Return only IIC_Exxxx status values from iicbus-layer functions. Most of

these functions are thin wrappers around calling the hardware-layer driver,
but some of them do sanity checks and return an error.  Since the hardware
layer can only return IIC_Exxxxx status values, the iicbus helper functions
must also adhere to that, so that drivers at higher layers can assume that
any non-zero status value is an IIC_Exxxx value that provides details about
what happened at the hardware layer (sometimes those details are important
for certain slave drivers).

diff --git a/sys/dev/iicbus/iiconf.c b/sys/dev/iicbus/iiconf.c
index 987bbb67441e9ca4d0b3cf4b3ce9f66100971527..41bb7c7661e919dec3484d41a77ad799816b7c3f 100644 (file)
--- a/sys/dev/iicbus/iiconf.c
+++ b/sys/dev/iicbus/iiconf.c
@@ -207,7 +207,7 @@ iicbus_start(device_t bus, u_char slave, int timeout)
        int error = 0;
 
        if (sc->started)
-               return (EINVAL);                /* bus already started */
+               return (IIC_ESTATUS); /* protocol error, bus already started */
 
        if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
                sc->started = slave;
@@ -229,7 +229,7 @@ iicbus_repeated_start(device_t bus, u_char slave, int timeout)
        int error = 0;
 
        if (!sc->started)
-               return (EINVAL);     /* bus should have been already started */
+               return (IIC_ESTATUS); /* protocol error, bus not started */
 
        if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
                sc->started = slave;
@@ -251,7 +251,7 @@ iicbus_stop(device_t bus)
        int error = 0;
 
        if (!sc->started)
-               return (EINVAL);                /* bus not started */
+               return (IIC_ESTATUS); /* protocol error, bus not started */
 
        error = IICBUS_STOP(device_get_parent(bus));
 
@@ -274,7 +274,7 @@ iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
        
        /* a slave must have been started for writing */
        if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
-               return (EINVAL);
+               return (IIC_ESTATUS);
 
        return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
 }
@@ -292,7 +292,7 @@ iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
        
        /* a slave must have been started for reading */
        if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
-               return (EINVAL);
+               return (IIC_ESTATUS);
 
        return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
 }
@@ -305,9 +305,14 @@ iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
 int
 iicbus_write_byte(device_t bus, char byte, int timeout)
 {
+       struct iicbus_softc *sc = device_get_softc(bus);
        char data = byte;
        int sent;
 
+       /* a slave must have been started for writing */
+       if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
+               return (IIC_ESTATUS);
+
        return (iicbus_write(bus, &data, 1, &sent, timeout));
 }
 
@@ -319,8 +324,13 @@ iicbus_write_byte(device_t bus, char byte, int timeout)
 int
 iicbus_read_byte(device_t bus, char *byte, int timeout)
 {
+       struct iicbus_softc *sc = device_get_softc(bus);
        int read;
 
+       /* a slave must have been started for reading */
+       if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
+               return (IIC_ESTATUS);
+
        return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
 }
 
@@ -381,6 +391,7 @@ iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
 int
 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
 {
+
        return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
 }
 
@@ -397,10 +408,10 @@ iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
        bool nostop;
 
        if ((error = device_get_children(dev, &children, &nkid)) != 0)
-               return (error);
+               return (IIC_ERESOURCE);
        if (nkid != 1) {
                free(children, M_TEMP);
-               return (EIO);
+               return (IIC_ENOTSUPP);
        }
        bus = children[0];
        rpstart = 0;

diff --git a/sys/dev/iicbus/iiconf.h b/sys/dev/iicbus/iiconf.h
index 92763a10ee6292dc7f5ba5e00e192432ca6e3587..462165682a859aa27a46d6a3b603df8366bc73be 100644 (file)
--- a/sys/dev/iicbus/iiconf.h
+++ b/sys/dev/iicbus/iiconf.h
@@ -93,6 +93,10 @@
 #define IIC_ENOADDR    0x9     /* no address assigned to the interface */
 #define IIC_ERESOURCE  0xa     /* resources (memory, whatever) unavailable */
 
+/*
+ * Note that all iicbus functions return IIC_Exxxxx status values,
+ * except iic2errno() (obviously) and iicbus_started() (returns bool).
+ */
 extern int iic2errno(int);
 extern int iicbus_request_bus(device_t, device_t, int);
 extern int iicbus_release_bus(device_t, device_t);