dm writecache: add cond_resched to loop in persistent_memory_claim()

[linux/fpc-iii.git] / drivers / soc / bcm / brcmstb / pm / pm-arm.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ARM-specific support for Broadcom STB S2/S3/S5 power management
 *
 * S2: clock gate CPUs and as many peripherals as possible
 * S3: power off all of the chip except the Always ON (AON) island; keep DDR is
 *     self-refresh
 * S5: (a.k.a. S3 cold boot) much like S3, except DDR is powered down, so we
 *     treat this mode like a soft power-off, with wakeup allowed from AON
 *
 * Copyright © 2014-2017 Broadcom
 */

#define pr_fmt(fmt) "brcmstb-pm: " fmt

#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/printk.h>
#include <linux/proc_fs.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/suspend.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/soc/brcmstb/brcmstb.h>

#include <asm/fncpy.h>
#include <asm/setup.h>
#include <asm/suspend.h>

#include "pm.h"
#include "aon_defs.h"

#define SHIMPHY_DDR_PAD_CNTRL           0x8c

/* Method #0 */
#define SHIMPHY_PAD_PLL_SEQUENCE        BIT(8)
#define SHIMPHY_PAD_GATE_PLL_S3         BIT(9)

/* Method #1 */
#define PWRDWN_SEQ_NO_SEQUENCING        0
#define PWRDWN_SEQ_HOLD_CHANNEL         1
#define PWRDWN_SEQ_RESET_PLL            2
#define PWRDWN_SEQ_POWERDOWN_PLL        3

#define SHIMPHY_PAD_S3_PWRDWN_SEQ_MASK  0x00f00000
#define SHIMPHY_PAD_S3_PWRDWN_SEQ_SHIFT 20

#define DDR_FORCE_CKE_RST_N             BIT(3)
#define DDR_PHY_RST_N                   BIT(2)
#define DDR_PHY_CKE                     BIT(1)

#define DDR_PHY_NO_CHANNEL              0xffffffff

#define MAX_NUM_MEMC                    3

struct brcmstb_memc {
        void __iomem *ddr_phy_base;
        void __iomem *ddr_shimphy_base;
        void __iomem *ddr_ctrl;
};

struct brcmstb_pm_control {
        void __iomem *aon_ctrl_base;
        void __iomem *aon_sram;
        struct brcmstb_memc memcs[MAX_NUM_MEMC];

        void __iomem *boot_sram;
        size_t boot_sram_len;

        bool support_warm_boot;
        size_t pll_status_offset;
        int num_memc;

        struct brcmstb_s3_params *s3_params;
        dma_addr_t s3_params_pa;
        int s3entry_method;
        u32 warm_boot_offset;
        u32 phy_a_standby_ctrl_offs;
        u32 phy_b_standby_ctrl_offs;
        bool needs_ddr_pad;
        struct platform_device *pdev;
};

enum bsp_initiate_command {
        BSP_CLOCK_STOP          = 0x00,
        BSP_GEN_RANDOM_KEY      = 0x4A,
        BSP_RESTORE_RANDOM_KEY  = 0x55,
        BSP_GEN_FIXED_KEY       = 0x63,
};

#define PM_INITIATE             0x01
#define PM_INITIATE_SUCCESS     0x00
#define PM_INITIATE_FAIL        0xfe

static struct brcmstb_pm_control ctrl;

static int (*brcmstb_pm_do_s2_sram)(void __iomem *aon_ctrl_base,
                void __iomem *ddr_phy_pll_status);

static int brcmstb_init_sram(struct device_node *dn)
{
        void __iomem *sram;
        struct resource res;
        int ret;

        ret = of_address_to_resource(dn, 0, &res);
        if (ret)
                return ret;

