svn commit: r322479 - head/sys/dev/iicbus

[Ian Lepore]

Author: ian
Date: Mon Aug 14 02:23:10 2017
New Revision: 322479
URL: https://svnweb.freebsd.org/changeset/base/322479

Log:
  Add hinted attachment for non-FDT systems.  Also, print a message if
  setting up the timer fails, because on some types of chips that's the
  first attempt to access the device.  If the chip is missing/non-responsive
  then you'd get a driver that attached and didn't register the rtc, with
  no clue about why.  On other chip types there are inits that come before
  timer setup, and they already print messages about errors.

Modified:
  head/sys/dev/iicbus/nxprtc.c

Modified: head/sys/dev/iicbus/nxprtc.c
==============================================================================
--- head/sys/dev/iicbus/nxprtc.c	Mon Aug 14 00:12:14 2017	(r322478)
+++ head/sys/dev/iicbus/nxprtc.c	Mon Aug 14 02:23:10 2017	(r322479)
@@ -191,15 +191,26 @@ struct nxprtc_softc {
 	u_int		chiptype;	/* Type of PCF85xx chip */
 	uint8_t		secaddr;	/* Address of seconds register */
 	uint8_t		tmcaddr;	/* Address of timer count register */
-	uint8_t		slave_addr;	/* PCF85xx slave address */
 	bool		use_timer;	/* Use timer for fractional sec */
 };
 
 #define	SC_F_CPOL	(1 << 0)	/* Century bit means 19xx */
 #define	SC_F_AMPM	(1 << 1)	/* Use PM flag in hours reg */
 
+/*
+ * We use the compat_data table to look up hint strings in the non-FDT case, so
+ * define the struct locally when we don't get it from ofw_bus_subr.h.
+ */
 #ifdef FDT
-static struct ofw_compat_data compat_data[] = {
+typedef struct ofw_compat_data nxprtc_compat_data;
+#else
+typedef struct {
+	const char *ocd_str;
+	uintptr_t  ocd_data;
+} nxprtc_compat_data;
+#endif
+
+static nxprtc_compat_data compat_data[] = {
 	{"nxp,pca2129",     TYPE_PCA2129},
 	{"nxp,pca8565",     TYPE_PCA8565},
 	{"nxp,pcf2127",     TYPE_PCF2127},
@@ -214,7 +225,6 @@ static struct ofw_compat_data compat_data[] = {
 
 	{NULL,              TYPE_NONE},
 };
-#endif
 
 static int
 read_reg(struct nxprtc_softc *sc, uint8_t reg, uint8_t *val)
@@ -476,19 +486,25 @@ nxprtc_start(void *dev)
 	case TYPE_PCF2127:
 		if (pcf8523_start(sc) != 0)
 			return;
-		if (pcf2127_start_timer(sc) != 0)
+		if (pcf2127_start_timer(sc) != 0) {
+			device_printf(sc->dev, "cannot set up timer\n");
 			return;
+		}
 		break;
 	case TYPE_PCF8523:
 		if (pcf8523_start(sc) != 0)
 			return;
-		if (pcf8523_start_timer(sc) != 0)
+		if (pcf8523_start_timer(sc) != 0) {
+			device_printf(sc->dev, "cannot set up timer\n");
 			return;
+		}
 		break;
 	case TYPE_PCA8565:
 	case TYPE_PCF8563:
-		if (pcf8563_start_timer(sc) != 0)
+		if (pcf8563_start_timer(sc) != 0) {
+			device_printf(sc->dev, "cannot set up timer\n");
 			return;
+		}
 		break;
 	default:
 		device_printf(sc->dev, "missing init code for this chiptype\n");
@@ -685,24 +701,59 @@ errout:
 }
 
 static int
-nxprtc_probe(device_t dev)
+nxprtc_get_chiptype(device_t dev)
 {
+#ifdef FDT
+
+	return (ofw_bus_search_compatible(dev, compat_data)->ocd_data);
+#else
+	nxprtc_compat_data *cdata;
+	const char *htype;
 	int chiptype;
 
+	/*
+	 * If given a chiptype hint string, loop through the ofw compat data
+	 * comparing the hinted chip type to the compat strings.  The table end
+	 * marker ocd_data is TYPE_NONE.
+	 */
+	if (resource_string_value(device_get_name(dev), 
+	    device_get_unit(dev), "compatible", &htype) == 0) {
+		for (cdata = compat_data; cdata->ocd_str != NULL; ++cdata) {
+			if (strcmp(htype, cdata->ocd_str) == 0)
+				break;
+		}
+		chiptype = cdata->ocd_data;
+	} else
+		chiptype = TYPE_NONE;
+
+	/*
+	 * On non-FDT systems the historical behavior of this driver was to
+	 * assume a PCF8563; keep doing that for compatibility.
+	 */
+	if (chiptype == TYPE_NONE)
+		return (TYPE_PCF8563);
+	else
+		return (chiptype);
+#endif
+}
+
+static int
+nxprtc_probe(device_t dev)
+{
+	int chiptype, rv;
+
 #ifdef FDT
 	if (!ofw_bus_status_okay(dev))
 		return (ENXIO);
-
-	chiptype = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
-	if (chiptype == TYPE_NONE)
-		return (ENXIO);
+	rv = BUS_PROBE_GENERIC;
 #else
-	/* Historically the non-FDT driver supports only PCF8563. */
-	chiptype = TYPE_PCF8563;
+	rv = BUS_PROBE_NOWILDCARD;
 #endif
-	device_set_desc(dev, desc_strings[chiptype]);
+	if ((chiptype = nxprtc_get_chiptype(dev)) == TYPE_NONE)
+		return (ENXIO);
 
-	return (BUS_PROBE_GENERIC);
+	device_set_desc(dev, desc_strings[chiptype]);
+	return (rv);
 }
 
 static int
@@ -713,21 +764,9 @@ nxprtc_attach(device_t dev)
 	sc = device_get_softc(dev);
 	sc->dev = dev;
 	sc->busdev = device_get_parent(dev);
-	sc->slave_addr = iicbus_get_addr(dev);
 
-	/*
-	 * We need to know what kind of chip we're driving.  Historically the
-	 * non-FDT driver supported only PCF8563.  There is no machine-readable
-	 * identifier in the chip so we would need a set of hints defined to use
-	 * the other chips on non-FDT systems.
-	 */
-#ifdef FDT
-	sc->chiptype = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
-#else
-	sc->chiptype = TYPE_PCF8563;
-	if (sc->slave_addr == 0)
-		sc->slave_addr = PCF8563_ADDR;
-#endif
+	/* We need to know what kind of chip we're driving. */
+	sc->chiptype = nxprtc_get_chiptype(dev);
 
 	/* The features and some register addresses vary by chip type. */
 	switch (sc->chiptype) {