watch library: implement SPI

apps/spi-test/app.c

@@ -3,40 +3,10 @@
 #include <peripheral_clk_config.h>
 #include "watch.h"
 
-// NOTE: as of this writing (10/25/21) there is no SPI controller functionality in the watch library.
-// this is a very basic app to confirm that SPI is working, tested with board OSO-MISC-21-001 and a GD25Q16C Flash chip.
-// The updated SPI Flash sensor board design is OSO-MISC-21-017 (it's easier to build, 0603 passives instead of 0402's).
-
-struct io_descriptor *io;
-struct spi_m_sync_descriptor SPI_0;
+// this is a very basic app to confirm that SPI is working, tested with board OSO-MISC-21-017 and a GD25Q16C Flash chip.
 
 void app_init(void) {
-    // SPI_0_CLOCK_init
-    hri_gclk_write_PCHCTRL_reg(GCLK, SERCOM3_GCLK_ID_CORE, CONF_GCLK_SERCOM3_CORE_SRC | (1 << GCLK_PCHCTRL_CHEN_Pos));
-    hri_gclk_write_PCHCTRL_reg(GCLK, SERCOM3_GCLK_ID_SLOW, CONF_GCLK_SERCOM3_SLOW_SRC | (1 << GCLK_PCHCTRL_CHEN_Pos));
-    hri_mclk_set_APBCMASK_SERCOM3_bit(MCLK);
-
-    spi_m_sync_init(&SPI_0, SERCOM3);
-
-    // SPI_0_PORT_init
-    gpio_set_pin_level(A3, true);
-    gpio_set_pin_direction(A3, GPIO_DIRECTION_OUT);
-    gpio_set_pin_function(A3, GPIO_PIN_FUNCTION_OFF);
-
-    gpio_set_pin_level(A2, false);
-    gpio_set_pin_direction(A2, GPIO_DIRECTION_OUT);
-    gpio_set_pin_function(A2, PINMUX_PB02C_SERCOM3_PAD0);
-
-    gpio_set_pin_direction(A4, GPIO_DIRECTION_IN);
-    gpio_set_pin_pull_mode(A4, GPIO_PULL_OFF);
-    gpio_set_pin_function(A4, PINMUX_PB00C_SERCOM3_PAD2);
-
-    gpio_set_pin_level(A1, false);
-    gpio_set_pin_direction(A1, GPIO_DIRECTION_OUT);
-    gpio_set_pin_function(A1, PINMUX_PB01C_SERCOM3_PAD3);
-
-    spi_m_sync_get_io_descriptor(&SPI_0, &io);
-    spi_m_sync_enable(&SPI_0);
+    watch_enable_spi();
 }
 
 void app_wake_from_backup(void) {
@@ -51,20 +21,23 @@ void app_prepare_for_standby(void) {
 void app_wake_from_standby(void) {
 }
 
-static uint8_t get_id_command[4] = {0x9F};
 
 bool app_loop(void) {
-    watch_set_pin_level(A3, false);
-    io_write(io, get_id_command, 1);
+    uint8_t get_id_command[1] = {0x9F};
     uint8_t buf[3] = {0};
 
+    watch_set_pin_level(A3, false);
+
     // should print 0, 0, 0
+    watch_spi_send(get_id_command, 1);
     printf("blank: %x, %x, %x\n", buf[0], buf[1], buf[2]);
-    io_read(io, buf, 3);
-    watch_set_pin_level(A3, true);
+
     // should print c8, 40, 15
+    watch_spi_receive(buf, 3);
     printf("ident: %x, %x, %x\n", buf[0], buf[1], buf[2]);
 