        /* Uncached, executable remapping of SRAM */
        sram = __arm_ioremap_exec(res.start, resource_size(&res), false);
        if (!sram)
                return -ENOMEM;

        ctrl.boot_sram = sram;
        ctrl.boot_sram_len = resource_size(&res);

        return 0;
}

static const struct of_device_id sram_dt_ids[] = {
        { .compatible = "mmio-sram" },
        { /* sentinel */ }
};

static int do_bsp_initiate_command(enum bsp_initiate_command cmd)
{
        void __iomem *base = ctrl.aon_ctrl_base;
        int ret;
        int timeo = 1000 * 1000; /* 1 second */

        writel_relaxed(0, base + AON_CTRL_PM_INITIATE);
        (void)readl_relaxed(base + AON_CTRL_PM_INITIATE);

        /* Go! */
        writel_relaxed((cmd << 1) | PM_INITIATE, base + AON_CTRL_PM_INITIATE);

        /*
         * If firmware doesn't support the 'ack', then just assume it's done
         * after 10ms. Note that this only works for command 0, BSP_CLOCK_STOP
         */
        if (of_machine_is_compatible("brcm,bcm74371a0")) {
                (void)readl_relaxed(base + AON_CTRL_PM_INITIATE);
                mdelay(10);
                return 0;
        }

        for (;;) {
                ret = readl_relaxed(base + AON_CTRL_PM_INITIATE);
                if (!(ret & PM_INITIATE))
                        break;
                if (timeo <= 0) {
                        pr_err("error: timeout waiting for BSP (%x)\n", ret);
                        break;
                }
                timeo -= 50;
                udelay(50);
        }

        return (ret & 0xff) != PM_INITIATE_SUCCESS;
}

static int brcmstb_pm_handshake(void)
{
        void __iomem *base = ctrl.aon_ctrl_base;
        u32 tmp;
        int ret;

        /* BSP power handshake, v1 */
        tmp = readl_relaxed(base + AON_CTRL_HOST_MISC_CMDS);
        tmp &= ~1UL;
        writel_relaxed(tmp, base + AON_CTRL_HOST_MISC_CMDS);
        (void)readl_relaxed(base + AON_CTRL_HOST_MISC_CMDS);

        ret = do_bsp_initiate_command(BSP_CLOCK_STOP);
        if (ret)
                pr_err("BSP handshake failed\n");

        /*
         * HACK: BSP may have internal race on the CLOCK_STOP command.
         * Avoid touching the BSP for a few milliseconds.
         */
        mdelay(3);

        return ret;
}

static inline void shimphy_set(u32 value, u32 mask)
{
        int i;

        if (!ctrl.needs_ddr_pad)
                return;

        for (i = 0; i < ctrl.num_memc; i++) {
                u32 tmp;

                tmp = readl_relaxed(ctrl.memcs[i].ddr_shimphy_base +
                        SHIMPHY_DDR_PAD_CNTRL);
                tmp = value | (tmp & mask);
                writel_relaxed(tmp, ctrl.memcs[i].ddr_shimphy_base +
                        SHIMPHY_DDR_PAD_CNTRL);
        }
        wmb(); /* Complete sequence in order. */
}

static inline void ddr_ctrl_set(bool warmboot)
{
        int i;

        for (i = 0; i < ctrl.num_memc; i++) {
                u32 tmp;

                tmp = readl_relaxed(ctrl.memcs[i].ddr_ctrl +
                                ctrl.warm_boot_offset);
                if (warmboot)
                        tmp |= 1;
                else
                        tmp &= ~1; /* Cold boot */
                writel_relaxed(tmp, ctrl.memcs[i].ddr_ctrl +
                                ctrl.warm_boot_offset);
        }
        /* Complete sequence in order */
        wmb();
}

static inline void s3entry_method0(void)
{
        shimphy_set(SHIMPHY_PAD_GATE_PLL_S3 | SHIMPHY_PAD_PLL_SEQUENCE,
                    0xffffffff);
}

static inline void s3entry_method1(void)
{
        /*
         * S3 Entry Sequence
         * -----------------
         * Step 1: SHIMPHY_ADDR_CNTL_0_DDR_PAD_CNTRL [ S3_PWRDWN_SEQ ] = 3
         * Step 2: MEMC_DDR_0_WARM_BOOT [ WARM_BOOT ] = 1
         */
        shimphy_set((PWRDWN_SEQ_POWERDOWN_PLL <<
                    SHIMPHY_PAD_S3_PWRDWN_SEQ_SHIFT),
                    ~SHIMPHY_PAD_S3_PWRDWN_SEQ_MASK);

        ddr_ctrl_set(true);
}

static inline void s5entry_method1(void)
{
        int i;

