USB: usb-storage: unusual_devs update for Super TOP SATA bridge

[linux/fpc-iii.git] / drivers / base / regmap / regmap.c

/*
 * Register map access API
 *
 * 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 as
 * published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/err.h>

#define CREATE_TRACE_POINTS
#include <trace/events/regmap.h>

#include "internal.h"

bool regmap_writeable(struct regmap *map, unsigned int reg)
{
        if (map->max_register && reg > map->max_register)
                return false;

        if (map->writeable_reg)
                return map->writeable_reg(map->dev, reg);

        return true;
}

bool regmap_readable(struct regmap *map, unsigned int reg)
{
        if (map->max_register && reg > map->max_register)
                return false;

        if (map->format.format_write)
                return false;

        if (map->readable_reg)
                return map->readable_reg(map->dev, reg);

        return true;
}

bool regmap_volatile(struct regmap *map, unsigned int reg)
{
        if (!regmap_readable(map, reg))
                return false;

        if (map->volatile_reg)
                return map->volatile_reg(map->dev, reg);

        return true;
}

bool regmap_precious(struct regmap *map, unsigned int reg)
{
        if (!regmap_readable(map, reg))
                return false;

        if (map->precious_reg)
                return map->precious_reg(map->dev, reg);

        return false;
}

static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
        unsigned int num)
{
        unsigned int i;

        for (i = 0; i < num; i++)
                if (!regmap_volatile(map, reg + i))
                        return false;

        return true;
}

static void regmap_format_2_6_write(struct regmap *map,
                                     unsigned int reg, unsigned int val)
{
        u8 *out = map->work_buf;

        *out = (reg << 6) | val;
}

static void regmap_format_4_12_write(struct regmap *map,
                                     unsigned int reg, unsigned int val)
{
        __be16 *out = map->work_buf;
        *out = cpu_to_be16((reg << 12) | val);
}

static void regmap_format_7_9_write(struct regmap *map,
                                    unsigned int reg, unsigned int val)
{
        __be16 *out = map->work_buf;
        *out = cpu_to_be16((reg << 9) | val);
}

static void regmap_format_10_14_write(struct regmap *map,
                                    unsigned int reg, unsigned int val)
{
        u8 *out = map->work_buf;

        out[2] = val;
        out[1] = (val >> 8) | (reg << 6);
        out[0] = reg >> 2;
}

static void regmap_format_8(void *buf, unsigned int val)
{
        u8 *b = buf;

        b[0] = val;
}

static void regmap_format_16(void *buf, unsigned int val)
{
        __be16 *b = buf;

        b[0] = cpu_to_be16(val);
}

static void regmap_format_32(void *buf, unsigned int val)
{
        __be32 *b = buf;

        b[0] = cpu_to_be32(val);
}

static unsigned int regmap_parse_8(void *buf)
{
        u8 *b = buf;

        return b[0];
}

static unsigned int regmap_parse_16(void *buf)
{
        __be16 *b = buf;

        b[0] = be16_to_cpu(b[0]);

        return b[0];
}

static unsigned int regmap_parse_32(void *buf)
{
        __be32 *b = buf;

        b[0] = be32_to_cpu(b[0]);

        return b[0];
}

/**
 * regmap_init(): Initialise register map
 *
 * @dev: Device that will be interacted with
 * @bus: Bus-specific callbacks to use with device
 * @config: Configuration for register map
 *
 * The return value will be an ERR_PTR() on error or a valid pointer to
 * a struct regmap.  This function should generally not be called
 * directly, it should be called by bus-specific init functions.
 */
struct regmap *regmap_init(struct device *dev,
                           const struct regmap_bus *bus,
                           const struct regmap_config *config)
{
        struct regmap *map;
        int ret = -EINVAL;

        if (!bus || !config)
                goto err;

        map = kzalloc(sizeof(*map), GFP_KERNEL);
        if (map == NULL) {
                ret = -ENOMEM;
                goto err;
        }

        mutex_init(&map->lock);
        map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
        map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
        map->format.pad_bytes = config->pad_bits / 8;
        map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
        map->format.buf_size += map->format.pad_bytes;
        map->dev = dev;
        map->bus = bus;
        map->max_register = config->max_register;
        map->writeable_reg = config->writeable_reg;
        map->readable_reg = config->readable_reg;
        map->volatile_reg = config->volatile_reg;
        map->precious_reg = config->precious_reg;
        map->cache_type = config->cache_type;

