Implement the foundation of Firmware node support for PCS driver.
To support this, implement a simple Provider API where a PCS driver can
expose multiple PCS with an xlate .get function.
PCS driver will have to call fwnode_pcs_add_provider() and pass the
firmware node pointer and a xlate function to return the correct PCS for
the passed #pcs-cells.
This will register the PCS in a global list of providers so that
consumer can access it.
The consumer will then use fwnode_pcs_get() to get the actual PCS by
passing the firmware node pointer and the index for #pcs-cells.
For a simple implementation where #pcs-cells is 0 and the PCS driver
expose a single PCS, the xlate function fwnode_pcs_simple_get() is
provided.
For an advanced implementation a custom xlate function is required.
One removal the PCS driver should first delete itself from the provider
list using fwnode_pcs_del_provider() and then call phylink_release_pcs()
on every PCS the driver provides.
A generic function fwnode_phylink_pcs_parse() is provided for MAC driver
that will declare PCS in DT (or ACPI).
This function will parse "pcs-handle" property and fill the passed array
with the parsed PCS in availabel_pcs up to the passed num_pcs value.
It's also possible to pass NULL as array to only parse the PCS and
update the num_pcs value with the count of scanned PCS.
Co-developed-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
drivers/net/pcs/Kconfig | 6 +
drivers/net/pcs/Makefile | 1 +
drivers/net/pcs/pcs.c | 201 +++++++++++++++++++++++++++++++
include/linux/pcs/pcs-provider.h | 41 +++++++
include/linux/pcs/pcs.h | 56 +++++++++
5 files changed, 305 insertions(+)
create mode 100644 drivers/net/pcs/pcs.c
create mode 100644 include/linux/pcs/pcs-provider.h
create mode 100644 include/linux/pcs/pcs.h
diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
index f6aa437473de..0d54bea1f663 100644
--- a/drivers/net/pcs/Kconfig
+++ b/drivers/net/pcs/Kconfig
@@ -5,6 +5,12 @@
menu "PCS device drivers"
+config FWNODE_PCS
+ tristate
+ depends on (ACPI || OF)
+ help
+ Firmware node PCS accessors
+
config PCS_XPCS
tristate "Synopsys DesignWare Ethernet XPCS"
select PHYLINK
diff --git a/drivers/net/pcs/Makefile b/drivers/net/pcs/Makefile
index 4f7920618b90..3005cdd89ab7 100644
--- a/drivers/net/pcs/Makefile
+++ b/drivers/net/pcs/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for Linux PCS drivers
+obj-$(CONFIG_FWNODE_PCS) += pcs.o
pcs_xpcs-$(CONFIG_PCS_XPCS) := pcs-xpcs.o pcs-xpcs-plat.o \
pcs-xpcs-nxp.o pcs-xpcs-wx.o
diff --git a/drivers/net/pcs/pcs.c b/drivers/net/pcs/pcs.c
new file mode 100644
index 000000000000..26d07a2edfce
--- /dev/null
+++ b/drivers/net/pcs/pcs.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/phylink.h>
+#include <linux/pcs/pcs.h>
+#include <linux/pcs/pcs-provider.h>
+
+MODULE_DESCRIPTION("PCS library");
+MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
+MODULE_LICENSE("GPL");
+
+struct fwnode_pcs_provider {
+ struct list_head link;
+
+ struct fwnode_handle *fwnode;
+ struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
+ void *data);
+
+ void *data;
+};
+
+static LIST_HEAD(fwnode_pcs_providers);
+static DEFINE_MUTEX(fwnode_pcs_mutex);
+
+struct phylink_pcs *fwnode_pcs_simple_get(struct fwnode_reference_args *pcsspec,
+ void *data)
+{
+ return data;
+}
+EXPORT_SYMBOL_GPL(fwnode_pcs_simple_get);
+
+int fwnode_pcs_add_provider(struct fwnode_handle *fwnode,
+ struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
+ void *data),
+ void *data)
+{
+ struct fwnode_pcs_provider *pp;
+
+ if (!fwnode)
+ return 0;
+
+ pp = kzalloc(sizeof(*pp), GFP_KERNEL);
+ if (!pp)
+ return -ENOMEM;
+
+ pp->fwnode = fwnode_handle_get(fwnode);
+ pp->data = data;
+ pp->get = get;
+
+ mutex_lock(&fwnode_pcs_mutex);
+ list_add(&pp->link, &fwnode_pcs_providers);
+ mutex_unlock(&fwnode_pcs_mutex);
