/*
 * linux/arch/arm/mach-omap1/pm.c
 *
 * OMAP Power Management Routines
 *
 * Original code for the SA11x0:
 * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
 *
 * Modified for the PXA250 by Nicolas Pitre:
 * Copyright (c) 2002 Monta Vista Software, Inc.
 *
 * Modified for the OMAP1510 by David Singleton:
 * Copyright (c) 2002 Monta Vista Software, Inc.
 *
 * Cleanup 2004 for OMAP1510/1610 by Dirk Behme <dirk.behme@de.bosch.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/suspend.h>
#include <linux/sched.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/atomic.h>
#include <linux/cpu.h>

#include <asm/fncpy.h>
#include <asm/system_misc.h>
#include <asm/irq.h>
#include <asm/mach/time.h>
#include <asm/mach/irq.h>

#include <mach/tc.h>
#include <mach/mux.h>
#include <linux/omap-dma.h>
#include <plat/dmtimer.h>

#include <mach/irqs.h>

#include "iomap.h"
#include "clock.h"
#include "pm.h"
#include "soc.h"
#include "sram.h"

static unsigned int arm_sleep_save[ARM_SLEEP_SAVE_SIZE];
static unsigned short dsp_sleep_save[DSP_SLEEP_SAVE_SIZE];
static unsigned short ulpd_sleep_save[ULPD_SLEEP_SAVE_SIZE];
static unsigned int mpui7xx_sleep_save[MPUI7XX_SLEEP_SAVE_SIZE];
static unsigned int mpui1510_sleep_save[MPUI1510_SLEEP_SAVE_SIZE];
static unsigned int mpui1610_sleep_save[MPUI1610_SLEEP_SAVE_SIZE];

static unsigned short enable_dyn_sleep;

static ssize_t idle_show(struct kobject *kobj, struct kobj_attribute *attr,
                         char *buf)
{
        return sprintf(buf, "%hu\n", enable_dyn_sleep);
}

static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
                          const char * buf, size_t n)
{
        unsigned short value;
        if (sscanf(buf, "%hu", &value) != 1 ||
            (value != 0 && value != 1) ||
            (value != 0 && !IS_ENABLED(CONFIG_OMAP_32K_TIMER))) {
                pr_err("idle_sleep_store: Invalid value\n");
                return -EINVAL;
        }
        enable_dyn_sleep = value;
        return n;
}

static struct kobj_attribute sleep_while_idle_attr =
        __ATTR(sleep_while_idle, 0644, idle_show, idle_store);


static void (*omap_sram_suspend)(unsigned long r0, unsigned long r1) = NULL;

/*
 * Let's power down on idle, but only if we are really
 * idle, because once we start down the path of
 * going idle we continue to do idle even if we get
 * a clock tick interrupt . .
 */
void omap1_pm_idle(void)
{
        extern __u32 arm_idlect1_mask;
        __u32 use_idlect1 = arm_idlect1_mask;

        local_fiq_disable();

#if defined(CONFIG_OMAP_MPU_TIMER) && !defined(CONFIG_OMAP_DM_TIMER)
        use_idlect1 = use_idlect1 & ~(1 << 9);
#endif

#ifdef CONFIG_OMAP_DM_TIMER
        use_idlect1 = omap_dm_timer_modify_idlect_mask(use_idlect1);
#endif

        if (omap_dma_running())
                use_idlect1 &= ~(1 << 6);

        /*
         * We should be able to remove the do_sleep variable and multiple
         * tests above as soon as drivers, timer and DMA code have been fixed.
         * Even the sleep block count should become obsolete.
         */
        if ((use_idlect1 != ~0) || !enable_dyn_sleep) {

