/*
 * Register map access API - SPMI support
 *
 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
 *
 * Based on regmap-i2c.c:
 * Copyright 2011 Wolfson Microelectronics plc
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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.
 *
 */
#include <linux/regmap.h>
#include <linux/spmi.h>
#include <linux/module.h>
#include <linux/init.h>

static int regmap_spmi_base_read(void *context,
                                 const void *reg, size_t reg_size,
                                 void *val, size_t val_size)
{
        u8 addr = *(u8 *)reg;
        int err = 0;

        BUG_ON(reg_size != 1);

        while (val_size-- && !err)
                err = spmi_register_read(context, addr++, val++);

        return err;
}

static int regmap_spmi_base_gather_write(void *context,
                                         const void *reg, size_t reg_size,
                                         const void *val, size_t val_size)
{
        const u8 *data = val;
        u8 addr = *(u8 *)reg;
        int err = 0;

        BUG_ON(reg_size != 1);

        /*
         * SPMI defines a more bandwidth-efficient 'Register 0 Write' sequence,
         * use it when possible.
         */
        if (addr == 0 && val_size) {
                err = spmi_register_zero_write(context, *data);
                if (err)
                        goto err_out;

                data++;
                addr++;
                val_size--;
        }

        while (val_size) {
                err = spmi_register_write(context, addr, *data);
                if (err)
                        goto err_out;

                data++;
                addr++;
                val_size--;
        }

err_out:
        return err;
}

static int regmap_spmi_base_write(void *context, const void *data,
                                  size_t count)
{
        BUG_ON(count < 1);
        return regmap_spmi_base_gather_write(context, data, 1, data + 1,
                                             count - 1);
}

static struct regmap_bus regmap_spmi_base = {
        .read                           = regmap_spmi_base_read,
        .write                          = regmap_spmi_base_write,
        .gather_write                   = regmap_spmi_base_gather_write,
        .reg_format_endian_default      = REGMAP_ENDIAN_NATIVE,
        .val_format_endian_default      = REGMAP_ENDIAN_NATIVE,
};

struct regmap *__regmap_init_spmi_base(struct spmi_device *sdev,
                                       const struct regmap_config *config,
                                       struct lock_class_key *lock_key,
                                       const char *lock_name)
{
        return __regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
                             lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__regmap_init_spmi_base);

struct regmap *__devm_regmap_init_spmi_base(struct spmi_device *sdev,
                                            const struct regmap_config *config,
                                            struct lock_class_key *lock_key,
                                            const char *lock_name)
{
        return __devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
                                  lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_base);

static int regmap_spmi_ext_read(void *context,
                                const void *reg, size_t reg_size,
                                void *val, size_t val_size)
{
        int err = 0;
        size_t len;
        u16 addr;

        BUG_ON(reg_size != 2);

        addr = *(u16 *)reg;

        /*
         * Split accesses into two to take advantage of the more
         * bandwidth-efficient 'Extended Register Read' command when possible
         */
        while (addr <= 0xFF && val_size) {
                len = min_t(size_t, val_size, 16);

                err = spmi_ext_register_read(context, addr, val, len);
                if (err)
                        goto err_out;

                addr += len;
                val += len;
                val_size -= len;
        }

        while (val_size) {
                len = min_t(size_t, val_size, 8);

                err = spmi_ext_register_readl(context, addr, val, len);
                if (err)
                        goto err_out;

                addr += len;
                val += len;
                val_size -= len;
        }

err_out:
        return err;
}

static int regmap_spmi_ext_gather_write(void *context,
                                        const void *reg, size_t reg_size,
                                        const void *val, size_t val_size)
{
        int err = 0;
        size_t len;
        u16 addr;

        BUG_ON(reg_size != 2);

        addr = *(u16 *)reg;

        while (addr <= 0xFF && val_size) {
                len = min_t(size_t, val_size, 16);

                err = spmi_ext_register_write(context, addr, val, len);
                if (err)
                        goto err_out;

                addr += len;
                val += len;
                val_size -= len;
        }

        while (val_size) {
                len = min_t(size_t, val_size, 8);

                err = spmi_ext_register_writel(context, addr, val, len);
                if (err)
                        goto err_out;

                addr += len;
                val += len;
                val_size -= len;
        }

err_out:
        return err;
}

static int regmap_spmi_ext_write(void *context, const void *data,
                                 size_t count)
{
        BUG_ON(count < 2);
        return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
                                            count - 2);
}

static struct regmap_bus regmap_spmi_ext = {
        .read                           = regmap_spmi_ext_read,
        .write                          = regmap_spmi_ext_write,
        .gather_write                   = regmap_spmi_ext_gather_write,
        .reg_format_endian_default      = REGMAP_ENDIAN_NATIVE,
        .val_format_endian_default      = REGMAP_ENDIAN_NATIVE,
};

struct regmap *__regmap_init_spmi_ext(struct spmi_device *sdev,
                                      const struct regmap_config *config,
                                      struct lock_class_key *lock_key,
                                      const char *lock_name)
{
        return __regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
                             lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__regmap_init_spmi_ext);

struct regmap *__devm_regmap_init_spmi_ext(struct spmi_device *sdev,
                                           const struct regmap_config *config,
                                           struct lock_class_key *lock_key,
                                           const char *lock_name)
{
        return __devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
                                  lock_key, lock_name);
}
EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_ext);

MODULE_LICENSE("GPL");