RT_ENOMEM;
                    }

                    /* Allocate RX buffer */
                    if ((iic->rx_buffer->data_ptr = \
                        rt_malloc(IIC_RX_BUFFER_SIZE)) == RT_NULL)
                    {
                        iic_debug("IIC err: no MEM for IIC RX buffer\n");
                        rt_free(iic->rx_buffer);
                        return -RT_ENOMEM;
                    }
                    rt_memset(iic->rx_buffer->data_ptr, 0, IIC_RX_BUFFER_SIZE);
                    iic->rx_buffer->data_size = IIC_RX_BUFFER_SIZE;
                    iic->rx_buffer->read_index = 0;
                    iic->rx_buffer->save_index = 0;
                }

                /* Enable slave mode */
                I2C_SlaveAddressSet(iic->iic_device, iic->address);
                I2C_SlaveAddressMaskSet(iic->iic_device, 0xFF);
                iic->iic_device->CTRL |= I2C_CTRL_SLAVE | I2C_CTRL_AUTOACK | I2C_CTRL_AUTOSN;

                /* Enable interrupts */
                I2C_IntEnable(iic->iic_device, I2C_IEN_ADDR | I2C_IEN_RXDATAV | I2C_IEN_SSTOP);
                I2C_IntClear(iic->iic_device, _I2C_IFC_MASK);

                /* Enable I2Cn interrupt vector in NVIC */
                if (dev == &iic0.device)
                {
                    NVIC_ClearPendingIRQ(I2C0_IRQn);
                    NVIC_SetPriority(I2C0_IRQn, EFM32_IRQ_PRI_DEFAULT);
                    NVIC_EnableIRQ(I2C0_IRQn);
                }
#if (I2C_COUNT > 1)
                if (dev == &iic1.device)
                {
                    NVIC_ClearPendingIRQ(I2C1_IRQn);
                    NVIC_SetPriority(I2C1_IRQn, EFM32_IRQ_PRI_DEFAULT);
                    NVIC_EnableIRQ(I2C1_IRQn);
                }
#endif
            }
        }
        break;
    }

    /* Unlock device */
    rt_sem_release(iic->lock);

    return RT_EOK;
}

/***************************************************************************//**
 * @brief
 *   IIC timeout interrupt handler
 *
 * @details
 *
 * @note
 *
 * @param[in] parameter
 *  Parameter
 ******************************************************************************/
static void rt_iic_timer(void *timeout)
{
    *(rt_bool_t *)timeout = true;
}

/***************************************************************************//**
 * @brief
 *  Register IIC device
 *
 * @details
 *
 * @note
 *
 * @param[in] device
 *  Pointer to device descriptor
 *
 * @param[in] name
 *  Device name
 *
 * @param[in] flag
 *  Configuration flags
 *
 * @param[in] iic
 *  Pointer to IIC device descriptor
 *
 * @return
 *  Error code
 ******************************************************************************/
rt_err_t rt_hw_iic_register(
    rt_device_t     device,
    const char      *name,
    rt_uint32_t     flag,
    struct efm32_iic_device_t *iic)
{
    RT_ASSERT(device != RT_NULL);

    if ((flag & RT_DEVICE_FLAG_DMA_TX) || (flag & RT_DEVICE_FLAG_DMA_RX) ||
        (flag & RT_DEVICE_FLAG_INT_TX))
    {
        RT_ASSERT(0);
    }

    device->type        = RT_Device_Class_Unknown;
    device->rx_indicate = RT_NULL;
    device->tx_complete = RT_NULL;
    device->init        = rt_iic_init;
    device->open        = rt_iic_open;
    device->close       = rt_iic_close;
    device->read        = rt_iic_read;
    device->write       = rt_iic_write;
    device->control     = rt_iic_control;
    device->user_data   = iic;

    /* register a character device */
    return rt_device_register(device, name, RT_DEVICE_FLAG_RDWR | flag);
}