                __u32 saved_idlect1 = omap_readl(ARM_IDLECT1);
                if (cpu_is_omap15xx())
                        use_idlect1 &= OMAP1510_BIG_SLEEP_REQUEST;
                else
                        use_idlect1 &= OMAP1610_IDLECT1_SLEEP_VAL;
                omap_writel(use_idlect1, ARM_IDLECT1);
                __asm__ volatile ("mcr  p15, 0, r0, c7, c0, 4");
                omap_writel(saved_idlect1, ARM_IDLECT1);

                local_fiq_enable();
                return;
        }
        omap_sram_suspend(omap_readl(ARM_IDLECT1),
                          omap_readl(ARM_IDLECT2));

        local_fiq_enable();
}

/*
 * Configuration of the wakeup event is board specific. For the
 * moment we put it into this helper function. Later it may move
 * to board specific files.
 */
static void omap_pm_wakeup_setup(void)
{
        u32 level1_wake = 0;
        u32 level2_wake = OMAP_IRQ_BIT(INT_UART2);

        /*
         * Turn off all interrupts except GPIO bank 1, L1-2nd level cascade,
         * and the L2 wakeup interrupts: keypad and UART2. Note that the
         * drivers must still separately call omap_set_gpio_wakeup() to
         * wake up to a GPIO interrupt.
         */
        if (cpu_is_omap7xx())
                level1_wake = OMAP_IRQ_BIT(INT_7XX_GPIO_BANK1) |
                        OMAP_IRQ_BIT(INT_7XX_IH2_IRQ);
        else if (cpu_is_omap15xx())
                level1_wake = OMAP_IRQ_BIT(INT_GPIO_BANK1) |
                        OMAP_IRQ_BIT(INT_1510_IH2_IRQ);
        else if (cpu_is_omap16xx())
                level1_wake = OMAP_IRQ_BIT(INT_GPIO_BANK1) |
                        OMAP_IRQ_BIT(INT_1610_IH2_IRQ);

        omap_writel(~level1_wake, OMAP_IH1_MIR);

        if (cpu_is_omap7xx()) {
                omap_writel(~level2_wake, OMAP_IH2_0_MIR);
                omap_writel(~(OMAP_IRQ_BIT(INT_7XX_WAKE_UP_REQ) |
                                OMAP_IRQ_BIT(INT_7XX_MPUIO_KEYPAD)),
                                OMAP_IH2_1_MIR);
        } else if (cpu_is_omap15xx()) {
                level2_wake |= OMAP_IRQ_BIT(INT_KEYBOARD);
                omap_writel(~level2_wake,  OMAP_IH2_MIR);
        } else if (cpu_is_omap16xx()) {
                level2_wake |= OMAP_IRQ_BIT(INT_KEYBOARD);
                omap_writel(~level2_wake, OMAP_IH2_0_MIR);

                /* INT_1610_WAKE_UP_REQ is needed for GPIO wakeup... */
                omap_writel(~OMAP_IRQ_BIT(INT_1610_WAKE_UP_REQ),
                            OMAP_IH2_1_MIR);
                omap_writel(~0x0, OMAP_IH2_2_MIR);
                omap_writel(~0x0, OMAP_IH2_3_MIR);
        }

        /*  New IRQ agreement, recalculate in cascade order */
        omap_writel(1, OMAP_IH2_CONTROL);
        omap_writel(1, OMAP_IH1_CONTROL);
}

#define EN_DSPCK        13      /* ARM_CKCTL */
#define EN_APICK        6       /* ARM_IDLECT2 */
#define DSP_EN          1       /* ARM_RSTCT1 */

void omap1_pm_suspend(void)
{
        unsigned long arg0 = 0, arg1 = 0;

        printk(KERN_INFO "PM: OMAP%x is trying to enter deep sleep...\n",
                omap_rev());

        omap_serial_wake_trigger(1);

        if (!cpu_is_omap15xx())
                omap_writew(0xffff, ULPD_SOFT_DISABLE_REQ_REG);

        /*
         * Step 1: turn off interrupts (FIXME: NOTE: already disabled)
         */

        local_irq_disable();
        local_fiq_disable();