+ pr_debug("Added pcs provider from %pfwf\n", fwnode);
+
+ fwnode_dev_initialized(fwnode, true);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fwnode_pcs_add_provider);
+
+void fwnode_pcs_del_provider(struct fwnode_handle *fwnode)
+{
+ struct fwnode_pcs_provider *pp;
+
+ if (!fwnode)
+ return;
+
+ mutex_lock(&fwnode_pcs_mutex);
+ list_for_each_entry(pp, &fwnode_pcs_providers, link) {
+ if (pp->fwnode == fwnode) {
+ list_del(&pp->link);
+ fwnode_dev_initialized(pp->fwnode, false);
+ fwnode_handle_put(pp->fwnode);
+ kfree(pp);
+ break;
+ }
+ }
+ mutex_unlock(&fwnode_pcs_mutex);
+}
+EXPORT_SYMBOL_GPL(fwnode_pcs_del_provider);
+
+static int fwnode_parse_pcsspec(const struct fwnode_handle *fwnode, int index,
+ const char *name,
+ struct fwnode_reference_args *out_args)
+{
+ int ret;
+
+ if (!fwnode)
+ return -ENOENT;
+
+ if (name)
+ index = fwnode_property_match_string(fwnode, "pcs-names",
+ name);
+
+ ret = fwnode_property_get_reference_args(fwnode, "pcs-handle",
+ "#pcs-cells",
+ -1, index, out_args);
+ if (ret || (name && index < 0))
+ return ret;
+
+ return 0;
+}
+
+static struct phylink_pcs *
+fwnode_pcs_get_from_pcsspec(struct fwnode_reference_args *pcsspec)
+{
+ struct fwnode_pcs_provider *provider;
+ struct phylink_pcs *pcs = ERR_PTR(-EPROBE_DEFER);
+
+ if (!pcsspec)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&fwnode_pcs_mutex);
+ list_for_each_entry(provider, &fwnode_pcs_providers, link) {
+ if (provider->fwnode == pcsspec->fwnode) {
+ pcs = provider->get(pcsspec, provider->data);
+ if (!IS_ERR(pcs))
+ break;
+ }
+ }
+ mutex_unlock(&fwnode_pcs_mutex);
+
+ return pcs;
+}
+
+static struct phylink_pcs *__fwnode_pcs_get(struct fwnode_handle *fwnode,
+ int index, const char *con_id)
+{
+ struct fwnode_reference_args pcsspec;
+ struct phylink_pcs *pcs;
+ int ret;
+
+ ret = fwnode_parse_pcsspec(fwnode, index, con_id, &pcsspec);
+ if (ret)
+ return ERR_PTR(ret);
+
+ pcs = fwnode_pcs_get_from_pcsspec(&pcsspec);
+ fwnode_handle_put(pcsspec.fwnode);
+
+ return pcs;
+}
+
+struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode, int index)
+{
+ return __fwnode_pcs_get(fwnode, index, NULL);
+}
+EXPORT_SYMBOL_GPL(fwnode_pcs_get);
+
+static int fwnode_phylink_pcs_count(struct fwnode_handle *fwnode,
+ unsigned int *num_pcs)
+{
+ struct fwnode_reference_args out_args;
+ int index = 0;
+ int ret;
+
+ while (true) {
+ ret = fwnode_property_get_reference_args(fwnode, "pcs-handle",
+ "#pcs-cells",
+ -1, index, &out_args);
+ /* We expect to reach an -ENOENT error while counting */
+ if (ret)
+ break;
+
+ fwnode_handle_put(out_args.fwnode);
+ index++;
+ }
+
+ /* Update num_pcs with parsed PCS */
+ *num_pcs = index;
+
+ /* Return error if we didn't found any PCS */
+ return index > 0 ? 0 : -ENOENT;
+}
+
+int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
+ struct phylink_pcs **available_pcs,
+ unsigned int *num_pcs)
+{
+ int i;
+
+ if (!fwnode_property_present(fwnode, "pcs-handle"))
+ return -ENODEV;
+
+ /* With available_pcs NULL, only count the PCS */
+ if (!available_pcs)
+ return fwnode_phylink_pcs_count(fwnode, num_pcs);
+
+ for (i = 0; i < *num_pcs; i++) {
+ struct phylink_pcs *pcs;
+
+ pcs = fwnode_pcs_get(fwnode, i);
+ if (IS_ERR(pcs))
+ return PTR_ERR(pcs);
+
+ available_pcs[i] = pcs;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fwnode_phylink_pcs_parse);
diff --git a/include/linux/pcs/pcs-provider.h b/include/linux/pcs/pcs-provider.h
new file mode 100644
index 000000000000..ae51c108147e
--- /dev/null
+++ b/include/linux/pcs/pcs-provider.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __LINUX_PCS_PROVIDER_H
+#define __LINUX_PCS_PROVIDER_H
+
+/**
+ * fwnode_pcs_simple_get - Simple xlate function to retrieve PCS
+ * @pcsspec: reference arguments
+ * @data: Context data (assumed assigned to the single PCS)
+ *
+ * Returns: the PCS pointed by data.
