ARM: mvebu: Add the PMSU related part of the cpu idle functions

The cpu idle support will need to access to Power Management Service
Unit. This commit adds the architecture related functions that will be
used in the idle path of the cpuidle driver.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-9-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 131 insertions, 1 deletions

diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index 7ccf14a065b1..78cf0279e1af 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -24,9 +24,12 @@
 #include <linux/io.h>
 #include <linux/smp.h>
 #include <linux/resource.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
 #include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
 #include "common.h"
-#include "pmsu.h"
 
 static void __iomem *pmsu_mp_base;
 
@@ -34,12 +37,33 @@ static void __iomem *pmsu_mp_base;
 #define PMSU_REG_SIZE       0x1000
 
 /* PMSU MP registers */
+#define PMSU_CONTROL_AND_CONFIG(cpu)        ((cpu * 0x100) + 0x104)
+#define PMSU_CONTROL_AND_CONFIG_DFS_REQ         BIT(18)
+#define PMSU_CONTROL_AND_CONFIG_PWDDN_REQ       BIT(16)
+#define PMSU_CONTROL_AND_CONFIG_L2_PWDDN        BIT(20)
+
+#define PMSU_CPU_POWER_DOWN_CONTROL(cpu)    ((cpu * 0x100) + 0x108)
+
+#define PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP      BIT(0)
+
+#define PMSU_STATUS_AND_MASK(cpu)           ((cpu * 0x100) + 0x10c)
+#define PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT      BIT(16)
+#define PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT   BIT(17)
+#define PMSU_STATUS_AND_MASK_IRQ_WAKEUP         BIT(20)
+#define PMSU_STATUS_AND_MASK_FIQ_WAKEUP         BIT(21)
+#define PMSU_STATUS_AND_MASK_DBG_WAKEUP         BIT(22)
+#define PMSU_STATUS_AND_MASK_IRQ_MASK           BIT(24)
+#define PMSU_STATUS_AND_MASK_FIQ_MASK           BIT(25)
+
 #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
 
 /* PMSU fabric registers */
 #define L2C_NFABRIC_PM_CTL                  0x4
 #define L2C_NFABRIC_PM_CTL_PWR_DOWN             BIT(20)
 
+extern void ll_disable_coherency(void);
+extern void ll_enable_coherency(void);
+
 static struct of_device_id of_pmsu_table[] = {
         { .compatible = "marvell,armada-370-pmsu", },
         { .compatible = "marvell,armada-370-xp-pmsu", },
@@ -110,4 +134,110 @@ static void armada_370_xp_pmsu_enable_l2_powerdown_onidle(void)
         writel(reg, pmsu_mp_base + L2C_NFABRIC_PM_CTL);
 }
 
+static void armada_370_xp_cpu_resume(void)
+{
+        asm volatile("bl    ll_add_cpu_to_smp_group\n\t"
+                     "bl    ll_enable_coherency\n\t"
+                     "b     cpu_resume\n\t");
+}
+
+/* No locking is needed because we only access per-CPU registers */
+void armada_370_xp_pmsu_idle_prepare(bool deepidle)
+{
+        unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
+        u32 reg;
+
+        if (pmsu_mp_base == NULL)
+                return;
+
+        /*
+         * Adjust the PMSU configuration to wait for WFI signal, enable
+         * IRQ and FIQ as wakeup events, set wait for snoop queue empty
+         * indication and mask IRQ and FIQ from CPU
+         */
+        reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
+        reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT    |
+               PMSU_STATUS_AND_MASK_IRQ_WAKEUP       |
+               PMSU_STATUS_AND_MASK_FIQ_WAKEUP       |
+               PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT |
+               PMSU_STATUS_AND_MASK_IRQ_MASK         |
+               PMSU_STATUS_AND_MASK_FIQ_MASK;
+        writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
+
+        reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
+        /* ask HW to power down the L2 Cache if needed */
+        if (deepidle)
+                reg |= PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
+
+        /* request power down */
+        reg |= PMSU_CONTROL_AND_CONFIG_PWDDN_REQ;
+        writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
+
+        /* Disable snoop disable by HW - SW is taking care of it */
+        reg = readl(pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
+        reg |= PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP;
+        writel(reg, pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
+}
+
+static noinline int do_armada_370_xp_cpu_suspend(unsigned long deepidle)
+{
+        armada_370_xp_pmsu_idle_prepare(deepidle);
+
+        v7_exit_coherency_flush(all);
+
+        ll_disable_coherency();
+
+        dsb();
+
+        wfi();
+
+        /* If we are here, wfi failed. As processors run out of
+         * coherency for some time, tlbs might be stale, so flush them
+         */
+        local_flush_tlb_all();
+
+        ll_enable_coherency();
+
+        /* Test the CR_C bit and set it if it was cleared */
+        asm volatile(
+        "mrc    p15, 0, %0, c1, c0, 0 \n\t"
+        "tst    %0, #(1 << 2) \n\t"
+        "orreq  %0, %0, #(1 << 2) \n\t"
+        "mcreq  p15, 0, %0, c1, c0, 0 \n\t"
+        "isb    "
+        : : "r" (0));
+
+        pr_warn("Failed to suspend the system\n");
+
+        return 0;
+}
+
+static int armada_370_xp_cpu_suspend(unsigned long deepidle)
+{
+        return cpu_suspend(deepidle, do_armada_370_xp_cpu_suspend);
+}
+
+/* No locking is needed because we only access per-CPU registers */
+static noinline void armada_370_xp_pmsu_idle_restore(void)
+{
+        unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
+        u32 reg;
+
+        if (pmsu_mp_base == NULL)
+                return;
+
+        /* cancel ask HW to power down the L2 Cache if possible */
+        reg = readl(pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
+        reg &= ~PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
+        writel(reg, pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
+
+        /* cancel Enable wakeup events and mask interrupts */
+        reg = readl(pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
+        reg &= ~(PMSU_STATUS_AND_MASK_IRQ_WAKEUP | PMSU_STATUS_AND_MASK_FIQ_WAKEUP);
+        reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
+        reg &= ~PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT;
+        reg &= ~(PMSU_STATUS_AND_MASK_IRQ_MASK | PMSU_STATUS_AND_MASK_FIQ_MASK);
+        writel(reg, pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
+}
+
 early_initcall(armada_370_xp_pmsu_init);