]> git.karo-electronics.de Git - linux-beck.git/commitdiff
ARM: tegra30: cpuidle: add powered-down state for secondary CPUs
authorJoseph Lo <josephl@nvidia.com>
Wed, 31 Oct 2012 09:41:17 +0000 (17:41 +0800)
committerStephen Warren <swarren@nvidia.com>
Thu, 15 Nov 2012 22:09:21 +0000 (15:09 -0700)
This supports power-gated idle on secondary CPUs for Tegra30. The
secondary CPUs can go into powered-down state independently. When
CPU goes into this state, it saves it's contexts and puts itself
to flow controlled WFI state. After that, it will been power gated.

Be aware of that, you may see the legacy power state "LP2" in the
code which is exactly the same meaning of "CPU power down".

Based on the work by:
Scott Williams <scwilliams@nvidia.com>

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
arch/arm/mach-tegra/Makefile
arch/arm/mach-tegra/cpuidle-tegra30.c
arch/arm/mach-tegra/pm.c [new file with mode: 0644]
arch/arm/mach-tegra/pm.h [new file with mode: 0644]
arch/arm/mach-tegra/reset.h
arch/arm/mach-tegra/sleep-tegra30.S
arch/arm/mach-tegra/sleep.S
arch/arm/mach-tegra/sleep.h

index 488159eaa429393ae1de0f19eb07ea370f29e90a..0979e8bba78ae1c2d632ecd07f0092cce6f64a98 100644 (file)
@@ -8,6 +8,7 @@ obj-y                                   += pmc.o
 obj-y                                  += flowctrl.o
 obj-y                                  += powergate.o
 obj-y                                  += apbio.o
+obj-y                                  += pm.o
 obj-$(CONFIG_CPU_IDLE)                 += cpuidle.o
 obj-$(CONFIG_CPU_IDLE)                 += sleep.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += tegra20_clocks.o
index 37e75512f697fface1a4b493d1e30b4295ef61a0..cc48d7fa3358d023ca0e1de9fecd2484c2844c96 100644 (file)
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/clockchips.h>
 
 #include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/smp_plat.h>
+
+#include "pm.h"
+#include "sleep.h"
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra30_idle_lp2(struct cpuidle_device *dev,
+                           struct cpuidle_driver *drv,
+                           int index);
+#endif
 
 static struct cpuidle_driver tegra_idle_driver = {
        .name = "tegra_idle",
        .owner = THIS_MODULE,
        .en_core_tk_irqen = 1,
+#ifdef CONFIG_PM_SLEEP
+       .state_count = 2,
+#else
        .state_count = 1,
+#endif
        .states = {
                [0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
+#ifdef CONFIG_PM_SLEEP
+               [1] = {
+                       .enter                  = tegra30_idle_lp2,
+                       .exit_latency           = 2000,
+                       .target_residency       = 2200,
+                       .power_usage            = 0,
+                       .flags                  = CPUIDLE_FLAG_TIME_VALID,
+                       .name                   = "powered-down",
+                       .desc                   = "CPU power gated",
+               },
+#endif
        },
 };
 
 static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
 
+#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_SMP
+static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
+                                       struct cpuidle_driver *drv,
+                                       int index)
+{
+       clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
+
+       smp_wmb();
+
+       save_cpu_arch_register();
+
+       cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
+
+       restore_cpu_arch_register();
+
+       clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
+
+       return true;
+}
+#else
+static inline bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
+                                              struct cpuidle_driver *drv,
+                                              int index)
+{
+       return true;
+}
+#endif
+
+static int __cpuinit tegra30_idle_lp2(struct cpuidle_device *dev,
+                                     struct cpuidle_driver *drv,
+                                     int index)
+{
+       u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
+       bool entered_lp2 = false;
+
+       local_fiq_disable();
+
+       tegra_set_cpu_in_lp2(cpu);
+       cpu_pm_enter();
+
+       if (cpu == 0)
+               cpu_do_idle();
+       else
+               entered_lp2 = tegra30_cpu_core_power_down(dev, drv, index);
+
+       cpu_pm_exit();
+       tegra_clear_cpu_in_lp2(cpu);
+
+       local_fiq_enable();
+
+       smp_rmb();
+
+       return (entered_lp2) ? index : 0;
+}
+#endif
+
 int __init tegra30_cpuidle_init(void)
 {
        int ret;
diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
new file mode 100644 (file)
index 0000000..f88595a
--- /dev/null
@@ -0,0 +1,74 @@
+/*
+ * CPU complex suspend & resume functions for Tegra SoCs
+ *
+ * Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/cpumask.h>
+
+#include "iomap.h"
+#include "reset.h"
+
+#ifdef CONFIG_PM_SLEEP
+static unsigned int g_diag_reg;
+static DEFINE_SPINLOCK(tegra_lp2_lock);
+
+void save_cpu_arch_register(void)
+{
+       /* read diagnostic register */
+       asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
+       return;
+}
+
+void restore_cpu_arch_register(void)
+{
+       /* write diagnostic register */
+       asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
+       return;
+}
+
+void __cpuinit tegra_clear_cpu_in_lp2(int phy_cpu_id)
+{
+       u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
+
+       spin_lock(&tegra_lp2_lock);
+
+       BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
+       *cpu_in_lp2 &= ~BIT(phy_cpu_id);
+
+       spin_unlock(&tegra_lp2_lock);
+}
+
+bool __cpuinit tegra_set_cpu_in_lp2(int phy_cpu_id)
+{
+       bool last_cpu = false;
+       cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
+       u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
+
+       spin_lock(&tegra_lp2_lock);
+
+       BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
+       *cpu_in_lp2 |= BIT(phy_cpu_id);
+
+       if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
+               last_cpu = true;
+
+       spin_unlock(&tegra_lp2_lock);
+       return last_cpu;
+}
+#endif
diff --git a/arch/arm/mach-tegra/pm.h b/arch/arm/mach-tegra/pm.h
new file mode 100644 (file)
index 0000000..bcfc45f
--- /dev/null
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ * Copyright (c) 2010-2012 NVIDIA Corporation. All rights reserved.
+ *
+ * Author:
+ *     Colin Cross <ccross@google.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _MACH_TEGRA_PM_H_
+#define _MACH_TEGRA_PM_H_
+
+void save_cpu_arch_register(void);
+void restore_cpu_arch_register(void);
+
+void tegra_clear_cpu_in_lp2(int phy_cpu_id);
+bool tegra_set_cpu_in_lp2(int phy_cpu_id);
+
+#endif /* _MACH_TEGRA_PM_H_ */
index de88bf851dd322ff350a390aed949619c2efa3c4..c90d8e9c4ad2331793d66e6a5cd0f6c82fbd15a1 100644 (file)
@@ -29,6 +29,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include "irammap.h"
+
 extern unsigned long __tegra_cpu_reset_handler_data[TEGRA_RESET_DATA_SIZE];
 