+ */
+struct phylink_pcs *fwnode_pcs_simple_get(struct fwnode_reference_args *pcsspec,
+ void *data);
+
+/**
+ * fwnode_pcs_add_provider - Registers a new PCS provider
+ * @fwnode: Firmware node
+ * @get: xlate function to retrieve the PCS
+ * @data: Context data
+ *
+ * Register and add a new PCS to the global providers list
+ * for the firmware node. A function to get the PCS from
+ * firmware node with the use fwnode reference arguments.
+ * To the get function is also passed the interface type
+ * requested for the PHY. PCS driver will use the passed
+ * interface to understand if the PCS can support it or not.
+ *
+ * Returns: 0 on success or -ENOMEM on allocation failure.
+ */
+int fwnode_pcs_add_provider(struct fwnode_handle *fwnode,
+ struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
+ void *data),
+ void *data);
+
+/**
+ * fwnode_pcs_del_provider - Removes a PCS provider
+ * @fwnode: Firmware node
+ */
+void fwnode_pcs_del_provider(struct fwnode_handle *fwnode);
+
+#endif /* __LINUX_PCS_PROVIDER_H */
diff --git a/include/linux/pcs/pcs.h b/include/linux/pcs/pcs.h
new file mode 100644
index 000000000000..33244e3a442b
--- /dev/null
+++ b/include/linux/pcs/pcs.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __LINUX_PCS_H
+#define __LINUX_PCS_H
+
+#include <linux/phylink.h>
+
+#if IS_ENABLED(CONFIG_FWNODE_PCS)
+/**
+ * fwnode_pcs_get - Retrieves a PCS from a firmware node
+ * @fwnode: firmware node
+ * @index: index fwnode PCS handle in firmware node
+ *
+ * Get a PCS from the firmware node at index.
+ *
+ * Returns: a pointer to the phylink_pcs or a negative
+ * error pointer. Can return -EPROBE_DEFER if the PCS is not
+ * present in global providers list (either due to driver
+ * still needs to be probed or it failed to probe/removed)
+ */
+struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode,
+ int index);
+
+/**
+ * fwnode_phylink_pcs_parse - generic PCS parse for fwnode PCS provider
+ * @fwnode: firmware node
+ * @available_pcs: pointer to preallocated array of PCS
+ * @num_pcs: where to store count of parsed PCS
+ *
+ * Generic helper function to fill available_pcs array with PCS parsed
+ * from a "pcs-handle" fwnode property defined in firmware node up to
+ * passed num_pcs.
+ *
+ * If available_pcs is NULL, num_pcs is updated with the count of the
+ * parsed PCS.
+ *
+ * Returns: 0 or a negative error.
+ */
+int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
+ struct phylink_pcs **available_pcs,
+ unsigned int *num_pcs);
+#else
+static inline struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode,
+ int index)
+{
+ return ERR_PTR(-ENOENT);
+}
+
+static inline int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
+ struct phylink_pcs **available_pcs,
+ unsigned int *num_pcs)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
+#endif /* __LINUX_PCS_H */
--
2.48.1On 5/11/25 16:12, Christian Marangi wrote:
> Implement the foundation of Firmware node support for PCS driver.
>
> To support this, implement a simple Provider API where a PCS driver can
> expose multiple PCS with an xlate .get function.
>
> PCS driver will have to call fwnode_pcs_add_provider() and pass the
> firmware node pointer and a xlate function to return the correct PCS for
> the passed #pcs-cells.
>
> This will register the PCS in a global list of providers so that
> consumer can access it.
>
> The consumer will then use fwnode_pcs_get() to get the actual PCS by
> passing the firmware node pointer and the index for #pcs-cells.
>
> For a simple implementation where #pcs-cells is 0 and the PCS driver
> expose a single PCS, the xlate function fwnode_pcs_simple_get() is
> provided.
