/*
 * Texas Instruments SoC Adaptive Body Bias(ABB) Regulator
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Mike Turquette <mturquette@ti.com>
 *
 * Copyright (C) 2012-2013 Texas Instruments, Inc.
 * Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
 * Nishanth Menon <nm@ti.com>
 *
 * 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.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>

/*
 * ABB LDO operating states:
 * NOMINAL_OPP: bypasses the ABB LDO
 * FAST_OPP:    sets ABB LDO to Forward Body-Bias
 * SLOW_OPP:    sets ABB LDO to Reverse Body-Bias
 */
#define TI_ABB_NOMINAL_OPP      0
#define TI_ABB_FAST_OPP         1
#define TI_ABB_SLOW_OPP         3

/**
 * struct ti_abb_info - ABB information per voltage setting
 * @opp_sel:    one of TI_ABB macro
 * @vset:       (optional) vset value that LDOVBB needs to be overriden with.
 *
 * Array of per voltage entries organized in the same order as regulator_desc's
 * volt_table list. (selector is used to index from this array)
 */
struct ti_abb_info {
        u32 opp_sel;
        u32 vset;
};

/**
 * struct ti_abb_reg - Register description for ABB block
 * @setup_off:                  setup register offset from base
 * @control_off:                control register offset from base
 * @sr2_wtcnt_value_mask:       setup register- sr2_wtcnt_value mask
 * @fbb_sel_mask:               setup register- FBB sel mask
 * @rbb_sel_mask:               setup register- RBB sel mask
 * @sr2_en_mask:                setup register- enable mask
 * @opp_change_mask:            control register - mask to trigger LDOVBB change
 * @opp_sel_mask:               control register - mask for mode to operate
 */
struct ti_abb_reg {
        u32 setup_off;
        u32 control_off;

        /* Setup register fields */
        u32 sr2_wtcnt_value_mask;
        u32 fbb_sel_mask;
        u32 rbb_sel_mask;
        u32 sr2_en_mask;

        /* Control register fields */
        u32 opp_change_mask;
        u32 opp_sel_mask;
};

/**
 * struct ti_abb - ABB instance data
 * @rdesc:                      regulator descriptor
 * @clk:                        clock(usually sysclk) supplying ABB block
 * @base:                       base address of ABB block
 * @setup_reg:                  setup register of ABB block
 * @control_reg:                control register of ABB block
 * @int_base:                   interrupt register base address
 * @efuse_base:                 (optional) efuse base address for ABB modes
 * @ldo_base:                   (optional) LDOVBB vset override base address
 * @regs:                       pointer to struct ti_abb_reg for ABB block
 * @txdone_mask:                mask on int_base for tranxdone interrupt
 * @ldovbb_override_mask:       mask to ldo_base for overriding default LDO VBB
 *                              vset with value from efuse
 * @ldovbb_vset_mask:           mask to ldo_base for providing the VSET override
 * @info:                       array to per voltage ABB configuration
 * @current_info_idx:           current index to info
 * @settling_time:              SoC specific settling time for LDO VBB
 */
struct ti_abb {
        struct regulator_desc rdesc;
        struct clk *clk;
        void __iomem *base;
        void __iomem *setup_reg;
        void __iomem *control_reg;
        void __iomem *int_base;
        void __iomem *efuse_base;
        void __iomem *ldo_base;

        const struct ti_abb_reg *regs;
        u32 txdone_mask;
        u32 ldovbb_override_mask;
        u32 ldovbb_vset_mask;

        struct ti_abb_info *info;
        int current_info_idx;

        u32 settling_time;
};

/**
 * ti_abb_rmw() - handy wrapper to set specific register bits
 * @mask:       mask for register field
 * @value:      value shifted to mask location and written
 * @reg:        register address
 *
 * Return: final register value (may be unused)
 */
static inline u32 ti_abb_rmw(u32 mask, u32 value, void __iomem *reg)
{
        u32 val;

        val = readl(reg);
        val &= ~mask;
        val |= (value << __ffs(mask)) & mask;
        writel(val, reg);

        return val;
}

/**
 * ti_abb_check_txdone() - handy wrapper to check ABB tranxdone status
 * @abb:        pointer to the abb instance
 *
 * Return: true or false
 */
static inline bool ti_abb_check_txdone(const struct ti_abb *abb)
{
        return !!(readl(abb->int_base) & abb->txdone_mask);
}

