iicbb is generic support for I2C bit-banging.

Other files: timeout management added to the I2C framework.

1 files changed, 96 insertions, 31 deletions

diff --git a/sys/dev/iicbus/iicbus.c b/sys/dev/iicbus/iicbus.c
index 41a0cea..930858f 100644
--- a/sys/dev/iicbus/iicbus.c
+++ b/sys/dev/iicbus/iicbus.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: iicbus.c,v 1.1.2.7 1998/08/29 16:54:16 son Exp $
+ *	$Id: iicbus.c,v 1.1.1.1 1998/09/03 20:51:50 nsouch Exp $
  *
  */
 
@@ -54,6 +54,7 @@ struct iicbus_device {
 	int iicd_class;			/* driver or slave device class */
 	const char *iicd_desc;		/* device descriptor */
 	u_char iicd_addr;		/* address of the device */
+	int iicd_waitack;		/* wait for ack timeout or delay */
 	int iicd_alive;			/* 1 if device found */
 };
 
@@ -61,8 +62,8 @@ struct iicbus_device {
  * Common I2C addresses
  */
 #define I2C_GENERAL_CALL	0x0
-#define I2C_MASTER_ADDRESS	0xaa
-#define I2C_INET_ADDRESS	0xaa
+#define PCF_MASTER_ADDRESS	0xaa
+#define FIRST_SLAVE_ADDR	0x2
 
 #define MAXSLAVE 256
 
@@ -74,11 +75,13 @@ struct iicbus_device {
  * list of known devices
  */
 struct iicbus_device iicbus_children[] = {
-	{ "iic", IICBUS_DRIVER_CLASS, "General Call", I2C_GENERAL_CALL },
 	{ "iicsmb", IICBUS_DRIVER_CLASS, "I2C to SMB bridge" },
 	{ "iic", IICBUS_DEVICE_CLASS, "PCF8574 I2C to 8 bits parallel i/o", 64},
-	{ "iic", IICBUS_DEVICE_CLASS, "PCF8584 as slave", I2C_MASTER_ADDRESS },
-	{ "ic", IICBUS_DEVICE_CLASS, "network interface", I2C_INET_ADDRESS },
+	{ "iic", IICBUS_DEVICE_CLASS, "PCF8584 as slave", PCF_MASTER_ADDRESS },
+	{ "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS },
+#if 0
+	{ "iic", IICBUS_DRIVER_CLASS, "General Call", I2C_GENERAL_CALL },
+#endif
 	{ NULL, 0 }
 };
 
@@ -91,6 +94,7 @@ static int iicbus_probe(device_t);
 static int iicbus_attach(device_t);
 static void iicbus_print_child(device_t, device_t);
 static int iicbus_read_ivar(device_t , device_t, int, u_long *);
+static int iicbus_write_ivar(device_t , device_t, int, u_long);
 
 static device_method_t iicbus_methods[] = {
         /* device interface */
@@ -102,7 +106,7 @@ static device_method_t iicbus_methods[] = {
         /* bus interface */
         DEVMETHOD(bus_print_child,      iicbus_print_child),
         DEVMETHOD(bus_read_ivar,        iicbus_read_ivar),
-        DEVMETHOD(bus_write_ivar,       bus_generic_write_ivar),
+        DEVMETHOD(bus_write_ivar,       iicbus_write_ivar),
         DEVMETHOD(bus_create_intr,      bus_generic_create_intr),
         DEVMETHOD(bus_connect_intr,     bus_generic_connect_intr),
 
@@ -116,50 +120,85 @@ static driver_t iicbus_driver = {
         sizeof(struct iicbus_softc),
 };
 
