diff options
Diffstat (limited to 'kernel/arch/arm/mach-tegra/platsmp.c')
| -rw-r--r-- | kernel/arch/arm/mach-tegra/platsmp.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-tegra/platsmp.c b/kernel/arch/arm/mach-tegra/platsmp.c new file mode 100644 index 000000000..b45086666 --- /dev/null +++ b/kernel/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 +}; |