        /*
         * Step 2: save registers
         *
         * The omap is a strange/beautiful device. The caches, memory
         * and register state are preserved across power saves.
         * We have to save and restore very little register state to
         * idle the omap.
         *
         * Save interrupt, MPUI, ARM and UPLD control registers.
         */

        if (cpu_is_omap7xx()) {
                MPUI7XX_SAVE(OMAP_IH1_MIR);
                MPUI7XX_SAVE(OMAP_IH2_0_MIR);
                MPUI7XX_SAVE(OMAP_IH2_1_MIR);
                MPUI7XX_SAVE(MPUI_CTRL);
                MPUI7XX_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI7XX_SAVE(MPUI_DSP_API_CONFIG);
                MPUI7XX_SAVE(EMIFS_CONFIG);
                MPUI7XX_SAVE(EMIFF_SDRAM_CONFIG);

        } else if (cpu_is_omap15xx()) {
                MPUI1510_SAVE(OMAP_IH1_MIR);
                MPUI1510_SAVE(OMAP_IH2_MIR);
                MPUI1510_SAVE(MPUI_CTRL);
                MPUI1510_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI1510_SAVE(MPUI_DSP_API_CONFIG);
                MPUI1510_SAVE(EMIFS_CONFIG);
                MPUI1510_SAVE(EMIFF_SDRAM_CONFIG);
        } else if (cpu_is_omap16xx()) {
                MPUI1610_SAVE(OMAP_IH1_MIR);
                MPUI1610_SAVE(OMAP_IH2_0_MIR);
                MPUI1610_SAVE(OMAP_IH2_1_MIR);
                MPUI1610_SAVE(OMAP_IH2_2_MIR);
                MPUI1610_SAVE(OMAP_IH2_3_MIR);
                MPUI1610_SAVE(MPUI_CTRL);
                MPUI1610_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI1610_SAVE(MPUI_DSP_API_CONFIG);
                MPUI1610_SAVE(EMIFS_CONFIG);
                MPUI1610_SAVE(EMIFF_SDRAM_CONFIG);
        }

        ARM_SAVE(ARM_CKCTL);
        ARM_SAVE(ARM_IDLECT1);
        ARM_SAVE(ARM_IDLECT2);
        if (!(cpu_is_omap15xx()))
                ARM_SAVE(ARM_IDLECT3);
        ARM_SAVE(ARM_EWUPCT);
        ARM_SAVE(ARM_RSTCT1);
        ARM_SAVE(ARM_RSTCT2);
        ARM_SAVE(ARM_SYSST);
        ULPD_SAVE(ULPD_CLOCK_CTRL);
        ULPD_SAVE(ULPD_STATUS_REQ);

        /* (Step 3 removed - we now allow deep sleep by default) */

        /*
         * Step 4: OMAP DSP Shutdown
         */

        /* stop DSP */
        omap_writew(omap_readw(ARM_RSTCT1) & ~(1 << DSP_EN), ARM_RSTCT1);

                /* shut down dsp_ck */
        if (!cpu_is_omap7xx())
                omap_writew(omap_readw(ARM_CKCTL) & ~(1 << EN_DSPCK), ARM_CKCTL);

        /* temporarily enabling api_ck to access DSP registers */
        omap_writew(omap_readw(ARM_IDLECT2) | 1 << EN_APICK, ARM_IDLECT2);

        /* save DSP registers */
        DSP_SAVE(DSP_IDLECT2);

        /* Stop all DSP domain clocks */
        __raw_writew(0, DSP_IDLECT2);

        /*
         * Step 5: Wakeup Event Setup
         */

        omap_pm_wakeup_setup();

        /*
         * Step 6: ARM and Traffic controller shutdown
         */

        /* disable ARM watchdog */
        omap_writel(0x00F5, OMAP_WDT_TIMER_MODE);
        omap_writel(0x00A0, OMAP_WDT_TIMER_MODE);

        /*
         * Step 6b: ARM and Traffic controller shutdown
         *
         * Step 6 continues here. Prepare jump to power management
         * assembly code in internal SRAM.
         *
         * Since the omap_cpu_suspend routine has been copied to
         * SRAM, we'll do an indirect procedure call to it and pass the
         * contents of arm_idlect1 and arm_idlect2 so it can restore
         * them when it wakes up and it will return.
         */

        arg0 = arm_sleep_save[ARM_SLEEP_SAVE_ARM_IDLECT1];
        arg1 = arm_sleep_save[ARM_SLEEP_SAVE_ARM_IDLECT2];

