dpll: zl3073x: Implement devlink flash callback

JIRA: https://issues.redhat.com/browse/RHEL-115367

commit a1e891f
Author: Ivan Vecera <ivecera@redhat.com>
Date:   Tue Sep 9 11:15:32 2025 +0200

    dpll: zl3073x: Implement devlink flash callback

    Use the introduced functionality to read firmware files and flash their
    contents into the device's internal flash memory to implement the devlink
    flash update callback.

    Sample output on EDS2 development board:
     # devlink -j dev info i2c/1-0070 | jq '.[][]["versions"]["running"]'
     {
       "fw": "6026"
     }
     # devlink dev flash i2c/1-0070 file firmware_fw2.hex
     [utility] Prepare flash mode
     [utility] Downloading image 100%
     [utility] Flash mode enabled
     [firmware1-part1] Downloading image 100%
     [firmware1-part1] Flashing image
     [firmware1-part2] Downloading image 100%
     [firmware1-part2] Flashing image
     [firmware1] Flashing done
     [firmware2] Downloading image 100%
     [firmware2] Flashing image 100%
     [firmware2] Flashing done
     [utility] Leaving flash mode
     Flashing done
     # devlink -j dev info i2c/1-0070 | jq '.[][]["versions"]["running"]'
     {
       "fw": "7006"
     }

    Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
    Signed-off-by: Ivan Vecera <ivecera@redhat.com>
    Link: https://patch.msgid.link/20250909091532.11790-6-ivecera@redhat.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Author: ivecera

Documentation/networking/devlink/zl3073x.rst

@@ -49,3 +49,17 @@ The ``zl3073x`` driver reports the following versions
       - running
       - 1.3.0.1
       - Device configuration version customized by OEM
+
+Flash Update
+============
+
+The ``zl3073x`` driver implements support for flash update using the
+``devlink-flash`` interface. It supports updating the device flash using a
+combined flash image ("bundle") that contains multiple components (firmware
+parts and configurations).
+
+During the flash procedure, the standard firmware interface is not available,
+so the driver unregisters all DPLLs and associated pins, and re-registers them
+once the flash procedure is complete.
+
+The driver does not support any overwrite mask flags.

drivers/dpll/zl3073x/devlink.c

@@ -9,6 +9,8 @@
 #include "core.h"
 #include "devlink.h"
 #include "dpll.h"
+#include "flash.h"
+#include "fw.h"
 #include "regs.h"
 
 /**
@@ -141,11 +143,138 @@ void zl3073x_devlink_flash_notify(struct zl3073x_dev *zldev, const char *msg,
 					   total);
 }
 
+/**
+ * zl3073x_devlink_flash_prepare - Prepare and enter flash mode
+ * @zldev: zl3073x device pointer
+ * @zlfw: pointer to loaded firmware
+ * @extack: netlink extack pointer to report errors
+ *
+ * The function stops normal operation and switches the device to flash mode.
+ * If an error occurs the normal operation is resumed.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int
+zl3073x_devlink_flash_prepare(struct zl3073x_dev *zldev,
+			      struct zl3073x_fw *zlfw,
+			      struct netlink_ext_ack *extack)
+{
+	struct zl3073x_fw_component *util;
+	int rc;
+
+	util = zlfw->component[ZL_FW_COMPONENT_UTIL];
+	if (!util) {
+		zl3073x_devlink_flash_notify(zldev,
+					     "Utility is missing in firmware",
+					     NULL, 0, 0);
+		zl3073x_fw_free(zlfw);
+		return -ENOEXEC;
+	}
+
+	/* Stop normal operation prior entering flash mode */
+	zl3073x_dev_stop(zldev);
+
+	rc = zl3073x_flash_mode_enter(zldev, util->data, util->size, extack);
+	if (rc) {
+		zl3073x_devlink_flash_notify(zldev,
+					     "Failed to enter flash mode",
+					     NULL, 0, 0);
+
+		/* Resume normal operation */
+		zl3073x_dev_start(zldev, true);
+
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * zl3073x_devlink_flash_finish - Leave flash mode and resume normal operation
+ * @zldev: zl3073x device pointer
+ * @extack: netlink extack pointer to report errors
+ *
+ * The function switches the device back to standard mode and resumes normal
+ * operation.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int
+zl3073x_devlink_flash_finish(struct zl3073x_dev *zldev,
+			     struct netlink_ext_ack *extack)
+{
+	int rc;
+
+	/* Reset device CPU to normal mode */
+	zl3073x_flash_mode_leave(zldev, extack);
+
+	/* Resume normal operation */
+	rc = zl3073x_dev_start(zldev, true);
+	if (rc)
+		zl3073x_devlink_flash_notify(zldev,
+					     "Failed to start normal operation",
+					     NULL, 0, 0);
+
+	return rc;
+}
+
+/**
+ * zl3073x_devlink_flash_update - Devlink flash update callback
+ * @devlink: devlink structure pointer
+ * @params: flashing parameters pointer
+ * @extack: netlink extack pointer to report errors
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int
+zl3073x_devlink_flash_update(struct devlink *devlink,
+			     struct devlink_flash_update_params *params,
+			     struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dev *zldev = devlink_priv(devlink);
+	struct zl3073x_fw *zlfw;
+	int rc = 0;
+
+	zlfw = zl3073x_fw_load(zldev, params->fw->data, params->fw->size,
+			       extack);
+	if (IS_ERR(zlfw)) {
+		zl3073x_devlink_flash_notify(zldev, "Failed to load firmware",
+					     NULL, 0, 0);
+		rc = PTR_ERR(zlfw);
+		goto finish;
+	}
+
+	/* Stop normal operation and enter flash mode */
+	rc = zl3073x_devlink_flash_prepare(zldev, zlfw, extack);
+	if (rc)
+		goto finish;
+
+	rc = zl3073x_fw_flash(zldev, zlfw, extack);
+	if (rc) {
+		zl3073x_devlink_flash_finish(zldev, extack);
+		goto finish;
+	}
+
+	/* Resume normal mode */
+	rc = zl3073x_devlink_flash_finish(zldev, extack);
+
+finish:
+	if (!IS_ERR(zlfw))
+		zl3073x_fw_free(zlfw);
+
+	zl3073x_devlink_flash_notify(zldev,
+				     rc ? "Flashing failed" : "Flashing done",
+				     NULL, 0, 0);
+
+	return rc;
+}
+
 static const struct devlink_ops zl3073x_devlink_ops = {
 	.info_get = zl3073x_devlink_info_get,
 	.reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
 	.reload_down = zl3073x_devlink_reload_down,
 	.reload_up = zl3073x_devlink_reload_up,
+	.flash_update = zl3073x_devlink_flash_update,
 };
 
 static void