[PATCH] HID: intel-ish-hid: loader: Add PRODUCT_FAMILY-based firmware matching

[Vishnu Sankar <vishnuocv@gmail.com>]

Add support for firmware filenames that include the CRC32 checksum of the
DMI product_family field. Several OEMs ship ISH firmware variants shared
across a product family while product_name or product_sku may differ. This
intermediate matching granularity reduces duplication and improves firmware
selection for vendor-customized platforms.

The newly supported filename forms are checked before existing patterns:

  ish_${gen}_${vendor}_${family}_${name}_${sku}.bin
  ish_${gen}_${vendor}_${family}_${sku}.bin
  ish_${gen}_${vendor}_${family}_${name}.bin
  ish_${gen}_${vendor}_${family}.bin

The legacy product_name/product_sku rules remain unchanged and continue
to provide fallback matching.

ISH_FW_FILENAME_LEN_MAX is changed to 72 to accommodate the product_family.

Tested with X9 series and X1 series.

Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: Richie Roy Jayme <rjayme.jp@gmail.com>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
---
 drivers/hid/intel-ish-hid/ishtp/loader.c | 50 +++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ishtp/loader.c b/drivers/hid/intel-ish-hid/ishtp/loader.c
index f34086b29cf0..4559d460fd83 100644
--- a/drivers/hid/intel-ish-hid/ishtp/loader.c
+++ b/drivers/hid/intel-ish-hid/ishtp/loader.c
@@ -194,6 +194,11 @@ static int prepare_dma_bufs(struct ishtp_device *dev,
 
 	return 0;
 }
+/* Patterns with PRODUCT_FAMILY */
+#define ISH_FW_FILE_VENDOR_FAMILY_NAME_SKU_FMT "intel/ish/ish_%s_%08x_%08x_%08x_%08x.bin"
+#define ISH_FW_FILE_VENDOR_FAMILY_SKU_FMT "intel/ish/ish_%s_%08x_%08x_%08x.bin"
+#define ISH_FW_FILE_VENDOR_FAMILY_NAME_FMT "intel/ish/ish_%s_%08x_%08x_%08x.bin"
+#define ISH_FW_FILE_VENDOR_FAMILY_FMT "intel/ish/ish_%s_%08x_%08x.bin"
 
 #define ISH_FW_FILE_VENDOR_NAME_SKU_FMT "intel/ish/ish_%s_%08x_%08x_%08x.bin"
 #define ISH_FW_FILE_VENDOR_SKU_FMT "intel/ish/ish_%s_%08x_%08x.bin"
@@ -201,7 +206,7 @@ static int prepare_dma_bufs(struct ishtp_device *dev,
 #define ISH_FW_FILE_VENDOR_FMT "intel/ish/ish_%s_%08x.bin"
 #define ISH_FW_FILE_DEFAULT_FMT "intel/ish/ish_%s.bin"
 
-#define ISH_FW_FILENAME_LEN_MAX 56
+#define ISH_FW_FILENAME_LEN_MAX 72
 
 #define ISH_CRC_INIT (~0u)
 #define ISH_CRC_XOROUT (~0u)
@@ -256,8 +261,9 @@ static int request_ish_firmware(const struct firmware **firmware_p,
 				struct device *dev)
 {
 	const char *gen, *sys_vendor, *product_name, *product_sku;
+	const char *product_family;
 	struct ishtp_device *ishtp = dev_get_drvdata(dev);
-	u32 vendor_crc, name_crc, sku_crc;
+	u32 vendor_crc, name_crc, sku_crc, family_crc;
 	char filename[ISH_FW_FILENAME_LEN_MAX];
 	int ret;
 
@@ -265,6 +271,7 @@ static int request_ish_firmware(const struct firmware **firmware_p,
 	sys_vendor = dmi_get_system_info(DMI_SYS_VENDOR);
 	product_name = dmi_get_system_info(DMI_PRODUCT_NAME);
 	product_sku = dmi_get_system_info(DMI_PRODUCT_SKU);
+	product_family = dmi_get_system_info(DMI_PRODUCT_FAMILY);
 
 	if (sys_vendor)
 		vendor_crc = crc32(ISH_CRC_INIT, sys_vendor, strlen(sys_vendor)) ^ ISH_CRC_XOROUT;
@@ -272,6 +279,45 @@ static int request_ish_firmware(const struct firmware **firmware_p,
 		name_crc = crc32(ISH_CRC_INIT, product_name, strlen(product_name)) ^ ISH_CRC_XOROUT;
 	if (product_sku)
 		sku_crc = crc32(ISH_CRC_INIT, product_sku, strlen(product_sku)) ^ ISH_CRC_XOROUT;
+	if (product_family)
+		family_crc = crc32(ISH_CRC_INIT, product_family, strlen(product_family)) ^ ISH_CRC_XOROUT;
+
+	/* PRODUCT_FAMILY-extended matching */
+	if (sys_vendor && product_family && product_name && product_sku) {
+		snprintf(filename, sizeof(filename),
+			 ISH_FW_FILE_VENDOR_FAMILY_NAME_SKU_FMT,
+			 gen, vendor_crc, family_crc, name_crc, sku_crc);
+		ret = _request_ish_firmware(firmware_p, filename, dev);
+		if (!ret)
+			return 0;
+	}
+
+	if (sys_vendor && product_family && product_sku) {
+		snprintf(filename, sizeof(filename),
+			 ISH_FW_FILE_VENDOR_FAMILY_SKU_FMT,
+			 gen, vendor_crc, family_crc, sku_crc);
+		ret = _request_ish_firmware(firmware_p, filename, dev);
+		if (!ret)
+			return 0;
+	}
+
+	if (sys_vendor && product_family && product_name) {
+		snprintf(filename, sizeof(filename),
+			 ISH_FW_FILE_VENDOR_FAMILY_NAME_FMT,
+			 gen, vendor_crc, family_crc, name_crc);
+		ret = _request_ish_firmware(firmware_p, filename, dev);
+		if (!ret)
+			return 0;
+	}
+
+	if (sys_vendor && product_family) {
+		snprintf(filename, sizeof(filename),
+			 ISH_FW_FILE_VENDOR_FAMILY_FMT,
+			 gen, vendor_crc, family_crc);
+		ret = _request_ish_firmware(firmware_p, filename, dev);
+		if (!ret)
+			return 0;
+}
 
 	if (sys_vendor && product_name && product_sku) {
 		snprintf(filename, sizeof(filename), ISH_FW_FILE_VENDOR_NAME_SKU_FMT, gen,
-- 
2.51.0