Diff: lpc17xx_spi.c

Revision:

0:84d7747641aa

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lpc17xx_spi.c	Sun Mar 20 18:45:15 2011 +0000
@@ -0,0 +1,431 @@
+/***********************************************************************//**
+ * @file        lpc17xx_spi.c
+ * @brief        Contains all functions support for SPI firmware library on LPC17xx
+ * @version        2.0
+ * @date        21. May. 2010
+ * @author        NXP MCU SW Application Team
+ **************************************************************************
+ * Software that is described herein is for illustrative purposes only
+ * which provides customers with programming information regarding the
+ * products. This software is supplied "AS IS" without any warranties.
+ * NXP Semiconductors assumes no responsibility or liability for the
+ * use of the software, conveys no license or title under any patent,
+ * copyright, or mask work right to the product. NXP Semiconductors
+ * reserves the right to make changes in the software without
+ * notification. NXP Semiconductors also make no representation or
+ * warranty that such application will be suitable for the specified
+ * use without further testing or modification.
+ **********************************************************************/
+
+/* Peripheral group ----------------------------------------------------------- */
+/** @addtogroup SPI
+ * @{
+ */
+
+/* Includes ------------------------------------------------------------------- */
+#include "lpc17xx_spi.h"
+#include "lpc17xx_clkpwr.h"
+
+/* If this source file built with example, the LPC17xx FW library configuration
+ * file in each example directory ("lpc17xx_libcfg.h") must be included,
+ * otherwise the default FW library configuration file must be included instead
+ */
+#ifdef __BUILD_WITH_EXAMPLE__
+#include "lpc17xx_libcfg.h"
+#else
+#include "lpc17xx_libcfg_default.h"
+#endif /* __BUILD_WITH_EXAMPLE__ */
+
+#ifdef _SPI
+
+
+/* Public Functions ----------------------------------------------------------- */
+/** @addtogroup SPI_Public_Functions
+ * @{
+ */
+
+/*********************************************************************//**
+ * @brief         Setup clock rate for SPI device
+ * @param[in]     SPIx    SPI peripheral definition, should be LPC_SPI
+ * @param[in]    target_clock : clock of SPI (Hz)
+ * @return         None
+ ***********************************************************************/
+void SPI_SetClock (LPC_SPI_TypeDef *SPIx, uint32_t target_clock)
+{
+    uint32_t spi_pclk;
+    uint32_t prescale, temp;
+
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    if (SPIx == LPC_SPI){
+        spi_pclk =  CLKPWR_GetPCLK (CLKPWR_PCLKSEL_SPI);
+    } else {
+        return;
+    }
+
+    prescale = 8;
+    // Find closest clock to target clock
+    while (1){
+        temp = target_clock * prescale;
+        if (temp >= spi_pclk){
+            break;
+        }
+        prescale += 2;
+        if(prescale >= 254){
+            break;
+        }
+    }
+
+    // Write to register
+    SPIx->SPCCR = SPI_SPCCR_COUNTER(prescale);
+}
+
+
+/*********************************************************************//**
+ * @brief        De-initializes the SPIx peripheral registers to their
+*                  default reset values.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return         None
+ **********************************************************************/
+void SPI_DeInit(LPC_SPI_TypeDef *SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    if (SPIx == LPC_SPI){
+        /* Set up clock and power for SPI module */
+        CLKPWR_ConfigPPWR (CLKPWR_PCONP_PCSPI, DISABLE);
+    }
+}
+
+/*********************************************************************//**
+ * @brief        Get data bit size per transfer
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return         number of bit per transfer, could be 8-16
+ **********************************************************************/
+uint8_t SPI_GetDataSize (LPC_SPI_TypeDef *SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+    return ((SPIx->SPCR)>>8 & 0xF);
+}
+
+/********************************************************************//**
+ * @brief        Initializes the SPIx peripheral according to the specified
+*               parameters in the UART_ConfigStruct.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @param[in]    SPI_ConfigStruct Pointer to a SPI_CFG_Type structure
+*                    that contains the configuration information for the
+*                    specified SPI peripheral.
