pcf.c: timeout management added

ppc.c: nsc code improved. Actually, a complete rewrite.

1 files changed, 90 insertions, 47 deletions

diff --git a/sys/dev/pcf/pcf.c b/sys/dev/pcf/pcf.c
index bee0e15..771dd30 100644
--- a/sys/dev/pcf/pcf.c
+++ b/sys/dev/pcf/pcf.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: pcf.c,v 1.1 1998/09/03 21:01:22 nsouch Exp $
+ *	$Id: pcf.c,v 1.2 1998/10/22 05:58:40 bde Exp $
  *
  */
 #include <sys/param.h>
@@ -41,7 +41,7 @@
 #include <dev/iicbus/iiconf.h>
 #include "iicbus_if.h"
 
-#define TIMEOUT	99999					/* XXX */
+#define TIMEOUT	9999					/* XXX */
 
 /* Status bits of S1 register (read only) */
 #define nBB	0x01		/* busy when low set/reset by STOP/START*/
@@ -67,13 +67,15 @@
 #define SLAVE_TRANSMITTER	0x1
 #define SLAVE_RECEIVER		0x2
 
+#define PCF_DEFAULT_ADDR	0xaa
+
 struct pcf_softc {
 
 	int pcf_base;			/* isa port */
+	u_char pcf_addr;		/* interface I2C address */
 
-	int pcf_count;
-	int pcf_own_address;		/* own address */
 	int pcf_slave_mode;		/* receiver or transmitter */
+	int pcf_started;		/* 1 if start condition sent */
 
 	device_t iicbus;		/* the corresponding iicbus */
 };
@@ -103,8 +105,8 @@ static int pcf_probe(device_t);
 static int pcf_attach(device_t);
 static void pcf_print_child(device_t, device_t);
 
-static int pcf_repeated_start(device_t, u_char);
-static int pcf_start(device_t, u_char);
+static int pcf_repeated_start(device_t, u_char, int);
+static int pcf_start(device_t, u_char, int);
 static int pcf_stop(device_t);
 static int pcf_write(device_t, char *, int, int *);
 static int pcf_read(device_t, char *, int, int *);
@@ -120,6 +122,7 @@ static device_method_t pcf_methods[] = {
 	DEVMETHOD(bus_print_child,	pcf_print_child),
 
 	/* iicbus interface */
+	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
 	DEVMETHOD(iicbus_repeated_start, pcf_repeated_start),
 	DEVMETHOD(iicbus_start,		pcf_start),
 	DEVMETHOD(iicbus_stop,		pcf_stop),
@@ -165,6 +168,7 @@ pcfprobe_isa(struct isa_device *dvp)
 
 	/* XXX add the pcf device to the root_bus until isa bus exists */
 	pcfdev = device_add_child(root_bus, "pcf", pcf->pcf_unit, NULL);
+	device_probe_and_attach(pcfdev);
 
 	if (!pcfdev)
 		goto error;
@@ -188,15 +192,20 @@ static int
 pcf_probe(device_t pcfdev)
 {
 	struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(pcfdev);
+	int unit = device_get_unit(pcfdev);
 
-	/* XXX try do detect chipset */
+	/* retrieve base address from isa initialization
+	 *
+	 * XXX should use ivars with isabus
+	 */
+	pcf->pcf_base = pcfdata[unit]->pcf_base;
 
-	device_set_desc(pcfdev, "PCF8584 I2C bus controller");
+	/* reset the chip */
+	pcf_rst_card(pcfdev, IIC_FASTEST, PCF_DEFAULT_ADDR, NULL);
 
-	pcf->iicbus = iicbus_alloc_bus(pcfdev);
+	/* XXX try do detect chipset */
 
-	if (!pcf->iicbus)
-		return (EINVAL);
+	device_set_desc(pcfdev, "PCF8584 I2C bus controller");
 
 	return (0);
 }
@@ -205,13 +214,11 @@ static int
 pcf_attach(device_t pcfdev)
 {
 	struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(pcfdev);
-	int unit = device_get_unit(pcfdev);
 
-	/* retrieve base address from isa initialization
-	 *
-	 * XXX should use ivars with isabus
-	 */
-	pcf->pcf_base = pcfdata[unit]->pcf_base;
+	pcf->iicbus = iicbus_alloc_bus(pcfdev);
+
+	if (!pcf->iicbus)
+		return (EINVAL);
 
 	/* probe and attach the iicbus */
 	device_probe_and_attach(pcf->iicbus);
@@ -222,8 +229,10 @@ pcf_attach(device_t pcfdev)
 static void
 pcf_print_child(device_t bus, device_t dev)
 {
+	struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(bus);
+
 	printf(" on %s%d addr 0x%x", device_get_name(bus),
-		device_get_unit(bus), iicbus_get_own_address(dev));
+		device_get_unit(bus), (int)pcf->pcf_addr);
 
 	return;
 }
@@ -293,13 +302,39 @@ static int pcf_stop(device_t pcfdev)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 
-	/* set stop condition and enable IT */
-	PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK);
+	/*
+	 * Send STOP condition iff the START condition was previously sent.
+	 * STOP is sent only once even if a iicbus_stop() is called after
+	 * an iicbus_read()... see pcf_read(): the pcf needs to send the stop
+	 * before the last char is read.
+	 */
+	if (pcf->pcf_started) {
+		/* set stop condition and enable IT */
+		PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK);
+
+		pcf->pcf_started = 0;
+	}
 
 	return (0);
 }
 
-static int pcf_repeated_start(device_t pcfdev, u_char slave)
+
+static int pcf_noack(struct pcf_softc *pcf, int timeout)
+{
+	int noack;
+	int k = timeout/10;
+
+	do {
+		noack = PCF_GET_S1(pcf) & LRB;
+		if (!noack)
+			break;
+		DELAY(10);				/* XXX wait 10 us */
+	} while (k--);
+
+	return (noack);
+}
+
+static int pcf_repeated_start(device_t pcfdev, u_char slave, int timeout)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 	int error = 0;
@@ -315,8 +350,8 @@ static int pcf_repeated_start(device_t pcfdev, u_char slave)
 	if ((error = pcf_wait_byte(pcf)))
 		goto error;
 