        /*
         * S5 Entry Sequence
         * -----------------
         * Step 1: SHIMPHY_ADDR_CNTL_0_DDR_PAD_CNTRL [ S3_PWRDWN_SEQ ] = 3
         * Step 2: MEMC_DDR_0_WARM_BOOT [ WARM_BOOT ] = 0
         * Step 3: DDR_PHY_CONTROL_REGS_[AB]_0_STANDBY_CONTROL[ CKE ] = 0
         *         DDR_PHY_CONTROL_REGS_[AB]_0_STANDBY_CONTROL[ RST_N ] = 0
         */
        shimphy_set((PWRDWN_SEQ_POWERDOWN_PLL <<
                    SHIMPHY_PAD_S3_PWRDWN_SEQ_SHIFT),
                    ~SHIMPHY_PAD_S3_PWRDWN_SEQ_MASK);

        ddr_ctrl_set(false);

        for (i = 0; i < ctrl.num_memc; i++) {
                u32 tmp;

                /* Step 3: Channel A (RST_N = CKE = 0) */
                tmp = readl_relaxed(ctrl.memcs[i].ddr_phy_base +
                                  ctrl.phy_a_standby_ctrl_offs);
                tmp &= ~(DDR_PHY_RST_N | DDR_PHY_RST_N);
                writel_relaxed(tmp, ctrl.memcs[i].ddr_phy_base +
                             ctrl.phy_a_standby_ctrl_offs);

                /* Step 3: Channel B? */
                if (ctrl.phy_b_standby_ctrl_offs != DDR_PHY_NO_CHANNEL) {
                        tmp = readl_relaxed(ctrl.memcs[i].ddr_phy_base +
                                          ctrl.phy_b_standby_ctrl_offs);
                        tmp &= ~(DDR_PHY_RST_N | DDR_PHY_RST_N);
                        writel_relaxed(tmp, ctrl.memcs[i].ddr_phy_base +
                                     ctrl.phy_b_standby_ctrl_offs);
                }
        }
        /* Must complete */
        wmb();
}

/*
 * Run a Power Management State Machine (PMSM) shutdown command and put the CPU
 * into a low-power mode
 */
static void brcmstb_do_pmsm_power_down(unsigned long base_cmd, bool onewrite)
{
        void __iomem *base = ctrl.aon_ctrl_base;

        if ((ctrl.s3entry_method == 1) && (base_cmd == PM_COLD_CONFIG))
                s5entry_method1();

        /* pm_start_pwrdn transition 0->1 */
        writel_relaxed(base_cmd, base + AON_CTRL_PM_CTRL);

        if (!onewrite) {
                (void)readl_relaxed(base + AON_CTRL_PM_CTRL);

                writel_relaxed(base_cmd | PM_PWR_DOWN, base + AON_CTRL_PM_CTRL);
                (void)readl_relaxed(base + AON_CTRL_PM_CTRL);
        }
        wfi();
}

/* Support S5 cold boot out of "poweroff" */
static void brcmstb_pm_poweroff(void)
{
        brcmstb_pm_handshake();

        /* Clear magic S3 warm-boot value */
        writel_relaxed(0, ctrl.aon_sram + AON_REG_MAGIC_FLAGS);
        (void)readl_relaxed(ctrl.aon_sram + AON_REG_MAGIC_FLAGS);

