Diff: targets/TARGET_Maxim/TARGET_MAX32630/spi_api.c

Revision:

157:ff67d9f36b67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Maxim/TARGET_MAX32630/spi_api.c	Thu Feb 02 17:01:33 2017 +0000
@@ -0,0 +1,181 @@
+/*******************************************************************************
+ * Copyright (c) 2016 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 "mbed_assert.h"
+#include "spi_api.h"        // mbed HAL
+#include "spim_regs.h"      // bare metal
+#include "spim.h"           // Maxim CMSIS driver
+#include "pinmap.h"
+#include "PeripheralPins.h"
+
+//******************************************************************************
+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;
+
+    // Control is SCK and optionaly SS
+    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);
+
+    obj->spi = (mxc_spim_regs_t *)spi;
+
+    // Merge pin function requests for use with CMSIS init func
+    ioman_req_t io_req;
+    pin_function_t *pin_func;
+    pin_func = (pin_function_t *)pinmap_find_function(mosi, PinMap_SPI_MOSI);
+    io_req.value  = pin_func->req_val;
+    pin_func = (pin_function_t *)pinmap_find_function(miso, PinMap_SPI_MISO);
+    io_req.value |= pin_func->req_val;
+    pin_func = (pin_function_t *)pinmap_find_function(sclk, PinMap_SPI_SCLK);
+    io_req.value |= pin_func->req_val;
+    if ((SPIName)spi_ssel != (SPIName)NC) {
+        pin_func = (pin_function_t *)pinmap_find_function(ssel, PinMap_SPI_SSEL);
+        io_req.value |= pin_func->req_val;
+    }
+
+    // Using req and ack pointers of last pin function lookup
+    sys_cfg_spim_t sys_cfg;
+    sys_cfg.io_cfg.req_reg = pin_func->reg_req;
+    sys_cfg.io_cfg.ack_reg = pin_func->reg_ack;
+    sys_cfg.io_cfg.req_val = io_req;
+    sys_cfg.clk_scale = CLKMAN_SCALE_AUTO;
+
+    // Defaults
+    spim_cfg_t spim_cfg;
+    spim_cfg.mode = 0;
+    spim_cfg.ssel_pol = 0;
+    spim_cfg.baud = 1000000;
+
+    SPIM_Init(obj->spi, &spim_cfg, &sys_cfg);
+
+    obj->index = MXC_SPIM_GET_IDX(obj->spi);
+}
+
+//******************************************************************************
+void spi_format(spi_t *obj, int bits, int mode, int slave)
+{
+    // Check the validity of the inputs
+    MBED_ASSERT(bits == 8);
+
+    // Only supports master mode
+    MBED_ASSERT(!slave);
+
+    // Set the mode
+    obj->spi->mstr_cfg &= ~(MXC_F_SPIM_MSTR_CFG_SPI_MODE);
+    obj->spi->mstr_cfg |= (mode << MXC_F_SPIM_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->sys_clk_ctrl_11_spi0 = clk_div;
+    } else if(obj->index == 1) {
+        MXC_CLKMAN->sys_clk_ctrl_12_spi1 = clk_div;
+    } else if(obj->index == 2) {
+        MXC_CLKMAN->sys_clk_ctrl_13_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_SPIM_MSTR_CFG_SCK_HI_CLK | MXC_F_SPIM_MSTR_CFG_SCK_LO_CLK),
+                  ((clocks << MXC_F_SPIM_MSTR_CFG_SCK_HI_CLK_POS) | (clocks << MXC_F_SPIM_MSTR_CFG_SCK_LO_CLK_POS)));
+}
+
+//******************************************************************************
+int spi_master_write(spi_t *obj, int value)
+{
+    spim_req_t req;
+    uint8_t out;
+    uint8_t in;
+
+    out = value;
+
+    req.ssel = 0;
+    req.deass = 0;
+    req.tx_data = &out;
+    req.rx_data = &in;
+    req.width = SPIM_WIDTH_1;
+    req.len = 1;
+    req.ssel = 0;
+    req.deass = 1;
+    req.callback = NULL;
+
+    SPIM_Trans(obj->spi, &req);
+
+    return *req.rx_data;
+}
+
+//******************************************************************************
+int spi_busy(spi_t *obj)
+{
+    return SPIM_Busy(obj->spi);
+}
+
+//******************************************************************************
+uint8_t spi_get_module(spi_t *obj)
+{
+    return obj->index;
+}
+