        /*
         * Step 6c: ARM and Traffic controller shutdown
         *
         * Jump to assembly code. The processor will stay there
         * until wake up.
         */
        omap_sram_suspend(arg0, arg1);

        /*
         * If we are here, processor is woken up!
         */

        /*
         * Restore DSP clocks
         */

        /* again temporarily enabling api_ck to access DSP registers */
        omap_writew(omap_readw(ARM_IDLECT2) | 1 << EN_APICK, ARM_IDLECT2);

        /* Restore DSP domain clocks */
        DSP_RESTORE(DSP_IDLECT2);

        /*
         * Restore ARM state, except ARM_IDLECT1/2 which omap_cpu_suspend did
         */

        if (!(cpu_is_omap15xx()))
                ARM_RESTORE(ARM_IDLECT3);
        ARM_RESTORE(ARM_CKCTL);
        ARM_RESTORE(ARM_EWUPCT);
        ARM_RESTORE(ARM_RSTCT1);
        ARM_RESTORE(ARM_RSTCT2);
        ARM_RESTORE(ARM_SYSST);
        ULPD_RESTORE(ULPD_CLOCK_CTRL);
        ULPD_RESTORE(ULPD_STATUS_REQ);

        if (cpu_is_omap7xx()) {
                MPUI7XX_RESTORE(EMIFS_CONFIG);
                MPUI7XX_RESTORE(EMIFF_SDRAM_CONFIG);
                MPUI7XX_RESTORE(OMAP_IH1_MIR);
                MPUI7XX_RESTORE(OMAP_IH2_0_MIR);
                MPUI7XX_RESTORE(OMAP_IH2_1_MIR);
        } else if (cpu_is_omap15xx()) {
                MPUI1510_RESTORE(MPUI_CTRL);
                MPUI1510_RESTORE(MPUI_DSP_BOOT_CONFIG);
                MPUI1510_RESTORE(MPUI_DSP_API_CONFIG);
                MPUI1510_RESTORE(EMIFS_CONFIG);
                MPUI1510_RESTORE(EMIFF_SDRAM_CONFIG);
                MPUI1510_RESTORE(OMAP_IH1_MIR);
                MPUI1510_RESTORE(OMAP_IH2_MIR);
        } else if (cpu_is_omap16xx()) {
                MPUI1610_RESTORE(MPUI_CTRL);
                MPUI1610_RESTORE(MPUI_DSP_BOOT_CONFIG);
                MPUI1610_RESTORE(MPUI_DSP_API_CONFIG);
                MPUI1610_RESTORE(EMIFS_CONFIG);
                MPUI1610_RESTORE(EMIFF_SDRAM_CONFIG);

                MPUI1610_RESTORE(OMAP_IH1_MIR);
                MPUI1610_RESTORE(OMAP_IH2_0_MIR);
                MPUI1610_RESTORE(OMAP_IH2_1_MIR);
                MPUI1610_RESTORE(OMAP_IH2_2_MIR);
                MPUI1610_RESTORE(OMAP_IH2_3_MIR);
        }

        if (!cpu_is_omap15xx())
                omap_writew(0, ULPD_SOFT_DISABLE_REQ_REG);

        /*
         * Re-enable interrupts
         */

        local_irq_enable();
        local_fiq_enable();

        omap_serial_wake_trigger(0);

        printk(KERN_INFO "PM: OMAP%x is re-starting from deep sleep...\n",
                omap_rev());
}

#ifdef CONFIG_DEBUG_FS
/*
 * Read system PM registers for debugging
 */
static int omap_pm_debug_show(struct seq_file *m, void *v)
{
        ARM_SAVE(ARM_CKCTL);
        ARM_SAVE(ARM_IDLECT1);
        ARM_SAVE(ARM_IDLECT2);
        if (!(cpu_is_omap15xx()))
                ARM_SAVE(ARM_IDLECT3);
        ARM_SAVE(ARM_EWUPCT);
        ARM_SAVE(ARM_RSTCT1);
        ARM_SAVE(ARM_RSTCT2);
        ARM_SAVE(ARM_SYSST);

