Diff: targets/hal/TARGET_STM/TARGET_STM32L0/spi_api.c

Revision:

491:b97b6b70036c

Parent:

414:4ec4c5b614b0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_STM32L0/spi_api.c	Mon Mar 16 09:45:08 2015 +0000
@@ -0,0 +1,269 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2014, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *******************************************************************************
+ */
+#include "mbed_assert.h"
+#include "spi_api.h"
+
+#if DEVICE_SPI
+
+#include <math.h>
+#include "cmsis.h"
+#include "pinmap.h"
+#include "PeripheralPins.h"
+
+static SPI_HandleTypeDef SpiHandle;
+
+static void init_spi(spi_t *obj)
+{
+    SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
+
+    __HAL_SPI_DISABLE(&SpiHandle);
+
+    SpiHandle.Init.Mode              = obj->mode;
+    SpiHandle.Init.BaudRatePrescaler = obj->br_presc;
+    SpiHandle.Init.Direction         = SPI_DIRECTION_2LINES;
+    SpiHandle.Init.CLKPhase          = obj->cpha;
+    SpiHandle.Init.CLKPolarity       = obj->cpol;
+    SpiHandle.Init.CRCCalculation    = SPI_CRCCALCULATION_DISABLED;
+    SpiHandle.Init.CRCPolynomial     = 7;
+    SpiHandle.Init.DataSize          = obj->bits;
+    SpiHandle.Init.FirstBit          = SPI_FIRSTBIT_MSB;
+    SpiHandle.Init.NSS               = obj->nss;
+    SpiHandle.Init.TIMode            = SPI_TIMODE_DISABLED;
+
+    HAL_SPI_Init(&SpiHandle);
+
+    __HAL_SPI_ENABLE(&SpiHandle);
+}
+
+void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
+{
+    // Determine the SPI to use
+    SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
+    SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
+    SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
+    SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
+
+    SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
+    SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
+
+    obj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
+    MBED_ASSERT(obj->spi != (SPIName)NC);
+
+    // Enable SPI clock
+    if (obj->spi == SPI_1) {
+        __SPI1_CLK_ENABLE();
+    }
+    if (obj->spi == SPI_2) {
+        __SPI2_CLK_ENABLE();
+    }
+
+    // Configure the SPI pins
+    pinmap_pinout(mosi, PinMap_SPI_MOSI);
+    pinmap_pinout(miso, PinMap_SPI_MISO);
+    pinmap_pinout(sclk, PinMap_SPI_SCLK);
+
+    // Save new values
+    obj->bits = SPI_DATASIZE_8BIT;
+    obj->cpol = SPI_POLARITY_LOW;
+    obj->cpha = SPI_PHASE_1EDGE;
+    obj->br_presc = SPI_BAUDRATEPRESCALER_256;
+
+    obj->pin_miso = miso;
+    obj->pin_mosi = mosi;
+    obj->pin_sclk = sclk;
+    obj->pin_ssel = ssel;
+
+    if (ssel == NC) { // SW NSS Master mode
+        obj->mode = SPI_MODE_MASTER;
+        obj->nss = SPI_NSS_SOFT;
+    } else { // Slave
+        pinmap_pinout(ssel, PinMap_SPI_SSEL);
+        obj->mode = SPI_MODE_SLAVE;
+        obj->nss = SPI_NSS_HARD_INPUT;
+    }
+
+    init_spi(obj);
+}
+
+void spi_free(spi_t *obj)
+{
+    // Reset SPI and disable clock
+    if (obj->spi == SPI_1) {
+        __SPI1_FORCE_RESET();
+        __SPI1_RELEASE_RESET();
+        __SPI1_CLK_DISABLE();
+    }
+
+    if (obj->spi == SPI_2) {
+        __SPI2_FORCE_RESET();
+        __SPI2_RELEASE_RESET();
+        __SPI2_CLK_DISABLE();
+    }
+
+    // Configure GPIO
+    pin_function(obj->pin_miso, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+    pin_function(obj->pin_mosi, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+    pin_function(obj->pin_sclk, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+    pin_function(obj->pin_ssel, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+}
+
+void spi_format(spi_t *obj, int bits, int mode, int slave)
+{
+    // Save new values
+    if (bits == 16) {
+        obj->bits = SPI_DATASIZE_16BIT;
+    } else {
+        obj->bits = SPI_DATASIZE_8BIT;
+    }
+
+    switch (mode) {
+        case 0:
+            obj->cpol = SPI_POLARITY_LOW;
+            obj->cpha = SPI_PHASE_1EDGE;
+            break;
+        case 1:
+            obj->cpol = SPI_POLARITY_LOW;
+            obj->cpha = SPI_PHASE_2EDGE;
+            break;
+        case 2:
+            obj->cpol = SPI_POLARITY_HIGH;
+            obj->cpha = SPI_PHASE_1EDGE;
+            break;
+        default:
+            obj->cpol = SPI_POLARITY_HIGH;
+            obj->cpha = SPI_PHASE_2EDGE;
+            break;
+    }
+
+    if (slave == 0) {
+        obj->mode = SPI_MODE_MASTER;
+        obj->nss = SPI_NSS_SOFT;
+    } else {
+        obj->mode = SPI_MODE_SLAVE;
+        obj->nss = SPI_NSS_HARD_INPUT;
+    }
+
+    init_spi(obj);
+}
+
+void spi_frequency(spi_t *obj, int hz)
+{
+    // Note: The frequencies are obtained with SPI1 clock = 32 MHz (APB2 clock)
+    if (hz < 250000) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz
+    } else if ((hz >= 250000) && (hz < 500000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz
+    } else if ((hz >= 500000) && (hz < 1000000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz
+    } else if ((hz >= 1000000) && (hz < 2000000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz
+    } else if ((hz >= 2000000) && (hz < 4000000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz
+    } else if ((hz >= 4000000) && (hz < 8000000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz
+    } else if ((hz >= 8000000) && (hz < 16000000)) {
+        obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz
+    } else { // >= 16000000
+        obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz
+    }
+    init_spi(obj);
+}
+
+static inline int ssp_readable(spi_t *obj)
+{
+    int status;
+    SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
+    // Check if data is received
+    status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_RXNE) != RESET) ? 1 : 0);
+    return status;
+}
+
+static inline int ssp_writeable(spi_t *obj)
+{
+    int status;
+    SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
+    // Check if data is transmitted
+    status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_TXE) != RESET) ? 1 : 0);
+    return status;
+}
+
+static inline void ssp_write(spi_t *obj, int value)
+{
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    while (!ssp_writeable(obj));
+    spi->DR = (uint16_t)value;
+}
+
+static inline int ssp_read(spi_t *obj)
+{
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    while (!ssp_readable(obj));
+    return (int)spi->DR;
+}
+
+static inline int ssp_busy(spi_t *obj)
+{
+    int status;
+    SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
+    status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_BSY) != RESET) ? 1 : 0);
+    return status;
+}
+
+int spi_master_write(spi_t *obj, int value)
+{
+    ssp_write(obj, value);
+    return ssp_read(obj);
+}
+
+int spi_slave_receive(spi_t *obj)
+{
+    return (ssp_readable(obj) ? 1 : 0);
+};
+
+int spi_slave_read(spi_t *obj)
+{
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    while (!ssp_readable(obj));
+    return (int)spi->DR;
+}
+
+void spi_slave_write(spi_t *obj, int value)
+{
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    while (!ssp_writeable(obj));
+    spi->DR = (uint16_t)value;
+}
+
+int spi_busy(spi_t *obj)
+{
+    return ssp_busy(obj);
+}
+
+#endif