Import and use SPI master routines

from https://github.com/ataradov/dgw/

4 files changed, 156 insertions, 0 deletions

diff --git a/firmware/main.c b/firmware/main.c
index 351098f..bf094de 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -38,6 +38,7 @@
 #include "usb.h"
 #include "uart.h"
 #include "i2c_master.h"
+#include "spi_master.h"
 
 /*- Definitions -------------------------------------------------------------*/
 #define USB_BUFFER_SIZE        64
@@ -303,6 +304,8 @@ int main(void)
   i2c_init(400000);
   clkgen_init();
 
+  spi_init(1000000, 0);
+
   usb_init();
   usb_cdc_init();
   set_status_state(false);
diff --git a/firmware/make/Makefile b/firmware/make/Makefile
index dbfc57d..f1f3fde 100644
--- a/firmware/make/Makefile
+++ b/firmware/make/Makefile
@@ -29,6 +29,7 @@ SRCS += \
   ../clkgen/clkgen.c \

   ../clkgen/si5351c.c \

   ../i2c_master.c \

+  ../spi_master.c \

   ../main.c \

   ../uart.c \

   ../usb.c \

diff --git a/firmware/spi_master.c b/firmware/spi_master.c
new file mode 100644
index 0000000..25ed6bb
--- /dev/null
+++ b/firmware/spi_master.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2016, Alex Taradov <alex@taradov.com>
+ * 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. The name of the author may not 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.
+ */
+
+/*- Includes ----------------------------------------------------------------*/
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include "samd21.h"
+#include "hal_gpio.h"
+#include "spi_master.h"
+
+/*- Definitions -------------------------------------------------------------*/
+HAL_GPIO_PIN(MISO,            A, 4);
+HAL_GPIO_PIN(MOSI,            A, 6);
+HAL_GPIO_PIN(SCLK,            A, 7);
+HAL_GPIO_PIN(SS,              A, 5);
+#define SPI_SERCOM            SERCOM0
+#define SPI_SERCOM_PMUX       PORT_PMUX_PMUXE_D_Val
+#define SPI_SERCOM_GCLK_ID    SERCOM0_GCLK_ID_CORE
+#define SPI_SERCOM_CLK_GEN    0
+#define SPI_SERCOM_APBCMASK   PM_APBCMASK_SERCOM0
+
+/*- Implementations ---------------------------------------------------------*/
+
+//-----------------------------------------------------------------------------
+int spi_init(int freq, int mode)
+{
+  int baud = F_CPU / (2 * freq) - 1;
+
+  if (baud < 0)
+    baud = 0;
+
+  if (baud > 255)
+    baud = 255;
+
+  freq = F_CPU / (2 * (baud + 1));
+
+  HAL_GPIO_MISO_in();
+  HAL_GPIO_MISO_pmuxen(SPI_SERCOM_PMUX);
+
+  HAL_GPIO_MOSI_out();
+  HAL_GPIO_MOSI_pmuxen(SPI_SERCOM_PMUX);
+
+  HAL_GPIO_SCLK_out();
+  HAL_GPIO_SCLK_pmuxen(SPI_SERCOM_PMUX);
+
+  HAL_GPIO_SS_out();
+  HAL_GPIO_SS_set();
+
+  PM->APBCMASK.reg |= SPI_SERCOM_APBCMASK;
+
+  GCLK->CLKCTRL.reg = GCLK_CLKCTRL_ID(SPI_SERCOM_GCLK_ID) |
+      GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN(SPI_SERCOM_CLK_GEN);
+
+  SPI_SERCOM->SPI.CTRLA.reg = SERCOM_SPI_CTRLA_SWRST;
+  while (SPI_SERCOM->SPI.CTRLA.reg & SERCOM_SPI_CTRLA_SWRST);
+
+  SPI_SERCOM->SPI.CTRLB.reg = SERCOM_SPI_CTRLB_RXEN;
+
+  SPI_SERCOM->SPI.BAUD.reg = baud;
+
+  SPI_SERCOM->SPI.CTRLA.reg = SERCOM_SPI_CTRLA_ENABLE |
+      SERCOM_SPI_CTRLA_DIPO(0) | SERCOM_SPI_CTRLA_DOPO(1) |
+      ((mode & 1) ? SERCOM_SPI_CTRLA_CPHA : 0) |
+      ((mode & 2) ? SERCOM_SPI_CTRLA_CPOL : 0) |
+      SERCOM_SPI_CTRLA_MODE_SPI_MASTER;
+
+  return freq;
+}
+
+//-----------------------------------------------------------------------------
+void spi_ss(int state)
+{
+  while (!SPI_SERCOM->SPI.INTFLAG.bit.DRE);
+  HAL_GPIO_SS_write(state);
+}
+
+//-----------------------------------------------------------------------------
+uint8_t spi_write_byte(uint8_t byte)
+{
+  SPI_SERCOM->SPI.DATA.reg = byte;
+  while (!SPI_SERCOM->SPI.INTFLAG.bit.RXC);
+  return SPI_SERCOM->SPI.DATA.reg;
+}
+
diff --git a/firmware/spi_master.h b/firmware/spi_master.h
new file mode 100644
index 0000000..c076d5e
--- /dev/null
+++ b/firmware/spi_master.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2016, Alex Taradov <alex@taradov.com>
+ * 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. The name of the author may not 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.
+ */
+
+#ifndef _SPI_MASTER_H_
+#define _SPI_MASTER_H_
+
+/*- Includes ----------------------------------------------------------------*/
+#include <stdint.h>
+#include <stdbool.h>
+
+/*- Prototypes --------------------------------------------------------------*/
+int spi_init(int freq, int mode);
+void spi_ss(int state);
+uint8_t spi_write_byte(uint8_t byte);
+
+#endif // _SPI_MASTER_H_
+