+ * @return         None
+ *********************************************************************/
+void SPI_Init(LPC_SPI_TypeDef *SPIx, SPI_CFG_Type *SPI_ConfigStruct)
+{
+    uint32_t tmp;
+
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    if(SPIx == LPC_SPI){
+        /* Set up clock and power for UART module */
+        CLKPWR_ConfigPPWR (CLKPWR_PCONP_PCSPI, ENABLE);
+    } else {
+        return;
+    }
+
+    // Configure SPI, interrupt is disable as default
+    tmp = ((SPI_ConfigStruct->CPHA) | (SPI_ConfigStruct->CPOL) \
+        | (SPI_ConfigStruct->DataOrder) | (SPI_ConfigStruct->Databit) \
+        | (SPI_ConfigStruct->Mode) | SPI_SPCR_BIT_EN) & SPI_SPCR_BITMASK;
+    // write back to SPI control register
+    SPIx->SPCR = tmp;
+
+    // Set clock rate for SPI peripheral
+    SPI_SetClock(SPIx, SPI_ConfigStruct->ClockRate);
+
+    // If interrupt flag is set, Write '1' to Clear interrupt flag
+    if (SPIx->SPINT & SPI_SPINT_INTFLAG){
+        SPIx->SPINT = SPI_SPINT_INTFLAG;
+    }
+}
+
+
+
+/*****************************************************************************//**
+* @brief        Fills each SPI_InitStruct member with its default value:
+*                 - CPHA = SPI_CPHA_FIRST
+*                 - CPOL = SPI_CPOL_HI
+*                 - ClockRate = 1000000
+*                 - DataOrder = SPI_DATA_MSB_FIRST
+*                 - Databit = SPI_DATABIT_8
+*                 - Mode = SPI_MASTER_MODE
+* @param[in]    SPI_InitStruct Pointer to a SPI_CFG_Type structure
+*                    which will be initialized.
+* @return        None
+*******************************************************************************/
+void SPI_ConfigStructInit(SPI_CFG_Type *SPI_InitStruct)
+{
+    SPI_InitStruct->CPHA = SPI_CPHA_FIRST;
+    SPI_InitStruct->CPOL = SPI_CPOL_HI;
+    SPI_InitStruct->ClockRate = 1000000;
+    SPI_InitStruct->DataOrder = SPI_DATA_MSB_FIRST;
+    SPI_InitStruct->Databit = SPI_DATABIT_8;
+    SPI_InitStruct->Mode = SPI_MASTER_MODE;
+}
+
+/*********************************************************************//**
+ * @brief        Transmit a single data through SPIx peripheral
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @param[in]    Data    Data to transmit (must be 16 or 8-bit long,
+ *                         this depend on SPI data bit number configured)
+ * @return         none
+ **********************************************************************/
+void SPI_SendData(LPC_SPI_TypeDef* SPIx, uint16_t Data)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    SPIx->SPDR = Data & SPI_SPDR_BITMASK;
+}
+
+
+
+/*********************************************************************//**
+ * @brief        Receive a single data from SPIx peripheral
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return         Data received (16-bit long)
+ **********************************************************************/
+uint16_t SPI_ReceiveData(LPC_SPI_TypeDef* SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    return ((uint16_t) (SPIx->SPDR & SPI_SPDR_BITMASK));
+}
+
+/*********************************************************************//**
+ * @brief         SPI     Read write data function
+ * @param[in]    SPIx     Pointer to SPI peripheral, should be LPC_SPI
+ * @param[in]    dataCfg    Pointer to a SPI_DATA_SETUP_Type structure that
+ *                         contains specified information about transmit
+ *                         data configuration.
+ * @param[in]    xfType    Transfer type, should be:
+ *                         - SPI_TRANSFER_POLLING: Polling mode
+ *                         - SPI_TRANSFER_INTERRUPT: Interrupt mode
+ * @return         Actual Data length has been transferred in polling mode.
