[PATCH v6 1/2] firmware: xilinx: Add pm api function for PL config reg readback

[Nava kishore Manne]

Adds PM API for performing Programmable Logic(PL) configuration
register readback. It provides an interface to the firmware(pmufw)
to readback the FPGA configuration register.

Signed-off-by: Nava kishore Manne <nava.kishore.manne@xxxxxxx>
---
changes for v2:
              - None.

Changes for v3:
              - Updated API and config reg read-back handling logic
              - Updated the commit msg to align with the changes.

Changes for v4:
              - Fixed some minor coding issues. No functional changes.
              - Updated Return value comments as suggested by Xu Yilun.

Changes for v5:
              - Fixed some minor coding issues as suggested by Xu Yilun.
                No functional changes.

Changes for v6:
              - None.

 drivers/firmware/xilinx/zynqmp.c     | 33 ++++++++++++++++++++++++++++
 include/linux/firmware/xlnx-zynqmp.h | 11 ++++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index 129f68d7a6f5..3d8cc6795b43 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -948,6 +948,39 @@ int zynqmp_pm_fpga_get_status(u32 *value)
 }
 EXPORT_SYMBOL_GPL(zynqmp_pm_fpga_get_status);
 
+/**
+ * zynqmp_pm_fpga_get_config_status - Get the FPGA configuration status.
+ * @value: Buffer to store FPGA configuration status.
+ *
+ * This function provides access to the pmufw to get the FPGA configuration
+ * status
+ *
+ * Return: 0 on success, a negative value on error
+ */
+int zynqmp_pm_fpga_get_config_status(u32 *value)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	u32 buf, lower_addr, upper_addr;
+	int ret;
+
+	if (!value)
+		return -EINVAL;
+
+	lower_addr = lower_32_bits((u64)&buf);
+	upper_addr = upper_32_bits((u64)&buf);
+
+	ret = zynqmp_pm_invoke_fn(PM_FPGA_READ,
+				  XILINX_ZYNQMP_PM_FPGA_CONFIG_STAT_OFFSET,
+				  lower_addr, upper_addr,
+				  XILINX_ZYNQMP_PM_FPGA_READ_CONFIG_REG,
+				  ret_payload);
+
+	*value = ret_payload[1];
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_fpga_get_config_status);
+
 /**
  * zynqmp_pm_pinctrl_request - Request Pin from firmware
  * @pin: Pin number to request
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index b09f443d3ab9..ce37d55ffa44 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -71,6 +71,10 @@
 #define XILINX_ZYNQMP_PM_FPGA_FULL	0x0U
 #define XILINX_ZYNQMP_PM_FPGA_PARTIAL	BIT(0)
 
+/* FPGA Status Reg */
+#define XILINX_ZYNQMP_PM_FPGA_CONFIG_STAT_OFFSET	7U
+#define XILINX_ZYNQMP_PM_FPGA_READ_CONFIG_REG		0U
+
 /*
  * Node IDs for the Error Events.
  */
@@ -120,6 +124,7 @@ enum pm_api_id {
 	PM_CLOCK_GETRATE = 42,
 	PM_CLOCK_SETPARENT = 43,
 	PM_CLOCK_GETPARENT = 44,
+	PM_FPGA_READ = 46,
 	PM_SECURE_AES = 47,
 	PM_FEATURE_CHECK = 63,
 };
@@ -515,6 +520,7 @@ int zynqmp_pm_aes_engine(const u64 address, u32 *out);
 int zynqmp_pm_sha_hash(const u64 address, const u32 size, const u32 flags);
 int zynqmp_pm_fpga_load(const u64 address, const u32 size, const u32 flags);
 int zynqmp_pm_fpga_get_status(u32 *value);
+int zynqmp_pm_fpga_get_config_status(u32 *value);
 int zynqmp_pm_write_ggs(u32 index, u32 value);
 int zynqmp_pm_read_ggs(u32 index, u32 *value);
 int zynqmp_pm_write_pggs(u32 index, u32 value);
@@ -721,6 +727,11 @@ static inline int zynqmp_pm_fpga_get_status(u32 *value)
 	return -ENODEV;
 }
 
+static inline int zynqmp_pm_fpga_get_config_status(u32 *value)
+{
+	return -ENODEV;
+}
+
 static inline int zynqmp_pm_write_ggs(u32 index, u32 value)
 {
 	return -ENODEV;
-- 
2.25.1