[PATCH v9 13/17] cpuidle: tegra: Squash Tegra30 driver into the common driver

From: Dmitry Osipenko
Date: Wed Dec 18 2019 - 16:07:17 EST


Tegra20 and Terga30 SoCs have common C1 and CC6 idling states and thus
share the same code paths, there is no point in having separate drivers
for a similar hardware. This patch merely moves functionality of the old
driver into the new, although the CC6 state is kept disabled for now since
old driver had a rudimentary support for this state (allowing to enter
into CC6 only when secondary CPUs are put offline), while new driver can
provide a full-featured support. The new feature will be enabled by
another patch.

Acked-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
arch/arm/mach-tegra/Makefile | 3 -
arch/arm/mach-tegra/cpuidle-tegra30.c | 123 --------------------------
arch/arm/mach-tegra/cpuidle.c | 5 +-
arch/arm/mach-tegra/cpuidle.h | 1 -
drivers/cpuidle/cpuidle-tegra.c | 74 ++++++++++++++--
5 files changed, 70 insertions(+), 136 deletions(-)
delete mode 100644 arch/arm/mach-tegra/cpuidle-tegra30.c

diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 8425bb5608d5..99c5f4274e5c 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -13,9 +13,6 @@ obj-y += sleep-tegra30.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += pm-tegra20.o
obj-$(CONFIG_ARCH_TEGRA_3x_SOC) += pm-tegra30.o
-ifeq ($(CONFIG_CPU_IDLE),y)
-obj-$(CONFIG_ARCH_TEGRA_3x_SOC) += cpuidle-tegra30.o
-endif
obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o

diff --git a/arch/arm/mach-tegra/cpuidle-tegra30.c b/arch/arm/mach-tegra/cpuidle-tegra30.c
deleted file mode 100644
index 80ae64bcdf50..000000000000
--- a/arch/arm/mach-tegra/cpuidle-tegra30.c
+++ /dev/null
@@ -1,123 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * CPU idle driver for Tegra CPUs
- *
- * Copyright (c) 2010-2012, NVIDIA Corporation.
- * Copyright (c) 2011 Google, Inc.
- * Author: Colin Cross <ccross@xxxxxxxxxxx>
- * Gary King <gking@xxxxxxxxxx>
- *
- * Rework for 3.3 by Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
- */
-
-#include <linux/clk/tegra.h>
-#include <linux/tick.h>
-#include <linux/cpuidle.h>
-#include <linux/cpu_pm.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-
-#include <soc/tegra/pm.h>
-
-#include <asm/cpuidle.h>
-#include <asm/smp_plat.h>
-#include <asm/suspend.h>
-
-#include "cpuidle.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,
-#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_TIMER_STOP,
- .name = "powered-down",
- .desc = "CPU power gated",
- },
-#endif
- },
-};
-
-#ifdef CONFIG_PM_SLEEP
-static bool tegra30_cpu_cluster_power_down(struct cpuidle_device *dev,
- struct cpuidle_driver *drv,
- int index)
-{
- /* All CPUs entering LP2 is not working.
- * Don't let CPU0 enter LP2 when any secondary CPU is online.
- */
- if (num_online_cpus() > 1 || !tegra_cpu_rail_off_ready()) {
- cpu_do_idle();
- return false;
- }
-
- return !tegra_pm_enter_lp2();
-}
-
-#ifdef CONFIG_SMP
-static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
- struct cpuidle_driver *drv,
- int index)
-{
- smp_wmb();
-
- cpu_suspend(0, tegra30_pm_secondary_cpu_suspend);
-
- 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 tegra30_idle_lp2(struct cpuidle_device *dev,
- struct cpuidle_driver *drv,
- int index)
-{
- bool entered_lp2 = false;
-
- local_fiq_disable();
-
- tegra_pm_set_cpu_in_lp2();
- cpu_pm_enter();
-
- if (dev->cpu == 0)
- entered_lp2 = tegra30_cpu_cluster_power_down(dev, drv, index);
- else
- entered_lp2 = tegra30_cpu_core_power_down(dev, drv, index);
-
- cpu_pm_exit();
- tegra_pm_clear_cpu_in_lp2();
-
- local_fiq_enable();
-
- return (entered_lp2) ? index : 0;
-}
-#endif
-
-int __init tegra30_cpuidle_init(void)
-{
- return cpuidle_register(&tegra_idle_driver, NULL);
-}
diff --git a/arch/arm/mach-tegra/cpuidle.c b/arch/arm/mach-tegra/cpuidle.c
index eee85d517783..fa0dcf3c2c45 100644
--- a/arch/arm/mach-tegra/cpuidle.c
+++ b/arch/arm/mach-tegra/cpuidle.c
@@ -24,11 +24,8 @@ void __init tegra_cpuidle_init(void)
{
switch (tegra_get_chip_id()) {
case TEGRA20:
- platform_device_register_simple("tegra-cpuidle", -1, NULL, 0);
- break;
case TEGRA30:
- if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC))
- tegra30_cpuidle_init();
+ platform_device_register_simple("tegra-cpuidle", -1, NULL, 0);
break;
case TEGRA114:
case TEGRA124:
diff --git a/arch/arm/mach-tegra/cpuidle.h b/arch/arm/mach-tegra/cpuidle.h
index eeb37baf18e1..5423a05a69f6 100644
--- a/arch/arm/mach-tegra/cpuidle.h
+++ b/arch/arm/mach-tegra/cpuidle.h
@@ -7,7 +7,6 @@
#define __MACH_TEGRA_CPUIDLE_H

