[RFC,05/13] qcom: msm-pm: Add cpu low power mode functions

Message ID 1407470722-23015-6-git-send-email-lina.iyer@linaro.org
State New
Headers show

Commit Message

Lina Iyer Aug. 8, 2014, 4:05 a.m.
Add interface layer to abstract and handle hardware specific
functionality for executing various cpu low power modes in QCOM
chipsets.

Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 drivers/soc/qcom/Makefile |   2 +-
 drivers/soc/qcom/msm-pm.c | 218 ++++++++++++++++++++++++++++++++++++++++++++++
 include/soc/qcom/pm.h     |  39 +++++++++
 3 files changed, 258 insertions(+), 1 deletion(-)
 create mode 100644 drivers/soc/qcom/msm-pm.c
 create mode 100644 include/soc/qcom/pm.h

Patch

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 3de7ed9..87c3b9704 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,5 +1,5 @@ 
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
-obj-$(CONFIG_QCOM_PM) +=	spm_devices.o spm.o
+obj-$(CONFIG_QCOM_PM) +=	spm_devices.o spm.o msm-pm.o
 
 CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
 obj-$(CONFIG_QCOM_SCM) += scm.o scm-boot.o
diff --git a/drivers/soc/qcom/msm-pm.c b/drivers/soc/qcom/msm-pm.c
new file mode 100644
index 0000000..17a7c8c
--- /dev/null
+++ b/drivers/soc/qcom/msm-pm.c
@@ -0,0 +1,218 @@ 
+/* Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/smp.h>
+#include <linux/tick.h>
+#include <linux/platform_device.h>
+#include <linux/cpu_pm.h>
+#include <linux/uaccess.h>
+
+#include <soc/qcom/spm.h>
+#include <soc/qcom/pm.h>
+#include <soc/qcom/scm.h>
+#include <soc/qcom/scm-boot.h>
+
+#include <asm/suspend.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+#define SCM_CMD_TERMINATE_PC	(0x2)
+#define SCM_CMD_CORE_HOTPLUGGED (0x10)
+#define SCM_FLUSH_FLAG_MASK	(0x3)
+
+static bool msm_pm_is_L1_writeback(void)
+{
+	u32 cache_id = 0;
+
+#if defined(CONFIG_CPU_V7)
+	u32 sel = 0;
+
+	asm volatile ("mcr p15, 2, %[ccselr], c0, c0, 0\n\t"
+		      "isb\n\t"
+		      "mrc p15, 1, %[ccsidr], c0, c0, 0\n\t"
+		      :[ccsidr]"=r" (cache_id)
+		      :[ccselr]"r" (sel)
+		     );
+	return cache_id & BIT(30);
+#elif defined(CONFIG_ARM64)
+	u32 sel = 0;
+	asm volatile("msr csselr_el1, %[ccselr]\n\t"
+		     "isb\n\t"
+		     "mrs %[ccsidr],ccsidr_el1\n\t"
+		     :[ccsidr]"=r" (cache_id)
+		     :[ccselr]"r" (sel)
+		    );
+	return cache_id & BIT(30);
+#else
+#error No valid CPU arch selected
+#endif
+}
+
+static inline void msm_arch_idle(void)
+{
+	mb();
+	wfi();
+}
+
+static bool msm_pm_swfi(bool from_idle)
+{
+	msm_arch_idle();
+	return true;
+}
+
+static bool msm_pm_retention(bool from_idle)
+{
+	int ret = 0;
+
+	ret = msm_spm_set_low_power_mode(MSM_SPM_MODE_RETENTION, false);
+	WARN_ON(ret);
+
+	msm_arch_idle();
+
+	ret = msm_spm_set_low_power_mode(MSM_SPM_MODE_CLOCK_GATING, false);
+	WARN_ON(ret);
+
+	return true;
+}
+
+static int msm_pm_collapse(unsigned long from_idle)
+{
+	enum msm_pm_l2_scm_flag flag = MSM_SCM_L2_ON;
+
+	/**
+	 * Single core processors need to have L2
+	 * flushed when powering down the core.
+	 * Notify SCM to flush secure L2 lines.
+	 */
+	if (num_possible_cpus() == 1)
+		flag = MSM_SCM_L2_OFF;
+
+	if (flag == MSM_SCM_L2_OFF)
+		flush_cache_all();
+	else if (msm_pm_is_L1_writeback())
+		flush_cache_louis();
+
+	flag &= SCM_FLUSH_FLAG_MASK;
+	if (!from_idle)
+		flag |= SCM_CMD_CORE_HOTPLUGGED;
+
+	scm_call_atomic1(SCM_SVC_BOOT, SCM_CMD_TERMINATE_PC, flag);