        if (config->read_flag_mask || config->write_flag_mask) {
                map->read_flag_mask = config->read_flag_mask;
                map->write_flag_mask = config->write_flag_mask;
        } else {
                map->read_flag_mask = bus->read_flag_mask;
        }

        switch (config->reg_bits) {
        case 2:
                switch (config->val_bits) {
                case 6:
                        map->format.format_write = regmap_format_2_6_write;
                        break;
                default:
                        goto err_map;
                }
                break;

        case 4:
                switch (config->val_bits) {
                case 12:
                        map->format.format_write = regmap_format_4_12_write;
                        break;
                default:
                        goto err_map;
                }
                break;

        case 7:
                switch (config->val_bits) {
                case 9:
                        map->format.format_write = regmap_format_7_9_write;
                        break;
                default:
                        goto err_map;
                }
                break;

        case 10:
                switch (config->val_bits) {
                case 14:
                        map->format.format_write = regmap_format_10_14_write;
                        break;
                default:
                        goto err_map;
                }
                break;

        case 8:
                map->format.format_reg = regmap_format_8;
                break;

        case 16:
                map->format.format_reg = regmap_format_16;
                break;

        case 32:
                map->format.format_reg = regmap_format_32;
                break;

        default:
                goto err_map;
        }

        switch (config->val_bits) {
        case 8:
                map->format.format_val = regmap_format_8;
                map->format.parse_val = regmap_parse_8;
                break;
        case 16:
                map->format.format_val = regmap_format_16;
                map->format.parse_val = regmap_parse_16;
                break;
        case 32:
                map->format.format_val = regmap_format_32;
                map->format.parse_val = regmap_parse_32;
                break;
        }

        if (!map->format.format_write &&
            !(map->format.format_reg && map->format.format_val))
                goto err_map;

        map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
        if (map->work_buf == NULL) {
                ret = -ENOMEM;
                goto err_map;
        }

        regmap_debugfs_init(map);

        ret = regcache_init(map, config);
        if (ret < 0)
                goto err_free_workbuf;

        return map;

err_free_workbuf:
        kfree(map->work_buf);
err_map:
        kfree(map);
err:
        return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(regmap_init);

static void devm_regmap_release(struct device *dev, void *res)
{
        regmap_exit(*(struct regmap **)res);
}

/**
 * devm_regmap_init(): Initialise managed register map
 *
 * @dev: Device that will be interacted with
 * @bus: Bus-specific callbacks to use with device
 * @config: Configuration for register map
 *
 * The return value will be an ERR_PTR() on error or a valid pointer
 * to a struct regmap.  This function should generally not be called
 * directly, it should be called by bus-specific init functions.  The
 * map will be automatically freed by the device management code.
 */
struct regmap *devm_regmap_init(struct device *dev,
                                const struct regmap_bus *bus,
                                const struct regmap_config *config)
{
        struct regmap **ptr, *regmap;

        ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
        if (!ptr)
                return ERR_PTR(-ENOMEM);

        regmap = regmap_init(dev, bus, config);
        if (!IS_ERR(regmap)) {
                *ptr = regmap;
                devres_add(dev, ptr);
        } else {
                devres_free(ptr);
        }

        return regmap;
}
EXPORT_SYMBOL_GPL(devm_regmap_init);

/**
 * regmap_reinit_cache(): Reinitialise the current register cache
 *
 * @map: Register map to operate on.
 * @config: New configuration.  Only the cache data will be used.
 *
 * Discard any existing register cache for the map and initialize a
 * new cache.  This can be used to restore the cache to defaults or to
 * update the cache configuration to reflect runtime discovery of the
 * hardware.
 */
int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
{
        int ret;

        mutex_lock(&map->lock);

        regcache_exit(map);
        regmap_debugfs_exit(map);

        map->max_register = config->max_register;
        map->writeable_reg = config->writeable_reg;
        map->readable_reg = config->readable_reg;
        map->volatile_reg = config->volatile_reg;
        map->precious_reg = config->precious_reg;
        map->cache_type = config->cache_type;

        regmap_debugfs_init(map);

        map->cache_bypass = false;
        map->cache_only = false;

        ret = regcache_init(map, config);

        mutex_unlock(&map->lock);

        return ret;
}

/**
 * regmap_exit(): Free a previously allocated register map
 */
void regmap_exit(struct regmap *map)
{
        regcache_exit(map);
        regmap_debugfs_exit(map);
        kfree(map->work_buf);
        kfree(map);
}
EXPORT_SYMBOL_GPL(regmap_exit);

static int _regmap_raw_write(struct regmap *map, unsigned int reg,
                             const void *val, size_t val_len)
{
        u8 *u8 = map->work_buf;
        void *buf;
        int ret = -ENOTSUPP;
        size_t len;
        int i;

