[PATCH net-next v3 5/5] net: pse-pd: pd692x0: Add devlink interface for configuration save/reset

Kory Maincent
2025-09-15T17:07:19Z

From: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>

Add devlink conf_save and conf_reset ops to enable userspace management
of the PSE's permanent configuration stored in non-volatile memory.
The save_conf allows saving the current configuration to non-volatile
memory. The reset_conf attribute restores factory defaults configurations.

Skip hardware configuration initialization on probe when a saved
configuration is already present in non-volatile memory (detected via user
byte set to 42).

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---

Changes in v2:
- Move on from sysfs to devlink param for userspace management.

Changes in v3:
- Move on from devlink param to new devlink conf uAPI.
---
Documentation/networking/devlink/index.rst | 1 +
Documentation/networking/devlink/pd692x0.rst | 24 ++++
MAINTAINERS | 1 +
drivers/net/pse-pd/pd692x0.c | 160 ++++++++++++++++++++++++++-
4 files changed, 183 insertions(+), 3 deletions(-)

diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index ba381ecadc3dc..336b4cc00bd14 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -97,6 +97,7 @@ parameters, info versions, and other features it supports.
netdevsim
nfp
octeontx2
+ pd692x0
prestera
qed
sfc
diff --git a/Documentation/networking/devlink/pd692x0.rst b/Documentation/networking/devlink/pd692x0.rst
new file mode 100644
index 0000000000000..d7166f6f3ba91
--- /dev/null
+++ b/Documentation/networking/devlink/pd692x0.rst
@@ -0,0 +1,24 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+PSE PD692x0 devlink support
+===========================
+
+This document describes the devlink features implemented by the PSE
+``PD692x0`` device drivers.
+
+Operations
+==========
+
+The ``PD692x0`` drivers implement the following devlink operations.
+
+.. list-table:: Devlink ops implemented
+ :widths: 5 85
+
+ * - Name
+ - Description
+ * - ``conf_save``
+ - Save the current configuration to non-volatile memory.
+ * - ``conf_reset``
+ - Reset the current and saved configuration located the non-volatile
+ memory.
diff --git a/MAINTAINERS b/MAINTAINERS
index 429303a9447f3..cc6f7a8986b04 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20300,6 +20300,7 @@ L: netdev@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/net/pse-pd/
F: Documentation/networking/devlink/devlink-conf.rst
+F: Documentation/networking/devlink/pd692x0.rst
F: drivers/net/pse-pd/
F: net/devlink/conf.c
F: net/ethtool/pse-pd.c
diff --git a/drivers/net/pse-pd/pd692x0.c b/drivers/net/pse-pd/pd692x0.c
index 782b1abf94cb1..97f9c0648fdb6 100644
--- a/drivers/net/pse-pd/pd692x0.c
+++ b/drivers/net/pse-pd/pd692x0.c
@@ -14,6 +14,7 @@
#include <linux/pse-pd/pse.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
+#include <net/devlink.h>

#define PD692X0_PSE_NAME "pd692x0_pse"

@@ -30,6 +31,8 @@
#define PD692X0_FW_MIN_VER 5
#define PD692X0_FW_PATCH_VER 5

+#define PD692X0_USER_BYTE 42
+
enum pd692x0_fw_state {
PD692X0_FW_UNKNOWN,
PD692X0_FW_OK,
@@ -80,6 +83,9 @@ enum {
PD692X0_MSG_GET_PORT_PARAM,
PD692X0_MSG_GET_POWER_BANK,
PD692X0_MSG_SET_POWER_BANK,
+ PD692X0_MSG_SET_USER_BYTE,
+ PD692X0_MSG_SAVE_SYS_SETTINGS,
+ PD692X0_MSG_RESTORE_FACTORY,

/* add new message above here */
PD692X0_MSG_CNT
@@ -103,11 +109,13 @@ struct pd692x0_priv {
bool last_cmd_key;
unsigned long last_cmd_key_time;