+static int
+iicbus_probe(device_t dev)
+{
+	/* always present if probed */
+	return (0);
+}
+
+#define MAXADDR	256
+static int iicdev_found[MAXADDR];
+
+static int 
+iic_probe_device(device_t dev, u_char addr)
+{
+	int count;
+	char byte;
+
+	if ((addr & 1) == 0) {
+		/* is device writable? */
+		if (!iicbus_start(dev, (u_char)addr, 0)) {
+			iicbus_stop(dev);
+			return (1);
+		}
+	} else {
+		/* is device readable? */
+		if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
+			return (1);
+	}
+
+	return (0);
+}
+
 /*
- * At 'probe' time, we add all the devices which we know about to the
- * bus.  The generic attach routine will probe and attach them if they
- * are alive.
+ * We add all the devices which we know about.
+ * The generic attach routine will attach them if they are alive.
  */
 static int
-iicbus_probe(device_t dev)
+iicbus_attach(device_t dev)
 {
 	struct iicbus_softc *sc = device_get_softc(dev);
 	struct iicbus_device *iicdev;
 	device_t child;
+	int addr, count;
+	char byte;
 
-	/* XXX should query parent */
-	sc->ownaddr = I2C_MASTER_ADDRESS;
+	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
 
-	iicbus_reset(dev, IIC_FASTEST);
+	printf("Probing for devices on iicbus%d:", device_get_unit(dev));
 
-	for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) {
+	/* probe any devices */
+	for (addr = FIRST_SLAVE_ADDR; addr < MAXADDR; addr++) {
+		if (iic_probe_device(dev, (u_char)addr)) {
+			printf(" <%x>", addr);
+		}
+	}
+	printf("\n");
 
+	/* attach known devices */
+	for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) {
 		/* probe devices, not drivers */
 		switch (iicdev->iicd_class) {
 		case IICBUS_DEVICE_CLASS:
-			if (!iicbus_start(dev, iicdev->iicd_addr)) {
-				iicbus_stop(dev);
+			if (iic_probe_device(dev, iicdev->iicd_addr))
 				iicdev->iicd_alive = 1;
-			}
 			break;
+
 		case IICBUS_DRIVER_CLASS:
-			iicdev->iicd_addr = sc->ownaddr;
+			iicdev->iicd_alive = 1;
 			break;
+
 		default:
 			panic("%s: unknown class!", __FUNCTION__);
 		}
 
-		child = device_add_child(dev, iicdev->iicd_name, -1, iicdev);
-		device_set_desc(child, iicdev->iicd_desc);
+		if (iicdev->iicd_alive) {
+			child = device_add_child(dev, iicdev->iicd_name,
+								-1, iicdev);
+			device_set_desc(child, iicdev->iicd_desc);
+		}
 	}
-
-	return (0);
-}
-
-static int
-iicbus_attach(device_t dev)
-{
 	bus_generic_attach(dev);
          
         return (0);
@@ -171,6 +210,18 @@ iicbus_generic_intr(device_t dev, int event, char *buf)
 	return (0);
 }
 
+int
+iicbus_null_callback(device_t dev, int index, caddr_t data)
+{
+	return (0);
+}
+
+int
+iicbus_null_repeated_start(device_t dev, u_char addr)
+{
+	return (IIC_ENOTSUPP);
+}
+
 static void
 iicbus_print_child(device_t bus, device_t dev)
 {
@@ -178,9 +229,8 @@ iicbus_print_child(device_t bus, device_t dev)
 
 	switch (iicdev->iicd_class) {	
 	case IICBUS_DEVICE_CLASS:
-		printf(" on %s%d addr %d %s", device_get_name(bus),
-			device_get_unit(bus), iicdev->iicd_addr,
-			(iicdev->iicd_alive) ? "found" : "not found");
+		printf(" on %s%d addr 0x%x", device_get_name(bus),
+			device_get_unit(bus), iicdev->iicd_addr);
 		break;
 
 	case IICBUS_DRIVER_CLASS:
@@ -212,4 +262,19 @@ iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result)
 	return (0);
 }
 
+static int
+iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val)
+{
+	struct iicbus_device* iicdev = DEVTOIICBUS(dev);
+
+	switch (index) {
+	default:
+		return (ENOENT);
+	}
+
+	return (0);
+}
+
 DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
+DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
+DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0);