Tegra: flowctrl: helper functions to assist with cluster power states

This patch adds helper functions to help platforms with cluster state entry
and exit decisions.

* tegra_fc_ccplex_pgexit_lock(): lock CPU power ungate
* tegra_fc_ccplex_pgexit_unlock(): unlock CPU power ungate
* tegra_fc_is_ccx_allowed(): CCx state entry allowed on this CPU?

Change-Id: I6490d34bf380dc03ae203eb3028f61984f06931c
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/drivers/flowctrl/flowctrl.c

 /*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -15,6 +15,7 @@
 #include <flowctrl.h>
 #include <pmc.h>
 #include <tegra_def.h>
+#include <utils_def.h>
 
 #define CLK_RST_DEV_L_SET		0x300
 #define CLK_RST_DEV_L_CLR		0x304
@@ -75,6 +76,47 @@ static void tegra_fc_prepare_suspend(int cpu_id, uint32_t csr)
 	tegra_fc_cpu_csr(cpu_id, val | csr);
 }
 
+/*******************************************************************************
+ * After this, no core can wake from C7 until the action is reverted.
+ * If a wake up event is asserted, the FC state machine will stall until
+ * the action is reverted.
+ ******************************************************************************/
+void tegra_fc_ccplex_pgexit_lock(void)
+{
+	unsigned int i, cpu = read_mpidr() & MPIDR_CPU_MASK;
+	uint32_t flags = tegra_fc_read_32(FLOWCTRL_FC_SEQ_INTERCEPT) & ~INTERCEPT_IRQ_PENDING;;
+	uint32_t icept_cpu_flags[] = {
+		INTERCEPT_EXIT_PG_CORE0,
+		INTERCEPT_EXIT_PG_CORE1,
+		INTERCEPT_EXIT_PG_CORE2,
+		INTERCEPT_EXIT_PG_CORE3
+	};
+
+	/* set the intercept flags */
+	for (i = 0; i < ARRAY_SIZE(icept_cpu_flags); i++) {
+
+		/* skip current CPU */
+		if (i == cpu)
+			continue;
+
+		/* enable power gate exit intercept locks */
+		flags |= icept_cpu_flags[i];
+	}
+
+	tegra_fc_write_32(FLOWCTRL_FC_SEQ_INTERCEPT, flags);
+	(void)tegra_fc_read_32(FLOWCTRL_FC_SEQ_INTERCEPT);
+}
+
+/*******************************************************************************
+ * Revert the ccplex powergate exit locks
+ ******************************************************************************/
+void tegra_fc_ccplex_pgexit_unlock(void)
+{
+	/* clear lock bits, clear pending interrupts */
+	tegra_fc_write_32(FLOWCTRL_FC_SEQ_INTERCEPT, INTERCEPT_IRQ_PENDING);
+	(void)tegra_fc_read_32(FLOWCTRL_FC_SEQ_INTERCEPT);
+}
+
 /*******************************************************************************
  * Powerdn the current CPU
  ******************************************************************************/
@@ -128,6 +170,31 @@ void tegra_fc_cluster_powerdn(uint32_t mpidr)
 	tegra_fc_prepare_suspend(cpu, val);
 }
 
+/*******************************************************************************
+ * Check if cluster idle or power down state is allowed from this CPU
+ ******************************************************************************/
+bool tegra_fc_is_ccx_allowed(void)
+{
+	unsigned int i, cpu = read_mpidr() & MPIDR_CPU_MASK;
+	uint32_t val;
+	bool ccx_allowed = true;
+
+	for (i = 0; i < ARRAY_SIZE(flowctrl_offset_cpu_csr); i++) {
+
+		/* skip current CPU */
+		if (i == cpu)
+			continue;
+
+		/* check if all other CPUs are already halted */
+		val = mmio_read_32(flowctrl_offset_cpu_csr[i]);
+		if ((val & FLOWCTRL_CSR_HALT_MASK) == 0U) {
+			ccx_allowed = false;
+		}
+	}
+
+	return ccx_allowed;
+}
+
 /*******************************************************************************
  * Suspend the entire SoC
  ******************************************************************************/

