spi: pxa2xx: Validate the correctness of the SSP type

Currently we blindly apply the SSP type value from any source of the
information. Increase robustness by validating the value before use.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221021190018.63646-2-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-pxa2xx.c

@@ -1460,7 +1460,7 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev)
 	struct resource *res;
 	struct pci_dev *pcidev = dev_is_pci(parent) ? to_pci_dev(parent) : NULL;
 	const struct pci_device_id *pcidev_id = NULL;
-	enum pxa_ssp_type type;
+	enum pxa_ssp_type type = SSP_UNDEFINED;
 	const void *match;
 	int status;
 	u64 uid;
@@ -1473,7 +1473,9 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev)
 		type = (enum pxa_ssp_type)match;
 	else if (pcidev_id)
 		type = (enum pxa_ssp_type)pcidev_id->driver_data;
-	else
+
+	/* Validate the SSP type correctness */
+	if (!(type > SSP_UNDEFINED && type < SSP_MAX))
 		return ERR_PTR(-EINVAL);
 
 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);

include/linux/pxa2xx_ssp.h

@@ -229,6 +229,7 @@ enum pxa_ssp_type {
 	LPSS_SPT_SSP,
 	LPSS_BXT_SSP,
 	LPSS_CNL_SSP,
+	SSP_MAX
 };
 
 struct ssp_device {