From f794bd4c8e2862033add275a6085f35ecd3b4033 Mon Sep 17 00:00:00 2001
From: Kees Bakker <kees@sodaq.com>
Date: Tue, 2 Aug 2016 21:56:31 +0200
Subject: [PATCH] cpu/samd21: spi: change #ifdef's to #if's
The board config can define SPI_1_EN as 0, and in that case #ifdef won't
work.
Add some more comments, and fix typos.
---
cpu/samd21/periph/spi.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/cpu/samd21/periph/spi.c b/cpu/samd21/periph/spi.c
index 415f742ef9..a58dcc9d7f 100644
--- a/cpu/samd21/periph/spi.c
+++ b/cpu/samd21/periph/spi.c
@@ -29,6 +29,7 @@
#include "board.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
+
#if SPI_0_EN || SPI_1_EN
/**
@@ -64,7 +65,7 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
uint8_t cpha = 0;
uint8_t cpol = 0;
uint32_t f_baud = 0;
- switch(speed)
+ switch (speed)
{
case SPI_SPEED_100KHZ:
f_baud = 100000;
@@ -90,7 +91,7 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
return -1;
#endif
}
- switch(conf)
+ switch (conf)
{
case SPI_CONF_FIRST_RISING: /**< first data bit is transacted on the first rising SCK edge */
cpha = 0;
@@ -109,9 +110,9 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
cpol = 1;
break;
}
- switch(dev)
+ switch (dev)
{
-#ifdef SPI_0_EN
+#if SPI_0_EN
case SPI_0:
spi_dev = &SPI_0_DEV;
@@ -149,7 +150,7 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
dipo = SPI_0_DIPO;
break;
#endif
-#ifdef SPI_1_EN
+#if SPI_1_EN
case SPI_1:
spi_dev = &SPI_1_DEV;
@@ -192,19 +193,19 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
_spi_poweroff(spi_dev);
spi_dev->CTRLA.reg |= SERCOM_SPI_CTRLA_MODE_SPI_MASTER;
- while (spi_dev->SYNCBUSY.reg) {}
+ while (spi_dev->SYNCBUSY.reg) {} // ???? not needed
- spi_dev->BAUD.bit.BAUD = (uint8_t) (((uint32_t)CLOCK_CORECLOCK) / (2 * f_baud) - 1); /* Syncronous mode*/
+ spi_dev->BAUD.bit.BAUD = (uint8_t) (((uint32_t)CLOCK_CORECLOCK) / (2 * f_baud) - 1); /* Synchronous mode*/
+ spi_dev->CTRLA.reg |= SERCOM_SPI_CTRLA_DOPO(dopo)
+ | SERCOM_SPI_CTRLA_DIPO(dipo)
+ | (cpha << SERCOM_SPI_CTRLA_CPHA_Pos)
+ | (cpol << SERCOM_SPI_CTRLA_CPOL_Pos);
+ while (spi_dev->SYNCBUSY.reg) {} // ???? not needed
- spi_dev->CTRLA.reg |= (SERCOM_SPI_CTRLA_DOPO(dopo))
- | (SERCOM_SPI_CTRLA_DIPO(dipo))
- | (cpha << SERCOM_SPI_CTRLA_CPHA_Pos)
- | (cpol << SERCOM_SPI_CTRLA_CPOL_Pos);
-
- while (spi_dev->SYNCBUSY.reg) {}
+ /* datasize 0 => 8 bits */
spi_dev->CTRLB.reg = (SERCOM_SPI_CTRLB_CHSIZE(0) | SERCOM_SPI_CTRLB_RXEN);
- while(spi_dev->SYNCBUSY.reg) {}
+ while (spi_dev->SYNCBUSY.reg) {} // ???? Only wait for clear of spi_dev->SYNCBUSY.bit.CTRLB
/* enable */
_spi_poweron(spi_dev);
@@ -247,12 +248,12 @@ int spi_transfer_byte(spi_t dev, char out, char *in)
switch(dev)
{
-#ifdef SPI_0_EN
+#if SPI_0_EN
case SPI_0:
spi_dev = &(SPI_0_DEV);
break;
#endif
-#ifdef SPI_1_EN
+#if SPI_1_EN
case SPI_1:
spi_dev = &(SPI_1_DEV);
break;
--
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