[PATCH] drivers: firmware: xilinx: Add support for feature check

[Rajan Vaja]

From: Ravi Patel <ravi.patel@xxxxxxxxxx>

Query for corresponding feature before calling EEMI API
from the driver.

Signed-off-by: Ravi Patel <ravi.patel@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
---
 drivers/firmware/xilinx/zynqmp.c     | 43 ++++++++++++++++++++++++++++++++++++
 include/linux/firmware/xlnx-zynqmp.h |  7 ++++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index 74d9f13..ecc339d 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -26,6 +26,9 @@
 
 static const struct zynqmp_eemi_ops *eemi_ops_tbl;
 
+static bool feature_check_enabled;
+static u32 zynqmp_pm_features[PM_API_MAX];
+
 static const struct mfd_cell firmware_devs[] = {
 	{
 		.name = "zynqmp_power_controller",
@@ -44,6 +47,8 @@ static int zynqmp_pm_ret_code(u32 ret_status)
 	case XST_PM_SUCCESS:
 	case XST_PM_DOUBLE_REQ:
 		return 0;
+	case XST_PM_NO_FEATURE:
+		return -ENOTSUPP;
 	case XST_PM_NO_ACCESS:
 		return -EACCES;
 	case XST_PM_ABORT_SUSPEND:
@@ -129,6 +134,39 @@ static noinline int do_fw_call_hvc(u64 arg0, u64 arg1, u64 arg2,
 }
 
 /**
+ * zynqmp_pm_feature() - Check weather given feature is supported or not
+ * @api_id:		API ID to check
+ *
+ * Return: Returns status, either success or error+reason
+ */
+static int zynqmp_pm_feature(u32 api_id)
+{
+	int ret;
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	u64 smc_arg[2];
+
+	if (!feature_check_enabled)
+		return 0;
+
+	/* Return value if feature is already checked */
+	if (zynqmp_pm_features[api_id] != PM_FEATURE_UNCHECKED)
+		return zynqmp_pm_features[api_id];
+
+	smc_arg[0] = PM_SIP_SVC | PM_FEATURE_CHECK;
+	smc_arg[1] = api_id;
+
+	ret = do_fw_call(smc_arg[0], smc_arg[1], 0, ret_payload);
+	if (ret) {
+		zynqmp_pm_features[api_id] = PM_FEATURE_INVALID;
+		return PM_FEATURE_INVALID;
+	}
+
+	zynqmp_pm_features[api_id] = ret_payload[1];
+
+	return zynqmp_pm_features[api_id];
+}
+
+/**
  * zynqmp_pm_invoke_fn() - Invoke the system-level platform management layer
  *			   caller function depending on the configuration
  * @pm_api_id:		Requested PM-API call
@@ -162,6 +200,9 @@ int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1,
 	 */
 	u64 smc_arg[4];
 
+	if (zynqmp_pm_feature(pm_api_id) == PM_FEATURE_INVALID)
+		return -ENOTSUPP;
+
 	smc_arg[0] = PM_SIP_SVC | pm_api_id;
 	smc_arg[1] = ((u64)arg1 << 32) | arg0;
 	smc_arg[2] = ((u64)arg3 << 32) | arg2;
@@ -717,6 +758,8 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
 		np = of_find_compatible_node(NULL, NULL, "xlnx,versal");
 		if (!np)
 			return 0;
+
+		feature_check_enabled = true;
 	}
 	of_node_put(np);
 
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 74d710d..f0d4558 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -48,6 +48,10 @@
 #define	ZYNQMP_PM_CAPABILITY_WAKEUP	0x4U
 #define	ZYNQMP_PM_CAPABILITY_UNUSABLE	0x8U
 
+/* Feature check status */
+#define PM_FEATURE_INVALID		-1
+#define PM_FEATURE_UNCHECKED		0
+
 /*
  * Firmware FPGA Manager flags
  * XILINX_ZYNQMP_PM_FPGA_FULL:	FPGA full reconfiguration
@@ -78,11 +82,14 @@ enum pm_api_id {
 	PM_CLOCK_GETRATE,
 	PM_CLOCK_SETPARENT,
 	PM_CLOCK_GETPARENT,
+	PM_FEATURE_CHECK = 63,
+	PM_API_MAX,
 };
 
 /* PMU-FW return status codes */
 enum pm_ret_status {
 	XST_PM_SUCCESS = 0,
+	XST_PM_NO_FEATURE = 19,
 	XST_PM_INTERNAL = 2000,
 	XST_PM_CONFLICT,
 	XST_PM_NO_ACCESS,
-- 
2.7.4