-	/* check ACK */
-	if (PCF_GET_S1(pcf) & LRB) {
+	/* check for ack */
+	if (pcf_noack(pcf, timeout)) {
 		error = IIC_ENOACK;
 		goto error;
 	}
@@ -328,7 +363,7 @@ error:
 	return (error);
 }
 
-static int pcf_start(device_t pcfdev, u_char slave)
+static int pcf_start(device_t pcfdev, u_char slave, int timeout)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 	int error = 0;
@@ -343,12 +378,14 @@ static int pcf_start(device_t pcfdev, u_char slave)
 	/* START only */
 	PCF_SET_S1(pcf, PIN|ES0|STA|ACK);
 
+	pcf->pcf_started = 1;
+
 	/* wait for address sent, polling */
 	if ((error = pcf_wait_byte(pcf)))
 		goto error;
 
-	/* check ACK */
-	if (PCF_GET_S1(pcf) & LRB) {
+	/* check for ACK */
+	if (pcf_noack(pcf, timeout)) {
 		error = IIC_ENOACK;
 		goto error;
 	}
@@ -468,19 +505,23 @@ error:
 	return;
 }
 
-static int pcf_rst_card(device_t pcfdev, u_char speed)
+static int pcf_rst_card(device_t pcfdev, u_char speed, u_char addr, u_char *oldaddr)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
-	u_char ownaddr;
+
+	if (oldaddr)
+		*oldaddr = pcf->pcf_addr;
 
 	/* retrieve own address from bus level */
-	if ((ownaddr = iicbus_get_own_address(pcf->iicbus)) == 0)
-		ownaddr = 0xaa;
+	if (!addr)
+		pcf->pcf_addr = PCF_DEFAULT_ADDR;
+	else
+		pcf->pcf_addr = addr;
 	
 	PCF_SET_S1(pcf, PIN);				/* initialize S1 */
 
 	/* own address S'O<>0 */
-	PCF_SET_S0(pcf, ownaddr >> 1);
+	PCF_SET_S0(pcf, pcf->pcf_addr >> 1);
 
 	/* select clock register */
 	PCF_SET_S1(pcf, PIN|ES1);
@@ -511,7 +552,7 @@ static int pcf_rst_card(device_t pcfdev, u_char speed)
 }
 
 static int
-pcf_write(device_t pcfdev, char *buf, int len, int *sent)
+pcf_write(device_t pcfdev, char *buf, int len, int *sent, int timeout /* us */)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 	int bytes, error = 0;
@@ -525,10 +566,12 @@ pcf_write(device_t pcfdev, char *buf, int len, int *sent)
 
 		PCF_SET_S0(pcf, *buf++);
 
+		/* wait for the byte to be send */
 		if ((error = pcf_wait_byte(pcf)))
 			goto error;
 
-		if (PCF_GET_S1(pcf) & LRB) {
+		/* check if ack received */
+		if (pcf_noack(pcf, timeout)) {
 			error = IIC_ENOACK;
 			goto error;
 		}
@@ -549,7 +592,8 @@ error:
 }
 
 static int
-pcf_read(device_t pcfdev, char *buf, int len, int *read)
+pcf_read(device_t pcfdev, char *buf, int len, int *read, int last,
+							int delay /* us */)
 {
 	struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 	int bytes, error = 0;
@@ -560,7 +604,7 @@ pcf_read(device_t pcfdev, char *buf, int len, int *read)
 
 	/* trig the bus to get the first data byte in S0 */
 	if (len) {
-		if (len == 1)
+		if (len == 1 && last)
 			/* just one byte to read */
 			PCF_SET_S1(pcf, ES0);		/* no ack */
 
@@ -570,26 +614,25 @@ pcf_read(device_t pcfdev, char *buf, int len, int *read)
 	bytes = 0;
 	while (len) {
 
+		/* XXX delay needed here */
+
+		/* wait for trigged byte */
 		if ((error = pcf_wait_byte(pcf))) {
 			pcf_stop(pcfdev);
 			goto error;
 		}
 
-		if (len == 1) {
-
-			/* ok, last data byte already in S0 */
+		if (len == 1 && last)
+			/* ok, last data byte already in S0, no I2C activity
+			 * on next PCF_GET_S0() */
 			pcf_stop(pcfdev);
 
-			*buf = PCF_GET_S0(pcf);
+		else if (len == 2 && last)
+			/* next trigged byte with no ack */
+			PCF_SET_S1(pcf, ES0);
 
-		} else {
-			if (len == 2)
-				/* next trigged byte with no ack */
-				PCF_SET_S1(pcf, ES0);
-
-			/* read last data byte, trig for next data byte */
-			*buf++ = PCF_GET_S0(pcf);
-		}
+		/* receive byte, trig next byte */
+		*buf++ = PCF_GET_S0(pcf);
 
 		len --;
 		bytes ++;