/**
 * ti_abb_clear_txdone() - handy wrapper to clear ABB tranxdone status
 * @abb:        pointer to the abb instance
 */
static inline void ti_abb_clear_txdone(const struct ti_abb *abb)
{
        writel(abb->txdone_mask, abb->int_base);
};

/**
 * ti_abb_wait_tranx() - waits for ABB tranxdone event
 * @dev:        device
 * @abb:        pointer to the abb instance
 *
 * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
 */
static int ti_abb_wait_txdone(struct device *dev, struct ti_abb *abb)
{
        int timeout = 0;
        bool status;

        while (timeout++ <= abb->settling_time) {
                status = ti_abb_check_txdone(abb);
                if (status)
                        return 0;

                udelay(1);
        }

        dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
                             __func__, timeout, readl(abb->int_base));
        return -ETIMEDOUT;
}

/**
 * ti_abb_clear_all_txdone() - clears ABB tranxdone event
 * @dev:        device
 * @abb:        pointer to the abb instance
 *
 * Return: 0 on success or -ETIMEDOUT if the event is not cleared on time.
 */
static int ti_abb_clear_all_txdone(struct device *dev, const struct ti_abb *abb)
{
        int timeout = 0;
        bool status;

        while (timeout++ <= abb->settling_time) {
                ti_abb_clear_txdone(abb);

                status = ti_abb_check_txdone(abb);
                if (!status)
                        return 0;

                udelay(1);
        }

        dev_warn_ratelimited(dev, "%s:TRANXDONE timeout(%duS) int=0x%08x\n",
                             __func__, timeout, readl(abb->int_base));
        return -ETIMEDOUT;
}

/**
 * ti_abb_program_ldovbb() - program LDOVBB register for override value
 * @dev:        device
 * @abb:        pointer to the abb instance
 * @info:       ABB info to program
 */
static void ti_abb_program_ldovbb(struct device *dev, const struct ti_abb *abb,
                                  struct ti_abb_info *info)
{
        u32 val;

        val = readl(abb->ldo_base);
        /* clear up previous values */
        val &= ~(abb->ldovbb_override_mask | abb->ldovbb_vset_mask);

        switch (info->opp_sel) {
        case TI_ABB_SLOW_OPP:
        case TI_ABB_FAST_OPP:
                val |= abb->ldovbb_override_mask;
                val |= info->vset << __ffs(abb->ldovbb_vset_mask);
                break;
        }

        writel(val, abb->ldo_base);
}

/**
 * ti_abb_set_opp() - Setup ABB and LDO VBB for required bias
 * @rdev:       regulator device
 * @abb:        pointer to the abb instance
 * @info:       ABB info to program
 *
 * Return: 0 on success or appropriate error value when fails
 */
static int ti_abb_set_opp(struct regulator_dev *rdev, struct ti_abb *abb,
                          struct ti_abb_info *info)
{
        const struct ti_abb_reg *regs = abb->regs;
        struct device *dev = &rdev->dev;
        int ret;

        ret = ti_abb_clear_all_txdone(dev, abb);
        if (ret)
                goto out;

        ti_abb_rmw(regs->fbb_sel_mask | regs->rbb_sel_mask, 0, abb->setup_reg);

        switch (info->opp_sel) {
        case TI_ABB_SLOW_OPP:
                ti_abb_rmw(regs->rbb_sel_mask, 1, abb->setup_reg);
                break;
        case TI_ABB_FAST_OPP:
                ti_abb_rmw(regs->fbb_sel_mask, 1, abb->setup_reg);
                break;
        }

        /* program next state of ABB ldo */
        ti_abb_rmw(regs->opp_sel_mask, info->opp_sel, abb->control_reg);

        /*
         * program LDO VBB vset override if needed for !bypass mode
         * XXX: Do not switch sequence - for !bypass, LDO override reset *must*
         * be performed *before* switch to bias mode else VBB glitches.
         */
        if (abb->ldo_base && info->opp_sel != TI_ABB_NOMINAL_OPP)
                ti_abb_program_ldovbb(dev, abb, info);

