[PATCH] of: support an enumerated-bus compatible value
Rob Herring
robherring2 at gmail.com
Mon Jul 2 05:36:22 EST 2012
On 06/28/2012 06:05 PM, Stephen Warren wrote:
> From: Stephen Warren <swarren at nvidia.com>
>
> An "enumerated" bus is one that is not memory-mapped, hence hence
> typically has #address-cells=1, and #size-cells=0. Such buses would be
> used to group related non-memory-mapped nodes together, often just under
> the top-level of the device tree. The ability to group nodes into a non-
> memory-mapped subnode of the root is important, since if nodes exist to
> describe multiple entities of the same type, the nodes will have the
> same name, and hence require a unit address to differentiate them. It
> doesn't make sense to assign bogus unit addresses from the CPU's own
> address space for this purpose. An example:
>
> regulators {
> compatible = "enumerated-bus";
> #address-cells = <1>;
> #size-cells = <0>;
>
> regulator at 0 {
> compatible = "regulator-fixed";
> reg = <0>;
> };
>
> regulator at 1 {
> compatible = "regulator-fixed";
> reg = <1>;
> };
> };
>
> Finally, because such buses are not memory-mapped, we avoid creating
> any IO/memory resources for the device.
This seems like a work-around to use reg instead of using cell-index
(which is discouraged). reg in this case is really not a hardware
description. Do you have an intended use or just trying to fix the error
messages?
Rob
>
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> ---
> drivers/of/platform.c | 79 ++++++++++++++++++++++++++++++++++----------
> include/linux/of_device.h | 2 +-
> 2 files changed, 62 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 3132ea0..3ebefa9 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -25,6 +25,7 @@
>
> const struct of_device_id of_default_bus_match_table[] = {
> { .compatible = "simple-bus", },
> + { .compatible = "enumerated-bus", },
> #ifdef CONFIG_ARM_AMBA
> { .compatible = "arm,amba-bus", },
> #endif /* CONFIG_ARM_AMBA */
> @@ -67,16 +68,25 @@ EXPORT_SYMBOL(of_find_device_by_node);
> /**
> * of_device_make_bus_id - Use the device node data to assign a unique name
> * @dev: pointer to device structure that is linked to a device tree node
> + * @enumerated: Is the parent bus of the device an "enumerated" bus?
> *
> * This routine will first try using either the dcr-reg or the reg property
> * value to derive a unique name. As a last resort it will use the node
> * name followed by a unique number.
> + *
> + * An "enumerated" bus is assumed to support #size-cells=0, and not be memory-
> + * mapped. This prevents of_translate_address() from being used on the
> + * device's reg property; performing address translation makes no logical
> + * sense, and fails if #size-cells=0. We use the first component of the reg
> + * property directly to form a unique name in this case; this value is only
> + * local to the bus, rather than typically globally unique.
> */
> -void of_device_make_bus_id(struct device *dev)
> +void of_device_make_bus_id(struct device *dev, bool enumerated)
> {
> static atomic_t bus_no_reg_magic;
> struct device_node *node = dev->of_node;
> const u32 *reg;
> + const __be32 *addrp;
> u64 addr;
> int magic;
>
> @@ -105,7 +115,15 @@ void of_device_make_bus_id(struct device *dev)
> */
> reg = of_get_property(node, "reg", NULL);
> if (reg) {
> - addr = of_translate_address(node, reg);
> + if (enumerated) {
> + addrp = of_get_address(node, 0, NULL, NULL);
> + if (addrp)
> + addr = of_read_number(addrp, 1);
> + else
> + addr = OF_BAD_ADDR;
> + } else {
> + addr = of_translate_address(node, reg);
> + }
> if (addr != OF_BAD_ADDR) {
> dev_set_name(dev, "%llx.%s",
> (unsigned long long)addr, node->name);
> @@ -126,10 +144,12 @@ void of_device_make_bus_id(struct device *dev)
> * @np: device node to assign to device
> * @bus_id: Name to assign to the device. May be null to use default name.
> * @parent: Parent device.
> + * @enumerated: Is the parent bus of the device an "enumerated" bus?
> */
> -struct platform_device *of_device_alloc(struct device_node *np,
> - const char *bus_id,
> - struct device *parent)
> +struct platform_device *__of_device_alloc(struct device_node *np,
> + const char *bus_id,
> + struct device *parent,
> + bool enumerated)
> {
> struct platform_device *dev;
> int rc, i, num_reg = 0, num_irq;
> @@ -140,8 +160,9 @@ struct platform_device *of_device_alloc(struct device_node *np,
> return NULL;
>
> /* count the io and irq resources */
> - while (of_address_to_resource(np, num_reg, &temp_res) == 0)
> - num_reg++;
> + if (!enumerated)
> + while (of_address_to_resource(np, num_reg, &temp_res) == 0)
> + num_reg++;
> num_irq = of_irq_count(np);
>
> /* Populate the resource table */
> @@ -170,10 +191,23 @@ struct platform_device *of_device_alloc(struct device_node *np,
> if (bus_id)
> dev_set_name(&dev->dev, "%s", bus_id);
> else
> - of_device_make_bus_id(&dev->dev);
> + of_device_make_bus_id(&dev->dev, enumerated);
>
> return dev;
> }
> +
> +/**
> + * of_device_alloc - Allocate and initialize an of_device
> + * @np: device node to assign to device
> + * @bus_id: Name to assign to the device. May be null to use default name.