        /* Skip wait-for-interrupt signal; just use a countdown */
        writel_relaxed(0x10, ctrl.aon_ctrl_base + AON_CTRL_PM_CPU_WAIT_COUNT);
        (void)readl_relaxed(ctrl.aon_ctrl_base + AON_CTRL_PM_CPU_WAIT_COUNT);

        if (ctrl.s3entry_method == 1) {
                shimphy_set((PWRDWN_SEQ_POWERDOWN_PLL <<
                             SHIMPHY_PAD_S3_PWRDWN_SEQ_SHIFT),
                             ~SHIMPHY_PAD_S3_PWRDWN_SEQ_MASK);
                ddr_ctrl_set(false);
                brcmstb_do_pmsm_power_down(M1_PM_COLD_CONFIG, true);
                return; /* We should never actually get here */
        }

        brcmstb_do_pmsm_power_down(PM_COLD_CONFIG, false);
}

static void *brcmstb_pm_copy_to_sram(void *fn, size_t len)
{
        unsigned int size = ALIGN(len, FNCPY_ALIGN);

        if (ctrl.boot_sram_len < size) {
                pr_err("standby code will not fit in SRAM\n");
                return NULL;
        }

        return fncpy(ctrl.boot_sram, fn, size);
}

/*
 * S2 suspend/resume picks up where we left off, so we must execute carefully
 * from SRAM, in order to allow DDR to come back up safely before we continue.
 */
static int brcmstb_pm_s2(void)
{
        /* A previous S3 can set a value hazardous to S2, so make sure. */
        if (ctrl.s3entry_method == 1) {
                shimphy_set((PWRDWN_SEQ_NO_SEQUENCING <<
                            SHIMPHY_PAD_S3_PWRDWN_SEQ_SHIFT),
                            ~SHIMPHY_PAD_S3_PWRDWN_SEQ_MASK);
                ddr_ctrl_set(false);
        }

        brcmstb_pm_do_s2_sram = brcmstb_pm_copy_to_sram(&brcmstb_pm_do_s2,
                        brcmstb_pm_do_s2_sz);
        if (!brcmstb_pm_do_s2_sram)
                return -EINVAL;

        return brcmstb_pm_do_s2_sram(ctrl.aon_ctrl_base,
                        ctrl.memcs[0].ddr_phy_base +
                        ctrl.pll_status_offset);
}

/*
 * This function is called on a new stack, so don't allow inlining (which will
 * generate stack references on the old stack). It cannot be made static because
 * it is referenced from brcmstb_pm_s3()
 */
noinline int brcmstb_pm_s3_finish(void)
{
        struct brcmstb_s3_params *params = ctrl.s3_params;
        dma_addr_t params_pa = ctrl.s3_params_pa;
        phys_addr_t reentry = virt_to_phys(&cpu_resume_arm);
        enum bsp_initiate_command cmd;
        u32 flags;

        /*
         * Clear parameter structure, but not DTU area, which has already been
         * filled in. We know DTU is a the end, so we can just subtract its
         * size.
         */
        memset(params, 0, sizeof(*params) - sizeof(params->dtu));

        flags = readl_relaxed(ctrl.aon_sram + AON_REG_MAGIC_FLAGS);

        flags &= S3_BOOTLOADER_RESERVED;
        flags |= S3_FLAG_NO_MEM_VERIFY;
        flags |= S3_FLAG_LOAD_RANDKEY;

        /* Load random / fixed key */
        if (flags & S3_FLAG_LOAD_RANDKEY)
                cmd = BSP_GEN_RANDOM_KEY;
        else
                cmd = BSP_GEN_FIXED_KEY;
        if (do_bsp_initiate_command(cmd)) {
                pr_info("key loading failed\n");
                return -EIO;
        }

        params->magic = BRCMSTB_S3_MAGIC;
        params->reentry = reentry;

        /* No more writes to DRAM */
        flush_cache_all();

        flags |= BRCMSTB_S3_MAGIC_SHORT;

        writel_relaxed(flags, ctrl.aon_sram + AON_REG_MAGIC_FLAGS);
        writel_relaxed(lower_32_bits(params_pa),
                       ctrl.aon_sram + AON_REG_CONTROL_LOW);
        writel_relaxed(upper_32_bits(params_pa),
                       ctrl.aon_sram + AON_REG_CONTROL_HIGH);

        switch (ctrl.s3entry_method) {
        case 0:
                s3entry_method0();
                brcmstb_do_pmsm_power_down(PM_WARM_CONFIG, false);
                break;
        case 1:
                s3entry_method1();
                brcmstb_do_pmsm_power_down(M1_PM_WARM_CONFIG, true);
                break;
        default:
                return -EINVAL;
        }