        ULPD_SAVE(ULPD_IT_STATUS);
        ULPD_SAVE(ULPD_CLOCK_CTRL);
        ULPD_SAVE(ULPD_SOFT_REQ);
        ULPD_SAVE(ULPD_STATUS_REQ);
        ULPD_SAVE(ULPD_DPLL_CTRL);
        ULPD_SAVE(ULPD_POWER_CTRL);

        if (cpu_is_omap7xx()) {
                MPUI7XX_SAVE(MPUI_CTRL);
                MPUI7XX_SAVE(MPUI_DSP_STATUS);
                MPUI7XX_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI7XX_SAVE(MPUI_DSP_API_CONFIG);
                MPUI7XX_SAVE(EMIFF_SDRAM_CONFIG);
                MPUI7XX_SAVE(EMIFS_CONFIG);
        } else if (cpu_is_omap15xx()) {
                MPUI1510_SAVE(MPUI_CTRL);
                MPUI1510_SAVE(MPUI_DSP_STATUS);
                MPUI1510_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI1510_SAVE(MPUI_DSP_API_CONFIG);
                MPUI1510_SAVE(EMIFF_SDRAM_CONFIG);
                MPUI1510_SAVE(EMIFS_CONFIG);
        } else if (cpu_is_omap16xx()) {
                MPUI1610_SAVE(MPUI_CTRL);
                MPUI1610_SAVE(MPUI_DSP_STATUS);
                MPUI1610_SAVE(MPUI_DSP_BOOT_CONFIG);
                MPUI1610_SAVE(MPUI_DSP_API_CONFIG);
                MPUI1610_SAVE(EMIFF_SDRAM_CONFIG);
                MPUI1610_SAVE(EMIFS_CONFIG);
        }

        seq_printf(m,
                   "ARM_CKCTL_REG:            0x%-8x     \n"
                   "ARM_IDLECT1_REG:          0x%-8x     \n"
                   "ARM_IDLECT2_REG:          0x%-8x     \n"
                   "ARM_IDLECT3_REG:          0x%-8x     \n"
                   "ARM_EWUPCT_REG:           0x%-8x     \n"
                   "ARM_RSTCT1_REG:           0x%-8x     \n"
                   "ARM_RSTCT2_REG:           0x%-8x     \n"
                   "ARM_SYSST_REG:            0x%-8x     \n"
                   "ULPD_IT_STATUS_REG:       0x%-4x     \n"
                   "ULPD_CLOCK_CTRL_REG:      0x%-4x     \n"
                   "ULPD_SOFT_REQ_REG:        0x%-4x     \n"
                   "ULPD_DPLL_CTRL_REG:       0x%-4x     \n"
                   "ULPD_STATUS_REQ_REG:      0x%-4x     \n"
                   "ULPD_POWER_CTRL_REG:      0x%-4x     \n",
                   ARM_SHOW(ARM_CKCTL),
                   ARM_SHOW(ARM_IDLECT1),
                   ARM_SHOW(ARM_IDLECT2),
                   ARM_SHOW(ARM_IDLECT3),
                   ARM_SHOW(ARM_EWUPCT),
                   ARM_SHOW(ARM_RSTCT1),
                   ARM_SHOW(ARM_RSTCT2),
                   ARM_SHOW(ARM_SYSST),
                   ULPD_SHOW(ULPD_IT_STATUS),
                   ULPD_SHOW(ULPD_CLOCK_CTRL),
                   ULPD_SHOW(ULPD_SOFT_REQ),
                   ULPD_SHOW(ULPD_DPLL_CTRL),
                   ULPD_SHOW(ULPD_STATUS_REQ),
                   ULPD_SHOW(ULPD_POWER_CTRL));