+    watch_set_pin_level(A3, true);
+
     delay_ms(100);
 
     return false;

make.mk

@@ -85,6 +85,7 @@ SRCS += \
   $(TOP)/watch-library/hardware/watch/watch_adc.c \
   $(TOP)/watch-library/hardware/watch/watch_gpio.c \
   $(TOP)/watch-library/hardware/watch/watch_i2c.c \
+  $(TOP)/watch-library/hardware/watch/watch_spi.c \
   $(TOP)/watch-library/hardware/watch/watch_uart.c \
   $(TOP)/watch-library/hardware/watch/watch_deepsleep.c \
   $(TOP)/watch-library/hardware/watch/watch_private.c \
@@ -152,6 +153,7 @@ SRCS += \
   $(TOP)/watch-library/simulator/watch/watch_adc.c \
   $(TOP)/watch-library/simulator/watch/watch_gpio.c \
   $(TOP)/watch-library/simulator/watch/watch_i2c.c \
+  $(TOP)/watch-library/simulator/watch/watch_spi.c \
   $(TOP)/watch-library/simulator/watch/watch_uart.c \
   $(TOP)/watch-library/simulator/watch/watch_deepsleep.c \
   $(TOP)/watch-library/simulator/watch/watch_private.c \

watch-library/hardware/hw/driver_init.c

@@ -15,6 +15,8 @@ struct slcd_sync_descriptor SEGMENT_LCD_0;
 
 struct i2c_m_sync_desc I2C_0;
 
+struct spi_m_sync_descriptor SPI_0;
+
 void I2C_0_PORT_init(void) {
 
 	gpio_set_pin_pull_mode(SDA,
@@ -50,6 +52,68 @@ void I2C_0_init(void) {
 	I2C_0_PORT_init();
 }
 
+void SPI_0_PORT_init(void) {
+
+	gpio_set_pin_level(A2,
+	                   // <y> Initial level
+	                   // <id> pad_initial_level
+	                   // <false"> Low
+	                   // <true"> High
+	                   false);
+
+	// Set pin direction to output
+	gpio_set_pin_direction(A2, GPIO_DIRECTION_OUT);
+
+	gpio_set_pin_function(A2, PINMUX_PB02C_SERCOM3_PAD0);
+
+	// Set pin direction to input
+	gpio_set_pin_direction(A4, GPIO_DIRECTION_IN);
+
+	gpio_set_pin_pull_mode(A4,
+	                       // <y> Pull configuration
+	                       // <id> pad_pull_config
+	                       // <GPIO_PULL_OFF"> Off
+	                       // <GPIO_PULL_UP"> Pull-up
+	                       // <GPIO_PULL_DOWN"> Pull-down
+	                       GPIO_PULL_OFF);
+
+	gpio_set_pin_function(A4, PINMUX_PB00C_SERCOM3_PAD2);
+
+	gpio_set_pin_level(A1,
+	                   // <y> Initial level
+	                   // <id> pad_initial_level
+	                   // <false"> Low
+	                   // <true"> High
+	                   false);
+
+	// Set pin direction to output
+	gpio_set_pin_direction(A1, GPIO_DIRECTION_OUT);
+
+	gpio_set_pin_function(A1, PINMUX_PB01C_SERCOM3_PAD3);
+
+	gpio_set_pin_level(A3,
+	                   // <y> Initial level
+	                   // <id> pad_initial_level
+	                   // <false"> Low
+	                   // <true"> High
+	                   true);
+
+	// Set pin direction to output
+	gpio_set_pin_direction(A3, GPIO_DIRECTION_OUT);
+}
+
+void SPI_0_CLOCK_init(void) {
+	hri_gclk_write_PCHCTRL_reg(GCLK, SERCOM3_GCLK_ID_CORE, CONF_GCLK_SERCOM3_CORE_SRC | (1 << GCLK_PCHCTRL_CHEN_Pos));
+	hri_gclk_write_PCHCTRL_reg(GCLK, SERCOM3_GCLK_ID_SLOW, CONF_GCLK_SERCOM3_SLOW_SRC | (1 << GCLK_PCHCTRL_CHEN_Pos));
+	hri_mclk_set_APBCMASK_SERCOM3_bit(MCLK);
+}
+
+void SPI_0_init(void) {
+	SPI_0_CLOCK_init();
+	spi_m_sync_init(&SPI_0, SERCOM3);
+	SPI_0_PORT_init();
+}
+
 void delay_driver_init(void) {
 	delay_init(SysTick);
 }

watch-library/hardware/hw/driver_init.h

@@ -43,12 +43,18 @@ extern struct i2c_m_sync_desc I2C_0;
 
 extern struct usart_sync_descriptor USART_0;
 