        /* Must have been interrupted from wfi()? */
        return -EINTR;
}

static int brcmstb_pm_do_s3(unsigned long sp)
{
        unsigned long save_sp;
        int ret;

        asm volatile (
                "mov    %[save], sp\n"
                "mov    sp, %[new]\n"
                "bl     brcmstb_pm_s3_finish\n"
                "mov    %[ret], r0\n"
                "mov    %[new], sp\n"
                "mov    sp, %[save]\n"
                : [save] "=&r" (save_sp), [ret] "=&r" (ret)
                : [new] "r" (sp)
        );

        return ret;
}

static int brcmstb_pm_s3(void)
{
        void __iomem *sp = ctrl.boot_sram + ctrl.boot_sram_len;

        return cpu_suspend((unsigned long)sp, brcmstb_pm_do_s3);
}

static int brcmstb_pm_standby(bool deep_standby)
{
        int ret;

        if (brcmstb_pm_handshake())
                return -EIO;

        if (deep_standby)
                ret = brcmstb_pm_s3();
        else
                ret = brcmstb_pm_s2();
        if (ret)
                pr_err("%s: standby failed\n", __func__);

        return ret;
}

static int brcmstb_pm_enter(suspend_state_t state)
{
        int ret = -EINVAL;

        switch (state) {
        case PM_SUSPEND_STANDBY:
                ret = brcmstb_pm_standby(false);
                break;
        case PM_SUSPEND_MEM:
                ret = brcmstb_pm_standby(true);
                break;
        }

        return ret;
}

static int brcmstb_pm_valid(suspend_state_t state)
{
        switch (state) {
        case PM_SUSPEND_STANDBY:
                return true;
        case PM_SUSPEND_MEM:
                return ctrl.support_warm_boot;
        default:
                return false;
        }
}

static const struct platform_suspend_ops brcmstb_pm_ops = {
        .enter          = brcmstb_pm_enter,
        .valid          = brcmstb_pm_valid,
};

static const struct of_device_id aon_ctrl_dt_ids[] = {
        { .compatible = "brcm,brcmstb-aon-ctrl" },
        {}
};

struct ddr_phy_ofdata {
        bool supports_warm_boot;
        size_t pll_status_offset;
        int s3entry_method;
        u32 warm_boot_offset;
        u32 phy_a_standby_ctrl_offs;
        u32 phy_b_standby_ctrl_offs;
};

static struct ddr_phy_ofdata ddr_phy_71_1 = {
        .supports_warm_boot = true,
        .pll_status_offset = 0x0c,
        .s3entry_method = 1,
        .warm_boot_offset = 0x2c,
        .phy_a_standby_ctrl_offs = 0x198,
        .phy_b_standby_ctrl_offs = DDR_PHY_NO_CHANNEL
};

static struct ddr_phy_ofdata ddr_phy_72_0 = {
        .supports_warm_boot = true,
        .pll_status_offset = 0x10,
        .s3entry_method = 1,
        .warm_boot_offset = 0x40,
        .phy_a_standby_ctrl_offs = 0x2a4,
        .phy_b_standby_ctrl_offs = 0x8a4
};

static struct ddr_phy_ofdata ddr_phy_225_1 = {
        .supports_warm_boot = false,
        .pll_status_offset = 0x4,
        .s3entry_method = 0
};

static struct ddr_phy_ofdata ddr_phy_240_1 = {
        .supports_warm_boot = true,
        .pll_status_offset = 0x4,
        .s3entry_method = 0
};

static const struct of_device_id ddr_phy_dt_ids[] = {
        {
                .compatible = "brcm,brcmstb-ddr-phy-v71.1",
                .data = &ddr_phy_71_1,
        },
        {
                .compatible = "brcm,brcmstb-ddr-phy-v72.0",
                .data = &ddr_phy_72_0,
        },
        {
                .compatible = "brcm,brcmstb-ddr-phy-v225.1",
                .data = &ddr_phy_225_1,
        },
        {
                .compatible = "brcm,brcmstb-ddr-phy-v240.1",
                .data = &ddr_phy_240_1,
        },
        {
                /* Same as v240.1, for the registers we care about */
                .compatible = "brcm,brcmstb-ddr-phy-v240.2",
                .data = &ddr_phy_240_1,
        },
        {}
};