        /* Initiate ABB ldo change */
        ti_abb_rmw(regs->opp_change_mask, 1, abb->control_reg);

        /* Wait for ABB LDO to complete transition to new Bias setting */
        ret = ti_abb_wait_txdone(dev, abb);
        if (ret)
                goto out;

        ret = ti_abb_clear_all_txdone(dev, abb);
        if (ret)
                goto out;

        /*
         * Reset LDO VBB vset override bypass mode
         * XXX: Do not switch sequence - for bypass, LDO override reset *must*
         * be performed *after* switch to bypass else VBB glitches.
         */
        if (abb->ldo_base && info->opp_sel == TI_ABB_NOMINAL_OPP)
                ti_abb_program_ldovbb(dev, abb, info);

out:
        return ret;
}

/**
 * ti_abb_set_voltage_sel() - regulator accessor function to set ABB LDO
 * @rdev:       regulator device
 * @sel:        selector to index into required ABB LDO settings (maps to
 *              regulator descriptor's volt_table)
 *
 * Return: 0 on success or appropriate error value when fails
 */
static int ti_abb_set_voltage_sel(struct regulator_dev *rdev, unsigned sel)
{
        const struct regulator_desc *desc = rdev->desc;
        struct ti_abb *abb = rdev_get_drvdata(rdev);
        struct device *dev = &rdev->dev;
        struct ti_abb_info *info, *oinfo;
        int ret = 0;

        if (!abb) {
                dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
                                    __func__);
                return -ENODEV;
        }

        if (!desc->n_voltages || !abb->info) {
                dev_err_ratelimited(dev,
                                    "%s: No valid voltage table entries?\n",
                                    __func__);
                return -EINVAL;
        }

        if (sel >= desc->n_voltages) {
                dev_err(dev, "%s: sel idx(%d) >= n_voltages(%d)\n", __func__,
                        sel, desc->n_voltages);
                return -EINVAL;
        }

        /* If we are in the same index as we were, nothing to do here! */
        if (sel == abb->current_info_idx) {
                dev_dbg(dev, "%s: Already at sel=%d\n", __func__, sel);
                return ret;
        }

        info = &abb->info[sel];
        /*
         * When Linux kernel is starting up, we are'nt sure of the
         * Bias configuration that bootloader has configured.
         * So, we get to know the actual setting the first time
         * we are asked to transition.
         */
        if (abb->current_info_idx == -EINVAL)
                goto just_set_abb;

        /* If data is exactly the same, then just update index, no change */
        oinfo = &abb->info[abb->current_info_idx];
        if (!memcmp(info, oinfo, sizeof(*info))) {
                dev_dbg(dev, "%s: Same data new idx=%d, old idx=%d\n", __func__,
                        sel, abb->current_info_idx);
                goto out;
        }

just_set_abb:
        ret = ti_abb_set_opp(rdev, abb, info);

out:
        if (!ret)
                abb->current_info_idx = sel;
        else
                dev_err_ratelimited(dev,
                                    "%s: Volt[%d] idx[%d] mode[%d] Fail(%d)\n",
                                    __func__, desc->volt_table[sel], sel,
                                    info->opp_sel, ret);
        return ret;
}

/**
 * ti_abb_get_voltage_sel() - Regulator accessor to get current ABB LDO setting
 * @rdev:       regulator device
 *
 * Return: 0 on success or appropriate error value when fails
 */
static int ti_abb_get_voltage_sel(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct ti_abb *abb = rdev_get_drvdata(rdev);
        struct device *dev = &rdev->dev;

        if (!abb) {
                dev_err_ratelimited(dev, "%s: No regulator drvdata\n",
                                    __func__);
                return -ENODEV;
        }

        if (!desc->n_voltages || !abb->info) {
                dev_err_ratelimited(dev,
                                    "%s: No valid voltage table entries?\n",
                                    __func__);
                return -EINVAL;
        }

        if (abb->current_info_idx >= (int)desc->n_voltages) {
                dev_err(dev, "%s: Corrupted data? idx(%d) >= n_voltages(%d)\n",
                        __func__, abb->current_info_idx, desc->n_voltages);
                return -EINVAL;
        }

        return abb->current_info_idx;
}

/**
 * ti_abb_init_timings() - setup ABB clock timing for the current platform
 * @dev:        device
 * @abb:        pointer to the abb instance
 *
 * Return: 0 if timing is updated, else returns error result.
 */
static int ti_abb_init_timings(struct device *dev, struct ti_abb *abb)
{
        u32 clock_cycles;
        u32 clk_rate, sr2_wt_cnt_val, cycle_rate;
        const struct ti_abb_reg *regs = abb->regs;
        int ret;
        char *pname = "ti,settling-time";