+ *                 In interrupt mode, always return (0)
+ *                 Return (-1) if error.
+ * Note: This function can be used in both master and slave mode.
+ ***********************************************************************/
+int32_t SPI_ReadWrite (LPC_SPI_TypeDef *SPIx, SPI_DATA_SETUP_Type *dataCfg, \
+                        SPI_TRANSFER_Type xfType)
+{
+    uint8_t *rdata8 = 0;
+    uint8_t *wdata8 = 0;
+    uint16_t *rdata16 = 0;
+    uint16_t *wdata16 = 0;
+    uint32_t stat = 0;
+    uint32_t temp;
+    uint8_t dataword;
+
+    //read for empty buffer
+    temp = SPIx->SPDR;
+    //dummy to clear status
+    temp = SPIx->SPSR;
+    dataCfg->counter = 0;
+    dataCfg->status = 0;
+
+    if(SPI_GetDataSize (SPIx) == 8)
+        dataword = 0;
+    else dataword = 1;
+    if (xfType == SPI_TRANSFER_POLLING){
+
+        if (dataword == 0){
+            rdata8 = (uint8_t *)dataCfg->rx_data;
+            wdata8 = (uint8_t *)dataCfg->tx_data;
+        } else {
+            rdata16 = (uint16_t *)dataCfg->rx_data;
+            wdata16 = (uint16_t *)dataCfg->tx_data;
+        }
+
+        while(dataCfg->counter < dataCfg->length)
+        {
+            // Write data to buffer
+            if(dataCfg->tx_data == NULL){
+                if (dataword == 0){
+                    SPI_SendData(SPIx, 0xFF);
+                } else {
+                    SPI_SendData(SPIx, 0xFFFF);
+                }
+            } else {
+                if (dataword == 0){
+                    SPI_SendData(SPIx, *wdata8);
+                    wdata8++;
+                } else {
+                    SPI_SendData(SPIx, *wdata16);
+                    wdata16++;
+                }
+            }
+            // Wait for transfer complete
+            while (!((stat = SPIx->SPSR) & SPI_SPSR_SPIF));
+            // Check for error
+            if (stat & (SPI_SPSR_ABRT | SPI_SPSR_MODF | SPI_SPSR_ROVR | SPI_SPSR_WCOL)){
+                // save status
+                dataCfg->status = stat | SPI_STAT_ERROR;
+                return (dataCfg->counter);
+            }
+            // Read data from SPI dat
+            temp = (uint32_t) SPI_ReceiveData(SPIx);
+
+            // Store data to destination
+            if (dataCfg->rx_data != NULL)
+            {
+                if (dataword == 0){
+                    *(rdata8) = (uint8_t) temp;
+                    rdata8++;
+                } else {
+                    *(rdata16) = (uint16_t) temp;
+                    rdata16++;
+                }
+            }
+            // Increase counter
+            if (dataword == 0){
+                dataCfg->counter++;
+            } else {
+                dataCfg->counter += 2;
+            }
+        }
+
+        // Return length of actual data transferred
+        // save status
+        dataCfg->status = stat | SPI_STAT_DONE;
+        return (dataCfg->counter);
+    }
+    // Interrupt mode
+    else {
+
+        // Check if interrupt flag is already set
+        if(SPIx->SPINT & SPI_SPINT_INTFLAG){
+            SPIx->SPINT = SPI_SPINT_INTFLAG;
+        }
+        if (dataCfg->counter < dataCfg->length){
+            // Write data to buffer
+            if(dataCfg->tx_data == NULL){
+                if (dataword == 0){
+                    SPI_SendData(SPIx, 0xFF);
+                } else {
+                    SPI_SendData(SPIx, 0xFFFF);
+                }
+            } else {
+                if (dataword == 0){
+                    SPI_SendData(SPIx, (*(uint8_t *)dataCfg->tx_data));
+                } else {
+                    SPI_SendData(SPIx, (*(uint16_t *)dataCfg->tx_data));
+                }
+            }
+            SPI_IntCmd(SPIx, ENABLE);
+        } else {
+            // Save status
+            dataCfg->status = SPI_STAT_DONE;
+        }
+        return (0);
+    }
+}
+
+
+/********************************************************************//**
+ * @brief         Enable or disable SPIx interrupt.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @param[in]    NewState New state of specified UART interrupt type,
+ *                 should be:
+ *                 - ENALBE: Enable this SPI interrupt.