        /* Check for unwritable registers before we start */
        if (map->writeable_reg)
                for (i = 0; i < val_len / map->format.val_bytes; i++)
                        if (!map->writeable_reg(map->dev, reg + i))
                                return -EINVAL;

        if (!map->cache_bypass && map->format.parse_val) {
                unsigned int ival;
                int val_bytes = map->format.val_bytes;
                for (i = 0; i < val_len / val_bytes; i++) {
                        memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
                        ival = map->format.parse_val(map->work_buf);
                        ret = regcache_write(map, reg + i, ival);
                        if (ret) {
                                dev_err(map->dev,
                                   "Error in caching of register: %u ret: %d\n",
                                        reg + i, ret);
                                return ret;
                        }
                }
                if (map->cache_only) {
                        map->cache_dirty = true;
                        return 0;
                }
        }

        map->format.format_reg(map->work_buf, reg);

        u8[0] |= map->write_flag_mask;

        trace_regmap_hw_write_start(map->dev, reg,
                                    val_len / map->format.val_bytes);

        /* If we're doing a single register write we can probably just
         * send the work_buf directly, otherwise try to do a gather
         * write.
         */
        if (val == (map->work_buf + map->format.pad_bytes +
                    map->format.reg_bytes))
                ret = map->bus->write(map->dev, map->work_buf,
                                      map->format.reg_bytes +
                                      map->format.pad_bytes +
                                      val_len);
        else if (map->bus->gather_write)
                ret = map->bus->gather_write(map->dev, map->work_buf,
                                             map->format.reg_bytes +
                                             map->format.pad_bytes,
                                             val, val_len);

        /* If that didn't work fall back on linearising by hand. */
        if (ret == -ENOTSUPP) {
                len = map->format.reg_bytes + map->format.pad_bytes + val_len;
                buf = kzalloc(len, GFP_KERNEL);
                if (!buf)
                        return -ENOMEM;

                memcpy(buf, map->work_buf, map->format.reg_bytes);
                memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
                       val, val_len);
                ret = map->bus->write(map->dev, buf, len);

                kfree(buf);
        }

        trace_regmap_hw_write_done(map->dev, reg,
                                   val_len / map->format.val_bytes);

        return ret;
}

int _regmap_write(struct regmap *map, unsigned int reg,
                  unsigned int val)
{
        int ret;
        BUG_ON(!map->format.format_write && !map->format.format_val);

        if (!map->cache_bypass && map->format.format_write) {
                ret = regcache_write(map, reg, val);
                if (ret != 0)
                        return ret;
                if (map->cache_only) {
                        map->cache_dirty = true;
                        return 0;
                }
        }

        trace_regmap_reg_write(map->dev, reg, val);

        if (map->format.format_write) {
                map->format.format_write(map, reg, val);

                trace_regmap_hw_write_start(map->dev, reg, 1);

                ret = map->bus->write(map->dev, map->work_buf,
                                      map->format.buf_size);

                trace_regmap_hw_write_done(map->dev, reg, 1);

                return ret;
        } else {
                map->format.format_val(map->work_buf + map->format.reg_bytes
                                       + map->format.pad_bytes, val);
                return _regmap_raw_write(map, reg,
                                         map->work_buf +
                                         map->format.reg_bytes +
                                         map->format.pad_bytes,
                                         map->format.val_bytes);
        }
}

/**
 * regmap_write(): Write a value to a single register
 *
 * @map: Register map to write to
 * @reg: Register to write to
 * @val: Value to be written
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
{
        int ret;

        mutex_lock(&map->lock);

        ret = _regmap_write(map, reg, val);

        mutex_unlock(&map->lock);

        return ret;
}
EXPORT_SYMBOL_GPL(regmap_write);