        /* read device tree properties */
        ret = of_property_read_u32(dev->of_node, pname, &abb->settling_time);
        if (ret) {
                dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
                return ret;
        }

        /* ABB LDO cannot be settle in 0 time */
        if (!abb->settling_time) {
                dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
                return -EINVAL;
        }

        pname = "ti,clock-cycles";
        ret = of_property_read_u32(dev->of_node, pname, &clock_cycles);
        if (ret) {
                dev_err(dev, "Unable to get property '%s'(%d)\n", pname, ret);
                return ret;
        }
        /* ABB LDO cannot be settle in 0 clock cycles */
        if (!clock_cycles) {
                dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
                return -EINVAL;
        }

        abb->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(abb->clk)) {
                ret = PTR_ERR(abb->clk);
                dev_err(dev, "%s: Unable to get clk(%d)\n", __func__, ret);
                return ret;
        }

        /*
         * SR2_WTCNT_VALUE is the settling time for the ABB ldo after a
         * transition and must be programmed with the correct time at boot.
         * The value programmed into the register is the number of SYS_CLK
         * clock cycles that match a given wall time profiled for the ldo.
         * This value depends on:
         * settling time of ldo in micro-seconds (varies per OMAP family)
         * # of clock cycles per SYS_CLK period (varies per OMAP family)
         * the SYS_CLK frequency in MHz (varies per board)
         * The formula is:
         *
         *                      ldo settling time (in micro-seconds)
         * SR2_WTCNT_VALUE = ------------------------------------------
         *                   (# system clock cycles) * (sys_clk period)
         *
         * Put another way:
         *
         * SR2_WTCNT_VALUE = settling time / (# SYS_CLK cycles / SYS_CLK rate))
         *
         * To avoid dividing by zero multiply both "# clock cycles" and
         * "settling time" by 10 such that the final result is the one we want.
         */

        /* Convert SYS_CLK rate to MHz & prevent divide by zero */
        clk_rate = DIV_ROUND_CLOSEST(clk_get_rate(abb->clk), 1000000);

        /* Calculate cycle rate */
        cycle_rate = DIV_ROUND_CLOSEST(clock_cycles * 10, clk_rate);

        /* Calulate SR2_WTCNT_VALUE */
        sr2_wt_cnt_val = DIV_ROUND_CLOSEST(abb->settling_time * 10, cycle_rate);

        dev_dbg(dev, "%s: Clk_rate=%ld, sr2_cnt=0x%08x\n", __func__,
                clk_get_rate(abb->clk), sr2_wt_cnt_val);

        ti_abb_rmw(regs->sr2_wtcnt_value_mask, sr2_wt_cnt_val, abb->setup_reg);

        return 0;
}

/**
 * ti_abb_init_table() - Initialize ABB table from device tree
 * @dev:        device
 * @abb:        pointer to the abb instance
 * @rinit_data: regulator initdata
 *
 * Return: 0 on success or appropriate error value when fails
 */
static int ti_abb_init_table(struct device *dev, struct ti_abb *abb,
                             struct regulator_init_data *rinit_data)
{
        struct ti_abb_info *info;
        const u32 num_values = 6;
        char *pname = "ti,abb_info";
        u32 i;
        unsigned int *volt_table;
        int num_entries, min_uV = INT_MAX, max_uV = 0;
        struct regulation_constraints *c = &rinit_data->constraints;