/***************************************************************************//**
 * @brief
 *  IIC slave mode RX data valid interrupt handler
 *
 * @details
 *
 * @note
 *
 * @param[in] dev
 *  Pointer to device descriptor
 ******************************************************************************/
static void rt_hw_iic_slave_isr(rt_device_t dev)
{
    struct efm32_iic_device_t   *iic;
    struct efm32_iic_int_mode_t *int_rx;
    rt_uint32_t                 status;
    volatile rt_uint32_t        temp;

    /* interrupt mode receive */
    RT_ASSERT(dev->flag & RT_DEVICE_FLAG_INT_RX);

    iic = (struct efm32_iic_device_t*)dev->user_data;
    int_rx = iic->rx_buffer;
    status = iic->iic_device->IF;

    if (status & I2C_IF_ADDR)
    {
        /* Address Match */
        /* Indicating that reception is started */
        temp = iic->iic_device->RXDATA & 0xFFUL;
        if ((temp != 0x00) || (iic->state & IIC_STATE_BROADCAST))
        {
            iic->state |= IIC_STATE_RX_BUSY;
        }
    }
    else if (status & I2C_IF_RXDATAV)
    {
        if (iic->state & IIC_STATE_RX_BUSY)
        {
            rt_base_t level;

            /* disable interrupt */
            level = rt_hw_interrupt_disable();

            /* save character */
            int_rx->data_ptr[int_rx->save_index] = \
                (rt_uint8_t)(iic->iic_device->RXDATA & 0xFFUL);
            int_rx->save_index ++;
            if (int_rx->save_index >= IIC_RX_BUFFER_SIZE)
                int_rx->save_index = 0;

            /* if the next position is read index, discard this 'read char' */
            if (int_rx->save_index == int_rx->read_index)
            {
                int_rx->read_index ++;
                if (int_rx->read_index >= IIC_RX_BUFFER_SIZE)
                {
                    int_rx->read_index = 0;
                }
            }

            /* enable interrupt */
            rt_hw_interrupt_enable(level);
        }
        else
        {
            temp = iic->iic_device->RXDATA;
        }
    }

    if(status & I2C_IF_SSTOP)
    {
        /* Stop received, reception is ended */
        iic->state &= ~(rt_uint8_t)IIC_STATE_RX_BUSY;
    }
}

/***************************************************************************//**
 * @brief
 *  Initialize the specified IIC unit
 *
 * @details
 *
 * @note
 *
 * @param[in] unitNumber
 *  Unit number
 *
 * @param[in] location
 *  Pin location number
 ******************************************************************************/
static struct efm32_iic_device_t *rt_hw_iic_unit_init(
    struct efm32_iic_block  *block,
    rt_uint8_t              unitNumber,
    rt_uint8_t              location)
{
    struct efm32_iic_device_t   *iic;
    CMU_Clock_TypeDef           iicClock;
    GPIO_Port_TypeDef           port_scl, port_sda;
    rt_uint32_t                 pin_scl, pin_sda;
    I2C_Init_TypeDef            init = I2C_INIT_DEFAULT;
    efm32_irq_hook_init_t       hook;
    rt_uint8_t                  name[RT_NAME_MAX];

    do
    {
        /* Allocate device */
        iic = rt_malloc(sizeof(struct efm32_iic_device_t));
        if (iic == RT_NULL)
        {
            iic_debug("IIC err: no MEM for IIC%d driver\n", unitNumber);
            break;
        }
        iic->counter        = 0;
        iic->timer          = &block->timer;
        iic->timeout        = false;
        iic->state          |= IIC_STATE_MASTER;
        iic->address        = 0x0000;
        iic->rx_buffer      = RT_NULL;