+*                 - DISALBE: Disable this SPI interrupt.
+ * @return         None
+ *********************************************************************/
+void SPI_IntCmd(LPC_SPI_TypeDef *SPIx, FunctionalState NewState)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+    CHECK_PARAM(PARAM_FUNCTIONALSTATE(NewState));
+
+    if (NewState == ENABLE)
+    {
+        SPIx->SPCR |= SPI_SPCR_SPIE;
+    }
+    else
+    {
+        SPIx->SPCR &= (~SPI_SPCR_SPIE) & SPI_SPCR_BITMASK;
+    }
+}
+
+
+/********************************************************************//**
+ * @brief         Checks whether the SPI interrupt flag is set or not.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return         The new state of SPI Interrupt Flag (SET or RESET)
+ *********************************************************************/
+IntStatus SPI_GetIntStatus (LPC_SPI_TypeDef *SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    return ((SPIx->SPINT & SPI_SPINT_INTFLAG) ? SET : RESET);
+}
+
+/********************************************************************//**
+ * @brief         Clear SPI interrupt flag.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return         None
+ *********************************************************************/
+void SPI_ClearIntPending(LPC_SPI_TypeDef *SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    SPIx->SPINT = SPI_SPINT_INTFLAG;
+}
+
+/********************************************************************//**
+ * @brief         Get current value of SPI Status register in SPIx peripheral.
+ * @param[in]    SPIx    SPI peripheral selected, should be LPC_SPI
+ * @return        Current value of SPI Status register in SPI peripheral.
+ * Note:    The return value of this function must be used with
+ *             SPI_CheckStatus() to determine current flag status
+ *             corresponding to each SPI status type. Because some flags in
+ *             SPI Status register will be cleared after reading, the next reading
+ *             SPI Status register could not be correct. So this function used to
+ *             read SPI status register in one time only, then the return value
+ *             used to check all flags.
+ *********************************************************************/
+uint32_t SPI_GetStatus(LPC_SPI_TypeDef* SPIx)
+{
+    CHECK_PARAM(PARAM_SPIx(SPIx));
+
+    return (SPIx->SPSR & SPI_SPSR_BITMASK);
+}
+
+/********************************************************************//**
+ * @brief         Checks whether the specified SPI Status flag is set or not
+ *                 via inputSPIStatus parameter.
+ * @param[in]    inputSPIStatus Value to check status of each flag type.
+ *                 This value is the return value from SPI_GetStatus().
+ * @param[in]    SPIStatus    Specifies the SPI status flag to check,
+ *                 should be one of the following:
+                - SPI_STAT_ABRT: Slave abort.
+                - SPI_STAT_MODF: Mode fault.
+                - SPI_STAT_ROVR: Read overrun.
+                - SPI_STAT_WCOL: Write collision.
+                - SPI_STAT_SPIF: SPI transfer complete.
+ * @return         The new state of SPIStatus (SET or RESET)
+ *********************************************************************/
+FlagStatus SPI_CheckStatus (uint32_t inputSPIStatus,  uint8_t SPIStatus)
+{
+    CHECK_PARAM(PARAM_SPI_STAT(SPIStatus));
+
+    return ((inputSPIStatus & SPIStatus) ? SET : RESET);
+}
+
+
+/**
+ * @}
+ */
+
+#endif /* _SPI */
+
+/**
+ * @}
+ */
+
+/* --------------------------------- End Of File ------------------------------ */