/**
 * regmap_raw_write(): Write raw values to one or more registers
 *
 * @map: Register map to write to
 * @reg: Initial register to write to
 * @val: Block of data to be written, laid out for direct transmission to the
 *       device
 * @val_len: Length of data pointed to by val.
 *
 * This function is intended to be used for things like firmware
 * download where a large block of data needs to be transferred to the
 * device.  No formatting will be done on the data provided.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_raw_write(struct regmap *map, unsigned int reg,
                     const void *val, size_t val_len)
{
        int ret;

        mutex_lock(&map->lock);

        ret = _regmap_raw_write(map, reg, val, val_len);

        mutex_unlock(&map->lock);

        return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_write);

/*
 * regmap_bulk_write(): Write multiple registers to the device
 *
 * @map: Register map to write to
 * @reg: First register to be write from
 * @val: Block of data to be written, in native register size for device
 * @val_count: Number of registers to write
 *
 * This function is intended to be used for writing a large block of
 * data to be device either in single transfer or multiple transfer.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
                     size_t val_count)
{
        int ret = 0, i;
        size_t val_bytes = map->format.val_bytes;
        void *wval;

        if (!map->format.parse_val)
                return -EINVAL;

        mutex_lock(&map->lock);

        /* No formatting is require if val_byte is 1 */
        if (val_bytes == 1) {
                wval = (void *)val;
        } else {
                wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
                if (!wval) {
                        ret = -ENOMEM;
                        dev_err(map->dev, "Error in memory allocation\n");
                        goto out;
                }
                for (i = 0; i < val_count * val_bytes; i += val_bytes)
                        map->format.parse_val(wval + i);
        }
        ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);

        if (val_bytes != 1)
                kfree(wval);

out:
        mutex_unlock(&map->lock);
        return ret;
}
EXPORT_SYMBOL_GPL(regmap_bulk_write);

static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
                            unsigned int val_len)
{
        u8 *u8 = map->work_buf;
        int ret;

        map->format.format_reg(map->work_buf, reg);

        /*
         * Some buses or devices flag reads by setting the high bits in the
         * register addresss; since it's always the high bits for all
         * current formats we can do this here rather than in
         * formatting.  This may break if we get interesting formats.
         */
        u8[0] |= map->read_flag_mask;

        trace_regmap_hw_read_start(map->dev, reg,
                                   val_len / map->format.val_bytes);

        ret = map->bus->read(map->dev, map->work_buf,
                             map->format.reg_bytes + map->format.pad_bytes,
                             val, val_len);

        trace_regmap_hw_read_done(map->dev, reg,
                                  val_len / map->format.val_bytes);

        return ret;
}

static int _regmap_read(struct regmap *map, unsigned int reg,
                        unsigned int *val)
{
        int ret;

        if (!map->cache_bypass) {
                ret = regcache_read(map, reg, val);
                if (ret == 0)
                        return 0;
        }

        if (!map->format.parse_val)
                return -EINVAL;

        if (map->cache_only)
                return -EBUSY;

        ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
        if (ret == 0) {
                *val = map->format.parse_val(map->work_buf);
                trace_regmap_reg_read(map->dev, reg, *val);
        }

        return ret;
}

/**
 * regmap_read(): Read a value from a single register
 *
 * @map: Register map to write to
 * @reg: Register to be read from
 * @val: Pointer to store read value
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
{
        int ret;

        mutex_lock(&map->lock);

        ret = _regmap_read(map, reg, val);

        mutex_unlock(&map->lock);

        return ret;
}
EXPORT_SYMBOL_GPL(regmap_read);

/**
 * regmap_raw_read(): Read raw data from the device
 *
 * @map: Register map to write to
 * @reg: First register to be read from
 * @val: Pointer to store read value
 * @val_len: Size of data to read
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
                    size_t val_len)
{
        size_t val_bytes = map->format.val_bytes;
        size_t val_count = val_len / val_bytes;
        unsigned int v;
        int ret, i;

        mutex_lock(&map->lock);

        if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
            map->cache_type == REGCACHE_NONE) {
                /* Physical block read if there's no cache involved */
                ret = _regmap_raw_read(map, reg, val, val_len);

        } else {
                /* Otherwise go word by word for the cache; should be low
                 * cost as we expect to hit the cache.
                 */
                for (i = 0; i < val_count; i++) {
                        ret = _regmap_read(map, reg + i, &v);
                        if (ret != 0)
                                goto out;

                        map->format.format_val(val + (i * val_bytes), v);
                }
        }

 out:
        mutex_unlock(&map->lock);

        return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_read);

