ARM: OMAP2+: Fix overwriting hwmod data with data from device tree

We have some device tree properties where the ti,hwmod have multiple
values:

am33xx.dtsi:	ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
am4372.dtsi:	ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
dra7.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2";
omap3.dtsi:	ti,hwmods = "mcbsp2", "mcbsp2_sidetone";
omap3.dtsi:	ti,hwmods = "mcbsp3", "mcbsp3_sidetone";
omap4.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2", "l3_main_3";
omap5.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2", "l3_main_3";

That's not correct way of doing things in this case because these are
separate devices with their own address space, interrupts, SYSCONFIG
registers and can set their PM states independently.

So they should all be fixed up to be separate devices in the .dts files.

We also have the related data removed for at least omap4 in commit
3b9b1015 (ARM: OMAP4: hwmod data: Clean up the data file), so
that data is wrongly initialized as null data.

So we need to fix two bugs:

1. We are only checking the first entry of the ti,hwmods property

   This means that we're only initializing the first hwmods entry
   instead of the ones listed in the ti,hwmods property.

2. We are only checking the child nodes, not the nodes themselves

   This means that anything listed at OCP level is currently just
   ignored and unitialized and at least the omap4 case, with the
   legacy data missing from the hwmod.

Fix both of the issues by using an index to the ti,hwmods property
and changing the hwmod lookup function to also check the current node
for ti,hwmods property instead of just the children.

While at it, let's also add some warnings for the bad data so it's
easier to fix.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap_hwmod.c

@@ -2326,38 +2326,80 @@ static int _shutdown(struct omap_hwmod *oh)
 	return 0;
 }
 
+static int of_dev_find_hwmod(struct device_node *np,
+			     struct omap_hwmod *oh)
+{
+	int count, i, res;
+	const char *p;
+
+	count = of_property_count_strings(np, "ti,hwmods");
+	if (count < 1)
+		return -ENODEV;
+
+	for (i = 0; i < count; i++) {
+		res = of_property_read_string_index(np, "ti,hwmods",
+						    i, &p);
+		if (res)
+			continue;
+		if (!strcmp(p, oh->name)) {
+			pr_debug("omap_hwmod: dt %s[%i] uses hwmod %s\n",
+				 np->name, i, oh->name);
+			return i;
+		}
+	}
+
+	return -ENODEV;
+}
+
 /**
  * of_dev_hwmod_lookup - look up needed hwmod from dt blob
  * @np: struct device_node *
  * @oh: struct omap_hwmod *
+ * @index: index of the entry found
+ * @found: struct device_node * found or NULL
  *
  * Parse the dt blob and find out needed hwmod. Recursive function is
  * implemented to take care hierarchical dt blob parsing.
- * Return: The device node on success or NULL on failure.
+ * Return: Returns 0 on success, -ENODEV when not found.
  */
-static struct device_node *of_dev_hwmod_lookup(struct device_node *np,
-						struct omap_hwmod *oh)
+static int of_dev_hwmod_lookup(struct device_node *np,
+			       struct omap_hwmod *oh,
+			       int *index,
+			       struct device_node **found)
 {
-	struct device_node *np0 = NULL, *np1 = NULL;
-	const char *p;
+	struct device_node *np0 = NULL;
+	int res;
+
+	res = of_dev_find_hwmod(np, oh);
+	if (res >= 0) {
+		*found = np;
+		*index = res;
+		return 0;
+	}
 
 	for_each_child_of_node(np, np0) {
-		if (of_find_property(np0, "ti,hwmods", NULL)) {
-			p = of_get_property(np0, "ti,hwmods", NULL);
-			if (!strcmp(p, oh->name))
-				return np0;
-			np1 = of_dev_hwmod_lookup(np0, oh);
-			if (np1)
-				return np1;
+		struct device_node *fc;
+		int i;
+
+		res = of_dev_hwmod_lookup(np0, oh, &i, &fc);
+		if (res == 0) {
+			*found = fc;
+			*index = i;
+			return 0;
 		}
 	}
-	return NULL;
+
+	*found = NULL;
+	*index = 0;
+
+	return -ENODEV;
 }
 
 /**
  * _init_mpu_rt_base - populate the virtual address for a hwmod
  * @oh: struct omap_hwmod * to locate the virtual address
  * @data: (unused, caller should pass NULL)
+ * @index: index of the reg entry iospace in device tree
  * @np: struct device_node * of the IP block's device node in the DT data
  *
  * Cache the virtual address used by the MPU to access this IP block's
@@ -2368,7 +2410,7 @@ static struct device_node *of_dev_hwmod_lookup(struct device_node *np,
  * -ENXIO on absent or invalid register target address space.
  */
 static int __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data,
-				    struct device_node *np)
+				    int index, struct device_node *np)
 {
 	struct omap_hwmod_addr_space *mem;
 	void __iomem *va_start = NULL;
@@ -2390,13 +2432,17 @@ static int __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data,
 		if (!np)
 			return -ENXIO;
 
-		va_start = of_iomap(np, oh->mpu_rt_idx);
+		va_start = of_iomap(np, index + oh->mpu_rt_idx);
 	} else {
 		va_start = ioremap(mem->pa_start, mem->pa_end - mem->pa_start);
 	}
 
 	if (!va_start) {
-		pr_err("omap_hwmod: %s: Could not ioremap\n", oh->name);
+		if (mem)
+			pr_err("omap_hwmod: %s: Could not ioremap\n", oh->name);
+		else
+			pr_err("omap_hwmod: %s: Missing dt reg%i for %s\n",
+			       oh->name, index, np->full_name);
 		return -ENXIO;
 	}
 
@@ -2422,17 +2468,29 @@ static int __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data,
  */
 static int __init _init(struct omap_hwmod *oh, void *data)
 {
-	int r;
+	int r, index;
 	struct device_node *np = NULL;
 
 	if (oh->_state != _HWMOD_STATE_REGISTERED)
 		return 0;
 
-	if (of_have_populated_dt())
-		np = of_dev_hwmod_lookup(of_find_node_by_name(NULL, "ocp"), oh);
+	if (of_have_populated_dt()) {
+		struct device_node *bus;
+
+		bus = of_find_node_by_name(NULL, "ocp");
+		if (!bus)
+			return -ENODEV;
+
+		r = of_dev_hwmod_lookup(bus, oh, &index, &np);
+		if (r)
+			pr_debug("omap_hwmod: %s missing dt data\n", oh->name);
+		else if (np && index)
+			pr_warn("omap_hwmod: %s using broken dt data from %s\n",
+				oh->name, np->name);
+	}
 
 	if (oh->class->sysc) {
-		r = _init_mpu_rt_base(oh, NULL, np);
+		r = _init_mpu_rt_base(oh, NULL, index, np);
 		if (r < 0) {
 			WARN(1, "omap_hwmod: %s: doesn't have mpu register target base\n",
 			     oh->name);