        /*
         * Each abb_info is a set of n-tuple, where n is num_values, consisting
         * of voltage and a set of detection logic for ABB information for that
         * voltage to apply.
         */
        num_entries = of_property_count_u32_elems(dev->of_node, pname);
        if (num_entries < 0) {
                dev_err(dev, "No '%s' property?\n", pname);
                return num_entries;
        }

        if (!num_entries || (num_entries % num_values)) {
                dev_err(dev, "All '%s' list entries need %d vals\n", pname,
                        num_values);
                return -EINVAL;
        }
        num_entries /= num_values;

        info = devm_kcalloc(dev, num_entries, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        abb->info = info;

        volt_table = devm_kcalloc(dev, num_entries, sizeof(unsigned int),
                                  GFP_KERNEL);
        if (!volt_table)
                return -ENOMEM;

        abb->rdesc.n_voltages = num_entries;
        abb->rdesc.volt_table = volt_table;
        /* We do not know where the OPP voltage is at the moment */
        abb->current_info_idx = -EINVAL;

        for (i = 0; i < num_entries; i++, info++, volt_table++) {
                u32 efuse_offset, rbb_mask, fbb_mask, vset_mask;
                u32 efuse_val;

                /* NOTE: num_values should equal to entries picked up here */
                of_property_read_u32_index(dev->of_node, pname, i * num_values,
                                           volt_table);
                of_property_read_u32_index(dev->of_node, pname,
                                           i * num_values + 1, &info->opp_sel);
                of_property_read_u32_index(dev->of_node, pname,
                                           i * num_values + 2, &efuse_offset);
                of_property_read_u32_index(dev->of_node, pname,
                                           i * num_values + 3, &rbb_mask);
                of_property_read_u32_index(dev->of_node, pname,
                                           i * num_values + 4, &fbb_mask);
                of_property_read_u32_index(dev->of_node, pname,
                                           i * num_values + 5, &vset_mask);

                dev_dbg(dev,
                        "[%d]v=%d ABB=%d ef=0x%x rbb=0x%x fbb=0x%x vset=0x%x\n",
                        i, *volt_table, info->opp_sel, efuse_offset, rbb_mask,
                        fbb_mask, vset_mask);

                /* Find min/max for voltage set */
                if (min_uV > *volt_table)
                        min_uV = *volt_table;
                if (max_uV < *volt_table)
                        max_uV = *volt_table;

                if (!abb->efuse_base) {
                        /* Ignore invalid data, but warn to help cleanup */
                        if (efuse_offset || rbb_mask || fbb_mask || vset_mask)
                                dev_err(dev, "prop '%s': v=%d,bad efuse/mask\n",
                                        pname, *volt_table);
                        goto check_abb;
                }

                efuse_val = readl(abb->efuse_base + efuse_offset);

                /* Use ABB recommendation from Efuse */
                if (efuse_val & rbb_mask)
                        info->opp_sel = TI_ABB_SLOW_OPP;
                else if (efuse_val & fbb_mask)
                        info->opp_sel = TI_ABB_FAST_OPP;
                else if (rbb_mask || fbb_mask)
                        info->opp_sel = TI_ABB_NOMINAL_OPP;

                dev_dbg(dev,
                        "[%d]v=%d efusev=0x%x final ABB=%d\n",
                        i, *volt_table, efuse_val, info->opp_sel);

                /* Use recommended Vset bits from Efuse */
                if (!abb->ldo_base) {
                        if (vset_mask)
                                dev_err(dev, "prop'%s':v=%d vst=%x LDO base?\n",
                                        pname, *volt_table, vset_mask);
                        continue;
                }
                info->vset = (efuse_val & vset_mask) >> __ffs(vset_mask);
                dev_dbg(dev, "[%d]v=%d vset=%x\n", i, *volt_table, info->vset);
check_abb:
                switch (info->opp_sel) {
                case TI_ABB_NOMINAL_OPP:
                case TI_ABB_FAST_OPP:
                case TI_ABB_SLOW_OPP:
                        /* Valid values */
                        break;
                default:
                        dev_err(dev, "%s:[%d]v=%d, ABB=%d is invalid! Abort!\n",
                                __func__, i, *volt_table, info->opp_sel);
                        return -EINVAL;
                }
        }

        /* Setup the min/max voltage constraints from the supported list */
        c->min_uV = min_uV;
        c->max_uV = max_uV;

        return 0;
}

static const struct regulator_ops ti_abb_reg_ops = {
        .list_voltage = regulator_list_voltage_table,

        .set_voltage_sel = ti_abb_set_voltage_sel,
        .get_voltage_sel = ti_abb_get_voltage_sel,
};