+
+	return 0;
+}
+
+static void set_up_boot_address(void *entry, int cpu, bool from_idle)
+{
+	static int flags[NR_CPUS] = {
+		SCM_FLAG_WARMBOOT_CPU0,
+		SCM_FLAG_WARMBOOT_CPU1,
+		SCM_FLAG_WARMBOOT_CPU2,
+		SCM_FLAG_WARMBOOT_CPU3,
+	};
+
+	scm_set_boot_addr(virt_to_phys(entry), flags[cpu]);
+}
+
+static bool __ref msm_pm_spm_power_collapse(
+	unsigned int cpu, bool from_idle)
+{
+	static DEFINE_PER_CPU(void *, last_known_entry);
+	void *entry;
+	bool collapsed = 0;
+	int ret;
+	bool save_cpu_regs = (cpu_online(cpu) || from_idle);
+
+	if (from_idle)
+		cpu_pm_enter();
+
+	ret = msm_spm_set_low_power_mode(
+			MSM_SPM_MODE_POWER_COLLAPSE, false);
+	WARN_ON(ret);
+
+	entry = save_cpu_regs ? cpu_resume : secondary_startup;
+	if (entry != per_cpu(last_known_entry, cpu)) {
+		per_cpu(last_known_entry, cpu) = entry;
+		set_up_boot_address(entry, cpu, from_idle);
+	}
+
+#ifdef CONFIG_CPU_V7
+	collapsed = !cpu_suspend(from_idle, msm_pm_collapse);
+#else
+	collapsed = !cpu_suspend(0);
+#endif
+
+	if (collapsed)
+		local_fiq_enable();
+
+	if (from_idle)
+		cpu_pm_exit();
+
+	ret = msm_spm_set_low_power_mode(MSM_SPM_MODE_CLOCK_GATING, false);
+	WARN_ON(ret);
+
+	return collapsed;
+}
+
+static bool msm_pm_power_collapse_standalone(bool from_idle)
+{
+	unsigned int cpu = smp_processor_id();
+	bool collapsed;
+
+	collapsed = msm_pm_spm_power_collapse(cpu, from_idle);
+
+	return collapsed;
+}
+
+static bool msm_pm_power_collapse(bool from_idle)
+{
+	unsigned int cpu = smp_processor_id();
+	bool collapsed;
+
+	collapsed = msm_pm_spm_power_collapse(cpu, from_idle);
+
+	return collapsed;
+}
+
+static bool (*execute[MSM_PM_SLEEP_MODE_NR])(bool idle) = {
+	[MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT] = msm_pm_swfi,
+	[MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE] =
+		msm_pm_power_collapse_standalone,
+	[MSM_PM_SLEEP_MODE_RETENTION] = msm_pm_retention,
+	[MSM_PM_SLEEP_MODE_POWER_COLLAPSE] = msm_pm_power_collapse,
+};
+
+/**
+ * msm_cpu_pm_enter_sleep(): Enter a low power mode on current cpu
+ *
+ * @mode - sleep mode to enter
+ * @from_idle - bool to indicate that the mode is exercised during idle/suspend
+ *
+ * The code should be with interrupts disabled and on the core on which the
+ * low power is to be executed.
+ *
+ */
+bool msm_cpu_pm_enter_sleep(enum msm_pm_sleep_mode mode, bool from_idle)
+{
+	bool exit_stat = false;
+
+	if (execute[mode])
+		exit_stat = execute[mode](from_idle);
+
+	return exit_stat;
+}
+EXPORT_SYMBOL(msm_cpu_pm_enter_sleep);
diff --git a/include/soc/qcom/pm.h b/include/soc/qcom/pm.h
new file mode 100644
index 0000000..01872ad
--- /dev/null
+++ b/include/soc/qcom/pm.h
@@ -0,0 +1,39 @@ 
+/*
+ * Copyright (c) 2009-2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#ifndef __QCOM_PM_H
+#define __QCOM_PM_H
+
+enum msm_pm_sleep_mode {
+	MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT,
+	MSM_PM_SLEEP_MODE_RETENTION,
+	MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE,
+	MSM_PM_SLEEP_MODE_POWER_COLLAPSE,
+	MSM_PM_SLEEP_MODE_NR,
+};
+
+enum msm_pm_l2_scm_flag {
+	MSM_SCM_L2_ON = 0,
+	MSM_SCM_L2_OFF = 1,
+};
+
+#ifdef CONFIG_QCOM_PM
+bool msm_cpu_pm_enter_sleep(enum msm_pm_sleep_mode mode, bool from_idle);
+#else
+static inline bool msm_cpu_pm_enter_sleep(enum msm_pm_sleep_mode mode,
+						bool from_idle)
+{ return true; }
+#endif
+
+#endif  /* __QCOM_PM_H */