Diff: targets/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c

Revision:

149:156823d33999

Child:

167:e84263d55307

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,286 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2013 Nordic Semiconductor
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//#include <math.h>
+#include "mbed_assert.h"
+#include "spi_api.h"
+#include "cmsis.h"
+#include "pinmap.h"
+#include "mbed_error.h"
+
+#define SPIS_MESSAGE_SIZE 1
+volatile uint8_t m_tx_buf[SPIS_MESSAGE_SIZE] = {0};
+volatile uint8_t m_rx_buf[SPIS_MESSAGE_SIZE] = {0};
+
+// nRF51822's I2C_0 and SPI_0 (I2C_1, SPI_1 and SPIS1) share the same address.
+// They can't be used at the same time. So we use two global variable to track the usage.
+// See nRF51822 address information at nRF51822_PS v2.0.pdf - Table 15 Peripheral instance reference
+extern volatile i2c_spi_peripheral_t i2c0_spi0_peripheral; // from i2c_api.c
+extern volatile i2c_spi_peripheral_t i2c1_spi1_peripheral;
+
+void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
+{
+    SPIName spi = SPI_0;
+    
+    if (ssel == NC && i2c0_spi0_peripheral.usage == I2C_SPI_PERIPHERAL_FOR_SPI &&
+            i2c0_spi0_peripheral.sda_mosi == (uint8_t)mosi &&
+            i2c0_spi0_peripheral.scl_miso == (uint8_t)miso &&
+            i2c0_spi0_peripheral.sclk     == (uint8_t)sclk) {
+        // The SPI with the same pins is already initialized
+        spi = SPI_0;
+        obj->peripheral = 0x1;
+    } else if (ssel == NC && i2c1_spi1_peripheral.usage == I2C_SPI_PERIPHERAL_FOR_SPI &&
+            i2c1_spi1_peripheral.sda_mosi == (uint8_t)mosi &&
+            i2c1_spi1_peripheral.scl_miso == (uint8_t)miso &&
+            i2c1_spi1_peripheral.sclk     == (uint8_t)sclk) {
+        // The SPI with the same pins is already initialized
+        spi = SPI_1;
+        obj->peripheral = 0x2;
+    } else if (i2c1_spi1_peripheral.usage == 0) {
+        i2c1_spi1_peripheral.usage = I2C_SPI_PERIPHERAL_FOR_SPI;
+        i2c1_spi1_peripheral.sda_mosi = (uint8_t)mosi;
+        i2c1_spi1_peripheral.scl_miso = (uint8_t)miso;
+        i2c1_spi1_peripheral.sclk     = (uint8_t)sclk;
+        
+        spi = SPI_1;
+        obj->peripheral = 0x2;
+    } else if (i2c0_spi0_peripheral.usage == 0) {
+        i2c0_spi0_peripheral.usage = I2C_SPI_PERIPHERAL_FOR_SPI;
+        i2c0_spi0_peripheral.sda_mosi = (uint8_t)mosi;
+        i2c0_spi0_peripheral.scl_miso = (uint8_t)miso;
+        i2c0_spi0_peripheral.sclk     = (uint8_t)sclk;
+        
+        spi = SPI_0;
+        obj->peripheral = 0x1;
+    } else {
+        // No available peripheral
+        error("No available SPI");
+    }
+
+    if (ssel==NC) {
+        obj->spi  = (NRF_SPI_Type *)spi;
+        obj->spis = (NRF_SPIS_Type *)NC;
+    } else {
+        obj->spi  = (NRF_SPI_Type *)NC;
+        obj->spis = (NRF_SPIS_Type *)spi;
+    }
+
+    // pin out the spi pins
+    if (ssel != NC) { //slave
+        obj->spis->POWER = 0;
+        obj->spis->POWER = 1;
+
+        NRF_GPIO->PIN_CNF[mosi] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
+        NRF_GPIO->PIN_CNF[miso] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
+        NRF_GPIO->PIN_CNF[sclk] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
+        NRF_GPIO->PIN_CNF[ssel] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
+
+        obj->spis->PSELMOSI = mosi;
+        obj->spis->PSELMISO = miso;
+        obj->spis->PSELSCK  = sclk;
+        obj->spis->PSELCSN  = ssel;
+
+        obj->spis->EVENTS_END      = 0;
+        obj->spis->EVENTS_ACQUIRED = 0;
+        obj->spis->MAXRX           = SPIS_MESSAGE_SIZE;
+        obj->spis->MAXTX           = SPIS_MESSAGE_SIZE;
+        obj->spis->TXDPTR          = (uint32_t)&m_tx_buf[0];
+        obj->spis->RXDPTR          = (uint32_t)&m_rx_buf[0];
+        obj->spis->SHORTS          = (SPIS_SHORTS_END_ACQUIRE_Enabled << SPIS_SHORTS_END_ACQUIRE_Pos);
+
+        spi_format(obj, 8, 0, 1);  // 8 bits, mode 0, slave
+    } else { //master
+        obj->spi->POWER = 0;
+        obj->spi->POWER = 1;
+
+        //NRF_GPIO->DIR |= (1<<mosi);
+        NRF_GPIO->PIN_CNF[mosi] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
+        obj->spi->PSELMOSI = mosi;
+
+        NRF_GPIO->PIN_CNF[sclk] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
+        obj->spi->PSELSCK = sclk;
