firmware: xilinx: Add support to get platform information

Add function to get family code and sub family code from the idcode. This
family code and sub family code helps to identify the platform.
Family code of any platform is on bits 21 to 27 and Sub family code is on
bits 19 and 20.

Signed-off-by: Dhaval Shah <[e-mail]>
Signed-off-by: Sai Krishna Potthuri <[e-mail]>
Reviewed-by: Michal Simek <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/firmware/xilinx/zynqmp.c

···
 
 static u32 pm_api_version;
 static u32 pm_tz_version;
+static u32 pm_family_code;
+static u32 pm_sub_family_code;
 
 int zynqmp_pm_register_sgi(u32 sgi_num, u32 reset)
 {
···
 	return ret;
 }
 EXPORT_SYMBOL_GPL(zynqmp_pm_get_chipid);
+
+/**
+ * zynqmp_pm_get_family_info() - Get family info of platform
+ * @family:	Returned family code value
+ * @subfamily:	Returned sub-family code value
+ *
+ * Return: Returns status, either success or error+reason
+ */
+static int zynqmp_pm_get_family_info(u32 *family, u32 *subfamily)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	u32 idcode;
+	int ret;
+
+	/* Check is family or sub-family code already received */
+	if (pm_family_code && pm_sub_family_code) {
+		*family = pm_family_code;
+		*subfamily = pm_sub_family_code;
+		return 0;
+	}
+
+	ret = zynqmp_pm_invoke_fn(PM_GET_CHIPID, 0, 0, 0, 0, ret_payload);
+	if (ret < 0)
+		return ret;
+
+	idcode = ret_payload[1];
+	pm_family_code = FIELD_GET(FAMILY_CODE_MASK, idcode);
+	pm_sub_family_code = FIELD_GET(SUB_FAMILY_CODE_MASK, idcode);
+	*family = pm_family_code;
+	*subfamily = pm_sub_family_code;
+
+	return 0;
+}
 
 /**
  * zynqmp_pm_get_trustzone_version() - Get secure trustzone firmware version
···
 
 	pr_info("%s Platform Management API v%d.%d\n", __func__,
 		pm_api_version >> 16, pm_api_version & 0xFFFF);
+
+	/* Get the Family code and sub family code of platform */
+	ret = zynqmp_pm_get_family_info(&pm_family_code, &pm_sub_family_code);
+	if (ret < 0)
+		return ret;
 
 	/* Check trustzone version number */
 	ret = zynqmp_pm_get_trustzone_version(&pm_tz_version);

include/linux/firmware/xlnx-zynqmp.h

···
 /* PM API versions */
 #define PM_API_VERSION_2	2
 
+#define ZYNQMP_FAMILY_CODE 0x23
+#define VERSAL_FAMILY_CODE 0x26
+
+/* When all subfamily of platform need to support */
+#define ALL_SUB_FAMILY_CODE		0x00
+#define VERSAL_SUB_FAMILY_CODE		0x01
+#define VERSALNET_SUB_FAMILY_CODE	0x03
+
+#define FAMILY_CODE_MASK	GENMASK(27, 21)
+#define SUB_FAMILY_CODE_MASK	GENMASK(20, 19)
+
 /* ATF only commands */
 #define TF_A_PM_REGISTER_SGI		0xa04
 #define PM_GET_TRUSTZONE_VERSION	0xa03