> + * @parent: Parent device.
> + */
> +struct platform_device *of_device_alloc(struct device_node *np,
> + const char *bus_id,
> + struct device *parent)
> +{
> + return __of_device_alloc(np, bus_id, parent, false);
> +}
> EXPORT_SYMBOL(of_device_alloc);
>
> /**
> @@ -190,14 +224,15 @@ struct platform_device *of_platform_device_create_pdata(
> struct device_node *np,
> const char *bus_id,
> void *platform_data,
> - struct device *parent)
> + struct device *parent,
> + bool enumerated)
> {
> struct platform_device *dev;
>
> if (!of_device_is_available(np))
> return NULL;
>
> - dev = of_device_alloc(np, bus_id, parent);
> + dev = __of_device_alloc(np, bus_id, parent, enumerated);
> if (!dev)
> return NULL;
>
> @@ -234,7 +269,7 @@ struct platform_device *of_platform_device_create(struct device_node *np,
> const char *bus_id,
> struct device *parent)
> {
> - return of_platform_device_create_pdata(np, bus_id, NULL, parent);
> + return of_platform_device_create_pdata(np, bus_id, NULL, parent, false);
> }
> EXPORT_SYMBOL(of_platform_device_create);
>
> @@ -265,7 +300,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> if (bus_id)
> dev_set_name(&dev->dev, "%s", bus_id);
> else
> - of_device_make_bus_id(&dev->dev);
> + of_device_make_bus_id(&dev->dev, false);
>
> /* setup amba-specific device info */
> dev->dma_mask = ~0;
> @@ -342,7 +377,8 @@ static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *l
> static int of_platform_bus_create(struct device_node *bus,
> const struct of_device_id *matches,
> const struct of_dev_auxdata *lookup,
> - struct device *parent, bool strict)
> + struct device *parent, bool strict,
> + bool enumerated)
> {
> const struct of_dev_auxdata *auxdata;
> struct device_node *child;
> @@ -369,13 +405,17 @@ static int of_platform_bus_create(struct device_node *bus,
> return 0;
> }
>
> - dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
> + dev = of_platform_device_create_pdata(bus, bus_id, platform_data,
> + parent, enumerated);
> if (!dev || !of_match_node(matches, bus))
> return 0;
>
> + enumerated = of_device_is_compatible(bus, "enumerated-bus");
> +
> for_each_child_of_node(bus, child) {
> pr_debug(" create child: %s\n", child->full_name);
> - rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
> + rc = of_platform_bus_create(child, matches, lookup, &dev->dev,
> + strict, enumerated);
> if (rc) {
> of_node_put(child);
> break;
> @@ -409,11 +449,13 @@ int of_platform_bus_probe(struct device_node *root,
>
> /* Do a self check of bus type, if there's a match, create children */
> if (of_match_node(matches, root)) {
> - rc = of_platform_bus_create(root, matches, NULL, parent, false);
> + rc = of_platform_bus_create(root, matches, NULL, parent, false,
> + false);
> } else for_each_child_of_node(root, child) {
> if (!of_match_node(matches, child))
> continue;
> - rc = of_platform_bus_create(child, matches, NULL, parent, false);
> + rc = of_platform_bus_create(child, matches, NULL, parent, false,
> + false);
> if (rc)
> break;
> }
> @@ -454,7 +496,8 @@ int of_platform_populate(struct device_node *root,
> return -EINVAL;
>
> for_each_child_of_node(root, child) {
> - rc = of_platform_bus_create(child, matches, lookup, parent, true);
> + rc = of_platform_bus_create(child, matches, lookup, parent,
> + true, false);
> if (rc)
> break;
> }
> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
> index 901b743..630972e 100644
> --- a/include/linux/of_device.h
> +++ b/include/linux/of_device.h
> @@ -12,7 +12,7 @@ struct device;
>
> extern const struct of_device_id *of_match_device(
> const struct of_device_id *matches, const struct device *dev);
> -extern void of_device_make_bus_id(struct device *dev);
> +extern void of_device_make_bus_id(struct device *dev, bool enumerated);
>
> /**
> * of_driver_match_device - Tell if a driver's of_match_table matches a device.
>
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