        if (cpu_is_omap7xx()) {
                seq_printf(m,
                           "MPUI7XX_CTRL_REG         0x%-8x \n"
                           "MPUI7XX_DSP_STATUS_REG:      0x%-8x \n"
                           "MPUI7XX_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
                           "MPUI7XX_DSP_API_CONFIG_REG:  0x%-8x \n"
                           "MPUI7XX_SDRAM_CONFIG_REG:    0x%-8x \n"
                           "MPUI7XX_EMIFS_CONFIG_REG:    0x%-8x \n",
                           MPUI7XX_SHOW(MPUI_CTRL),
                           MPUI7XX_SHOW(MPUI_DSP_STATUS),
                           MPUI7XX_SHOW(MPUI_DSP_BOOT_CONFIG),
                           MPUI7XX_SHOW(MPUI_DSP_API_CONFIG),
                           MPUI7XX_SHOW(EMIFF_SDRAM_CONFIG),
                           MPUI7XX_SHOW(EMIFS_CONFIG));
        } else if (cpu_is_omap15xx()) {
                seq_printf(m,
                           "MPUI1510_CTRL_REG             0x%-8x \n"
                           "MPUI1510_DSP_STATUS_REG:      0x%-8x \n"
                           "MPUI1510_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
                           "MPUI1510_DSP_API_CONFIG_REG:  0x%-8x \n"
                           "MPUI1510_SDRAM_CONFIG_REG:    0x%-8x \n"
                           "MPUI1510_EMIFS_CONFIG_REG:    0x%-8x \n",
                           MPUI1510_SHOW(MPUI_CTRL),
                           MPUI1510_SHOW(MPUI_DSP_STATUS),
                           MPUI1510_SHOW(MPUI_DSP_BOOT_CONFIG),
                           MPUI1510_SHOW(MPUI_DSP_API_CONFIG),
                           MPUI1510_SHOW(EMIFF_SDRAM_CONFIG),
                           MPUI1510_SHOW(EMIFS_CONFIG));
        } else if (cpu_is_omap16xx()) {
                seq_printf(m,
                           "MPUI1610_CTRL_REG             0x%-8x \n"
                           "MPUI1610_DSP_STATUS_REG:      0x%-8x \n"
                           "MPUI1610_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
                           "MPUI1610_DSP_API_CONFIG_REG:  0x%-8x \n"
                           "MPUI1610_SDRAM_CONFIG_REG:    0x%-8x \n"
                           "MPUI1610_EMIFS_CONFIG_REG:    0x%-8x \n",
                           MPUI1610_SHOW(MPUI_CTRL),
                           MPUI1610_SHOW(MPUI_DSP_STATUS),
                           MPUI1610_SHOW(MPUI_DSP_BOOT_CONFIG),
                           MPUI1610_SHOW(MPUI_DSP_API_CONFIG),
                           MPUI1610_SHOW(EMIFF_SDRAM_CONFIG),
                           MPUI1610_SHOW(EMIFS_CONFIG));
        }

        return 0;
}

static int omap_pm_debug_open(struct inode *inode, struct file *file)
{
        return single_open(file, omap_pm_debug_show,
                                &inode->i_private);
}

static const struct file_operations omap_pm_debug_fops = {
        .open           = omap_pm_debug_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static void omap_pm_init_debugfs(void)
{
        struct dentry *d;

        d = debugfs_create_dir("pm_debug", NULL);
        if (!d)
                return;

        (void) debugfs_create_file("omap_pm", S_IWUSR | S_IRUGO,
                                        d, NULL, &omap_pm_debug_fops);
}

#endif /* CONFIG_DEBUG_FS */

/*
 *      omap_pm_prepare - Do preliminary suspend work.
 *
 */
static int omap_pm_prepare(void)
{
        /* We cannot sleep in idle until we have resumed */
        cpu_idle_poll_ctrl(true);
        return 0;
}


