[PATCH v3 net-next 4/8] mfd: zl3073x: Add support for devlink device info

[Ivan Vecera <ivecera@redhat.com>]

Use devlink_alloc() to alloc zl3073x_dev structure, register the device
as a devlink device and add devlink callback to provide devlink device
info.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
v2->v3:
* merged devlink device allocation, registration and device info
  callback

v1->v2:
- dependency on NET moved to MFD_ZL3073X_CORE in Kconfig
- devlink register managed way
---
 drivers/mfd/Kconfig        |   2 +
 drivers/mfd/zl3073x-core.c | 106 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 106 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7d7902ec1d89a..e4eca15af175d 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2424,6 +2424,8 @@ config MFD_UPBOARD_FPGA
 
 config MFD_ZL3073X_CORE
 	tristate
+	depends on NET
+	select NET_DEVLINK
 	select MFD_CORE
 
 config MFD_ZL3073X_I2C
diff --git a/drivers/mfd/zl3073x-core.c b/drivers/mfd/zl3073x-core.c
index 0455d6ae37da5..8a15237e0f731 100644
--- a/drivers/mfd/zl3073x-core.c
+++ b/drivers/mfd/zl3073x-core.c
@@ -8,7 +8,10 @@
 #include <linux/mfd/zl3073x.h>
 #include <linux/mfd/zl3073x_regs.h>
 #include <linux/module.h>
+#include <linux/netlink.h>
 #include <linux/regmap.h>
+#include <linux/sprintf.h>
+#include <net/devlink.h>
 #include "zl3073x.h"
 
 /* Chip IDs for zl30731 */
@@ -112,6 +115,83 @@ static const struct regmap_config zl3073x_regmap_config = {
 	.volatile_reg	= zl3073x_is_volatile_reg,
 };
 
+/**
+ * zl3073x_devlink_info_get - Devlink device info callback
+ * @devlink: devlink structure pointer
+ * @req: devlink request pointer to store information
+ * @extack: netlink extack pointer to report errors
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_devlink_info_get(struct devlink *devlink,
+				    struct devlink_info_req *req,
+				    struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dev *zldev = devlink_priv(devlink);
+	u16 id, revision, fw_ver;
+	char buf[16];
+	u32 cfg_ver;
+	int rc;
+
+	rc = zl3073x_read_id(zldev, &id);
+	if (rc)
+		return rc;
+
+	snprintf(buf, sizeof(buf), "%X", id);
+	rc = devlink_info_version_fixed_put(req,
+					    DEVLINK_INFO_VERSION_GENERIC_ASIC_ID,
+					    buf);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_revision(zldev, &revision);
+	if (rc)
+		return rc;
+
+	snprintf(buf, sizeof(buf), "%X", revision);
+	rc = devlink_info_version_fixed_put(req,
+					    DEVLINK_INFO_VERSION_GENERIC_ASIC_REV,
+					    buf);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_fw_ver(zldev, &fw_ver);
+	if (rc)
+		return rc;
+
+	snprintf(buf, sizeof(buf), "%u", fw_ver);
+	rc = devlink_info_version_fixed_put(req,
+					    DEVLINK_INFO_VERSION_GENERIC_FW,
+					    buf);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_custom_config_ver(zldev, &cfg_ver);
+	if (rc)
+		return rc;
+
+	/* No custom config version */
+	if (cfg_ver == U32_MAX)
+		return 0;
+
+	snprintf(buf, sizeof(buf), "%lu.%lu.%lu.%lu",
+		 FIELD_GET(GENMASK(31, 24), cfg_ver),
+		 FIELD_GET(GENMASK(23, 16), cfg_ver),
+		 FIELD_GET(GENMASK(15, 8), cfg_ver),
+		 FIELD_GET(GENMASK(7, 0), cfg_ver));
+
+	return devlink_info_version_running_put(req, "cfg.custom_ver", buf);
+}
+
+static const struct devlink_ops zl3073x_devlink_ops = {
+	.info_get = zl3073x_devlink_info_get,
+};
+
+static void zl3073x_devlink_free(void *ptr)
+{
+	devlink_free(ptr);
+}
+
 /**
  * zl3073x_devm_alloc - allocates zl3073x device structure
  * @dev: pointer to device structure
@@ -124,12 +204,18 @@ static const struct regmap_config zl3073x_regmap_config = {
 struct zl3073x_dev *zl3073x_devm_alloc(struct device *dev)
 {
 	struct zl3073x_dev *zldev;
+	struct devlink *devlink;
 	int rc;
 
-	zldev = devm_kzalloc(dev, sizeof(*zldev), GFP_KERNEL);
-	if (!zldev)
+	devlink = devlink_alloc(&zl3073x_devlink_ops, sizeof(*zldev), dev);
+	if (!devlink)
 		return ERR_PTR(-ENOMEM);
 
+	/* Add devres action to free devlink device */
+	if (devm_add_action_or_reset(dev, zl3073x_devlink_free, devlink))
+		return ERR_PTR(-ENOMEM);
+
+	zldev = devlink_priv(devlink);
 	zldev->dev = dev;
 
 	/* We have to initialize regmap mutex here because during
@@ -158,6 +244,11 @@ void zl3073x_dev_init_regmap_config(struct regmap_config *regmap_cfg)
 }
 EXPORT_SYMBOL_NS_GPL(zl3073x_dev_init_regmap_config, "ZL3073X");
 
+static void zl3073x_devlink_unregister(void *ptr)
+{
+	devlink_unregister(ptr);
+}
+
 /**
  * zl3073x_dev_probe - initialize zl3073x device
  * @zldev: pointer to zl3073x device
@@ -171,6 +262,7 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev,
 		      const struct zl3073x_chip_info *chip_info)
 {
 	u16 id, revision, fw_ver;
+	struct devlink *devlink;
 	u32 cfg_ver;
 	int i, rc;
 
@@ -209,6 +301,16 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev,
 		FIELD_GET(GENMASK(15, 8), cfg_ver),
 		FIELD_GET(GENMASK(7, 0), cfg_ver));
 
+	/* Register the device as devlink device */
+	devlink = priv_to_devlink(zldev);
+	devlink_register(devlink);
+
+	/* Add devres action to unregister devlink device */
+	rc = devm_add_action_or_reset(zldev->dev, zl3073x_devlink_unregister,
+				      devlink);
+	if (rc)
+		return rc;
+
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(zl3073x_dev_probe, "ZL3073X");
-- 
2.48.1