+
+        //NRF_GPIO->DIR &= ~(1<<miso);
+        NRF_GPIO->PIN_CNF[miso] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
+                                    | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
+                                    | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
+                                    | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+                                    | (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos);
+
+        obj->spi->PSELMISO = miso;
+
+        obj->spi->EVENTS_READY = 0U;
+
+        spi_format(obj, 8, 0, 0);  // 8 bits, mode 0, master
+        spi_frequency(obj, 1000000);
+    }
+}
+
+void spi_free(spi_t *obj)
+{
+}
+
+static inline void spi_disable(spi_t *obj, int slave)
+{
+    if (slave) {
+        obj->spis->ENABLE = (SPIS_ENABLE_ENABLE_Disabled << SPIS_ENABLE_ENABLE_Pos);
+    } else {
+        obj->spi->ENABLE = (SPI_ENABLE_ENABLE_Disabled << SPI_ENABLE_ENABLE_Pos);
+    }
+}
+
+static inline void spi_enable(spi_t *obj, int slave)
+{
+    if (slave) {
+        obj->spis->ENABLE = (SPIS_ENABLE_ENABLE_Enabled << SPIS_ENABLE_ENABLE_Pos);
+    } else {
+        obj->spi->ENABLE = (SPI_ENABLE_ENABLE_Enabled << SPI_ENABLE_ENABLE_Pos);
+    }
+}
+
+void spi_format(spi_t *obj, int bits, int mode, int slave)
+{
+    uint32_t config_mode = 0;
+    spi_disable(obj, slave);
+
+    if (bits != 8) {
+        error("Only 8bits SPI supported");
+    }
+
+    switch (mode) {
+        case 0:
+            config_mode = (SPI_CONFIG_CPHA_Leading << SPI_CONFIG_CPHA_Pos) | (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos);
+            break;
+        case 1:
+            config_mode = (SPI_CONFIG_CPHA_Trailing << SPI_CONFIG_CPHA_Pos) | (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos);
+            break;
+        case 2:
+            config_mode = (SPI_CONFIG_CPHA_Leading << SPI_CONFIG_CPHA_Pos) | (SPI_CONFIG_CPOL_ActiveLow << SPI_CONFIG_CPOL_Pos);
+            break;
+        case 3:
+            config_mode = (SPI_CONFIG_CPHA_Trailing << SPI_CONFIG_CPHA_Pos) | (SPI_CONFIG_CPOL_ActiveLow << SPI_CONFIG_CPOL_Pos);
+            break;
+        default:
+            error("SPI format error");
+            break;
+    }
+    //default to msb first
+    if (slave) {
+        obj->spis->CONFIG = (config_mode | (SPI_CONFIG_ORDER_MsbFirst << SPI_CONFIG_ORDER_Pos));
+    } else {
+        obj->spi->CONFIG = (config_mode | (SPI_CONFIG_ORDER_MsbFirst << SPI_CONFIG_ORDER_Pos));
+    }
+
+    spi_enable(obj, slave);
+}
+
+void spi_frequency(spi_t *obj, int hz)
+{
+    if ((int)obj->spi==NC) {
+        return;
+    }
+    spi_disable(obj, 0);
+
+    if (hz<250000) { //125Kbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_K125;
+    } else if (hz<500000) { //250Kbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_K250;
+    } else if (hz<1000000) { //500Kbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_K500;
+    } else if (hz<2000000) { //1Mbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_M1;
+    } else if (hz<4000000) { //2Mbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_M2;
+    } else if (hz<8000000) { //4Mbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_M4;
+    } else { //8Mbps
+        obj->spi->FREQUENCY = (uint32_t) SPI_FREQUENCY_FREQUENCY_M8;
+    }
+
+    spi_enable(obj, 0);
+}
+
+static inline int spi_readable(spi_t *obj)
+{
+    return (obj->spi->EVENTS_READY == 1);
+}
+
+static inline int spi_writeable(spi_t *obj)
+{
+    return (obj->spi->EVENTS_READY == 0);
+}
+
+static inline int spi_read(spi_t *obj)
+{
+    while (!spi_readable(obj)) {
+    }
+
+    obj->spi->EVENTS_READY = 0;
+    return (int)obj->spi->RXD;
+}
+
+int spi_master_write(spi_t *obj, int value)
+{
+    while (!spi_writeable(obj)) {
+    }
+    obj->spi->TXD = (uint32_t)value;
+    return spi_read(obj);
+}
+
+//static inline int spis_writeable(spi_t *obj) {
+//    return (obj->spis->EVENTS_ACQUIRED==1);
+//}
+
+int spi_slave_receive(spi_t *obj)
+{
+    return obj->spis->EVENTS_END;
+}
+
+int spi_slave_read(spi_t *obj)
+{
+    return m_rx_buf[0];
+}
+
+void spi_slave_write(spi_t *obj, int value)
+{
+    m_tx_buf[0]                = value & 0xFF;
+    obj->spis->TASKS_RELEASE   = 1;
+    obj->spis->EVENTS_ACQUIRED = 0;
+    obj->spis->EVENTS_END      = 0;
+}