Diff: targets/TARGET_Maxim/TARGET_MAX32610/spi_api.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Maxim/TARGET_MAX32610/spi_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,186 @@
+/*******************************************************************************
+ * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+ * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Maxim Integrated
+ * Products, Inc. shall not be used except as stated in the Maxim Integrated
+ * Products, Inc. Branding Policy.
+ *
+ * The mere transfer of this software does not imply any licenses
+ * of trade secrets, proprietary technology, copyrights, patents,
+ * trademarks, maskwork rights, or any other form of intellectual
+ * property whatsoever. Maxim Integrated Products, Inc. retains all
+ * ownership rights.
+ *******************************************************************************
+ */
+
+#include <string.h>
+#include "mbed_assert.h"
+#include "cmsis.h"
+#include "spi_api.h"
+#include "pinmap.h"
+#include "ioman_regs.h"
+#include "clkman_regs.h"
+#include "PeripheralPins.h"
+
+#define DEFAULT_CHAR	8
+#define DEFAULT_MODE	0
+#define DEFAULT_FREQ 	1000000
+
+// Formatting settings
+static int spi_bits;
+
+//******************************************************************************
+void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
+{
+    // Make sure pins are pointing to the same SPI instance
+    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;
+
+    // Give the application the option to manually control Slave Select
+    if((SPIName)spi_ssel != (SPIName)NC) {
+        spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
+    } else {
+        spi_cntl = spi_sclk;
+    }
+
+    SPIName spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
+
+    MBED_ASSERT((SPIName)spi != (SPIName)NC);
+
+    // Set the obj pointer to the proper SPI Instance
+    obj->spi = (mxc_spi_regs_t*)spi;
+
+    // Set the SPI index and FIFOs
+    obj->index = MXC_SPI_BASE_TO_INSTANCE(obj->spi);
+    obj->rxfifo = MXC_SPI_GET_RXFIFO(obj->index);
+    obj->txfifo = MXC_SPI_GET_TXFIFO(obj->index);
+
+    // Configure the pins
+    pinmap_pinout(mosi, PinMap_SPI_MOSI);
+    pinmap_pinout(miso, PinMap_SPI_MISO);
+    pinmap_pinout(sclk, PinMap_SPI_SCLK);
+    pinmap_pinout(ssel, PinMap_SPI_SSEL);
+
+    // Enable SPI and FIFOs
+    obj->spi->gen_ctrl = (MXC_F_SPI_GEN_CTRL_SPI_MSTR_EN |
+                          MXC_F_SPI_GEN_CTRL_TX_FIFO_EN |
+                          MXC_F_SPI_GEN_CTRL_RX_FIFO_EN );
+}
+
+//******************************************************************************
+void spi_format(spi_t *obj, int bits, int mode, int slave)
+{
+    // Check the validity of the inputs
+    MBED_ASSERT(((bits >= 1) && (bits <= 32)) && ((mode >= 0) && (mode <= 3)));
+
+    // Only supports master mode
+    MBED_ASSERT(!slave);
+
+    // Save formatting data
+    spi_bits = bits;
+
+    // Set the mode
+    obj->spi->mstr_cfg &= ~(MXC_F_SPI_MSTR_CFG_SPI_MODE);
+    obj->spi->mstr_cfg |= (mode << MXC_F_SPI_MSTR_CFG_SPI_MODE_POS);
+}
+
+//******************************************************************************
+void spi_frequency(spi_t *obj, int hz)
+{
+    // Maximum frequency is half the system frequency
+    MBED_ASSERT((unsigned int)hz <= (SystemCoreClock / 2));
+    unsigned clocks = ((SystemCoreClock/2)/(hz));
+
+    // Figure out the divider ratio
+    int clk_div = 1;
+    while(clk_div < 10) {
+        if(clocks < 0x10) {
+            break;
+        }
+        clk_div++;
+        clocks = clocks >> 1;
+    }
+
+    // Turn on the SPI clock
+    if(obj->index == 0) {
+        MXC_CLKMAN->clk_ctrl_3_spi0 = clk_div;
+    } else if(obj->index == 1) {
+        MXC_CLKMAN->clk_ctrl_4_spi1 = clk_div;
+    } else if(obj->index == 2) {
+        MXC_CLKMAN->clk_ctrl_5_spi2 = clk_div;
+    } else {
+        MBED_ASSERT(0);
+    }
+
+    // Set the number of clocks to hold sclk high and low
+    MXC_SET_FIELD(&obj->spi->mstr_cfg, (MXC_F_SPI_MSTR_CFG_SCK_HI_CLK | MXC_F_SPI_MSTR_CFG_SCK_LO_CLK),
+        ((clocks << MXC_F_SPI_MSTR_CFG_SCK_HI_CLK_POS) | (clocks << MXC_F_SPI_MSTR_CFG_SCK_LO_CLK_POS)));
+}
+
+//******************************************************************************
+int spi_master_write(spi_t *obj, int value)
+{
+    int bits = spi_bits;
+    if(spi_bits == 32) {
+        bits = 0;
+    }
+    // Create the header
+    uint16_t header = ((0x3 << MXC_F_SPI_FIFO_DIR_POS ) |  // TX and RX
+                       (0x0 << MXC_F_SPI_FIFO_UNIT_POS) | // Send bits
+                       (bits << MXC_F_SPI_FIFO_SIZE_POS) | // Number of units
+                       (0x1 << MXC_F_SPI_FIFO_DASS_POS));      // Deassert SS
+
+    // Send the message header
+    obj->txfifo->txfifo_16 = header;
+
+    // Send the data
+    if(spi_bits < 17) {
+        obj->txfifo->txfifo_16 = (uint16_t)value;
+    } else {
+        obj->txfifo->txfifo_32 = (uint32_t)value;
+    }
+
+    // Get the data
+    bits = spi_bits;
+    int result = 0;
+    int i = 0;
+    while(bits > 0) {
+        // Wait for data
+        while(((obj->spi->fifo_ctrl & MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED)
+                >> MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED_POS) < 1) {}
+
+        result |= (obj->rxfifo->rxfifo_8 << (i++*8));
+        bits-=8;
+    }
+
+    return result;
+}
+
+//******************************************************************************
+int spi_busy(spi_t *obj)
+{
+    return !(obj->spi->intfl & MXC_F_SPI_INTFL_TX_READY);
+}