/* Default ABB block offsets, IF this changes in future, create new one */
static const struct ti_abb_reg abb_regs_v1 = {
        /* WARNING: registers are wrongly documented in TRM */
        .setup_off              = 0x04,
        .control_off            = 0x00,

        .sr2_wtcnt_value_mask   = (0xff << 8),
        .fbb_sel_mask           = (0x01 << 2),
        .rbb_sel_mask           = (0x01 << 1),
        .sr2_en_mask            = (0x01 << 0),

        .opp_change_mask        = (0x01 << 2),
        .opp_sel_mask           = (0x03 << 0),
};

static const struct ti_abb_reg abb_regs_v2 = {
        .setup_off              = 0x00,
        .control_off            = 0x04,

        .sr2_wtcnt_value_mask   = (0xff << 8),
        .fbb_sel_mask           = (0x01 << 2),
        .rbb_sel_mask           = (0x01 << 1),
        .sr2_en_mask            = (0x01 << 0),

        .opp_change_mask        = (0x01 << 2),
        .opp_sel_mask           = (0x03 << 0),
};

static const struct ti_abb_reg abb_regs_generic = {
        .sr2_wtcnt_value_mask   = (0xff << 8),
        .fbb_sel_mask           = (0x01 << 2),
        .rbb_sel_mask           = (0x01 << 1),
        .sr2_en_mask            = (0x01 << 0),

        .opp_change_mask        = (0x01 << 2),
        .opp_sel_mask           = (0x03 << 0),
};

static const struct of_device_id ti_abb_of_match[] = {
        {.compatible = "ti,abb-v1", .data = &abb_regs_v1},
        {.compatible = "ti,abb-v2", .data = &abb_regs_v2},
        {.compatible = "ti,abb-v3", .data = &abb_regs_generic},
        { },
};

MODULE_DEVICE_TABLE(of, ti_abb_of_match);

/**
 * ti_abb_probe() - Initialize an ABB ldo instance
 * @pdev: ABB platform device
 *
 * Initializes an individual ABB LDO for required Body-Bias. ABB is used to
 * addional bias supply to SoC modules for power savings or mandatory stability
 * configuration at certain Operating Performance Points(OPPs).
 *
 * Return: 0 on success or appropriate error value when fails
 */
static int ti_abb_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        const struct of_device_id *match;
        struct resource *res;
        struct ti_abb *abb;
        struct regulator_init_data *initdata = NULL;
        struct regulator_dev *rdev = NULL;
        struct regulator_desc *desc;
        struct regulation_constraints *c;
        struct regulator_config config = { };
        char *pname;
        int ret = 0;

        match = of_match_device(ti_abb_of_match, dev);
        if (!match) {
                /* We do not expect this to happen */
                dev_err(dev, "%s: Unable to match device\n", __func__);
                return -ENODEV;
        }
        if (!match->data) {
                dev_err(dev, "%s: Bad data in match\n", __func__);
                return -EINVAL;
        }

        abb = devm_kzalloc(dev, sizeof(struct ti_abb), GFP_KERNEL);
        if (!abb)
                return -ENOMEM;
        abb->regs = match->data;

        /* Map ABB resources */
        if (abb->regs->setup_off || abb->regs->control_off) {
                pname = "base-address";
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
                abb->base = devm_ioremap_resource(dev, res);
                if (IS_ERR(abb->base))
                        return PTR_ERR(abb->base);

                abb->setup_reg = abb->base + abb->regs->setup_off;
                abb->control_reg = abb->base + abb->regs->control_off;

        } else {
                pname = "control-address";
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
                abb->control_reg = devm_ioremap_resource(dev, res);
                if (IS_ERR(abb->control_reg))
                        return PTR_ERR(abb->control_reg);

                pname = "setup-address";
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
                abb->setup_reg = devm_ioremap_resource(dev, res);
                if (IS_ERR(abb->setup_reg))
                        return PTR_ERR(abb->setup_reg);
        }

        pname = "int-address";
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
        if (!res) {
                dev_err(dev, "Missing '%s' IO resource\n", pname);
                return -ENODEV;
        }
        /*
         * We may have shared interrupt register offsets which are
         * write-1-to-clear between domains ensuring exclusivity.
         */
        abb->int_base = devm_ioremap(dev, res->start,
                                             resource_size(res));
        if (!abb->int_base) {
                dev_err(dev, "Unable to map '%s'\n", pname);
                return -ENOMEM;
        }