+ bool cfg_saved;
enum ethtool_c33_pse_admin_state admin_state[PD692X0_MAX_PIS];
struct regulator_dev *manager_reg[PD692X0_MAX_MANAGERS];
int manager_pw_budget[PD692X0_MAX_MANAGERS];
int nmanagers;
struct pd692x0_matrix *port_matrix;
+ struct devlink *dl;
};

/* Template list of communication messages. The non-null bytes defined here
@@ -193,6 +201,24 @@ static const struct pd692x0_msg pd692x0_msg_template_list[PD692X0_MSG_CNT] = {
.key = PD692X0_KEY_CMD,
.sub = {0x07, 0x0b, 0x57},
},
+ [PD692X0_MSG_SET_USER_BYTE] = {
+ .key = PD692X0_KEY_PRG,
+ .sub = {0x41, PD692X0_USER_BYTE},
+ .data = {0x4e, 0x4e, 0x4e, 0x4e,
+ 0x4e, 0x4e, 0x4e, 0x4e},
+ },
+ [PD692X0_MSG_SAVE_SYS_SETTINGS] = {
+ .key = PD692X0_KEY_PRG,
+ .sub = {0x06, 0x0f},
+ .data = {0x4e, 0x4e, 0x4e, 0x4e,
+ 0x4e, 0x4e, 0x4e, 0x4e},
+ },
+ [PD692X0_MSG_RESTORE_FACTORY] = {
+ .key = PD692X0_KEY_PRG,
+ .sub = {0x2d, 0x4e},
+ .data = {0x4e, 0x4e, 0x4e, 0x4e,
+ 0x4e, 0x4e, 0x4e, 0x4e},
+ },
};

static u8 pd692x0_build_msg(struct pd692x0_msg *msg, u8 echo)
@@ -1268,9 +1294,12 @@ static int pd692x0_setup_pi_matrix(struct pse_controller_dev *pcdev)
if (ret)
goto err_managers_req_pw;

- ret = pd692x0_hw_conf_init(priv);
- if (ret)
- goto err_managers_req_pw;
+ /* Do not init the conf if it is already saved */
+ if (!priv->cfg_saved) {
+ ret = pd692x0_hw_conf_init(priv);
+ if (ret)
+ goto err_managers_req_pw;
+ }

pd692x0_of_put_managers(priv, manager);
kfree(manager);
@@ -1727,14 +1756,118 @@ static const struct fw_upload_ops pd692x0_fw_ops = {
.cleanup = pd692x0_fw_cleanup,
};