#ifdef CONFIG_CPU_IDLE
-int tegra30_cpuidle_init(void);
int tegra114_cpuidle_init(void);
void tegra_cpuidle_init(void);
#else
diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
index a58d2773d45f..59398c76cf68 100644
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -37,6 +37,7 @@

enum tegra_state {
TEGRA_C1,
+ TEGRA_C7,
TEGRA_CC6,
TEGRA_STATE_COUNT,
};
@@ -119,6 +120,11 @@ static int tegra_cpuidle_cc6_enter(unsigned int cpu)
return ret;
}

+static int tegra_cpuidle_c7_enter(void)
+{
+ return cpu_suspend(0, tegra30_pm_secondary_cpu_suspend);
+}
+
static int tegra_cpuidle_coupled_barrier(struct cpuidle_device *dev)
{
if (tegra_pending_sgi()) {
@@ -166,6 +172,10 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
cpu_pm_enter();

switch (index) {
+ case TEGRA_C7:
+ ret = tegra_cpuidle_c7_enter();
+ break;
+
case TEGRA_CC6:
ret = tegra_cpuidle_cc6_enter(cpu);
break;
@@ -182,6 +192,24 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
return ret;
}

+static int tegra_cpuidle_adjust_state_index(int index, unsigned int cpu)
+{
+ /*
+ * On Tegra30 CPU0 can't be power-gated separately from secondary
+ * cores because it gates the whole CPU cluster.
+ */
+ if (cpu > 0 || index != TEGRA_C7 || tegra_get_chip_id() != TEGRA30)
+ return index;
+
+ /* put CPU0 into C1 if C7 is requested and secondaries are online */
+ if (!IS_ENABLED(CONFIG_PM_SLEEP) || num_online_cpus() > 1)
+ index = TEGRA_C1;
+ else
+ index = TEGRA_CC6;
+
+ return index;
+}
+
static int tegra_cpuidle_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
@@ -189,10 +217,17 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
unsigned int cpu = cpu_logical_map(dev->cpu);
int err;

- err = tegra_cpuidle_state_enter(dev, index, cpu);
- if (err && err != -EINTR)
- pr_err_once("cpu%u failed to enter idle state %d err: %d\n",
- cpu, index, err);
+ index = tegra_cpuidle_adjust_state_index(index, cpu);
+ if (dev->states_usage[index].disable)
+ return -1;
+
+ if (index == TEGRA_C1)
+ err = arm_cpuidle_simple_enter(dev, drv, index);
+ else
+ err = tegra_cpuidle_state_enter(dev, index, cpu);
+
+ if (err && (err != -EINTR || index != TEGRA_CC6))
+ pr_err_once("failed to enter state %d err: %d\n", index, err);

return err ? -1 : index;
}
@@ -218,6 +253,15 @@ static struct cpuidle_driver tegra_idle_driver = {
.name = "tegra_idle",
.states = {
[TEGRA_C1] = ARM_CPUIDLE_WFI_STATE_PWR(600),
+ [TEGRA_C7] = {
+ .enter = tegra_cpuidle_enter,
+ .exit_latency = 2000,
+ .target_residency = 2200,
+ .power_usage = 100,
+ .flags = CPUIDLE_FLAG_TIMER_STOP,
+ .name = "C7",
+ .desc = "CPU core powered off",
+ },
[TEGRA_CC6] = {
.enter = tegra_cpuidle_enter,
.exit_latency = 5000,
@@ -262,8 +306,28 @@ static int tegra_cpuidle_probe(struct platform_device *pdev)
* Tegra-arch core and PMC driver, is unavailable if PM-sleep option
* is disabled.
*/
- if (!IS_ENABLED(CONFIG_PM_SLEEP))
+ if (!IS_ENABLED(CONFIG_PM_SLEEP)) {
+ tegra_cpuidle_disable_state(TEGRA_C7);
tegra_cpuidle_disable_state(TEGRA_CC6);
+ }
+
+ /*
+ * Generic WFI state (also known as C1 or LP3) and the coupled CPU
+ * cluster power-off (CC6 or LP2) states are common for all Tegra SoCs.
+ */
+ switch (tegra_get_chip_id()) {
+ case TEGRA20:
+ /* Tegra20 isn't capable to power-off individual CPU cores */
+ tegra_cpuidle_disable_state(TEGRA_C7);
+ break;
+
+ case TEGRA30:
+ tegra_cpuidle_disable_state(TEGRA_CC6);
+ break;
+
+ default:
+ return -EINVAL;
+ }

return cpuidle_register(&tegra_idle_driver, cpu_possible_mask);
}
--
2.24.0