plat/nvidia/tegra/include/drivers/flowctrl.h

@@ -11,7 +11,7 @@
 
 #include <tegra_def.h>
 
-#define FLOWCTRL_HALT_CPU0_EVENTS	0x0U
+#define FLOWCTRL_HALT_CPU0_EVENTS	(0x0U)
 #define  FLOWCTRL_WAITEVENT		(2U << 29)
 #define  FLOWCTRL_WAIT_FOR_INTERRUPT	(4U << 29)
 #define  FLOWCTRL_JTAG_RESUME		(1U << 28)
@@ -20,21 +20,46 @@
 #define  FLOWCTRL_HALT_LIC_FIQ		(1U << 10)
 #define  FLOWCTRL_HALT_GIC_IRQ		(1U << 9)
 #define  FLOWCTRL_HALT_GIC_FIQ		(1U << 8)
-#define FLOWCTRL_HALT_BPMP_EVENTS	0x4U
-#define FLOWCTRL_CPU0_CSR		0x8U
-#define  FLOW_CTRL_CSR_PWR_OFF_STS	(1U << 16)
+#define FLOWCTRL_HALT_BPMP_EVENTS	(0x4U)
+#define FLOWCTRL_CPU0_CSR		(0x8U)
+#define  FLOWCTRL_CSR_HALT_MASK		(1U << 22)
+#define  FLOWCTRL_CSR_PWR_OFF_STS	(1U << 16)
 #define  FLOWCTRL_CSR_INTR_FLAG		(1U << 15)
 #define  FLOWCTRL_CSR_EVENT_FLAG	(1U << 14)
 #define  FLOWCTRL_CSR_IMMEDIATE_WAKE	(1U << 3)
 #define  FLOWCTRL_CSR_ENABLE		(1U << 0)
-#define FLOWCTRL_HALT_CPU1_EVENTS	0x14U
-#define FLOWCTRL_CPU1_CSR		0x18U
-#define FLOW_CTLR_FLOW_DBG_QUAL		0x50U
+#define FLOWCTRL_HALT_CPU1_EVENTS	(0x14U)
+#define FLOWCTRL_CPU1_CSR		(0x18U)
+#define FLOW_CTLR_FLOW_DBG_QUAL		(0x50U)
 #define  FLOWCTRL_FIQ2CCPLEX_ENABLE	(1U << 28)
-#define FLOWCTRL_CC4_CORE0_CTRL		0x6cU
-#define FLOWCTRL_WAIT_WFI_BITMAP	0x100U
-#define FLOWCTRL_L2_FLUSH_CONTROL	0x94U
-#define FLOWCTRL_BPMP_CLUSTER_CONTROL	0x98U
+#define FLOWCTRL_FC_SEQ_INTERCEPT	(0x5cU)
+#define  INTERCEPT_IRQ_PENDING		(0xffU)
+#define  INTERCEPT_HVC			(U(1) << 21)
+#define  INTERCEPT_ENTRY_CC4		(U(1) << 20)
+#define  INTERCEPT_ENTRY_PG_NONCPU	(U(1) << 19)
+#define  INTERCEPT_EXIT_PG_NONCPU	(U(1) << 18)
+#define  INTERCEPT_ENTRY_RG_CPU		(U(1) << 17)
+#define  INTERCEPT_EXIT_RG_CPU		(U(1) << 16)
+#define  INTERCEPT_ENTRY_PG_CORE0	(U(1) << 15)
+#define  INTERCEPT_EXIT_PG_CORE0	(U(1) << 14)
+#define  INTERCEPT_ENTRY_PG_CORE1	(U(1) << 13)
+#define  INTERCEPT_EXIT_PG_CORE1	(U(1) << 12)
+#define  INTERCEPT_ENTRY_PG_CORE2	(U(1) << 11)
+#define  INTERCEPT_EXIT_PG_CORE2	(U(1) << 10)
+#define  INTERCEPT_ENTRY_PG_CORE3	(U(1) << 9)
+#define  INTERCEPT_EXIT_PG_CORE3	(U(1) << 8)
+#define  INTERRUPT_PENDING_NONCPU	(U(1) << 7)
+#define  INTERRUPT_PENDING_CRAIL	(U(1) << 6)
+#define  INTERRUPT_PENDING_CORE0	(U(1) << 5)
+#define  INTERRUPT_PENDING_CORE1	(U(1) << 4)
+#define  INTERRUPT_PENDING_CORE2	(U(1) << 3)
+#define  INTERRUPT_PENDING_CORE3	(U(1) << 2)
+#define  CC4_INTERRUPT_PENDING		(U(1) << 1)
+#define  HVC_INTERRUPT_PENDING		(U(1) << 0)
+#define FLOWCTRL_CC4_CORE0_CTRL		(0x6cU)
+#define FLOWCTRL_WAIT_WFI_BITMAP	(0x100U)
+#define FLOWCTRL_L2_FLUSH_CONTROL	(0x94U)
+#define FLOWCTRL_BPMP_CLUSTER_CONTROL	(0x98U)
 #define  FLOWCTRL_BPMP_CLUSTER_PWRON_LOCK	(1U << 2)
 
 #define FLOWCTRL_ENABLE_EXT		12U
@@ -52,6 +77,8 @@ static inline void tegra_fc_write_32(uint32_t off, uint32_t val)
 	mmio_write_32(TEGRA_FLOWCTRL_BASE + off, val);
 }
 
+void tegra_fc_ccplex_pgexit_lock(void);
+void tegra_fc_ccplex_pgexit_unlock(void);
 void tegra_fc_cluster_idle(uint32_t midr);
 void tegra_fc_cpu_powerdn(uint32_t mpidr);
 void tegra_fc_cluster_powerdn(uint32_t midr);
@@ -59,6 +86,7 @@ void tegra_fc_cpu_on(int cpu);
 void tegra_fc_cpu_off(int cpu);
 void tegra_fc_disable_fiq_to_ccplex_routing(void);
 void tegra_fc_enable_fiq_to_ccplex_routing(void);
+bool tegra_fc_is_ccx_allowed(void);
 void tegra_fc_lock_active_cluster(void);
 void tegra_fc_reset_bpmp(void);
 void tegra_fc_soc_powerdn(uint32_t midr);