+/* Devlink Params APIs */
+enum pd692x0_devlink_param_id {
+ PD692X0_DEVLINK_PARAM_ID_BASE = DEVLINK_PARAM_GENERIC_ID_MAX,
+ PD692X0_DEVLINK_PARAM_ID_SAVE_CONF,
+ PD692X0_DEVLINK_PARAM_ID_RESET_CONF,
+};
+
+struct pd692x0_devlink {
+ struct pd692x0_priv *priv;
+};
+
+static int pd692x0_dl_conf_save(struct devlink *devlink,
+ struct netlink_ext_ack *extack)
+{
+ struct pd692x0_devlink *dl = devlink_priv(devlink);
+ struct pd692x0_priv *priv = dl->priv;
+ struct pd692x0_msg msg, buf = {0};
+ int ret;
+
+ mutex_lock(&priv->pcdev.lock);
+ ret = pd692x0_fw_unavailable(priv);
+ if (ret)
+ goto out;
+
+ msg = pd692x0_msg_template_list[PD692X0_MSG_SET_USER_BYTE];
+ ret = pd692x0_sendrecv_msg(priv, &msg, &buf);
+ if (ret)
+ goto out;
+
+ msg = pd692x0_msg_template_list[PD692X0_MSG_SAVE_SYS_SETTINGS];
+ ret = pd692x0_send_msg(priv, &msg);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "Failed to save the configuration (%pe)\n",
+ ERR_PTR(ret));
+ goto out;
+ }
+
+ msleep(50); /* Sleep 50ms as described in the datasheet */
+
+ ret = i2c_master_recv(priv->client, (u8 *)&buf, sizeof(buf));
+ if (ret != sizeof(buf)) {
+ if (ret >= 0)
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+ mutex_unlock(&priv->pcdev.lock);
+ return ret;
+}
+
+static int pd692x0_dl_conf_reset(struct devlink *devlink,
+ struct netlink_ext_ack *extack)
+{
+ struct pd692x0_devlink *dl = devlink_priv(devlink);
+ struct pd692x0_priv *priv = dl->priv;
+ struct pd692x0_msg msg, buf = {0};
+ int ret;
+
+ mutex_lock(&priv->pcdev.lock);
+ ret = pd692x0_fw_unavailable(priv);
+ if (ret)
+ goto out;
+
+ msg = pd692x0_msg_template_list[PD692X0_MSG_RESTORE_FACTORY];
+ ret = pd692x0_send_msg(priv, &msg);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "Failed to reset the configuration (%pe)\n",
+ ERR_PTR(ret));
+ goto out;
+ }
+
+ msleep(100); /* Sleep 100ms as described in the datasheet */
+
+ ret = i2c_master_recv(priv->client, (u8 *)&buf, sizeof(buf));
+ if (ret != sizeof(buf)) {
+ if (ret >= 0)
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = pd692x0_hw_conf_init(priv);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "Error configuring ports matrix (%pe)\n",
+ ERR_PTR(ret));
+ }
+
+out:
+ mutex_unlock(&priv->pcdev.lock);
+ return ret;
+}
+
+static const struct devlink_ops pd692x0_dl_ops = {
+ .conf_save = pd692x0_dl_conf_save,
+ .conf_reset = pd692x0_dl_conf_reset,
+};
+
static int pd692x0_i2c_probe(struct i2c_client *client)
{
static const char * const regulators[] = { "vdd", "vdda" };
struct pd692x0_msg msg, buf = {0}, zero = {0};
+ struct pd692x0_devlink *pd692x0_dl;
struct device *dev = &client->dev;
struct pd692x0_msg_ver ver;
struct pd692x0_priv *priv;
struct fw_upload *fwl;
+ struct devlink *dl;
int ret;

ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
@@ -1793,6 +1926,9 @@ static int pd692x0_i2c_probe(struct i2c_client *client)
}
}

+ if (buf.data[2] == PD692X0_USER_BYTE)
+ priv->cfg_saved = true;
+
priv->np = dev->of_node;
priv->pcdev.nr_lines = PD692X0_MAX_PIS;
priv->pcdev.owner = THIS_MODULE;
@@ -1813,7 +1949,24 @@ static int pd692x0_i2c_probe(struct i2c_client *client)
"failed to register to the Firmware Upload API\n");
priv->fwl = fwl;

+ dl = devlink_alloc(&pd692x0_dl_ops, sizeof(*pd692x0_dl), dev);
+ if (!dl) {
+ dev_err(dev, "devlink_alloc failed\n");
+ ret = -ENOMEM;
+ goto err_unregister_fw;
+ }
+
+ pd692x0_dl = devlink_priv(dl);
+ pd692x0_dl->priv = priv;
+ priv->dl = dl;
+ devlink_register(dl);
+
return 0;
+
+err_unregister_fw:
+ firmware_upload_unregister(priv->fwl);
+
+ return ret;
}

static void pd692x0_i2c_remove(struct i2c_client *client)
@@ -1821,6 +1974,7 @@ static void pd692x0_i2c_remove(struct i2c_client *client)
struct pd692x0_priv *priv = i2c_get_clientdata(client);

pd692x0_managers_free_pw_budget(priv);
+ devlink_unregister(priv->dl);
firmware_upload_unregister(priv->fwl);
}

--
2.43.0