/*
   * CPU complex suspend & resume functions for Tegra SoCs
   *
   * Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/kernel.h>
  #include <linux/spinlock.h>
  #include <linux/io.h>
  #include <linux/cpumask.h>
  #include <linux/delay.h>
  #include <linux/cpu_pm.h>
  #include <linux/suspend.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  #include <linux/clk/tegra.h>
  
  #include <asm/smp_plat.h>
  #include <asm/cacheflush.h>
  #include <asm/suspend.h>
  #include <asm/idmap.h>
  #include <asm/proc-fns.h>
  #include <asm/tlbflush.h>
  
  #include "iomap.h"
  #include "reset.h"
  #include "flowctrl.h"
  #include "fuse.h"
  #include "pm.h"
  #include "pmc.h"
  #include "sleep.h"
  
  #ifdef CONFIG_PM_SLEEP
  static DEFINE_SPINLOCK(tegra_lp2_lock);
  static u32 iram_save_size;
  static void *iram_save_addr;
  struct tegra_lp1_iram tegra_lp1_iram;
  void (*tegra_tear_down_cpu)(void);
  void (*tegra_sleep_core_finish)(unsigned long v2p);
  static int (*tegra_sleep_func)(unsigned long v2p);
  
  static void tegra_tear_down_cpu_init(void)
  {
  	switch (tegra_chip_id) {
  	case TEGRA20:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
  			tegra_tear_down_cpu = tegra20_tear_down_cpu;
  		break;
  	case TEGRA30:
  	case TEGRA114:
  	case TEGRA124:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
  			tegra_tear_down_cpu = tegra30_tear_down_cpu;
  		break;
  	}
  }
  
  /*
   * restore_cpu_complex
   *
   * restores cpu clock setting, clears flow controller
   *
   * Always called on CPU 0.
   */
  static void restore_cpu_complex(void)
  {
  	int cpu = smp_processor_id();
  
  	BUG_ON(cpu != 0);
  
  #ifdef CONFIG_SMP
  	cpu = cpu_logical_map(cpu);
  #endif
  
  	/* Restore the CPU clock settings */
  	tegra_cpu_clock_resume();
  
  	flowctrl_cpu_suspend_exit(cpu);
  }
  
  /*
   * suspend_cpu_complex
   *
   * saves pll state for use by restart_plls, prepares flow controller for
   * transition to suspend state
   *
   * Must always be called on cpu 0.
   */
  static void suspend_cpu_complex(void)
  {
  	int cpu = smp_processor_id();
  
  	BUG_ON(cpu != 0);
  
  #ifdef CONFIG_SMP
  	cpu = cpu_logical_map(cpu);
  #endif
  
  	/* Save the CPU clock settings */
  	tegra_cpu_clock_suspend();
  
  	flowctrl_cpu_suspend_enter(cpu);
  }
  
  void tegra_clear_cpu_in_lp2(void)
  {
  	int phy_cpu_id = cpu_logical_map(smp_processor_id());
  	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
  
  	spin_lock(&tegra_lp2_lock);
  
  	BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
  	*cpu_in_lp2 &= ~BIT(phy_cpu_id);
  
  	spin_unlock(&tegra_lp2_lock);
  }
  
  bool tegra_set_cpu_in_lp2(void)
  {
  	int phy_cpu_id = cpu_logical_map(smp_processor_id());
  	bool last_cpu = false;
  	cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
  	u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
  
  	spin_lock(&tegra_lp2_lock);
  
  	BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
  	*cpu_in_lp2 |= BIT(phy_cpu_id);
  
  	if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
  		last_cpu = true;
  	else if (tegra_chip_id == TEGRA20 && phy_cpu_id == 1)
  		tegra20_cpu_set_resettable_soon();
  
  	spin_unlock(&tegra_lp2_lock);
  	return last_cpu;
  }
  
  int tegra_cpu_do_idle(void)
  {
  	return cpu_do_idle();
  }
  
  static int tegra_sleep_cpu(unsigned long v2p)
  {
  	setup_mm_for_reboot();
  	tegra_sleep_cpu_finish(v2p);
  
  	/* should never here */
  	BUG();
  
  	return 0;
  }
  
  void tegra_idle_lp2_last(void)
  {
  	tegra_pmc_pm_set(TEGRA_SUSPEND_LP2);
  
  	cpu_cluster_pm_enter();
  	suspend_cpu_complex();
  
  	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
  
  	restore_cpu_complex();
  	cpu_cluster_pm_exit();
  }
  
  enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
  				enum tegra_suspend_mode mode)
  {
  	/*
  	 * The Tegra devices support suspending to LP1 or lower currently.
  	 */
  	if (mode > TEGRA_SUSPEND_LP1)
  		return TEGRA_SUSPEND_LP1;
  
  	return mode;
  }
  
  static int tegra_sleep_core(unsigned long v2p)
  {
  	setup_mm_for_reboot();
  	tegra_sleep_core_finish(v2p);
  