        /* Initialization */
        if (unitNumber >= I2C_COUNT)
        {
            break;
        }
        switch (unitNumber)
        {
        case 0:
            iic->iic_device = I2C0;
            iicClock        = (CMU_Clock_TypeDef)cmuClock_I2C0;
            port_scl            = AF_I2C0_SCL_PORT(location);
            pin_scl             = AF_I2C0_SCL_PIN(location);
            port_sda            = AF_I2C0_SDA_PORT(location);
            pin_sda             = AF_I2C0_SDA_PIN(location);
            break;
#if (I2C_COUNT > 1)
        case 1:
            iic->iic_device = I2C1;
            iicClock        = (CMU_Clock_TypeDef)cmuClock_I2C1;
            port_scl            = AF_I2C1_SCL_PORT(location);
            pin_scl             = AF_I2C1_SCL_PIN(location);
            port_sda            = AF_I2C1_SDA_PORT(location);
            pin_sda             = AF_I2C1_SDA_PIN(location);
            break;
#endif
        default:
            break;
        }
        rt_sprintf(name, "iic%d", unitNumber);

        /* Enabling clock */
        CMU_ClockEnable(iicClock, true);

        /* Reset */
        I2C_Reset(iic->iic_device);

        /* Config GPIO */
        GPIO_PinModeSet(
            port_scl,
            pin_scl,
            gpioModeWiredAndPullUpFilter,
            1);
        GPIO_PinModeSet(
            port_sda,
            pin_sda,
            gpioModeWiredAndPullUpFilter,
            1);

        hook.type       = efm32_irq_type_iic;
        hook.unit       = unitNumber;
        hook.cbFunc     = rt_hw_iic_slave_isr;
        hook.userPtr    = (void *)&block->device;
        efm32_irq_hook_register(&hook);

        /* Enable SDZ and SCL pins and set location */
        iic->iic_device->ROUTE = I2C_ROUTE_SDAPEN | I2C_ROUTE_SCLPEN | \
                    (location << _I2C_ROUTE_LOCATION_SHIFT);

        /* Initializing IIC */
        init.enable = false;
        I2C_Init(iic->iic_device, &init);

        /* Abort current TX data and clear TX buffers */
        iic->iic_device->CMD = I2C_CMD_ABORT | I2C_CMD_CLEARPC | I2C_CMD_CLEARTX;

        /* Initialize lock */
        iic->lock = &block->lock;
        if (rt_sem_init(iic->lock, name, 1, RT_IPC_FLAG_FIFO) != RT_EOK)
        {
            break;
        }

        /* Initialize timer */
        rt_timer_init(iic->timer, name, rt_iic_timer, &iic->timeout,
            IIC_TIMEOUT_PERIOD, RT_TIMER_FLAG_ONE_SHOT);

        return iic;
    } while(0);

    if (iic)
    {
        rt_free(iic);
    }

    iic_debug("IIC err: Unit %d init failed!\n", unitNumber);
    return RT_NULL;
}

/***************************************************************************//**
 * @brief
 *  Initialize all IIC module related hardware and register IIC device to kernel
 *
 * @details
 *
 * @note
 ******************************************************************************/
void rt_hw_iic_init(void)
{
    struct efm32_iic_device_t *iic;
    rt_uint32_t flag;

    do
    {
        flag = RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX;
        /* Initialize and register iic0 */
        if ((iic = rt_hw_iic_unit_init(&iic0, 0, RT_USING_IIC0)) != RT_NULL)
        {
            rt_hw_iic_register(&iic0.device, RT_IIC0_NAME, flag, iic);
        }
        else
        {
            break;
        }

#if (I2C_COUNT > 1)
        /* Initialize and register iic1 */
        if ((iic = rt_hw_iic_unit_init(&iic1, 1, RT_USING_IIC1)) != RT_NULL)
        {
            rt_hw_iic_register(&iic1.device, RT_IIC1_NAME, flag, iic);
        }
        else
        {
            break;
        }
#endif

        iic_debug("IIC: H/W init OK!\n");
        return;
    } while (0);

    rt_kprintf("IIC: H/W init failed!\n");
}

#endif /* (defined(RT_USING_IIC0) || defined(RT_USING_IIC1)) */
/***************************************************************************//**
 * @}
 ******************************************************************************/