+extern struct spi_m_sync_descriptor SPI_0;
+
 extern struct slcd_sync_descriptor SEGMENT_LCD_0;
 
 void I2C_0_CLOCK_init(void);
 void I2C_0_init(void);
 void I2C_0_PORT_init(void);
 
+void SPI_0_PORT_init(void);
+void SPI_0_CLOCK_init(void);
+void SPI_0_init(void);
+
 void delay_driver_init(void);
 
 void EXTERNAL_IRQ_0_init(void);

watch-library/hardware/watch/watch_spi.c

@@ -0,0 +1,46 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2022 Joey Castillo
+ *
+ * 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 THE
+ * AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#include "watch_spi.h"
+
+struct io_descriptor *spi_io;
+
+void watch_enable_spi(void) {
+    SPI_0_init();
+    spi_m_sync_get_io_descriptor(&SPI_0, &spi_io);
+    spi_m_sync_enable(&SPI_0);
+}
+
+void watch_disable_spi(void) {
+    spi_m_sync_disable(&SPI_0);
+    spi_io = NULL;
+}
+
+void watch_spi_send(uint8_t *buf, uint16_t length) {
+	io_write(spi_io, buf, length);
+}
+
+void watch_spi_receive(uint8_t *buf, uint16_t length) {
+	io_read(spi_io, buf, length);
+}

watch-library/shared/watch/watch.h

@@ -60,6 +60,7 @@
 #include "watch_adc.h"
 #include "watch_gpio.h"
 #include "watch_i2c.h"
+#include "watch_spi.h"
 #include "watch_uart.h"
 #include "watch_deepsleep.h"
 

watch-library/shared/watch/watch_spi.h

@@ -0,0 +1,59 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2022 Joey Castillo
+ *
+ * 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 THE
+ * AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#ifndef _WATCH_SPI_H_INCLUDED
+#define _WATCH_SPI_H_INCLUDED
+////< @file watch_spi.h
+
+#include "watch.h"
+
+/** @addtogroup spi SPI Controller Driver
+  * @brief This section covers functions related to the SAM L22's built-in SPI driver, including
+  *        configuring the SPI bus and writing to / reading from devices.
+  */
+/// @{
+/** @brief Enables the SPI peripheral. Call this before attempting to interface with SPI devices.
+  */
+void watch_enable_spi(void);
+
+/** @brief Disables the SPI peripheral.
+  */
+void watch_disable_spi(void);
+
+/** @brief Sends a series of values to a device on the SPI bus.
+  * @param buf A series of unsigned bytes; the data you wish to transmit.
+  * @param length The number of bytes in buf that you wish to send.
+  * @note This function does not manage the chip select pin (usually A3).
+  */
+void watch_spi_send(uint8_t *buf, uint16_t length);
+
+/** @brief Receives a series of values from a device on the SPI bus.
+  * @param buf Storage for the incoming bytes; on return, it will contain the received data.
+  * @param length The number of bytes that you wish to receive.
+  * @note This function does not manage the chip select pin (usually A3).
+  */
+void watch_spi_receive(uint8_t *buf, uint16_t length);
+
+/// @}
+#endif

watch-library/simulator/watch/watch_spi.c

@@ -0,0 +1,33 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2022 Joey Castillo
+ *
+ * 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 THE
+ * AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#include "watch_spi.h"
+
+void watch_enable_spi(void) {}
+
+void watch_disable_spi(void) {}
+
+void watch_spi_send(uint8_t *buf, uint16_t length) {}
+
+void watch_spi_receive(uint8_t *buf, uint16_t length) {}