[PATCH net-next 2/2] net: pse-pd: pd692x0: Add sysfs interface for configuration save/reset

[Kory Maincent <kory.maincent@bootlin.com>]

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

Add sysfs attributes save_conf and reset_conf to enable userspace
management of the PSE's permanent configuration stored in EEPROM.

The save_conf attribute allows saving the current configuration to
EEPROM by writing '1'. The reset_conf attribute restores factory
defaults and reinitializes the port matrix configuration.

Skip hardware configuration initialization on probe when a saved
configuration is already present in EEPROM (detected via user byte 42).

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---
 drivers/net/pse-pd/pd692x0.c | 151 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 148 insertions(+), 3 deletions(-)

diff --git a/drivers/net/pse-pd/pd692x0.c b/drivers/net/pse-pd/pd692x0.c
index 8b94967bb4fb..202e91ec9b9a 100644
--- a/drivers/net/pse-pd/pd692x0.c
+++ b/drivers/net/pse-pd/pd692x0.c
@@ -30,6 +30,8 @@
 #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 +82,9 @@ 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
@@ -103,6 +108,7 @@ 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];
@@ -193,6 +199,24 @@ 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)
@@ -1266,9 +1290,12 @@ 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);
 	return 0;
@@ -1722,6 +1749,104 @@ static const struct fw_upload_ops pd692x0_fw_ops = {
 	.cleanup = pd692x0_fw_cleanup,
 };
 
+static ssize_t save_conf_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *save_buf, size_t count)
+{
+	struct pd692x0_priv *priv = dev_get_drvdata(dev);
+	struct pd692x0_msg msg, buf = {0};
+	bool save;
+	int ret;
+
+	if (kstrtobool(save_buf, &save) || !save)
+		return -EINVAL;
+
+	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 = count;
+out:
+	mutex_unlock(&priv->pcdev.lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(save_conf);
+
+static ssize_t reset_conf_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *reset_buf, size_t count)
+{
+	struct pd692x0_priv *priv = dev_get_drvdata(dev);
+	struct pd692x0_msg msg, buf = {0};
+	bool reset;
+	int ret;
+
+	if (kstrtobool(reset_buf, &reset) || !reset)
+		return -EINVAL;
+
+	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 < 0) {
+		dev_err(&priv->client->dev,
+			"Error configuring ports matrix (%pe)\n",
+			ERR_PTR(ret));
+	}
+
+	ret = count;
+out:
+	mutex_unlock(&priv->pcdev.lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(reset_conf);
+
 static int pd692x0_i2c_probe(struct i2c_client *client)
 {
 	static const char * const regulators[] = { "vdd", "vdda" };
@@ -1788,6 +1913,9 @@ 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;
@@ -1808,7 +1936,22 @@ static int pd692x0_i2c_probe(struct i2c_client *client)
 				     "failed to register to the Firmware Upload API\n");
 	priv->fwl = fwl;
 
+	ret = sysfs_create_file(&dev->kobj, &dev_attr_save_conf.attr);
+	if (ret)
+		goto err_sysfs;
+
+	ret = sysfs_create_file(&dev->kobj, &dev_attr_reset_conf.attr);
+	if (ret)
+		goto err_sysfs_reset_conf;
+
 	return 0;
+
+err_sysfs_reset_conf:
+	sysfs_remove_file(&dev->kobj, &dev_attr_save_conf.attr);
+err_sysfs:
+	firmware_upload_unregister(priv->fwl);
+
+	return ret;
 }
 
 static void pd692x0_i2c_remove(struct i2c_client *client)
@@ -1816,6 +1959,8 @@ static void pd692x0_i2c_remove(struct i2c_client *client)
 	struct pd692x0_priv *priv = i2c_get_clientdata(client);
 
 	pd692x0_managers_free_pw_budget(priv);
+	sysfs_remove_file(&client->dev.kobj, &dev_attr_reset_conf.attr);
+	sysfs_remove_file(&client->dev.kobj, &dev_attr_save_conf.attr);
 	firmware_upload_unregister(priv->fwl);
 }
 

-- 
2.43.0