  	/* should never here */
  	BUG();
  
  	return 0;
  }
  
  /*
   * tegra_lp1_iram_hook
   *
   * Hooking the address of LP1 reset vector and SDRAM self-refresh code in
   * SDRAM. These codes not be copied to IRAM in this fuction. We need to
   * copy these code to IRAM before LP0/LP1 suspend and restore the content
   * of IRAM after resume.
   */
  static bool tegra_lp1_iram_hook(void)
  {
  	switch (tegra_chip_id) {
  	case TEGRA20:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
  			tegra20_lp1_iram_hook();
  		break;
  	case TEGRA30:
  	case TEGRA114:
  	case TEGRA124:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
  			tegra30_lp1_iram_hook();
  		break;
  	default:
  		break;
  	}
  
  	if (!tegra_lp1_iram.start_addr || !tegra_lp1_iram.end_addr)
  		return false;
  
  	iram_save_size = tegra_lp1_iram.end_addr - tegra_lp1_iram.start_addr;
  	iram_save_addr = kmalloc(iram_save_size, GFP_KERNEL);
  	if (!iram_save_addr)
  		return false;
  
  	return true;
  }
  
  static bool tegra_sleep_core_init(void)
  {
  	switch (tegra_chip_id) {
  	case TEGRA20:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC))
  			tegra20_sleep_core_init();
  		break;
  	case TEGRA30:
  	case TEGRA114:
  	case TEGRA124:
  		if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) ||
  		    IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC))
  			tegra30_sleep_core_init();
  		break;
  	default:
  		break;
  	}
  
  	if (!tegra_sleep_core_finish)
  		return false;
  
  	return true;
  }
  
  static void tegra_suspend_enter_lp1(void)
  {
  	tegra_pmc_suspend();
  
  	/* copy the reset vector & SDRAM shutdown code into IRAM */
  	memcpy(iram_save_addr, IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
  		iram_save_size);
  	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA),
  		tegra_lp1_iram.start_addr, iram_save_size);
  
  	*((u32 *)tegra_cpu_lp1_mask) = 1;
  }
  
  static void tegra_suspend_exit_lp1(void)
  {
  	tegra_pmc_resume();
  
  	/* restore IRAM */
  	memcpy(IO_ADDRESS(TEGRA_IRAM_LPx_RESUME_AREA), iram_save_addr,
  		iram_save_size);
  
  	*(u32 *)tegra_cpu_lp1_mask = 0;
  }
  
  static const char *lp_state[TEGRA_MAX_SUSPEND_MODE] = {
  	[TEGRA_SUSPEND_NONE] = "none",
  	[TEGRA_SUSPEND_LP2] = "LP2",
  	[TEGRA_SUSPEND_LP1] = "LP1",
  	[TEGRA_SUSPEND_LP0] = "LP0",
  };
  
  static int tegra_suspend_enter(suspend_state_t state)
  {
  	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
  
  	if (WARN_ON(mode < TEGRA_SUSPEND_NONE ||
  		    mode >= TEGRA_MAX_SUSPEND_MODE))
  		return -EINVAL;
  
  	pr_info("Entering suspend state %s
  ", lp_state[mode]);
  
  	tegra_pmc_pm_set(mode);
  
  	local_fiq_disable();
  
  	suspend_cpu_complex();
  	switch (mode) {
  	case TEGRA_SUSPEND_LP1:
  		tegra_suspend_enter_lp1();
  		break;
  	case TEGRA_SUSPEND_LP2:
  		tegra_set_cpu_in_lp2();
  		break;
  	default:
  		break;
  	}
  
  	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, tegra_sleep_func);
  
  	switch (mode) {
  	case TEGRA_SUSPEND_LP1:
  		tegra_suspend_exit_lp1();
  		break;
  	case TEGRA_SUSPEND_LP2:
  		tegra_clear_cpu_in_lp2();
  		break;
  	default:
  		break;
  	}
  	restore_cpu_complex();
  
  	local_fiq_enable();
  
  	return 0;
  }
  
  static const struct platform_suspend_ops tegra_suspend_ops = {
  	.valid		= suspend_valid_only_mem,
  	.enter		= tegra_suspend_enter,
  };
  
  void __init tegra_init_suspend(void)
  {
  	enum tegra_suspend_mode mode = tegra_pmc_get_suspend_mode();
  
  	if (mode == TEGRA_SUSPEND_NONE)
  		return;
  
  	tegra_tear_down_cpu_init();
  	tegra_pmc_suspend_init();
  
  	if (mode >= TEGRA_SUSPEND_LP1) {
  		if (!tegra_lp1_iram_hook() || !tegra_sleep_core_init()) {
  			pr_err("%s: unable to allocate memory for SDRAM"
  			       "self-refresh -- LP0/LP1 unavailable
  ",
  			       __func__);
  			tegra_pmc_set_suspend_mode(TEGRA_SUSPEND_LP2);
  			mode = TEGRA_SUSPEND_LP2;
  		}
  	}
  
  	/* set up sleep function for cpu_suspend */
  	switch (mode) {
  	case TEGRA_SUSPEND_LP1:
  		tegra_sleep_func = tegra_sleep_core;
  		break;
  	case TEGRA_SUSPEND_LP2:
  		tegra_sleep_func = tegra_sleep_cpu;
  		break;
  	default:
  		break;
  	}
  
  	suspend_set_ops(&tegra_suspend_ops);
  }
  #endif