regmap.c

 * If supported by the underlying bus the write will be scheduled
 * asynchronously, helping maximise I/O speed on higher speed buses
 * like SPI.  regmap_async_complete() can be called to ensure that all
 * asynchrnous writes have been completed.
 *
 * A value of zero will be returned on success, a negative errno will
 * be returned in error cases.
 */
int regmap_raw_write_async(struct regmap *map, unsigned int reg,
			   const void *val, size_t val_len)
{
	int ret;

	if (val_len % map->format.val_bytes)
		return -EINVAL;
	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	map->async = true;

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

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_write_async);

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

	WARN_ON(!map->bus);

	range = _regmap_range_lookup(map, reg);
	if (range) {
		ret = _regmap_select_page(map, &reg, range,
					  val_len / map->format.val_bytes);
		if (ret != 0)
			return ret;
	}

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

	/*
	 * 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, reg, val_len / map->format.val_bytes);

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

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

	return ret;
}

static int _regmap_bus_reg_read(void *context, unsigned int reg,
				unsigned int *val)
{
	struct regmap *map = context;

	return map->bus->reg_read(map->bus_context, reg, val);
}

static int _regmap_bus_read(void *context, unsigned int reg,
			    unsigned int *val)
{
	int ret;
	struct regmap *map = context;

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

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

	return ret;
}

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

	WARN_ON(!map->reg_read);

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

	if (map->cache_only)
		return -EBUSY;

	if (!regmap_readable(map, reg))
		return -EIO;

	ret = map->reg_read(context, reg, val);
	if (ret == 0) {
#ifdef LOG_DEVICE
		if (map->dev && strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
			dev_info(map->dev, "%x => %x\n", reg, *val);
#endif

		trace_regmap_reg_read(map, reg, *val);

		if (!map->cache_bypass)
			regcache_write(map, reg, *val);
	}

	return ret;
}

/**
 * regmap_read(): Read a value from a single register
 *
 * @map: Register map to read from
 * @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;

	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	ret = _regmap_read(map, reg, val);

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_read);

/**
 * regmap_raw_read(): Read raw data from the device
 *
 * @map: Register map to read from
 * @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;

	if (!map->bus)
		return -EINVAL;
	if (val_len % map->format.val_bytes)
		return -EINVAL;
	if (reg % map->reg_stride)
		return -EINVAL;

	map->lock(map->lock_arg);

	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 * map->reg_stride),
					   &v);
			if (ret != 0)
				goto out;

			map->format.format_val(val + (i * val_bytes), v, 0);
		}
	}

 out:
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_raw_read);

/**
 * regmap_field_read(): Read a value to a single register field
 *
 * @field: Register field to 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_field_read(struct regmap_field *field, unsigned int *val)
{
	int ret;
	unsigned int reg_val;
	ret = regmap_read(field->regmap, field->reg, &reg_val);
	if (ret != 0)
		return ret;

	reg_val &= field->mask;
	reg_val >>= field->shift;
	*val = reg_val;

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_field_read);

/**
 * regmap_fields_read(): Read a value to a single register field with port ID
 *
 * @field: Register field to read from
 * @id: port ID
 * @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_fields_read(struct regmap_field *field, unsigned int id,
		       unsigned int *val)
{
	int ret;
	unsigned int reg_val;

	if (id >= field->id_size)
		return -EINVAL;

	ret = regmap_read(field->regmap,
			  field->reg + (field->id_offset * id),
			  &reg_val);
	if (ret != 0)
		return ret;

	reg_val &= field->mask;
	reg_val >>= field->shift;
	*val = reg_val;

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_fields_read);

/**
 * regmap_bulk_read(): Read multiple registers from the device
 *
 * @map: Register map to read from
 * @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 (reg % map->reg_stride)
		return -EINVAL;

	if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
		/*
		 * Some devices does not support bulk read, for
		 * them we have a series of single read operations.
		 */
		if (map->use_single_rw) {
			for (i = 0; i < val_count; i++) {
				ret = regmap_raw_read(map,
						reg + (i * map->reg_stride),
						val + (i * val_bytes),
						val_bytes);
				if (ret != 0)
					return ret;
			}
		} else {
			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_inplace(val + i);
	} else {
		for (i = 0; i < val_count; i++) {
			unsigned int ival;
			ret = regmap_read(map, reg + (i * map->reg_stride),
					  &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;

