[U-Boot] [PATCH v2 9/9] apalis-tk1: remove non-esential power rails on boot

[Igor Opaniuk]

From: Dominik Sliwa <dominik.sliwa at toradex.com>

When mainline kernels reboot TK1 they use SW_RESET,
that reset mode does not reset PMIC. Some rails
need to be off for RAM Re-repair to work correctly.

Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov at toradex.com>
Signed-off-by: Dominik Sliwa <dominik.sliwa at toradex.com>
Signed-off-by: Igor Opaniuk <igor.opaniuk at toradex.com>
---

 arch/arm/mach-tegra/tegra124/cpu.c     | 45 ++++++++++++++++++++++++++
 board/toradex/apalis-tk1/as3722_init.c | 23 +++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/arch/arm/mach-tegra/tegra124/cpu.c b/arch/arm/mach-tegra/tegra124/cpu.c
index 992c0beb04..abc050c27b 100644
--- a/arch/arm/mach-tegra/tegra124/cpu.c
+++ b/arch/arm/mach-tegra/tegra124/cpu.c
@@ -238,6 +238,45 @@ static bool is_partition_powered(u32 partid)
 	return !!(reg & (1 << partid));
 }
 
+static void unpower_partition(u32 partid)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
+
+	debug("%s: part ID = %08X\n", __func__, partid);
+	/* Is the partition on? */
+	if (is_partition_powered(partid)) {
+		/* Yes, toggle the partition power state (ON -> OFF) */
+		debug("power_partition, toggling state\n");
+		writel(START_CP | partid, &pmc->pmc_pwrgate_toggle);
+
+		/* Wait for the power to come down */
+		while (is_partition_powered(partid))
+			;
+
+		/* Give I/O signals time to stabilize */
+		udelay(IO_STABILIZATION_DELAY);
+	}
+}
+
+void unpower_cpus(void)
+{
+	debug("%s entry: G cluster\n", __func__);
+
+	/* Power down the fast cluster rail partition */
+	debug("%s: CRAIL\n", __func__);
+	unpower_partition(CRAIL);
+
+	/* Power down the fast cluster non-CPU partition */
+	debug("%s: C0NC\n", __func__);
+	unpower_partition(C0NC);
+
+	/* Power down the fast cluster CPU0 partition */
+	debug("%s: CE0\n", __func__);
+	unpower_partition(CE0);
+
+	debug("%s: done\n", __func__);
+}
+
 static void power_partition(u32 partid)
 {
 	struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
@@ -284,6 +323,12 @@ void start_cpu(u32 reset_vector)
 
 	debug("%s entry, reset_vector = %x\n", __func__, reset_vector);
 
+	/*
+	 * High power clusters are on after software reset,
+	 * it may interfere with tegra124_ram_repair.
+	 * unpower them.
+	 */
+	unpower_cpus();
 	tegra124_init_clocks();
 
 	/* Set power-gating timer multiplier */
diff --git a/board/toradex/apalis-tk1/as3722_init.c b/board/toradex/apalis-tk1/as3722_init.c
index bd754e5fcf..15f8dce2f1 100644
--- a/board/toradex/apalis-tk1/as3722_init.c
+++ b/board/toradex/apalis-tk1/as3722_init.c
@@ -43,6 +43,29 @@ void pmic_enable_cpu_vdd(void)
 	udelay(10 * 1000);
 #endif
 
+	/*
+	 * Make sure all non-fused regulators are down.
+	 * That way we're in known state after software reboot from linux
+	 */
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x0003, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x0004, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x001b, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x0014, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x001a, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+	tegra_i2c_ll_write_addr(AS3722_I2C_ADDR, 2);
+	tegra_i2c_ll_write_data(0x0019, I2C_SEND_2_BYTES);
+	udelay(10 * 1000);
+
 	debug("%s: Setting VDD_CPU to 1.0V via AS3722 reg 0/4D\n", __func__);
 	/*
 	 * Bring up VDD_CPU via the AS3722 PMIC on the PWR I2C bus.
-- 
2.17.1