struct ddr_seq_ofdata {
        bool needs_ddr_pad;
        u32 warm_boot_offset;
};

static const struct ddr_seq_ofdata ddr_seq_b22 = {
        .needs_ddr_pad = false,
        .warm_boot_offset = 0x2c,
};

static const struct ddr_seq_ofdata ddr_seq = {
        .needs_ddr_pad = true,
};

static const struct of_device_id ddr_shimphy_dt_ids[] = {
        { .compatible = "brcm,brcmstb-ddr-shimphy-v1.0" },
        {}
};

static const struct of_device_id brcmstb_memc_of_match[] = {
        {
                .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.1",
                .data = &ddr_seq,
        },
        {
                .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.2",
                .data = &ddr_seq_b22,
        },
        {
                .compatible = "brcm,brcmstb-memc-ddr-rev-b.2.3",
                .data = &ddr_seq_b22,
        },
        {
                .compatible = "brcm,brcmstb-memc-ddr-rev-b.3.0",
                .data = &ddr_seq_b22,
        },
        {
                .compatible = "brcm,brcmstb-memc-ddr-rev-b.3.1",
                .data = &ddr_seq_b22,
        },
        {
                .compatible = "brcm,brcmstb-memc-ddr",
                .data = &ddr_seq,
        },
        {},
};

static void __iomem *brcmstb_ioremap_match(const struct of_device_id *matches,
                                           int index, const void **ofdata)
{
        struct device_node *dn;
        const struct of_device_id *match;

        dn = of_find_matching_node_and_match(NULL, matches, &match);
        if (!dn)
                return ERR_PTR(-EINVAL);

        if (ofdata)
                *ofdata = match->data;

        return of_io_request_and_map(dn, index, dn->full_name);
}

static int brcmstb_pm_panic_notify(struct notifier_block *nb,
                unsigned long action, void *data)
{
        writel_relaxed(BRCMSTB_PANIC_MAGIC, ctrl.aon_sram + AON_REG_PANIC);

        return NOTIFY_DONE;
}

static struct notifier_block brcmstb_pm_panic_nb = {
        .notifier_call = brcmstb_pm_panic_notify,
};

static int brcmstb_pm_probe(struct platform_device *pdev)
{
        const struct ddr_phy_ofdata *ddr_phy_data;
        const struct ddr_seq_ofdata *ddr_seq_data;
        const struct of_device_id *of_id = NULL;
        struct device_node *dn;
        void __iomem *base;
        int ret, i;

        /* AON ctrl registers */
        base = brcmstb_ioremap_match(aon_ctrl_dt_ids, 0, NULL);
        if (IS_ERR(base)) {
                pr_err("error mapping AON_CTRL\n");
                return PTR_ERR(base);
        }
        ctrl.aon_ctrl_base = base;

        /* AON SRAM registers */
        base = brcmstb_ioremap_match(aon_ctrl_dt_ids, 1, NULL);
        if (IS_ERR(base)) {
                /* Assume standard offset */
                ctrl.aon_sram = ctrl.aon_ctrl_base +
                                     AON_CTRL_SYSTEM_DATA_RAM_OFS;
        } else {
                ctrl.aon_sram = base;
        }

        writel_relaxed(0, ctrl.aon_sram + AON_REG_PANIC);