/*
 *      omap_pm_enter - Actually enter a sleep state.
 *      @state:         State we're entering.
 *
 */

static int omap_pm_enter(suspend_state_t state)
{
        switch (state)
        {
        case PM_SUSPEND_STANDBY:
        case PM_SUSPEND_MEM:
                omap1_pm_suspend();
                break;
        default:
                return -EINVAL;
        }

        return 0;
}


/**
 *      omap_pm_finish - Finish up suspend sequence.
 *
 *      This is called after we wake back up (or if entering the sleep state
 *      failed).
 */

static void omap_pm_finish(void)
{
        cpu_idle_poll_ctrl(false);
}


static irqreturn_t omap_wakeup_interrupt(int irq, void *dev)
{
        return IRQ_HANDLED;
}

static struct irqaction omap_wakeup_irq = {
        .name           = "peripheral wakeup",
        .handler        = omap_wakeup_interrupt
};



static const struct platform_suspend_ops omap_pm_ops = {
        .prepare        = omap_pm_prepare,
        .enter          = omap_pm_enter,
        .finish         = omap_pm_finish,
        .valid          = suspend_valid_only_mem,
};

static int __init omap_pm_init(void)
{
        int error = 0;

        if (!cpu_class_is_omap1())
                return -ENODEV;

        pr_info("Power Management for TI OMAP.\n");

        if (!IS_ENABLED(CONFIG_OMAP_32K_TIMER))
                pr_info("OMAP1 PM: sleep states in idle disabled due to no 32KiHz timer\n");

        if (!IS_ENABLED(CONFIG_OMAP_DM_TIMER))
                pr_info("OMAP1 PM: sleep states in idle disabled due to no DMTIMER support\n");

        if (IS_ENABLED(CONFIG_OMAP_32K_TIMER) &&
            IS_ENABLED(CONFIG_OMAP_DM_TIMER)) {
                /* OMAP16xx only */
                pr_info("OMAP1 PM: sleep states in idle enabled\n");
                enable_dyn_sleep = 1;
        }

        /*
         * We copy the assembler sleep/wakeup routines to SRAM.
         * These routines need to be in SRAM as that's the only
         * memory the MPU can see when it wakes up.
         */
        if (cpu_is_omap7xx()) {
                omap_sram_suspend = omap_sram_push(omap7xx_cpu_suspend,
                                                   omap7xx_cpu_suspend_sz);
        } else if (cpu_is_omap15xx()) {
                omap_sram_suspend = omap_sram_push(omap1510_cpu_suspend,
                                                   omap1510_cpu_suspend_sz);
        } else if (cpu_is_omap16xx()) {
                omap_sram_suspend = omap_sram_push(omap1610_cpu_suspend,
                                                   omap1610_cpu_suspend_sz);
        }

        if (omap_sram_suspend == NULL) {
                printk(KERN_ERR "PM not initialized: Missing SRAM support\n");
                return -ENODEV;
        }

        arm_pm_idle = omap1_pm_idle;

        if (cpu_is_omap7xx())
                setup_irq(INT_7XX_WAKE_UP_REQ, &omap_wakeup_irq);
        else if (cpu_is_omap16xx())
                setup_irq(INT_1610_WAKE_UP_REQ, &omap_wakeup_irq);

        /* Program new power ramp-up time
         * (0 for most boards since we don't lower voltage when in deep sleep)
         */
        omap_writew(ULPD_SETUP_ANALOG_CELL_3_VAL, ULPD_SETUP_ANALOG_CELL_3);

        /* Setup ULPD POWER_CTRL_REG - enter deep sleep whenever possible */
        omap_writew(ULPD_POWER_CTRL_REG_VAL, ULPD_POWER_CTRL);

        /* Configure IDLECT3 */
        if (cpu_is_omap7xx())
                omap_writel(OMAP7XX_IDLECT3_VAL, OMAP7XX_IDLECT3);
        else if (cpu_is_omap16xx())
                omap_writel(OMAP1610_IDLECT3_VAL, OMAP1610_IDLECT3);

        suspend_set_ops(&omap_pm_ops);

#ifdef CONFIG_DEBUG_FS
        omap_pm_init_debugfs();
#endif

        error = sysfs_create_file(power_kobj, &sleep_while_idle_attr.attr);
        if (error)
                printk(KERN_ERR "sysfs_create_file failed: %d\n", error);

        if (cpu_is_omap16xx()) {
                /* configure LOW_PWR pin */
                omap_cfg_reg(T20_1610_LOW_PWR);
        }

        return error;
}
__initcall(omap_pm_init);