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pm.c

/*
 *  Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 */

/*
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/suspend.h>
#include <linux/proc_fs.h>
#include <linux/cpufreq.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
#include <asm/mach/map.h>
#include <mach/hardware.h>
#include "crm_regs.h"

static struct cpu_wp *cpu_wp_tbl;
static struct clk *cpu_clk;

#if defined(CONFIG_CPU_FREQ)
static int org_freq;
extern int cpufreq_suspended;
extern int set_cpu_freq(int wp);
#endif


static struct device *pm_dev;
struct clk *gpc_dvfs_clk;
extern void cpu_do_suspend_workaround(u32 sdclk_iomux_addr);
extern void cpu_cortexa8_do_idle(void *);
extern struct cpu_wp *(*get_cpu_wp)(int *wp);

extern int iram_ready;
void *suspend_iram_base;
void (*suspend_in_iram)(void *sdclk_iomux_addr) = NULL;

static int mx51_suspend_enter(suspend_state_t state)
{
      void __iomem *sdclk_iomux_addr = IO_ADDRESS(IOMUXC_BASE_ADDR + 0x4b8);

      if (gpc_dvfs_clk == NULL)
            gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs_clk");
      /* gpc clock is needed for SRPG */
      clk_enable(gpc_dvfs_clk);
      switch (state) {
      case PM_SUSPEND_MEM:
            mxc_cpu_lp_set(STOP_POWER_OFF);
            break;
      case PM_SUSPEND_STANDBY:
            mxc_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
            break;
      default:
            return -EINVAL;
      }

      if (tzic_enable_wake(0) != 0)
            return -EAGAIN;

      if (state == PM_SUSPEND_MEM) {
            local_flush_tlb_all();
            flush_cache_all();

            /* Run the suspend code from iRAM. */
            suspend_in_iram(sdclk_iomux_addr);

            /*clear the EMPGC0/1 bits */
            __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
            __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
      } else {
            if ((mxc_cpu_is_rev(CHIP_REV_2_0)) < 0) {
                  /* do cpu_idle_workaround */
                  u32 l2_iram_addr = IDLE_IRAM_BASE_ADDR;
                  if (!iram_ready)
                        return 0;
                  if (l2_iram_addr > 0x1FFE8000)
                        cpu_cortexa8_do_idle(IO_ADDRESS(l2_iram_addr));
            } else {
                  cpu_do_idle();
            }
      }
      clk_disable(gpc_dvfs_clk);

      return 0;
}

/*
 * Called after processes are frozen, but before we shut down devices.
 */
static int mx51_suspend_prepare(void)
{
#if defined(CONFIG_CPU_FREQ)
      struct cpufreq_freqs freqs;
      org_freq = clk_get_rate(cpu_clk);
      freqs.old = org_freq / 1000;
      freqs.new = cpu_wp_tbl[0].cpu_rate / 1000;
      freqs.cpu = 0;
      freqs.flags = 0;

      cpufreq_suspended = 1;
      if (clk_get_rate(cpu_clk) != cpu_wp_tbl[0].cpu_rate) {
            set_cpu_freq(cpu_wp_tbl[0].cpu_rate);
            cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
            cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
      }
#endif
      return 0;
}

/*
 * Called before devices are re-setup.
 */
static void mx51_suspend_finish(void)
{
#if defined(CONFIG_CPU_FREQ)
      struct cpufreq_freqs freqs;

      freqs.old = clk_get_rate(cpu_clk) / 1000;
      freqs.new = org_freq / 1000;
      freqs.cpu = 0;
      freqs.flags = 0;

      cpufreq_suspended = 0;

      if (org_freq != clk_get_rate(cpu_clk)) {
            set_cpu_freq(org_freq);
            cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
            cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
      }
#endif
}

/*
 * Called after devices are re-setup, but before processes are thawed.
 */
static void mx51_suspend_end(void)
{
}

static int mx51_pm_valid(suspend_state_t state)
{
      return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
}

struct platform_suspend_ops mx51_suspend_ops = {
      .valid = mx51_pm_valid,
      .prepare = mx51_suspend_prepare,
      .enter = mx51_suspend_enter,
      .finish = mx51_suspend_finish,
      .end = mx51_suspend_end,
};


static int __devinit mx51_pm_probe(struct platform_device *pdev)
{
      pm_dev = &pdev->dev;
      return 0;
}

static struct platform_driver mx51_pm_driver = {
      .driver = {
               .name = "mx51_pm",
               },
      .probe = mx51_pm_probe,
};

static int __init pm_init(void)
{
      int cpu_wp_nr;

      pr_info("Static Power Management for Freescale i.MX51\n");
      if (platform_driver_register(&mx51_pm_driver) != 0) {
            printk(KERN_ERR "mx51_pm_driver register failed\n");
            return -ENODEV;
      }
      suspend_set_ops(&mx51_suspend_ops);
      /* Move suspend routine into iRAM */
      suspend_iram_base = IO_ADDRESS(SUSPEND_IRAM_BASE_ADDR);
      memcpy(suspend_iram_base, cpu_do_suspend_workaround, SZ_4K);
      /* Need to remap the area here since we want the memory region
             to be executable. */
      suspend_iram_base = __arm_ioremap(SUSPEND_IRAM_BASE_ADDR, SZ_4K,
                                                            MT_HIGH_VECTORS);
      suspend_in_iram = (void *)suspend_iram_base;

      cpu_wp_tbl = get_cpu_wp(&cpu_wp_nr);

      cpu_clk = clk_get(NULL, "cpu_clk");
      if (IS_ERR(cpu_clk)) {
            printk(KERN_DEBUG "%s: failed to get cpu_clk\n", __func__);
            return PTR_ERR(cpu_clk);
      }
      printk(KERN_INFO "PM driver module loaded\n");

      return 0;
}


static void __exit pm_cleanup(void)
{
      /* Unregister the device structure */
      platform_driver_unregister(&mx51_pm_driver);
}

module_init(pm_init);
module_exit(pm_cleanup);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("PM driver");
MODULE_LICENSE("GPL");

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