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-rw-r--r--drivers/cpuidle/Kconfig.arm8
-rw-r--r--drivers/cpuidle/Makefile1
-rw-r--r--drivers/cpuidle/cpuidle-tegra.c280
3 files changed, 289 insertions, 0 deletions
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 62272ecfa771..99a2d72ac02b 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -86,3 +86,11 @@ config ARM_MVEBU_V7_CPUIDLE
depends on (ARCH_MVEBU || COMPILE_TEST) && !ARM64
help
Select this to enable cpuidle on Armada 370, 38x and XP processors.
+
+config ARM_TEGRA_CPUIDLE
+ bool "CPU Idle Driver for NVIDIA Tegra SoCs"
+ depends on ARCH_TEGRA && !ARM64
+ select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
+ select ARM_CPU_SUSPEND
+ help
+ Select this to enable cpuidle for NVIDIA Tegra20/30/114/124 SoCs.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index cc8c769d7fa9..55a464f6a78b 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o
obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle_psci.o
cpuidle_psci-y := cpuidle-psci.o
cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o
+obj-$(CONFIG_ARM_TEGRA_CPUIDLE) += cpuidle-tegra.o
###############################################################################
# MIPS drivers
diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
new file mode 100644
index 000000000000..5691bdcf11cb
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPU idle driver for Tegra CPUs
+ *
+ * Copyright (c) 2010-2013, NVIDIA Corporation.
+ * Copyright (c) 2011 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ * Gary King <gking@nvidia.com>
+ *
+ * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
+ *
+ * Tegra20/124 driver unification by Dmitry Osipenko <digetx@gmail.com>
+ */
+
+#define pr_fmt(fmt) "tegra-cpuidle: " fmt
+
+#include <linux/atomic.h>
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#include <linux/clk/tegra.h>
+
+#include <soc/tegra/cpuidle.h>
+#include <soc/tegra/flowctrl.h>
+#include <soc/tegra/fuse.h>
+#include <soc/tegra/irq.h>
+#include <soc/tegra/pm.h>
+
+#include <asm/cpuidle.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+enum tegra_state {
+ TEGRA_C1,
+ TEGRA_CC6,
+ TEGRA_STATE_COUNT,
+};
+
+static atomic_t tegra_idle_barrier;
+static atomic_t tegra_abort_flag;
+
+static void tegra_cpuidle_report_cpus_state(void)
+{
+ unsigned long cpu, lcpu, csr;
+
+ for_each_cpu(lcpu, cpu_possible_mask) {
+ cpu = cpu_logical_map(lcpu);
+ csr = flowctrl_read_cpu_csr(cpu);
+
+ pr_err("cpu%lu: online=%d flowctrl_csr=0x%08lx\n",
+ cpu, cpu_online(lcpu), csr);
+ }
+}
+
+static int tegra_cpuidle_wait_for_secondary_cpus_parking(void)
+{
+ unsigned int retries = 3;
+
+ while (retries--) {
+ unsigned int delay_us = 10;
+ unsigned int timeout_us = 500 * 1000 / delay_us;
+
+ /*
+ * The primary CPU0 core shall wait for the secondaries
+ * shutdown in order to power-off CPU's cluster safely.
+ * The timeout value depends on the current CPU frequency,
+ * it takes about 40-150us in average and over 1000us in
+ * a worst case scenario.
+ */
+ do {
+ if (tegra_cpu_rail_off_ready())
+ return 0;
+
+ udelay(delay_us);
+
+ } while (timeout_us--);
+
+ pr_err("secondary CPU taking too long to park\n");
+
+ tegra_cpuidle_report_cpus_state();
+ }
+
+ pr_err("timed out waiting secondaries to park\n");
+
+ return -ETIMEDOUT;
+}
+
+static void tegra_cpuidle_unpark_secondary_cpus(void)
+{
+ unsigned int cpu, lcpu;
+
+ for_each_cpu(lcpu, cpu_online_mask) {
+ cpu = cpu_logical_map(lcpu);
+
+ if (cpu > 0) {
+ tegra_enable_cpu_clock(cpu);
+ tegra_cpu_out_of_reset(cpu);
+ flowctrl_write_cpu_halt(cpu, 0);
+ }
+ }
+}
+
+static int tegra_cpuidle_cc6_enter(unsigned int cpu)
+{
+ int ret;
+
+ if (cpu > 0) {
+ ret = cpu_suspend(cpu, tegra_pm_park_secondary_cpu);
+ } else {
+ ret = tegra_cpuidle_wait_for_secondary_cpus_parking();
+ if (!ret)
+ ret = tegra_pm_enter_lp2();
+
+ tegra_cpuidle_unpark_secondary_cpus();
+ }
+
+ return ret;
+}
+
+static int tegra_cpuidle_coupled_barrier(struct cpuidle_device *dev)
+{
+ if (tegra_pending_sgi()) {
+ /*
+ * CPU got local interrupt that will be lost after GIC's
+ * shutdown because GIC driver doesn't save/restore the
+ * pending SGI state across CPU cluster PM. Abort and retry
+ * next time.
