[PATCH 12/20] arm: mach-k3: j721e: Enable LPM resume flow for J7200/J721e SOC

[Richard Genoud (TI)]

From: "Thomas Richard (TI)" <thomas.richard at bootlin.com>

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.

First, add the board specific part of the exit retention sequence for
k3-ddrss following the DDR resume sequence:
   - exit DDR from retention
   - de-assert the DDR_RET pin
   - restore DDR max frequency
   - exit DDR from low power

Then:
   - 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.
(All those steps are done in do_resume())

The context address area is firewalled by TIFS to protect it from
other hosts.

Co-developed-by: Gregory CLEMENT (TI) <gregory.clement at bootlin.com>
Signed-off-by: Gregory CLEMENT (TI) <gregory.clement at bootlin.com>
Signed-off-by: Thomas Richard (TI) <thomas.richard at bootlin.com>
Co-developed-by: Prasanth Babu Mantena <p-mantena at ti.com>
Signed-off-by: Prasanth Babu Mantena <p-mantena at ti.com>
Co-developed-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
Signed-off-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
---
 arch/arm/mach-k3/j721e/j721e_init.c | 64 +++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/arch/arm/mach-k3/j721e/j721e_init.c b/arch/arm/mach-k3/j721e/j721e_init.c
index f9af0288cf66..a1f87e653299 100644
--- a/arch/arm/mach-k3/j721e/j721e_init.c
+++ b/arch/arm/mach-k3/j721e/j721e_init.c
@@ -20,9 +20,12 @@
 #include <mmc.h>
 #include <remoteproc.h>
 #include <k3-avs.h>
+#include <power/pmic.h>
+#include <mach/k3-ddr.h>
 
 #include "../sysfw-loader.h"
 #include "../common.h"
+#include "../lpm-common.h"
 
 /* NAVSS North Bridge (NB) registers */
 #define NAVSS0_NBSS_NB0_CFG_MMRS		0x03802000
@@ -294,10 +297,55 @@ void do_dt_magic(void)
 }
 #endif
 
+#define GPIO_OUT_1 0x3D
+#define DDR_RET_VAL BIT(1)
+#define DDR_RET_CLK BIT(2)
+#define PMIC_NSLEEP_REG 0x86
+
+static void __maybe_unused k3_deassert_DDR_RET(void)
+{
+	struct udevice *pmica;
+	struct udevice *pmicb;
+	int regval;
+	int ret;
+
+	ret = uclass_get_device_by_name(UCLASS_PMIC,
+					"pmic at 48", &pmica);
+	if (ret) {
+		printf("Getting PMICA init failed: %d\n", ret);
+		return;
+	}
+
+	ret = uclass_get_device_by_name(UCLASS_PMIC,
+					"pmic at 4c", &pmicb);
+	if (ret) {
+		printf("Getting PMICB init failed: %d\n", ret);
+		return;
+	}
+	/* Set DDR_RET Signal Low on PMIC B */
+	regval = pmic_reg_read(pmicb, GPIO_OUT_1) & ~DDR_RET_VAL;
+
+	pmic_reg_write(pmicb, GPIO_OUT_1, regval);
+
+	/* Now toggle the CLK of the latch for DDR ret */
+	pmic_reg_write(pmicb, GPIO_OUT_1, regval | DDR_RET_CLK);
+	pmic_reg_write(pmicb, GPIO_OUT_1, regval & ~(DDR_RET_CLK));
+	pmic_reg_write(pmicb, GPIO_OUT_1, regval | DDR_RET_CLK);
+	pmic_reg_write(pmicb, GPIO_OUT_1, regval & ~(DDR_RET_CLK));
+
+	pmic_reg_write(pmica, PMIC_NSLEEP_REG, 0x3);
+}
+
+__weak bool j7xx_board_is_resuming(void)
+{
+	return false;
+}
+
 void board_init_f(ulong dummy)
 {
 	int ret;
 #if defined(CONFIG_K3_J721E_DDRSS) || defined(CONFIG_K3_LOAD_SYSFW)
+	struct k3_ddrss_regs regs;
 	struct udevice *dev;
 #endif
 	/*
@@ -410,6 +458,22 @@ void board_init_f(ulong dummy)
 	ret = uclass_get_device(UCLASS_RAM, 0, &dev);
 	if (ret)
 		panic("DRAM init failed: %d\n", ret);
+
+	if (j7xx_board_is_resuming()) {
+		/*
+		 * The DDR resume sequence is:
+		 * - exit DDR from retention
+		 * - de-assert the DDR_RET pin
+		 * - restore DDR max frequency
+		 * - exit DDR from low power
+		 */
+		k3_ddrss_lpddr4_exit_retention(dev, &regs);
+		k3_deassert_DDR_RET();
+		k3_ddrss_lpddr4_change_freq(dev);
+		k3_ddrss_lpddr4_exit_low_power(dev, &regs);
+
+		do_resume();
+	}
 #endif
 	spl_enable_cache();