soc: aspeed: lpc-snoop: Ensure model_data is valid

of_device_get_match_data() can return NULL, though shouldn't in current
circumstances. Regardless, initialise model_data closer to use so it's
clear we need to test for validity prior to dereferencing.

Acked-by: Jean Delvare <jdelvare@suse.de>
Link: https://patch.msgid.link/20250616-aspeed-lpc-snoop-fixes-v2-3-3cdd59c934d3@codeconstruct.com.au
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

Author: amboar

drivers/soc/aspeed/aspeed-lpc-snoop.c

@@ -186,10 +186,9 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
 				   struct device *dev,
 				   int channel, u16 lpc_port)
 {
-	int rc = 0;
+	const struct aspeed_lpc_snoop_model_data *model_data;
 	u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
-	const struct aspeed_lpc_snoop_model_data *model_data =
-		of_device_get_match_data(dev);
+	int rc = 0;
 
 	if (WARN_ON(lpc_snoop->chan[channel].enabled))
 		return -EBUSY;
@@ -236,9 +235,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
 	regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
 	regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
 			   lpc_port << snpwadr_shift);
-	if (model_data->has_hicrb_ensnp)
-		regmap_update_bits(lpc_snoop->regmap, HICRB,
-				hicrb_en, hicrb_en);
+
+	model_data = of_device_get_match_data(dev);
+	if (model_data && model_data->has_hicrb_ensnp)
+		regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en);
 
 	lpc_snoop->chan[channel].enabled = true;