+ */
+ atomic_set(&tegra_abort_flag, 1);
+ }
+
+ cpuidle_coupled_parallel_barrier(dev, &tegra_idle_barrier);
+
+ if (atomic_read(&tegra_abort_flag)) {
+ cpuidle_coupled_parallel_barrier(dev, &tegra_idle_barrier);
+ atomic_set(&tegra_abort_flag, 0);
+ return -EINTR;
+ }
+
+ return 0;
+}
+
+static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
+ int index, unsigned int cpu)
+{
+ int ret;
+
+ /*
+ * CC6 state is the "CPU cluster power-off" state. In order to
+ * enter this state, at first the secondary CPU cores need to be
+ * parked into offline mode, then the last CPU should clean out
+ * remaining dirty cache lines into DRAM and trigger Flow Controller
+ * logic that turns off the cluster's power domain (which includes
+ * CPU cores, GIC and L2 cache).
+ */
+ if (index == TEGRA_CC6) {
+ ret = tegra_cpuidle_coupled_barrier(dev);
+ if (ret)
+ return ret;
+ }
+
+ local_fiq_disable();
+ tegra_pm_set_cpu_in_lp2();
+ cpu_pm_enter();
+
+ switch (index) {
+ case TEGRA_CC6:
+ ret = tegra_cpuidle_cc6_enter(cpu);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ cpu_pm_exit();
+ tegra_pm_clear_cpu_in_lp2();
+ local_fiq_enable();
+
+ return ret;
+}
+
+static int tegra_cpuidle_enter(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ 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);
+
+ return err ? -1 : index;
+}
+
+/*
+ * The previous versions of Tegra CPUIDLE driver used a different "legacy"
+ * terminology for naming of the idling states, while this driver uses the
+ * new terminology.
+ *
+ * Mapping of the old terms into the new ones:
+ *
+ * Old | New
+ * ---------
+ * LP3 | C1 (CPU core clock gating)
+ * LP2 | C7 (CPU core power gating)
+ * LP2 | CC6 (CPU cluster power gating)
+ *
+ * Note that that the older CPUIDLE driver versions didn't explicitly
+ * differentiate the LP2 states because these states either used the same
+ * code path or because CC6 wasn't supported.
+ */
+static struct cpuidle_driver tegra_idle_driver = {
+ .name = "tegra_idle",
+ .states = {
+ [TEGRA_C1] = ARM_CPUIDLE_WFI_STATE_PWR(600),
+ [TEGRA_CC6] = {
+ .enter = tegra_cpuidle_enter,
+ .exit_latency = 5000,
+ .target_residency = 10000,
+ .power_usage = 0,
+ .flags = CPUIDLE_FLAG_TIMER_STOP |
+ CPUIDLE_FLAG_COUPLED,
+ .name = "CC6",
+ .desc = "CPU cluster powered off",
+ },
+ },
+ .state_count = TEGRA_STATE_COUNT,
+ .safe_state_index = TEGRA_C1,
+};
+
+static inline void tegra_cpuidle_disable_state(enum tegra_state state)
+{
+ cpuidle_driver_state_disabled(&tegra_idle_driver, state, true);
+}
+
+/*
+ * Tegra20 HW appears to have a bug such that PCIe device interrupts, whether
+ * they are legacy IRQs or MSI, are lost when CC6 is enabled. To work around
+ * this, simply disable CC6 if the PCI driver and DT node are both enabled.
+ */
+void tegra_cpuidle_pcie_irqs_in_use(void)
+{
+ struct cpuidle_state *state_cc6 = &tegra_idle_driver.states[TEGRA_CC6];
+
+ if ((state_cc6->flags & CPUIDLE_FLAG_UNUSABLE) ||
+ tegra_get_chip_id() != TEGRA20)
+ return;
+
+ pr_info("disabling CC6 state, since PCIe IRQs are in use\n");
+ tegra_cpuidle_disable_state(TEGRA_CC6);
+}
+
+static int tegra_cpuidle_probe(struct platform_device *pdev)
+{
+ /*
+ * Required suspend-resume functionality, which is provided by the
+ * Tegra-arch core and PMC driver, is unavailable if PM-sleep option
+ * is disabled.
+ */
+ if (!IS_ENABLED(CONFIG_PM_SLEEP))
+ tegra_cpuidle_disable_state(TEGRA_CC6);
+
+ return cpuidle_register(&tegra_idle_driver, cpu_possible_mask);
+}
+
+static struct platform_driver tegra_cpuidle_driver = {
+ .probe = tegra_cpuidle_probe,
+ .driver = {
+ .name = "tegra-cpuidle",
+ },
+};
+builtin_platform_driver(tegra_cpuidle_driver);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-27 20:10:32 +0300