[RFC PATCH 18/19] arm: mach-k3: j7200: Enable lpm resume flow for J7200 SOC

[Prasanth Babu Mantena]

Add support for resuming from suspend in board_init_f.
The resume state of the SOC is identified and lpm resume
sequence is followed accordingly.

- Extract context address from devicetree and send to TIFS.
- Power on the rproc cluster.
- Replay the certificates attached to saved images of ATF and OPTEE.
- Resume sequence for context restore and rproc resume.
- Image entry to DM firmware.

The context address area is firewalled by TIFS to protect it from
other hosts. Same with the resume flow.

Signed-off-by: Prasanth Babu Mantena <p-mantena at ti.com>
---
 arch/arm/mach-k3/j721e/j721e_init.c           | 64 +++++++++++++++++++
 .../arm64/ti/k3-j7200-ti-ipc-firmware.dtsi    |  7 ++
 2 files changed, 71 insertions(+)

diff --git a/arch/arm/mach-k3/j721e/j721e_init.c b/arch/arm/mach-k3/j721e/j721e_init.c
index 220cb700ff7..2a492826e7f 100644
--- a/arch/arm/mach-k3/j721e/j721e_init.c
+++ b/arch/arm/mach-k3/j721e/j721e_init.c
@@ -243,6 +243,48 @@ static void store_boot_info_from_rom(void)
 	       sizeof(struct rom_extended_boot_data));
 }
 
+void lpm_process(void)
+{
+	int ret = 0;
+	struct ti_sci_handle *ti_sci = get_ti_sci_handle();
+
+	save_certificate();
+	ret = ti_sci->ops.lpm_ops.lpm_save_addr(ti_sci, (uintptr_t)mem_addr_lpm.context_save_addr, mem_addr_lpm.size);
+	if (ret)
+		pr_err("TIFS lpm save addr fail\n");
+}
+
+int extract_lpm_region(void)
+{
+    ofnode node;
+	u32 lpm_reg_addr, lpm_reg_size;
+
+	node = ofnode_path("/reserved-memory/lpm-memory");
+	if (!ofnode_valid(node)) {
+		printf("lpm will not be functional\n");
+		return -ENODEV;
+	}
+
+	lpm_reg_addr = ofnode_get_addr(node);
+	if (lpm_reg_addr == FDT_ADDR_T_NONE) {
+		printf("Can't find a valid reserved node!\n");
+		return -ENODEV;
+    }
+
+	lpm_reg_size = ofnode_get_size(node);
+	if (lpm_reg_size == FDT_ADDR_T_NONE) {
+		printf("Can't find a valid reserved node!\n");
+		return -ENODEV;
+    }
+
+	mem_addr_lpm.context_save_addr = (u32 *)(uintptr_t)lpm_reg_addr;
+	mem_addr_lpm.atf_cert_addr =  (u32 *)((uintptr_t)mem_addr_lpm.context_save_addr + FW_IMAGE_SIZE);
+	mem_addr_lpm.optee_cert_addr = (u32 *)((uintptr_t)mem_addr_lpm.atf_cert_addr + FW_IMAGE_SIZE);
+	mem_addr_lpm.dm_save_addr = (u32 *)((uintptr_t)mem_addr_lpm.optee_cert_addr + (2*FW_IMAGE_SIZE));
+	mem_addr_lpm.size = lpm_reg_size;
+	return 0;
+}
+
 #ifdef CONFIG_SPL_OF_LIST
 void do_dt_magic(void)
 {
@@ -458,6 +500,9 @@ void board_init_f(ulong dummy)
 		panic("DRAM init failed: %d\n", ret);
 
 	if (board_is_resuming()) {
+		typedef void __noreturn (*image_entry_noargs_t)(void);
+		u32 loadaddr, size_int;
+		void *image_addr;
 		/*
 		 * The DDR resume sequence is:
 		 * - exit DDR from retention
@@ -469,6 +514,25 @@ void board_init_f(ulong dummy)
 		k3_deassert_DDR_RET();
 		k3_ddrss_lpddr4_change_freq(dev);
 		k3_ddrss_lpddr4_exit_low_power(dev, &regs);
+		ret = extract_lpm_region();
+		if (ret)
+			panic("Cannot find valid LPM address range..LPM resume failed \n");
+		image_addr = (void *)mem_addr_lpm.atf_cert_addr;
+		ret = rproc_load(1, (ulong)image_addr, 0x200);
+		if (ret)
+			panic("rproc failed to be initialized (%d)\n", ret);
+
+		image_addr = mem_addr_lpm.atf_cert_addr;
+		size_int = FW_IMAGE_SIZE;
+		ti_secure_image_replay_cert(&image_addr, &size_int);
+		image_addr = mem_addr_lpm.optee_cert_addr;
+		ti_secure_image_replay_cert(&image_addr, &size_int);
+		loadaddr = resume_to_dm_f();
+		printf("Starting ATF on ARM64 core...\n\n");
+		resume_rproc_f();
+
+		image_entry_noargs_t image_entry = (image_entry_noargs_t)loadaddr;
+		image_entry();
 	}
 #endif
 	spl_enable_cache();
diff --git a/dts/upstream/src/arm64/ti/k3-j7200-ti-ipc-firmware.dtsi b/dts/upstream/src/arm64/ti/k3-j7200-ti-ipc-firmware.dtsi
index 9477f1efbbc..c5bec876a8a 100644
--- a/dts/upstream/src/arm64/ti/k3-j7200-ti-ipc-firmware.dtsi
+++ b/dts/upstream/src/arm64/ti/k3-j7200-ti-ipc-firmware.dtsi
@@ -47,6 +47,13 @@
 		alignment = <0x1000>;
 		no-map;
 	};
+
+	lpm_memory_region: lpm-memory at a4800000 {
+		reg = <0x00 0xa4800000 0x00 0x00300000>;
+		alignment = <0x1000>;
+		no-map;
+		bootph-all;
+	};
 };
 
 &mailbox0_cluster0 {
-- 
2.34.1