        /* DDR PHY registers */
        base = brcmstb_ioremap_match(ddr_phy_dt_ids, 0,
                                     (const void **)&ddr_phy_data);
        if (IS_ERR(base)) {
                pr_err("error mapping DDR PHY\n");
                return PTR_ERR(base);
        }
        ctrl.support_warm_boot = ddr_phy_data->supports_warm_boot;
        ctrl.pll_status_offset = ddr_phy_data->pll_status_offset;
        /* Only need DDR PHY 0 for now? */
        ctrl.memcs[0].ddr_phy_base = base;
        ctrl.s3entry_method = ddr_phy_data->s3entry_method;
        ctrl.phy_a_standby_ctrl_offs = ddr_phy_data->phy_a_standby_ctrl_offs;
        ctrl.phy_b_standby_ctrl_offs = ddr_phy_data->phy_b_standby_ctrl_offs;
        /*
         * Slightly grosss to use the phy ver to get a memc,
         * offset but that is the only versioned things so far
         * we can test for.
         */
        ctrl.warm_boot_offset = ddr_phy_data->warm_boot_offset;

        /* DDR SHIM-PHY registers */
        for_each_matching_node(dn, ddr_shimphy_dt_ids) {
                i = ctrl.num_memc;
                if (i >= MAX_NUM_MEMC) {
                        pr_warn("too many MEMCs (max %d)\n", MAX_NUM_MEMC);
                        break;
                }

                base = of_io_request_and_map(dn, 0, dn->full_name);
                if (IS_ERR(base)) {
                        if (!ctrl.support_warm_boot)
                                break;

                        pr_err("error mapping DDR SHIMPHY %d\n", i);
                        return PTR_ERR(base);
                }
                ctrl.memcs[i].ddr_shimphy_base = base;
                ctrl.num_memc++;
        }

        /* Sequencer DRAM Param and Control Registers */
        i = 0;
        for_each_matching_node(dn, brcmstb_memc_of_match) {
                base = of_iomap(dn, 0);
                if (!base) {
                        pr_err("error mapping DDR Sequencer %d\n", i);
                        return -ENOMEM;
                }

                of_id = of_match_node(brcmstb_memc_of_match, dn);
                if (!of_id) {
                        iounmap(base);
                        return -EINVAL;
                }

                ddr_seq_data = of_id->data;
                ctrl.needs_ddr_pad = ddr_seq_data->needs_ddr_pad;
                /* Adjust warm boot offset based on the DDR sequencer */
                if (ddr_seq_data->warm_boot_offset)
                        ctrl.warm_boot_offset = ddr_seq_data->warm_boot_offset;

                ctrl.memcs[i].ddr_ctrl = base;
                i++;
        }

        pr_debug("PM: supports warm boot:%d, method:%d, wboffs:%x\n",
                ctrl.support_warm_boot, ctrl.s3entry_method,
                ctrl.warm_boot_offset);

        dn = of_find_matching_node(NULL, sram_dt_ids);
        if (!dn) {
                pr_err("SRAM not found\n");
                return -EINVAL;
        }

        ret = brcmstb_init_sram(dn);
        if (ret) {
                pr_err("error setting up SRAM for PM\n");
                return ret;
        }

        ctrl.pdev = pdev;

        ctrl.s3_params = kmalloc(sizeof(*ctrl.s3_params), GFP_KERNEL);
        if (!ctrl.s3_params)
                return -ENOMEM;
        ctrl.s3_params_pa = dma_map_single(&pdev->dev, ctrl.s3_params,
                                           sizeof(*ctrl.s3_params),
                                           DMA_TO_DEVICE);
        if (dma_mapping_error(&pdev->dev, ctrl.s3_params_pa)) {
                pr_err("error mapping DMA memory\n");
                ret = -ENOMEM;
                goto out;
        }

        atomic_notifier_chain_register(&panic_notifier_list,
                                       &brcmstb_pm_panic_nb);

        pm_power_off = brcmstb_pm_poweroff;
        suspend_set_ops(&brcmstb_pm_ops);

        return 0;

out:
        kfree(ctrl.s3_params);

        pr_warn("PM: initialization failed with code %d\n", ret);

        return ret;
}

static struct platform_driver brcmstb_pm_driver = {
        .driver = {
                .name   = "brcmstb-pm",
                .of_match_table = aon_ctrl_dt_ids,
        },
};

static int __init brcmstb_pm_init(void)
{
        return platform_driver_probe(&brcmstb_pm_driver,
                                     brcmstb_pm_probe);
}
module_init(brcmstb_pm_init);