>
> For an advanced implementation a custom xlate function is required.
There is no use case for this. All PCSs have a fwnode per PCS. Removing
support for pcs cells will simplify the lookup code as well as the
registration code and API.
> One removal the PCS driver should first delete itself from the provider
> list using fwnode_pcs_del_provider() and then call phylink_release_pcs()
> on every PCS the driver provides.
And things like this can be done automatically.
> A generic function fwnode_phylink_pcs_parse() is provided for MAC driver
> that will declare PCS in DT (or ACPI).
> This function will parse "pcs-handle" property and fill the passed array
> with the parsed PCS in availabel_pcs up to the passed num_pcs value.
> It's also possible to pass NULL as array to only parse the PCS and
> update the num_pcs value with the count of scanned PCS.
When is this useful?
> Co-developed-by: Daniel Golle <daniel@makrotopia.org>
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> ---
> drivers/net/pcs/Kconfig | 6 +
> drivers/net/pcs/Makefile | 1 +
> drivers/net/pcs/pcs.c | 201 +++++++++++++++++++++++++++++++
> include/linux/pcs/pcs-provider.h | 41 +++++++
> include/linux/pcs/pcs.h | 56 +++++++++
> 5 files changed, 305 insertions(+)
> create mode 100644 drivers/net/pcs/pcs.c
> create mode 100644 include/linux/pcs/pcs-provider.h
> create mode 100644 include/linux/pcs/pcs.h
>
> diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
> index f6aa437473de..0d54bea1f663 100644
> --- a/drivers/net/pcs/Kconfig
> +++ b/drivers/net/pcs/Kconfig
> @@ -5,6 +5,12 @@
>
> menu "PCS device drivers"
>
> +config FWNODE_PCS
> + tristate
> + depends on (ACPI || OF)
> + help
> + Firmware node PCS accessors
> +
> config PCS_XPCS
> tristate "Synopsys DesignWare Ethernet XPCS"
> select PHYLINK
> diff --git a/drivers/net/pcs/Makefile b/drivers/net/pcs/Makefile
> index 4f7920618b90..3005cdd89ab7 100644
> --- a/drivers/net/pcs/Makefile
> +++ b/drivers/net/pcs/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> # Makefile for Linux PCS drivers
>
> +obj-$(CONFIG_FWNODE_PCS) += pcs.o
> pcs_xpcs-$(CONFIG_PCS_XPCS) := pcs-xpcs.o pcs-xpcs-plat.o \
> pcs-xpcs-nxp.o pcs-xpcs-wx.o
>
> diff --git a/drivers/net/pcs/pcs.c b/drivers/net/pcs/pcs.c
> new file mode 100644
> index 000000000000..26d07a2edfce
> --- /dev/null
> +++ b/drivers/net/pcs/pcs.c
> @@ -0,0 +1,201 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/mutex.h>
> +#include <linux/property.h>
> +#include <linux/phylink.h>
> +#include <linux/pcs/pcs.h>
> +#include <linux/pcs/pcs-provider.h>
> +
> +MODULE_DESCRIPTION("PCS library");
> +MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
> +MODULE_LICENSE("GPL");
> +
> +struct fwnode_pcs_provider {
> + struct list_head link;
> +
> + struct fwnode_handle *fwnode;
> + struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
> + void *data);
> +
> + void *data;
> +};
> +
> +static LIST_HEAD(fwnode_pcs_providers);
> +static DEFINE_MUTEX(fwnode_pcs_mutex);
> +
> +struct phylink_pcs *fwnode_pcs_simple_get(struct fwnode_reference_args *pcsspec,
> + void *data)
> +{
> + return data;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_pcs_simple_get);
> +
> +int fwnode_pcs_add_provider(struct fwnode_handle *fwnode,
> + struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
> + void *data),
> + void *data)
> +{
> + struct fwnode_pcs_provider *pp;
> +
> + if (!fwnode)
> + return 0;
> +
> + pp = kzalloc(sizeof(*pp), GFP_KERNEL);
> + if (!pp)
> + return -ENOMEM;
> +
> + pp->fwnode = fwnode_handle_get(fwnode);
> + pp->data = data;
> + pp->get = get;
> +
> + mutex_lock(&fwnode_pcs_mutex);
> + list_add(&pp->link, &fwnode_pcs_providers);
> + mutex_unlock(&fwnode_pcs_mutex);
> + pr_debug("Added pcs provider from %pfwf\n", fwnode);
> +
> + fwnode_dev_initialized(fwnode, true);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_pcs_add_provider);
> +
> +void fwnode_pcs_del_provider(struct fwnode_handle *fwnode)
> +{
> + struct fwnode_pcs_provider *pp;
> +
> + if (!fwnode)
> + return;
> +