/**
 * regmap_bulk_read(): Read multiple registers from the device
 *
 * @map: Register map to write to
 * @reg: First register to be read from
 * @val: Pointer to store read value, in native register size for device
 * @val_count: Number of registers to read
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
                     size_t val_count)
{
        int ret, i;
        size_t val_bytes = map->format.val_bytes;
        bool vol = regmap_volatile_range(map, reg, val_count);

        if (!map->format.parse_val)
                return -EINVAL;

        if (vol || map->cache_type == REGCACHE_NONE) {
                ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
                if (ret != 0)
                        return ret;

                for (i = 0; i < val_count * val_bytes; i += val_bytes)
                        map->format.parse_val(val + i);
        } else {
                for (i = 0; i < val_count; i++) {
                        unsigned int ival;
                        ret = regmap_read(map, reg + i, &ival);
                        if (ret != 0)
                                return ret;
                        memcpy(val + (i * val_bytes), &ival, val_bytes);
                }
        }

        return 0;
}
EXPORT_SYMBOL_GPL(regmap_bulk_read);

static int _regmap_update_bits(struct regmap *map, unsigned int reg,
                               unsigned int mask, unsigned int val,
                               bool *change)
{
        int ret;
        unsigned int tmp, orig;

        mutex_lock(&map->lock);

        ret = _regmap_read(map, reg, &orig);
        if (ret != 0)
                goto out;

        tmp = orig & ~mask;
        tmp |= val & mask;

        if (tmp != orig) {
                ret = _regmap_write(map, reg, tmp);
                *change = true;
        } else {
                *change = false;
        }

out:
        mutex_unlock(&map->lock);

        return ret;
}

/**
 * regmap_update_bits: Perform a read/modify/write cycle on the register map
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits(struct regmap *map, unsigned int reg,
                       unsigned int mask, unsigned int val)
{
        bool change;
        return _regmap_update_bits(map, reg, mask, val, &change);
}
EXPORT_SYMBOL_GPL(regmap_update_bits);

/**
 * regmap_update_bits_check: Perform a read/modify/write cycle on the
 *                           register map and report if updated
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 * @change: Boolean indicating if a write was done
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_check(struct regmap *map, unsigned int reg,
                             unsigned int mask, unsigned int val,
                             bool *change)
{
        return _regmap_update_bits(map, reg, mask, val, change);
}
EXPORT_SYMBOL_GPL(regmap_update_bits_check);

/**
 * regmap_register_patch: Register and apply register updates to be applied
 *                        on device initialistion
 *
 * @map: Register map to apply updates to.
 * @regs: Values to update.
 * @num_regs: Number of entries in regs.
 *
 * Register a set of register updates to be applied to the device
 * whenever the device registers are synchronised with the cache and
 * apply them immediately.  Typically this is used to apply
 * corrections to be applied to the device defaults on startup, such
 * as the updates some vendors provide to undocumented registers.
 */
int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
                          int num_regs)
{
        int i, ret;
        bool bypass;

        /* If needed the implementation can be extended to support this */
        if (map->patch)
                return -EBUSY;

        mutex_lock(&map->lock);

        bypass = map->cache_bypass;

        map->cache_bypass = true;

        /* Write out first; it's useful to apply even if we fail later. */
        for (i = 0; i < num_regs; i++) {
                ret = _regmap_write(map, regs[i].reg, regs[i].def);
                if (ret != 0) {
                        dev_err(map->dev, "Failed to write %x = %x: %d\n",
                                regs[i].reg, regs[i].def, ret);
                        goto out;
                }
        }

        map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
        if (map->patch != NULL) {
                memcpy(map->patch, regs,
                       num_regs * sizeof(struct reg_default));
                map->patch_regs = num_regs;
        } else {
                ret = -ENOMEM;
        }

out:
        map->cache_bypass = bypass;

        mutex_unlock(&map->lock);

        return ret;
}
EXPORT_SYMBOL_GPL(regmap_register_patch);

/*
 * regmap_get_val_bytes(): Report the size of a register value
 *
 * Report the size of a register value, mainly intended to for use by
 * generic infrastructure built on top of regmap.
 */
int regmap_get_val_bytes(struct regmap *map)
{
        if (map->format.format_write)
                return -EINVAL;

        return map->format.val_bytes;
}
EXPORT_SYMBOL_GPL(regmap_get_val_bytes);

static int __init regmap_initcall(void)
{
        regmap_debugfs_initcall();

        return 0;
}
postcore_initcall(regmap_initcall);