From 179a3cb89e19670557ed5aedfd110af673ce8808 Mon Sep 17 00:00:00 2001
From: Matthew Kennedy <matthewkennedy@outlook.com>
Date: Wed, 17 Feb 2021 11:48:21 -0800
Subject: [PATCH] use spiPolledExchange for small transfers (#2358)

* configure for no cache

* this doesn't need a setting

* now we don't need invalidate

* reorder and comment

* mmc

* sw knock

* use spiPolledExchange for small transfers

* mock spi

Co-authored-by: Matthew Kennedy <makenne@microsoft.com>
---
 firmware/hw_layer/drivers/gpio/tle8888.c |  3 +--
 firmware/hw_layer/mc33816.cpp            | 14 +++-----------
 firmware/hw_layer/sensors/cj125.cpp      | 17 ++++++-----------
 simulator/simulator/boards.h             |  1 +
 4 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/firmware/hw_layer/drivers/gpio/tle8888.c b/firmware/hw_layer/drivers/gpio/tle8888.c
index fd45d83746..aa9ae3a538 100644
--- a/firmware/hw_layer/drivers/gpio/tle8888.c
+++ b/firmware/hw_layer/drivers/gpio/tle8888.c
@@ -344,7 +344,6 @@ static int tle8888_spi_rw(struct tle8888_priv *chip, uint16_t tx, uint16_t *rx_p
 	spiSelect(spi);
 	/* Atomic transfer operations. */
 	rx = spiPolledExchange(spi, tx);
-	//spiExchange(spi, 2, &tx, &rxb); 8 bit version just in case?
 	/* Slave Select de-assertion. */
 	spiUnselect(spi);
 	/* Ownership release. */
@@ -393,7 +392,7 @@ static int tle8888_spi_rw_array(struct tle8888_priv *chip, const uint16_t *tx, u
 		spiSelect(spi);
 		/* data transfer */
 		rxdata = spiPolledExchange(spi, tx[i]);
-		//spiExchange(spi, 2, &tx, &rxb); 8 bit version just in case?
+
 		if (rx)
 			rx[i] = rxdata;
 		/* Slave Select de-assertion. */
diff --git a/firmware/hw_layer/mc33816.cpp b/firmware/hw_layer/mc33816.cpp
index 30901ac640..1a0846d951 100644
--- a/firmware/hw_layer/mc33816.cpp
+++ b/firmware/hw_layer/mc33816.cpp
@@ -84,26 +84,18 @@ static void mcRestart();
 
 // Receive 16bits
 unsigned short recv_16bit_spi() {
-	unsigned short ret;
-	//spiSelect(driver);
-	spiReceive(driver, 1, &ret);
-	//spiUnselect(driver);
-	return ret;
+	return spiPolledExchange(driver, 0xFFFF);
 }
 
 // This could be used to detect if check byte is wrong.. or use a FLAG after init
 unsigned short txrx_16bit_spi(const unsigned short param) {
-	unsigned short ret;
-	//spiSelect(driver);
-	spiExchange(driver, 1, &param, &ret);
-	//spiUnselect(driver);
-	return ret;
+	return spiPolledExchange(driver, param);
 }
 
 // Send 16bits
 static void spi_writew(unsigned short param) {
 	//spiSelect(driver);
-	spiSend(driver, 1, &param);
+	spiPolledExchange(driver, param);
 	//spiUnselect(driver);
 }
 
diff --git a/firmware/hw_layer/sensors/cj125.cpp b/firmware/hw_layer/sensors/cj125.cpp
index 7248a73997..0ee3956c18 100644
--- a/firmware/hw_layer/sensors/cj125.cpp
+++ b/firmware/hw_layer/sensors/cj125.cpp
@@ -38,9 +38,6 @@ EXTERN_ENGINE;
 
 static Logging *logger;
 
-static uint8_t tx_buff[2] NO_CACHE;
-static uint8_t rx_buff[1] NO_CACHE;
-
 static CJ125 globalInstance;
 
 #if ! EFI_UNIT_TEST
@@ -97,30 +94,28 @@ static constexpr float lambdaLsu49[] = {
 static uint8_t cjReadRegister(uint8_t regAddr) {
 #if ! EFI_UNIT_TEST
 	spiSelect(driver);
-	tx_buff[0] = regAddr;
-	spiSend(driver, 1, tx_buff);
-	spiReceive(driver, 1, rx_buff);
+	spiPolledExchange(driver, regAddr);
+	uint8_t result = spiPolledExchange(driver, 0xFF);
 	spiUnselect(driver);
 
 #ifdef CJ125_DEBUG_SPI
-	scheduleMsg(logger, "cjReadRegister: addr=%d answer=%d", regAddr, rx_buff[0]);
+	scheduleMsg(logger, "cjReadRegister: addr=%d answer=%d", regAddr, result);
 #endif /* CJ125_DEBUG_SPI */
-	return rx_buff[0];
+	return result;
 #else /* EFI_UNIT_TEST */
 	return 0;
 #endif /* EFI_UNIT_TEST */
 }
 
 static void cjWriteRegister(uint8_t regAddr, uint8_t regValue) {
-	tx_buff[0] = regAddr;
-	tx_buff[1] = regValue;
 #ifdef CJ125_DEBUG_SPI
 	scheduleMsg(logger, "cjWriteRegister: addr=%d value=%d", regAddr, regValue);
 #endif /* CJ125_DEBUG_SPI */
 	// todo: extract 'sendSync' method?
 #if HAL_USE_SPI
 	spiSelect(driver);
-	spiSend(driver, 2, tx_buff);
+	spiPolledExchange(driver, regAddr);
+	spiPolledExchange(driver, regValue);
 	spiUnselect(driver);
 #endif /* HAL_USE_SPI */
 }
diff --git a/simulator/simulator/boards.h b/simulator/simulator/boards.h
index b930a769ab..1dc4d01351 100644
--- a/simulator/simulator/boards.h
+++ b/simulator/simulator/boards.h
@@ -32,6 +32,7 @@ typedef uint16_t adcsample_t;
 #define spiStop(x) {}
 #define spiSelect(x) {}
 #define spiSelectI(x) {}
+#define spiPolledExchange(x, y) {}
 #define spiSend(x, y, z) {}
 #define spiReceive(x, y, z) {}
 #define spiExchange(x,y,w,z) {}