> + mutex_lock(&fwnode_pcs_mutex);
> + list_for_each_entry(pp, &fwnode_pcs_providers, link) {
> + if (pp->fwnode == fwnode) {
> + list_del(&pp->link);
> + fwnode_dev_initialized(pp->fwnode, false);
> + fwnode_handle_put(pp->fwnode);
> + kfree(pp);
> + break;
> + }
> + }
> + mutex_unlock(&fwnode_pcs_mutex);
> +}
> +EXPORT_SYMBOL_GPL(fwnode_pcs_del_provider);
> +
> +static int fwnode_parse_pcsspec(const struct fwnode_handle *fwnode, int index,
> + const char *name,
> + struct fwnode_reference_args *out_args)
> +{
> + int ret;
> +
> + if (!fwnode)
> + return -ENOENT;
> +
> + if (name)
> + index = fwnode_property_match_string(fwnode, "pcs-names",
> + name);
> +
> + ret = fwnode_property_get_reference_args(fwnode, "pcs-handle",
> + "#pcs-cells",
> + -1, index, out_args);
> + if (ret || (name && index < 0))
> + return ret;
> +
> + return 0;
> +}
> +
> +static struct phylink_pcs *
> +fwnode_pcs_get_from_pcsspec(struct fwnode_reference_args *pcsspec)
> +{
> + struct fwnode_pcs_provider *provider;
> + struct phylink_pcs *pcs = ERR_PTR(-EPROBE_DEFER);
> +
> + if (!pcsspec)
> + return ERR_PTR(-EINVAL);
> +
> + mutex_lock(&fwnode_pcs_mutex);
> + list_for_each_entry(provider, &fwnode_pcs_providers, link) {
> + if (provider->fwnode == pcsspec->fwnode) {
> + pcs = provider->get(pcsspec, provider->data);
> + if (!IS_ERR(pcs))
> + break;
> + }
> + }
> + mutex_unlock(&fwnode_pcs_mutex);
> +
> + return pcs;
> +}
> +
> +static struct phylink_pcs *__fwnode_pcs_get(struct fwnode_handle *fwnode,
> + int index, const char *con_id)
Many existing drivers have to support non-standard PCS handle names
(e.g. pcsphy-handle, phy-handle, etc.). Support for this is important
for converting those drivers to use this system.
--Sean
> +{
> + struct fwnode_reference_args pcsspec;
> + struct phylink_pcs *pcs;
> + int ret;
> +
> + ret = fwnode_parse_pcsspec(fwnode, index, con_id, &pcsspec);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + pcs = fwnode_pcs_get_from_pcsspec(&pcsspec);
> + fwnode_handle_put(pcsspec.fwnode);
> +
> + return pcs;
> +}
> +
> +struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode, int index)
> +{
> + return __fwnode_pcs_get(fwnode, index, NULL);
> +}
> +EXPORT_SYMBOL_GPL(fwnode_pcs_get);
> +
> +static int fwnode_phylink_pcs_count(struct fwnode_handle *fwnode,
> + unsigned int *num_pcs)
> +{
> + struct fwnode_reference_args out_args;
> + int index = 0;
> + int ret;
> +
> + while (true) {
> + ret = fwnode_property_get_reference_args(fwnode, "pcs-handle",
> + "#pcs-cells",
> + -1, index, &out_args);
> + /* We expect to reach an -ENOENT error while counting */
> + if (ret)
> + break;
> +
> + fwnode_handle_put(out_args.fwnode);
> + index++;
> + }
> +
> + /* Update num_pcs with parsed PCS */
> + *num_pcs = index;
> +
> + /* Return error if we didn't found any PCS */
> + return index > 0 ? 0 : -ENOENT;
> +}
> +
> +int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
> + struct phylink_pcs **available_pcs,
> + unsigned int *num_pcs)
> +{
> + int i;
> +
> + if (!fwnode_property_present(fwnode, "pcs-handle"))
> + return -ENODEV;
> +
> + /* With available_pcs NULL, only count the PCS */
> + if (!available_pcs)
> + return fwnode_phylink_pcs_count(fwnode, num_pcs);
> +
> + for (i = 0; i < *num_pcs; i++) {
> + struct phylink_pcs *pcs;
> +
> + pcs = fwnode_pcs_get(fwnode, i);
> + if (IS_ERR(pcs))
> + return PTR_ERR(pcs);
> +
> + available_pcs[i] = pcs;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_phylink_pcs_parse);
> diff --git a/include/linux/pcs/pcs-provider.h b/include/linux/pcs/pcs-provider.h
> new file mode 100644
> index 000000000000..ae51c108147e
> --- /dev/null
> +++ b/include/linux/pcs/pcs-provider.h
> @@ -0,0 +1,41 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +#ifndef __LINUX_PCS_PROVIDER_H
> +#define __LINUX_PCS_PROVIDER_H
> +
> +/**
> + * fwnode_pcs_simple_get - Simple xlate function to retrieve PCS
> + * @pcsspec: reference arguments
> + * @data: Context data (assumed assigned to the single PCS)
> + *
> + * Returns: the PCS pointed by data.
