Add reference implementation for the FRDM-K66F.

It only supports I²S 16bit data 32bit word Stereo at 16000
sample/second.
The actual implementation might not reflect exactly what the format
structure requires.

Author: ithinuel

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/TARGET_FRDM/PeripheralNames.h

@@ -131,6 +131,10 @@ typedef enum {
     SPI_2 = 2,
 } SPIName;
 
+typedef enum {
+    SAI_0 = 0
+} SAIName;
+
 #ifdef __cplusplus
 }
 #endif

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/TARGET_FRDM/PeripheralPins.c

@@ -299,3 +299,65 @@ const PinMap PinMap_PWM[] = {
 
     {NC   , NC    , 0}
 };
+
+/************I2S***************/
+const PinMap PinMap_SAI_MCLK[] = {
+    {PTA17, SAI_0, 6},
+    {PTC6 , SAI_0, 6},
+    {PTC8 , SAI_0, 4},
+    {PTE6 , SAI_0, 4},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_TXSD[] = {
+    {PTA12, SAI_0, 6},
+    {PTA14, SAI_0, 7},
+    {PTC0 , SAI_0, 6},
+    {PTC1 , SAI_0, 6},
+    {PTE9 , SAI_0, 2},
+    {PTE10, SAI_0, 4},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_TXBCLK[] = {
+    {PTA5 , SAI_0, 6},
+    {PTB18, SAI_0, 4},
+    {PTC3 , SAI_0, 6},
+    {PTE12, SAI_0, 4},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_TXWCLK[] = {
+    {PTA13, SAI_0, 6},
+    {PTB19, SAI_0, 4},
+    {PTC2 , SAI_0, 6},
+    {PTE11, SAI_0, 4},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_RXSD[] = {
+    {PTA15, SAI_0, 6},
+    {PTA16, SAI_0, 7},
+    {PTC5 , SAI_0, 4},
+    {PTC11, SAI_0, 4},
+    {PTE7 , SAI_0, 4},
+    {PTE8 , SAI_0, 2},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_RXBCLK[] = {
+    {PTA14, SAI_0, 6},
+    {PTC6 , SAI_0, 4},
+    {PTC9 , SAI_0, 4},
+    {PTE9 , SAI_0, 4},
+
+    {NC   , NC, 0}
+};
+const PinMap PinMap_SAI_RXWCLK[] = {
+    {PTA16, SAI_0, 6},
+    {PTC7 , SAI_0, 4},
+    {PTC10, SAI_0, 4},
+    {PTE8 , SAI_0, 4},
+
+    {NC, NC, 0}
+};

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/TARGET_FRDM/PinNames.h

@@ -191,6 +191,10 @@ typedef enum {
     PTE30 = (4 << GPIO_PORT_SHIFT | 30),
     PTE31 = (4 << GPIO_PORT_SHIFT | 31),
 
+    // Not connected
+    NC = (int)0xFFFFFFFF,
+
+    // common name
     LED_RED   = PTC9,
     LED_GREEN = PTE6,
     LED_BLUE  = PTA11,
@@ -212,6 +216,16 @@ typedef enum {
     USBTX = PTB17,
     USBRX = PTB16,
 
+    // Audio bus
+    SAI_A_MCLK = PTC6,
+    SAI_A_SD   = PTE7,
+    SAI_A_BCLK = PTE9,
+    SAI_A_WCLK = PTE8,
+    SAI_B_MCLK = PTC6,
+    SAI_B_SD   = PTC1,
+    SAI_B_BCLK = PTE12,
+    SAI_B_WCLK = PTE11,
+
     // Arduino Headers
     D0 = PTC3,
     D1 = PTC4,
@@ -241,9 +255,6 @@ typedef enum {
     A5 = PTB2,
 
     DAC0_OUT = 0xFEFE, /* DAC does not have Pin Name in RM */
-
-    // Not connected
-    NC = (int)0xFFFFFFFF
 } PinName;
 
 

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/TARGET_FRDM/device.h

@@ -26,7 +26,7 @@
 
 
 
-
+#define SAI_DEFAULT_SAMPLE_RATE (16000)
 
