dev/i2c: report -ENODEV if device not responding

78486bb6 · Tomasz Wlostowski · 8cdc1250 · 78486bb6 · 78486bb6 · 78486bb6
Commit 78486bb6 authored Oct 16, 2020 by Tomasz Wlostowski
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Showing with 15 additions and 6 deletions

24aa025.c dev/24aa025.c +9 -2

bb_i2c.c dev/bb_i2c.c +5 -3

bb_i2c.h include/dev/bb_i2c.h +1 -1

No files found.
--- a/dev/24aa025.c
+++ b/dev/24aa025.c
@@ -23,6 +23,8 @@
 #include "dev/i2c.h"
 #include "dev/24aa025.h"

+#include <errno.h>
+
 int m24aa025_init(struct m24aa025_device *dev, struct i2c_bus *i2c, uint8_t addr)
 {
    dev->bus = i2c;
@@ -36,8 +38,13 @@ int m24aa025_read_mac(struct m24aa025_device *dev, uint8_t *mac)
    int i;

    bb_i2c_start( dev->bus );
-    
-    bb_i2c_put_byte (dev->bus, dev->addr << 1);
+
+    if ( bb_i2c_put_byte (dev->bus, dev->addr << 1) < 0)
+    {
+        bb_i2c_stop( dev->bus );
+        return -ENODEV;
+    }
+
    bb_i2c_put_byte (dev->bus, 0xfa );
    bb_i2c_repeat_start( dev->bus );
    bb_i2c_put_byte (dev->bus, (dev->addr << 1) | 1);

--- a/dev/bb_i2c.c
+++ b/dev/bb_i2c.c
@@ -13,6 +13,8 @@
 #include "dev/bb_i2c.h"
 #include "dev/gpio.h"

+#include <errno.h>
+
 void bb_i2c_delay(uint32_t delay)
 {
 	int i;
@@ -45,7 +47,7 @@ void bb_i2c_stop(struct i2c_bus *bus)
 	M_SDA_OUT(1);
 }

-unsigned char bb_i2c_put_byte(struct i2c_bus *bus, uint8_t data)
+int bb_i2c_put_byte(struct i2c_bus *bus, uint8_t data)
 {
 	int i;
 	uint8_t ack;
@@ -59,11 +61,11 @@ unsigned char bb_i2c_put_byte(struct i2c_bus *bus, uint8_t data)
 	M_SDA_OUT(1);
 	M_SCL_OUT(1);

-	ack = M_SDA_IN;	/* ack: sda is pulled low ->success.     */
+	ack = M_SDA_IN;	/* ack: sda is pulled low -> success.     */
 	M_SCL_OUT(0);
 	M_SDA_OUT(0);

-	return ack != 0;
+	return ack == 0 ? 0 : -ENODEV;
 }

 void bb_i2c_get_byte(struct i2c_bus *bus, uint8_t *data, uint8_t last)

--- a/include/dev/bb_i2c.h
+++ b/include/dev/bb_i2c.h
@@ -22,7 +22,7 @@ void bb_i2c_start(struct i2c_bus *bus);
 void bb_i2c_repeat_start(struct i2c_bus *bus);
 void bb_i2c_stop(struct i2c_bus *bus);
 void bb_i2c_get_byte(struct i2c_bus *bus, uint8_t *data, uint8_t last);
-uint8_t bb_i2c_put_byte(struct i2c_bus *bus, uint8_t data);
+int bb_i2c_put_byte(struct i2c_bus *bus, uint8_t data);
 void bb_i2c_delay(uint32_t delay);
 void bb_i2c_scan(struct i2c_bus *bus);