1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/net/can/usb/etas_es58x/es58x_devlink.c b/drivers/net/can/usb/etas_es58x/es58x_devlink.c
new file mode 100644
index 000000000000..9fba29e2f57c
--- /dev/null
+++ b/drivers/net/can/usb/etas_es58x/es58x_devlink.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
+ *
+ * File es58x_devlink.c: report the product information using devlink.
+ *
+ * Copyright (c) 2022 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/usb.h>
+#include <net/devlink.h>
+
+#include "es58x_core.h"
+
+/* USB descriptor index containing the product information string. */
+#define ES58X_PROD_INFO_IDX 6
+
+/**
+ * es58x_parse_sw_version() - Extract boot loader or firmware version.
+ * @es58x_dev: ES58X device.
+ * @prod_info: USB custom string returned by the device.
+ * @prefix: Select which information should be parsed. Set it to "FW"
+ *	to parse the firmware version or to "BL" to parse the
+ *	bootloader version.
+ *
+ * The @prod_info string contains the firmware and the bootloader
+ * version number all prefixed by a magic string and concatenated with
+ * other numbers. Depending on the device, the firmware (bootloader)
+ * format is either "FW_Vxx.xx.xx" ("BL_Vxx.xx.xx") or "FW:xx.xx.xx"
+ * ("BL:xx.xx.xx") where 'x' represents a digit. @prod_info must
+ * contains the common part of those prefixes: "FW" or "BL".
+ *
+ * Parse @prod_info and store the version number in
+ * &es58x_dev.firmware_version or &es58x_dev.bootloader_version
+ * according to @prefix value.
+ *
+ * Return: zero on success, -EINVAL if @prefix contains an invalid
+ *	value and -EBADMSG if @prod_info could not be parsed.
+ */
+static int es58x_parse_sw_version(struct es58x_device *es58x_dev,
+				  const char *prod_info, const char *prefix)
+{
+	struct es58x_sw_version *version;
+	int major, minor, revision;
+
+	if (!strcmp(prefix, "FW"))
+		version = &es58x_dev->firmware_version;
+	else if (!strcmp(prefix, "BL"))
+		version = &es58x_dev->bootloader_version;
+	else
+		return -EINVAL;
+
+	/* Go to prefix */
+	prod_info = strstr(prod_info, prefix);
+	if (!prod_info)
+		return -EBADMSG;
+	/* Go to beginning of the version number */
+	while (!isdigit(*prod_info)) {
+		prod_info++;
+		if (!*prod_info)
+			return -EBADMSG;
+	}
+
+	if (sscanf(prod_info, "%2u.%2u.%2u", &major, &minor, &revision) != 3)
+		return -EBADMSG;
+
+	version->major = major;
+	version->minor = minor;
+	version->revision = revision;
+
+	return 0;
+}
+
+/**
+ * es58x_parse_hw_rev() - Extract hardware revision number.
+ * @es58x_dev: ES58X device.
+ * @prod_info: USB custom string returned by the device.
+ *
+ * @prod_info contains the hardware revision prefixed by a magic
+ * string and conquenated together with other numbers. Depending on
+ * the device, the hardware revision format is either
+ * "HW_VER:axxx/xxx" or "HR:axxx/xxx" where 'a' represents a letter
+ * and 'x' a digit.
+ *
+ * Parse @prod_info and store the hardware revision number in
+ * &es58x_dev.hardware_revision.
+ *
+ * Return: zero on success, -EBADMSG if @prod_info could not be
+ *	parsed.
+ */
+static int es58x_parse_hw_rev(struct es58x_device *es58x_dev,
+			      const char *prod_info)
+{
+	char letter;
+	int major, minor;
+
+	/* The only occurrence of 'H' is in the hardware revision prefix. */
+	prod_info = strchr(prod_info, 'H');
+	if (!prod_info)
+		return -EBADMSG;
+	/* Go to beginning of the hardware revision */
+	prod_info = strchr(prod_info, ':');
+	if (!prod_info)
+		return -EBADMSG;
+	prod_info++;
+
+	if (sscanf(prod_info, "%c%3u/%3u", &letter, &major, &minor) != 3)
+		return -EBADMSG;
+
+	es58x_dev->hardware_revision.letter = letter;
+	es58x_dev->hardware_revision.major = major;
+	es58x_dev->hardware_revision.minor = minor;
+
+	return 0;
+}
+
+/**
+ * es58x_parse_product_info() - Parse the ES58x product information
+ *	string.