        /* Map Optional resources */
        pname = "efuse-address";
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
        if (!res) {
                dev_dbg(dev, "Missing '%s' IO resource\n", pname);
                ret = -ENODEV;
                goto skip_opt;
        }

        /*
         * We may have shared efuse register offsets which are read-only
         * between domains
         */
        abb->efuse_base = devm_ioremap(dev, res->start,
                                               resource_size(res));
        if (!abb->efuse_base) {
                dev_err(dev, "Unable to map '%s'\n", pname);
                return -ENOMEM;
        }

        pname = "ldo-address";
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, pname);
        if (!res) {
                dev_dbg(dev, "Missing '%s' IO resource\n", pname);
                ret = -ENODEV;
                goto skip_opt;
        }
        abb->ldo_base = devm_ioremap_resource(dev, res);
        if (IS_ERR(abb->ldo_base))
                return PTR_ERR(abb->ldo_base);

        /* IF ldo_base is set, the following are mandatory */
        pname = "ti,ldovbb-override-mask";
        ret =
            of_property_read_u32(pdev->dev.of_node, pname,
                                 &abb->ldovbb_override_mask);
        if (ret) {
                dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
                return ret;
        }
        if (!abb->ldovbb_override_mask) {
                dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
                return -EINVAL;
        }

        pname = "ti,ldovbb-vset-mask";
        ret =
            of_property_read_u32(pdev->dev.of_node, pname,
                                 &abb->ldovbb_vset_mask);
        if (ret) {
                dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
                return ret;
        }
        if (!abb->ldovbb_vset_mask) {
                dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
                return -EINVAL;
        }

skip_opt:
        pname = "ti,tranxdone-status-mask";
        ret =
            of_property_read_u32(pdev->dev.of_node, pname,
                                 &abb->txdone_mask);
        if (ret) {
                dev_err(dev, "Missing '%s' (%d)\n", pname, ret);
                return ret;
        }
        if (!abb->txdone_mask) {
                dev_err(dev, "Invalid property:'%s' set as 0!\n", pname);
                return -EINVAL;
        }

        initdata = of_get_regulator_init_data(dev, pdev->dev.of_node,
                                              &abb->rdesc);
        if (!initdata) {
                dev_err(dev, "%s: Unable to alloc regulator init data\n",
                        __func__);
                return -ENOMEM;
        }

        /* init ABB opp_sel table */
        ret = ti_abb_init_table(dev, abb, initdata);
        if (ret)
                return ret;

        /* init ABB timing */
        ret = ti_abb_init_timings(dev, abb);
        if (ret)
                return ret;

        desc = &abb->rdesc;
        desc->name = dev_name(dev);
        desc->owner = THIS_MODULE;
        desc->type = REGULATOR_VOLTAGE;
        desc->ops = &ti_abb_reg_ops;

        c = &initdata->constraints;
        if (desc->n_voltages > 1)
                c->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
        c->always_on = true;

        config.dev = dev;
        config.init_data = initdata;
        config.driver_data = abb;
        config.of_node = pdev->dev.of_node;

        rdev = devm_regulator_register(dev, desc, &config);
        if (IS_ERR(rdev)) {
                ret = PTR_ERR(rdev);
                dev_err(dev, "%s: failed to register regulator(%d)\n",
                        __func__, ret);
                return ret;
        }
        platform_set_drvdata(pdev, rdev);

        /* Enable the ldo if not already done by bootloader */
        ti_abb_rmw(abb->regs->sr2_en_mask, 1, abb->setup_reg);

        return 0;
}

MODULE_ALIAS("platform:ti_abb");

static struct platform_driver ti_abb_driver = {
        .probe = ti_abb_probe,
        .driver = {
                   .name = "ti_abb",
                   .of_match_table = of_match_ptr(ti_abb_of_match),
                   },
};
module_platform_driver(ti_abb_driver);

MODULE_DESCRIPTION("Texas Instruments ABB LDO regulator driver");
MODULE_AUTHOR("Texas Instruments Inc.");
MODULE_LICENSE("GPL v2");