summaryrefslogtreecommitdiff
path: root/arch/arm/mach-tegra/platsmp.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/mach-tegra/platsmp.c
Initial import
Diffstat (limited to 'arch/arm/mach-tegra/platsmp.c')
-rw-r--r--arch/arm/mach-tegra/platsmp.c203
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
new file mode 100644
index 000000000..b45086666
--- /dev/null
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -0,0 +1,203 @@
+/*
+ * linux/arch/arm/mach-tegra/platsmp.c
+ *
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ *
+ * Copyright (C) 2009 Palm
+ * 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 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk/tegra.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/smp.h>
+
+#include <soc/tegra/fuse.h>
+#include <soc/tegra/pmc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/mach-types.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#include "common.h"
+#include "flowctrl.h"
+#include "iomap.h"
+#include "reset.h"
+
+static cpumask_t tegra_cpu_init_mask;
+
+static void tegra_secondary_init(unsigned int cpu)
+{
+ cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
+}
+
+
+static int tegra20_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ cpu = cpu_logical_map(cpu);
+
+ /*
+ * Force the CPU into reset. The CPU must remain in reset when
+ * the flow controller state is cleared (which will cause the
+ * flow controller to stop driving reset if the CPU has been
+ * power-gated via the flow controller). This will have no
+ * effect on first boot of the CPU since it should already be
+ * in reset.
+ */
+ tegra_put_cpu_in_reset(cpu);
+
+ /*
+ * Unhalt the CPU. If the flow controller was used to
+ * power-gate the CPU this will cause the flow controller to
+ * stop driving reset. The CPU will remain in reset because the
+ * clock and reset block is now driving reset.
+ */
+ flowctrl_write_cpu_halt(cpu, 0);
+
+ tegra_enable_cpu_clock(cpu);
+ flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
+ tegra_cpu_out_of_reset(cpu);
+ return 0;
+}
+
+static int tegra30_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ int ret;
+ unsigned long timeout;
+
+ cpu = cpu_logical_map(cpu);
+ tegra_put_cpu_in_reset(cpu);
+ flowctrl_write_cpu_halt(cpu, 0);
+
+ /*
+ * The power up sequence of cold boot CPU and warm boot CPU
+ * was different.
+ *
+ * For warm boot CPU that was resumed from CPU hotplug, the
+ * power will be resumed automatically after un-halting the
+ * flow controller of the warm boot CPU. We need to wait for
+ * the confirmaiton that the CPU is powered then removing
+ * the IO clamps.
+ * For cold boot CPU, do not wait. After the cold boot CPU be
+ * booted, it will run to tegra_secondary_init() and set
+ * tegra_cpu_init_mask which influences what tegra30_boot_secondary()
+ * next time around.
+ */
+ if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
+ timeout = jiffies + msecs_to_jiffies(50);
+ do {
+ if (tegra_pmc_cpu_is_powered(cpu))
+ goto remove_clamps;
+ udelay(10);
+ } while (time_before(jiffies, timeout));
+ }
+
+ /*
+ * The power status of the cold boot CPU is power gated as
+ * default. To power up the cold boot CPU, the power should
+ * be un-gated by un-toggling the power gate register
+ * manually.
+ */
+ if (!tegra_pmc_cpu_is_powered(cpu)) {
+ ret = tegra_pmc_cpu_power_on(cpu);
+ if (ret)
+ return ret;
+
+ /* Wait for the power to come up. */
+ timeout = jiffies + msecs_to_jiffies(100);
+ while (!tegra_pmc_cpu_is_powered(cpu)) {
+ if (time_after(jiffies, timeout))
+ return -ETIMEDOUT;
+ udelay(10);
+ }
+ }
+
+remove_clamps:
+ /* CPU partition is powered. Enable the CPU clock. */
+ tegra_enable_cpu_clock(cpu);
+ udelay(10);
+
+ /* Remove I/O clamps. */
+ ret = tegra_pmc_cpu_remove_clamping(cpu);
+ if (ret)
+ return ret;
+
+ udelay(10);
+
+ flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
+ tegra_cpu_out_of_reset(cpu);
+ return 0;
+}
+
+static int tegra114_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ int ret = 0;
+
+ cpu = cpu_logical_map(cpu);
+
+ if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
+ /*
+ * Warm boot flow
+ * The flow controller in charge of the power state and
+ * control for each CPU.
+ */
+ /* set SCLK as event trigger for flow controller */
+ flowctrl_write_cpu_csr(cpu, 1);
+ flowctrl_write_cpu_halt(cpu,
+ FLOW_CTRL_WAITEVENT | FLOW_CTRL_SCLK_RESUME);
+ } else {
+ /*
+ * Cold boot flow
+ * The CPU is powered up by toggling PMC directly. It will
+ * also initial power state in flow controller. After that,
+ * the CPU's power state is maintained by flow controller.
+ */
+ ret = tegra_pmc_cpu_power_on(cpu);
+ }
+
+ return ret;
+}
+
+static int tegra_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && tegra_get_chip_id() == TEGRA20)
+ return tegra20_boot_secondary(cpu, idle);
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) && tegra_get_chip_id() == TEGRA30)
+ return tegra30_boot_secondary(cpu, idle);
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) && tegra_get_chip_id() == TEGRA114)
+ return tegra114_boot_secondary(cpu, idle);
+ if (IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC) && tegra_get_chip_id() == TEGRA124)
+ return tegra114_boot_secondary(cpu, idle);
+
+ return -EINVAL;
+}
+
+static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
+{
+ /* Always mark the boot CPU (CPU0) as initialized. */
+ cpumask_set_cpu(0, &tegra_cpu_init_mask);
+
+ if (scu_a9_has_base())
+ scu_enable(IO_ADDRESS(scu_a9_get_base()));
+}
+
+struct smp_operations tegra_smp_ops __initdata = {
+ .smp_prepare_cpus = tegra_smp_prepare_cpus,
+ .smp_secondary_init = tegra_secondary_init,
+ .smp_boot_secondary = tegra_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_kill = tegra_cpu_kill,
+ .cpu_die = tegra_cpu_die,
+#endif
+};