Adding Mark Brown who finished off introducing IORESOURCE_REG.

On 09/08/14 07:52, Grant Likely wrote:

On Tue,  2 Sep 2014 18:45:00 +0300, Stanimir Varbanov [off-list ref] wrote:

quoted

+
 unsigned long __weak pci_address_to_pio(phys_addr_t address)
 {
 	if (address > IO_SPACE_LIMIT)

@@ -665,6 +691,29 @@ int of_address_to_resource(struct device_node *dev, int index,
 }
 EXPORT_SYMBOL_GPL(of_address_to_resource);
 
+int of_localbus_address_to_resource(struct device_node *dev, int index,
+				    struct resource *r)
+{
+	const char *name = NULL;
+	const __be32 *addrp;
+	u64 size;
+
+	addrp = of_get_localbus_address(dev, index, &size);
+	if (!addrp)
+		return -EINVAL;
+
+	of_property_read_string_index(dev, "reg-names", index, &name);
+
+	memset(r, 0, sizeof(*r));
+	r->start = be32_to_cpup(addrp);
+	r->end = r->start + size - 1;
+	r->flags = IORESOURCE_REG;

This is problematic. A resource is created, but there is absolutely no
indication that the resource represents a localbus address instead of a
CPU address. platform_device reg resources represent CPU addresses.
Trying to overload it will cause confusion in drivers.

quoted

+	r->name = name ? name : dev->full_name;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_localbus_address_to_resource);
+
 struct device_node *of_find_matching_node_by_address(struct device_node *from,
 					const struct of_device_id *matches,
 					u64 base_address)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 0197725..36dcbd7 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c

@@ -106,8 +106,9 @@ struct platform_device *of_device_alloc(struct device_node *np,
 				  struct device *parent)
 {
 	struct platform_device *dev;
-	int rc, i, num_reg = 0, num_irq;
+	int rc, i, num_reg = 0, num_localbus_reg = 0, num_irq;
 	struct resource *res, temp_res;
+	int num_resources;
 
 	dev = platform_device_alloc("", -1);
 	if (!dev)

@@ -116,22 +117,33 @@ struct platform_device *of_device_alloc(struct device_node *np,
 	/* count the io and irq resources */
 	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 		num_reg++;
+
+	while (of_localbus_address_to_resource(np,
+					num_localbus_reg, &temp_res) == 0)
+		num_localbus_reg++;
+

No, I don't support doing this. The moment a platform_driver depends on
a local bus address it is doing something special. It needs to decode
its own address in that case, which it can easily do.

Any platform_driver that interprets a IORESOURCE_REG as a localbus
address instead of a CPU address is *BROKEN*. It should be changed to
either decode the address itself, of a new bus type should be created
that can make its own decisions about what address resources mean.

Where is this described? From the commit text that introduces
IORESOURCE_REG I see:

"Currently a bunch of I2C/SPI MFD drivers are using IORESOURCE_IO for
register address ranges. Since this causes some confusion due to the
primary use of this resource type for PCI/ISA I/O ports create a new
resource type IORESOURCE_REG."

And the comment next to the #define says "Register offsets". I don't see
anywhere where it mentions these are CPU addresses. Certainly the
current IORESOURCE_REG users aren't CPU addresses because they're
SPI/I2C device drivers.

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