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SubjectRe: [PATCH] of/platform: Support dynamic device tree on AMBA bus
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Hi Jaewon,

On 10/25/18 9:39 AM, Jaewon Kim wrote:
> This patch supports dynamic device-tree for AMBA device.

Add AMBA devices and buses to of_platform_notify() so that dynamic device-tree
will support AMBA.

> The AMBA device must be registered on the AMBA bus, not the platform bus.
>
> Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
> ---
> drivers/of/platform.c | 93 ++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 73 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 04ad312..b9ac105 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -286,6 +286,22 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> of_node_clear_flag(node, OF_POPULATED);
> return NULL;
> }
> +
> +/**
> + * of_find_amba_device_by_node - Find the amba_device associated with a node
> + * @np: Pointer to device tree node
> + *
> + * Returns amba_device pointer, or NULL if not found
> + */
> +struct amba_device *of_find_amba_device_by_node(struct device_node *np)
> +{
> + struct device *dev;
> +
> + dev = bus_find_device(&amba_bustype, NULL, np, of_dev_node_match);
> + return dev ? to_amba_device(dev) : NULL;
> +}
> +EXPORT_SYMBOL(of_find_amba_device_by_node);
> +
> #else /* CONFIG_ARM_AMBA */
> static struct amba_device *of_amba_device_create(struct device_node *node,
> const char *bus_id,
> @@ -294,6 +310,12 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> {
> return NULL;
> }
> +
> +struct amba_device *of_find_amba_device_by_node(struct device_node *np)
> +{
> + return NULL;
> +}
> +EXPORT_SYMBOL(of_find_amba_device_by_node);
> #endif /* CONFIG_ARM_AMBA */
>
> /**
> @@ -665,6 +687,7 @@ static int of_platform_notify(struct notifier_block *nb,
> {
> struct of_reconfig_data *rd = arg;
> struct platform_device *pdev_parent, *pdev;
> + struct amba_device *adev_p, *adev;
> bool children_left;
>
> switch (of_reconfig_get_state_change(action, rd)) {
> @@ -677,17 +700,34 @@ static int of_platform_notify(struct notifier_block *nb,
> if (of_node_check_flag(rd->dn, OF_POPULATED))
> return NOTIFY_OK;
>
> - /* pdev_parent may be NULL when no bus platform device */
> - pdev_parent = of_find_device_by_node(rd->dn->parent);
> - pdev = of_platform_device_create(rd->dn, NULL,
> - pdev_parent ? &pdev_parent->dev : NULL);
> - of_dev_put(pdev_parent);
> -
> - if (pdev == NULL) {
> - pr_err("%s: failed to create for '%pOF'\n",
> - __func__, rd->dn);
> - /* of_platform_device_create tosses the error code */
> - return notifier_from_errno(-EINVAL);
> + if (of_device_is_compatible(rd->dn, "arm,primecell")) {
> + /* adev_p may be NULL when no bus amba device */
> + adev_p = of_find_amba_device_by_node(rd->dn->parent);
> + adev = of_amba_device_create(rd->dn, NULL, NULL,
> + adev_p ? &adev_p->dev : NULL);
> +

> + if (adev_p)
> + put_device(&adev_p->dev);

Please follow the same model as of_dev_put() here, create a new function
of_amba_dev_put() to implement these two lines.


> +
> + if (adev == NULL) {
> + pr_err("%s: failed to create for '%s'\n",
> + __func__, rd->dn->full_name);
> + /* of_amba_device_create tosses the error */
> + return notifier_from_errno(-EINVAL);
> + }
> + } else {
> + /* pdev_parent may be NULL when no bus platform device*/
> + pdev_parent = of_find_device_by_node(rd->dn->parent);
> + pdev = of_platform_device_create(rd->dn, NULL,
> + pdev_parent ? &pdev_parent->dev : NULL);
> + of_dev_put(pdev_parent);
> +
> + if (pdev == NULL) {
> + pr_err("%s: failed to create for '%pOF'\n",
> + __func__, rd->dn);
> + /* of_platform_device_create tosses the error */
> + return notifier_from_errno(-EINVAL);
> + }
> }
> break;
>
> @@ -698,15 +738,28 @@ static int of_platform_notify(struct notifier_block *nb,
> return NOTIFY_OK;
>
> /* find our device by node */
> - pdev = of_find_device_by_node(rd->dn);
> - if (pdev == NULL)
> - return NOTIFY_OK; /* no? not meant for us */
> -
> - /* unregister takes one ref away */
> - of_platform_device_destroy(&pdev->dev, &children_left);
> -
> - /* and put the reference of the find */
> - of_dev_put(pdev);
> + if (of_device_is_compatible(rd->dn, "arm,primecell")) {
> + adev = of_find_amba_device_by_node(rd->dn);
> + if (adev == NULL)
> + return NOTIFY_OK; /* no? not meant for us */
> +
> + /* unregister takes one ref away */
> + of_platform_device_destroy(&adev->dev, &children_left);
> +
> + /* and put the reference of the find */

> + if (adev)
> + put_device(&adev->dev);

of_amba_dev_put() here also

-Frank


> + } else {
> + pdev = of_find_device_by_node(rd->dn);
> + if (pdev == NULL)
> + return NOTIFY_OK; /* no? not meant for us */
> +
> + /* unregister takes one ref away */
> + of_platform_device_destroy(&pdev->dev, &children_left);
> +
> + /* and put the reference of the find */
> + of_dev_put(pdev);
> + }
> break;
> }
>
>

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