xilinx: versal: add firmware access to CRP Boot mode register

Added extended support for retrieving the boot mode register
via the firmware interface, which is preferred when U-Boot
runs in EL2 and cannot directly access CRP registers via raw
reads. Ideally, all secure registers should be accessed via
xilinx_pm_request(). Introduced the secure zynqmp_pm_get_bootmode_reg()
call, which uses xilinx_pm_request() to read the boot mode register.

When CONFIG_ZYNQMP_FIRMWARE is enabled, the secure
zynqmp_pm_get_bootmode_reg() call is used; otherwise,
direct raw reads are performed in the case of mini U-Boot.

Signed-off-by: Prasad Kummari <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michal Simek <[email protected]>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/firmware/firmware-zynqmp.c b/drivers/firmware/firmware-zynqmp.c
index 4b1b80d7abe..2adc132b4cc 100644
--- a/drivers/firmware/firmware-zynqmp.c
+++ b/drivers/firmware/firmware-zynqmp.c
@@ -195,6 +195,29 @@ int zynqmp_pm_set_sd_config(u32 node, enum pm_sd_config_type config, u32 value)
 	return ret;
 }
 
+u32 zynqmp_pm_get_bootmode_reg(void)
+{
+	int ret;
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+
+	ret = zynqmp_pm_is_function_supported(PM_IOCTL, IOCTL_READ_REG);
+	if (ret) {
+		printf("%s: IOCTL_READ_REG is not supported failed with error code: %d\n"
+		       , __func__, ret);
+		return 0;
+	}
+
+	ret = xilinx_pm_request(PM_IOCTL, CRP_BOOT_MODE_REG_NODE, IOCTL_READ_REG,
+				CRP_BOOT_MODE_REG_OFFSET, 0, ret_payload);
+	if (ret) {
+		printf("%s: node 0x%x: get_bootmode 0x%x failed\n",
+		       __func__, CRP_BOOT_MODE_REG_NODE, CRP_BOOT_MODE_REG_OFFSET);
+		return 0;
+	}
+
+	return ret_payload[1];
+}
+
 int zynqmp_pm_feature(const u32 api_id)
 {
 	int ret;