 void __tegra_cpu_reset_handler_start(void);
@@ -36,6 +38,13 @@ void __tegra_cpu_reset_handler(void);
 void __tegra_cpu_reset_handler_end(void);
 void tegra_secondary_startup(void);
 
+#ifdef CONFIG_PM_SLEEP
+#define tegra_cpu_lp2_mask \
+       (IO_ADDRESS(TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET + \
+       ((u32)&__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_LP2] - \
+        (u32)__tegra_cpu_reset_handler_start)))
+#endif
+
 #define tegra_cpu_reset_handler_offset \
                ((u32)__tegra_cpu_reset_handler - \
                 (u32)__tegra_cpu_reset_handler_start)
index be7614b7c5cb5304e20d2b42fbfad4e75cec5568..59984d7184810420954d275458edcd1f59e57892 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/linkage.h>
 
 #include <asm/assembler.h>
+#include <asm/asm-offsets.h>
 
 #include "sleep.h"
 #include "flowctrl.h"
@@ -80,6 +81,7 @@ delay_1:
        ldr     r3, [r1]                        @ read CSR
        str     r3, [r1]                        @ clear CSR
        tst     r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
+       moveq   r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT       @ For LP2
        movne   r3, #FLOW_CTRL_WAITEVENT                @ For hotplug
        str     r3, [r2]
        ldr     r0, [r2]
@@ -103,3 +105,23 @@ wfe_war:
 
 ENDPROC(tegra30_cpu_shutdown)
 #endif
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra30_sleep_cpu_secondary_finish(unsigned long v2p)
+ *
+ * Enters LP2 on secondary CPU by exiting coherency and powergating the CPU.
+ */
+ENTRY(tegra30_sleep_cpu_secondary_finish)
+       mov     r7, lr
+
+       /* Flush and disable the L1 data cache */
+       bl      tegra_disable_clean_inv_dcache
+
+       /* Powergate this CPU. */
+       mov     r0, #0                          @ power mode flags (!hotplug)
+       bl      tegra30_cpu_shutdown
+       mov     r0, #1                          @ never return here
+       mov     pc, r7
+ENDPROC(tegra30_sleep_cpu_secondary_finish)
+#endif
index 08e9481c049e9be69db064b784ceb03d60f287d3..91548a77dd954c6edf7650190b3e02efd618ac5c 100644 (file)
 #include <linux/linkage.h>
 
 #include <asm/assembler.h>
+#include <asm/cp15.h>
 
 #include "iomap.h"
 
 #include "flowctrl.h"
 #include "sleep.h"
 
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra_disable_clean_inv_dcache
+ *
+ * disable, clean & invalidate the D-cache
+ *
+ * Corrupted registers: r1-r3, r6, r8, r9-r11
+ */
+ENTRY(tegra_disable_clean_inv_dcache)
+       stmfd   sp!, {r0, r4-r5, r7, r9-r11, lr}
+       dmb                                     @ ensure ordering
+
+       /* Disable the D-cache */
+       mrc     p15, 0, r2, c1, c0, 0
+       bic     r2, r2, #CR_C
+       mcr     p15, 0, r2, c1, c0, 0
+       isb
+
+       /* Flush the D-cache */
+       bl      v7_flush_dcache_louis
+
+       /* Trun off coherency */
+       exit_smp r4, r5
+
+       ldmfd   sp!, {r0, r4-r5, r7, r9-r11, pc}
+ENDPROC(tegra_disable_clean_inv_dcache)
+
+#endif
index addb83f5bc734f23d95a6eab671fe99770bb7e67..bacf549bd54d5e3dd8ded3926eecc1a9bff94bf8 100644 (file)
@@ -82,5 +82,7 @@ static inline void tegra20_hotplug_init(void) {}
 static inline void tegra30_hotplug_init(void) {}
 #endif
 
+int tegra30_sleep_cpu_secondary_finish(unsigned long);
+
 #endif
 #endif