 #define DEVICE_ID_LENGTH       24
 

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_K66F/sai_api.c

@@ -0,0 +1,183 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2018 ARM Limited
+ *
+ * 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 "sai_api.h"
+
+#if DEVICE_SAI
+
+// math.h required for floating point operations for baud rate calculation
+#include <math.h>
+#include "mbed_assert.h"
+
+#include <string.h>
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "fsl_sai.h"
+#include "peripheral_clock_defines.h"
+#include "PeripheralPins.h"
+#include "fsl_clock_config.h"
+
+static I2S_Type *const sai_addrs[] = I2S_BASE_PTRS;
+
+sai_result_t sai_init(sai_t *obj, sai_init_t *init) {
+    int32_t base = NC;
+    int32_t tx = NC;
+    int32_t rx = NC;
+
+    MBED_ASSERT(init != NULL);
+    if (memcmp(&(init->format), &sai_mode_i2s16w32, sizeof(sai_format_t)) != 0) {
+        // we only support 1 format so far
+        return SAI_RESULT_CONFIG_UNSUPPORTED;
+    }
+    if ((init->mclk_source != SAI_CLOCK_SOURCE_Internal) || (init->input_mclk_frequency != 0)) {
+        return SAI_RESULT_CONFIG_UNSUPPORTED;
+    }
+    uint32_t mclk_freq = CLOCK_GetFreq(kCLOCK_CoreSysClk);
+
+    obj->is_receiver = init->is_receiver;
+
+    // validate pins & fetch base peripheral address
+    int32_t mclk = pinmap_peripheral(init->mclk, PinMap_SAI_MCLK);
+    if (obj->is_receiver) {
+        int32_t sd = pinmap_peripheral(init->sd, PinMap_SAI_RXSD);
+        int32_t bclk = pinmap_peripheral(init->bclk, PinMap_SAI_RXBCLK);
+        int32_t wclk = pinmap_peripheral(init->wclk, PinMap_SAI_RXWCLK);
+        MBED_ASSERT((sd != NC) && (bclk != NC) && (wclk != NC));
+        rx = pinmap_merge(pinmap_merge(sd, bclk), wclk);
+        MBED_ASSERT(rx != NC);
+    } else {
+        int32_t sd = pinmap_peripheral(init->sd, PinMap_SAI_TXSD);
+        int32_t bclk = pinmap_peripheral(init->bclk, PinMap_SAI_TXBCLK);
+        int32_t wclk = pinmap_peripheral(init->wclk, PinMap_SAI_TXWCLK);
+        MBED_ASSERT((sd != NC) && (bclk != NC) && (wclk != NC));
+        tx = pinmap_merge(pinmap_merge(sd, bclk), wclk);
+        MBED_ASSERT(tx != NC);
+    }
+    base = pinmap_merge(pinmap_merge(tx, rx), mclk);
+    MBED_ASSERT(base != NC);
+
+    obj->base = sai_addrs[base];
+
+    // enable recv
+    sai_config_t config;
+    sai_transfer_format_t format;
+
+    if (init->mclk != NC) {
+        pinmap_pinout(init->mclk, PinMap_SAI_MCLK);
+    }
+    if (obj->is_receiver) {
+        if (init->sd != NC) {
+            pinmap_pinout(init->sd, PinMap_SAI_RXSD);
+        }
+        if (init->bclk != NC) {
+            pinmap_pinout(init->bclk, PinMap_SAI_RXBCLK);
+        }
+        if (init->wclk != NC) {
+            pinmap_pinout(init->wclk, PinMap_SAI_RXWCLK);
+        }
+
+        /* Initialize SAI Rx */
+        SAI_RxGetDefaultConfig(&config);
+    } else {
+        if (init->sd != NC) {
+            pinmap_pinout(init->sd, PinMap_SAI_TXSD);
+        }
+        if (init->bclk != NC) {
+            pinmap_pinout(init->bclk, PinMap_SAI_TXBCLK);
+        }
+        if (init->wclk != NC) {
+            pinmap_pinout(init->wclk, PinMap_SAI_TXWCLK);
+        }
+
+        SAI_TxGetDefaultConfig(&config);
+    }
+
+    obj->channel = 0U; // we should get it from the sd pin
+
+    config.protocol = kSAI_BusI2S;
+
+    if (init->is_receiver) {
+        config.masterSlave = kSAI_Slave;
+        SAI_RxInit(obj->base, &config);
+    } else {
+        SAI_TxInit(obj->base, &config);
+    }
+
+    /* Configure the audio format */
+    format.bitWidth = init->format.data_length;
+    format.channel = obj->channel;
+    format.sampleRate_Hz = init->sample_rate;
+    format.masterClockHz = init->output_mclk_frequency;
+
+    format.protocol = config.protocol;
+    format.stereo = kSAI_Stereo;
+    // FSL_FEATURE_SAI_FIFO_COUNT = 8 on MK66F18
+    format.watermark = FSL_FEATURE_SAI_FIFO_COUNT / 2U;
+
+    if (obj->is_receiver) {
+        SAI_RxSetFormat(obj->base, &format, mclk_freq, format.masterClockHz);
+    } else {
+        SAI_TxSetFormat(obj->base, &format, mclk_freq, format.masterClockHz);
+    }
+
+    return SAI_RESULT_OK;
+}
+
+bool sai_xfer(sai_t *obj, uint32_t *sample) {
+    bool ret = false;
+    if (obj->is_receiver) {
+        if (sample != NULL) {
+            uint32_t flags = SAI_RxGetStatusFlag(obj->base);
+            if ((flags & I2S_RCSR_RE_MASK) == 0) {
+                SAI_RxEnable(obj->base, true);
+            }
+            ret = (flags & I2S_RCSR_FRF_MASK) == I2S_RCSR_FRF_MASK;
+            if (ret) {
+                *sample = SAI_ReadData(obj->base, obj->channel);
+            }
+            if ((flags & I2S_RCSR_FEF_MASK) == I2S_RCSR_FEF_MASK) {
+                SAI_RxClearStatusFlags(obj->base, I2S_RCSR_FEF_MASK);
+            }
+        }
+    } else {
+        uint32_t tmp_sample = 0;
+        if (sample != NULL) { tmp_sample = *sample; }
+
+        uint32_t flags = SAI_TxGetStatusFlag(obj->base);
+        if ((flags & I2S_TCSR_TE_MASK) == 0) {
+            SAI_TxEnable(obj->base, true);
+        }
+        if ((flags & I2S_TCSR_FEF_MASK) == I2S_TCSR_FEF_MASK) {
+            SAI_TxClearStatusFlags(obj->base, I2S_TCSR_FEF_MASK);
+        }
+        ret = (flags & I2S_TCSR_FWF_MASK) == I2S_TCSR_FWF_MASK;
+        if (ret) {
+            SAI_WriteData(obj->base, obj->channel, tmp_sample);
+        }
+    }
+    return ret;
+}
+
+/** Releases & de-initialize the referenced peripherals. */
+void sai_free(sai_t *obj) {
+    if (obj->is_receiver) {
+        SAI_RxEnable(obj->base, false);
+    } else {
+        SAI_TxEnable(obj->base, false);
+    }
+    // Should it also unclock the periph ?
+}
+#endif