> + */
> +struct phylink_pcs *fwnode_pcs_simple_get(struct fwnode_reference_args *pcsspec,
> + void *data);
> +
> +/**
> + * fwnode_pcs_add_provider - Registers a new PCS provider
> + * @fwnode: Firmware node
> + * @get: xlate function to retrieve the PCS
> + * @data: Context data
> + *
> + * Register and add a new PCS to the global providers list
> + * for the firmware node. A function to get the PCS from
> + * firmware node with the use fwnode reference arguments.
> + * To the get function is also passed the interface type
> + * requested for the PHY. PCS driver will use the passed
> + * interface to understand if the PCS can support it or not.
> + *
> + * Returns: 0 on success or -ENOMEM on allocation failure.
> + */
> +int fwnode_pcs_add_provider(struct fwnode_handle *fwnode,
> + struct phylink_pcs *(*get)(struct fwnode_reference_args *pcsspec,
> + void *data),
> + void *data);
> +
> +/**
> + * fwnode_pcs_del_provider - Removes a PCS provider
> + * @fwnode: Firmware node
> + */
> +void fwnode_pcs_del_provider(struct fwnode_handle *fwnode);
> +
> +#endif /* __LINUX_PCS_PROVIDER_H */
> diff --git a/include/linux/pcs/pcs.h b/include/linux/pcs/pcs.h
> new file mode 100644
> index 000000000000..33244e3a442b
> --- /dev/null
> +++ b/include/linux/pcs/pcs.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +#ifndef __LINUX_PCS_H
> +#define __LINUX_PCS_H
> +
> +#include <linux/phylink.h>
> +
> +#if IS_ENABLED(CONFIG_FWNODE_PCS)
> +/**
> + * fwnode_pcs_get - Retrieves a PCS from a firmware node
> + * @fwnode: firmware node
> + * @index: index fwnode PCS handle in firmware node
> + *
> + * Get a PCS from the firmware node at index.
> + *
> + * Returns: a pointer to the phylink_pcs or a negative
> + * error pointer. Can return -EPROBE_DEFER if the PCS is not
> + * present in global providers list (either due to driver
> + * still needs to be probed or it failed to probe/removed)
> + */
> +struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode,
> + int index);
> +
> +/**
> + * fwnode_phylink_pcs_parse - generic PCS parse for fwnode PCS provider
> + * @fwnode: firmware node
> + * @available_pcs: pointer to preallocated array of PCS
> + * @num_pcs: where to store count of parsed PCS
> + *
> + * Generic helper function to fill available_pcs array with PCS parsed
> + * from a "pcs-handle" fwnode property defined in firmware node up to
> + * passed num_pcs.
> + *
> + * If available_pcs is NULL, num_pcs is updated with the count of the
> + * parsed PCS.
> + *
> + * Returns: 0 or a negative error.
> + */
> +int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
> + struct phylink_pcs **available_pcs,
> + unsigned int *num_pcs);
> +#else
> +static inline struct phylink_pcs *fwnode_pcs_get(struct fwnode_handle *fwnode,
> + int index)
> +{
> + return ERR_PTR(-ENOENT);
> +}
> +
> +static inline int fwnode_phylink_pcs_parse(struct fwnode_handle *fwnode,
> + struct phylink_pcs **available_pcs,
> + unsigned int *num_pcs)
> +{
> + return -EOPNOTSUPP;
> +}
> +#endif
> +
> +#endif /* __LINUX_PCS_H */
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