+ * @es58x_dev: ES58X device.
+ *
+ * Retrieve the product information string and parse it to extract the
+ * firmware version, the bootloader version and the hardware
+ * revision.
+ *
+ * If the function fails, simply emit a log message and continue
+ * because product information is not critical for the driver to
+ * operate.
+ */
+void es58x_parse_product_info(struct es58x_device *es58x_dev)
+{
+	char *prod_info;
+
+	prod_info = usb_cache_string(es58x_dev->udev, ES58X_PROD_INFO_IDX);
+	if (!prod_info) {
+		dev_warn(es58x_dev->dev,
+			 "could not retrieve the product info string\n");
+		return;
+	}
+
+	if (es58x_parse_sw_version(es58x_dev, prod_info, "FW") ||
+	    es58x_parse_sw_version(es58x_dev, prod_info, "BL") ||
+	    es58x_parse_hw_rev(es58x_dev, prod_info))
+		dev_info(es58x_dev->dev,
+			 "could not parse product info: '%s'\n", prod_info);
+
+	kfree(prod_info);
+}
+
+/**
+ * es58x_sw_version_is_set() - Check if the version is a valid number.
+ * @sw_ver: Version number of either the firmware or the bootloader.
+ *
+ * If &es58x_sw_version.major, &es58x_sw_version.minor and
+ * &es58x_sw_version.revision are all zero, the product string could
+ * not be parsed and the version number is invalid.
+ */
+static inline bool es58x_sw_version_is_set(struct es58x_sw_version *sw_ver)
+{
+	return sw_ver->major || sw_ver->minor || sw_ver->revision;
+}
+
+/**
+ * es58x_hw_revision_is_set() - Check if the revision is a valid number.
+ * @hw_rev: Revision number of the hardware.
+ *
+ * If &es58x_hw_revision.letter is the null character, the product
+ * string could not be parsed and the hardware revision number is
+ * invalid.
+ */
+static inline bool es58x_hw_revision_is_set(struct es58x_hw_revision *hw_rev)
+{
+	return hw_rev->letter != '\0';
+}
+
+/**
+ * es58x_devlink_info_get() - Report the product information.
+ * @devlink: Devlink.
+ * @req: skb wrapper where to put requested information.
+ * @extack: Unused.
+ *
+ * Report the firmware version, the bootloader version, the hardware
+ * revision and the serial number through netlink.
+ *
+ * Return: zero on success, errno when any error occurs.
+ */
+static int es58x_devlink_info_get(struct devlink *devlink,
+				  struct devlink_info_req *req,
+				  struct netlink_ext_ack *extack)
+{
+	struct es58x_device *es58x_dev = devlink_priv(devlink);
+	struct es58x_sw_version *fw_ver = &es58x_dev->firmware_version;
+	struct es58x_sw_version *bl_ver = &es58x_dev->bootloader_version;
+	struct es58x_hw_revision *hw_rev = &es58x_dev->hardware_revision;
+	char buf[max(sizeof("xx.xx.xx"), sizeof("axxx/xxx"))];
+	int ret = 0;
+
+	if (es58x_sw_version_is_set(fw_ver)) {
+		snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
+			 fw_ver->major, fw_ver->minor, fw_ver->revision);
+		ret = devlink_info_version_running_put(req,
+						       DEVLINK_INFO_VERSION_GENERIC_FW,
+						       buf);
+		if (ret)
+			return ret;
+	}
+
+	if (es58x_sw_version_is_set(bl_ver)) {
+		snprintf(buf, sizeof(buf), "%02u.%02u.%02u",
+			 bl_ver->major, bl_ver->minor, bl_ver->revision);
+		ret = devlink_info_version_running_put(req,
+						       DEVLINK_INFO_VERSION_GENERIC_FW_BOOTLOADER,
+						       buf);
+		if (ret)
+			return ret;
+	}
+
+	if (es58x_hw_revision_is_set(hw_rev)) {
+		snprintf(buf, sizeof(buf), "%c%03u/%03u",
+			 hw_rev->letter, hw_rev->major, hw_rev->minor);
+		ret = devlink_info_version_fixed_put(req,
+						     DEVLINK_INFO_VERSION_GENERIC_BOARD_REV,
+						     buf);
+		if (ret)
+			return ret;
+	}
+
+	return devlink_info_serial_number_put(req, es58x_dev->udev->serial);
+}
+
+const struct devlink_ops es58x_dl_ops = {
+	.info_get = es58x_devlink_info_get,
+};