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/api/PeripheralPins.h

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
- 
+
 #ifndef MBED_PERIPHERALPINS_H
 #define MBED_PERIPHERALPINS_H
 
@@ -47,4 +47,13 @@ extern const PinMap PinMap_SPI_SSEL[];
 /************PWM***************/
 extern const PinMap PinMap_PWM[];
 
+/************I2S***************/
+extern const PinMap PinMap_SAI_MCLK[];
+extern const PinMap PinMap_SAI_TXSD[];
+extern const PinMap PinMap_SAI_TXBCLK[];
+extern const PinMap PinMap_SAI_TXWCLK[];
+extern const PinMap PinMap_SAI_RXSD[];
+extern const PinMap PinMap_SAI_RXBCLK[];
+extern const PinMap PinMap_SAI_RXWCLK[];
+
 #endif

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/api/objects.h

@@ -95,6 +95,14 @@ struct flash_s {
     flash_config_t flash_config;
 };
 
+#ifdef DEVICE_SAI
+struct sai_s {
+    I2S_Type *base;
+    uint32_t channel;
+    bool is_receiver;
+};
+#endif // DEVICE_SAI
+
 #include "gpio_object.h"
 
 #ifdef __cplusplus

targets/targets.json

@@ -697,7 +697,7 @@
         "macros": ["CPU_MK66FN2M0VMD18", "FSL_RTOS_MBED"],
         "inherits": ["Target"],
         "detect_code": ["0311"],
-        "device_has": ["USTICKER", "LPTICKER", "RTC", "ANALOGIN", "ANALOGOUT", "EMAC", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG", "FLASH"],
+        "device_has": ["SAI", "USTICKER", "LPTICKER", "RTC", "ANALOGIN", "ANALOGOUT", "EMAC", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG", "FLASH"],
         "features": ["LWIP"],
         "release_versions": ["2", "5"],
         "device_name": "MK66FN2M0xxx18",