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

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

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

	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)
{
	int ret;

	map->lock(map->lock_arg);
	ret = _regmap_update_bits(map, reg, mask, val, NULL);
	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits);

/**
 * regmap_update_bits_async: Perform a read/modify/write cycle on the register
 *                           map asynchronously
 *
 * @map: Register map to update
 * @reg: Register to update
 * @mask: Bitmask to change
 * @val: New value for bitmask
 *
 * With most buses the read must be done synchronously so this is most
 * useful for devices with a cache which do not need to interact with
 * the hardware to determine the current register value.
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_async(struct regmap *map, unsigned int reg,
			     unsigned int mask, unsigned int val)
{
	int ret;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_update_bits(map, reg, mask, val, NULL);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_async);

/**
 * 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)
{
	int ret;

	map->lock(map->lock_arg);
	ret = _regmap_update_bits(map, reg, mask, val, change);
	map->unlock(map->lock_arg);
	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_check);

/**
 * regmap_update_bits_check_async: Perform a read/modify/write cycle on the
 *                                 register map asynchronously 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
 *
 * With most buses the read must be done synchronously so this is most
 * useful for devices with a cache which do not need to interact with
 * the hardware to determine the current register value.
 *
 * Returns zero for success, a negative number on error.
 */
int regmap_update_bits_check_async(struct regmap *map, unsigned int reg,
				   unsigned int mask, unsigned int val,
				   bool *change)
{
	int ret;

	map->lock(map->lock_arg);

	map->async = true;

	ret = _regmap_update_bits(map, reg, mask, val, change);

	map->async = false;

	map->unlock(map->lock_arg);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_update_bits_check_async);

void regmap_async_complete_cb(struct regmap_async *async, int ret)
{
	struct regmap *map = async->map;
	bool wake;

	trace_regmap_async_io_complete(map);

	spin_lock(&map->async_lock);
	list_move(&async->list, &map->async_free);
	wake = list_empty(&map->async_list);

	if (ret != 0)
		map->async_ret = ret;

	spin_unlock(&map->async_lock);

	if (wake)
		wake_up(&map->async_waitq);
}
EXPORT_SYMBOL_GPL(regmap_async_complete_cb);

static int regmap_async_is_done(struct regmap *map)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&map->async_lock, flags);
	ret = list_empty(&map->async_list);
	spin_unlock_irqrestore(&map->async_lock, flags);

	return ret;
}

/**
 * regmap_async_complete: Ensure all asynchronous I/O has completed.
 *
 * @map: Map to operate on.
 *
 * Blocks until any pending asynchronous I/O has completed.  Returns
 * an error code for any failed I/O operations.
 */
int regmap_async_complete(struct regmap *map)
{
	unsigned long flags;
	int ret;

	/* Nothing to do with no async support */
	if (!map->bus || !map->bus->async_write)
		return 0;

	trace_regmap_async_complete_start(map);

	wait_event(map->async_waitq, regmap_async_is_done(map));

	spin_lock_irqsave(&map->async_lock, flags);
	ret = map->async_ret;
	map->async_ret = 0;
	spin_unlock_irqrestore(&map->async_lock, flags);

	trace_regmap_async_complete_done(map);

	return ret;
}
EXPORT_SYMBOL_GPL(regmap_async_complete);

/**
 * 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.
 *
 * The caller must ensure that this function cannot be called
 * concurrently with either itself or regcache_sync().
 */
int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
			  int num_regs)
{
	struct reg_default *p;
	int ret;
	bool bypass;

	if (WARN_ONCE(num_regs <= 0, "invalid registers number (%d)\n",
	    num_regs))
		return 0;

	p = krealloc(map->patch,
		     sizeof(struct reg_default) * (map->patch_regs + num_regs),
		     GFP_KERNEL);
	if (p) {
		memcpy(p + map->patch_regs, regs, num_regs * sizeof(*regs));
		map->patch = p;
		map->patch_regs += num_regs;
	} else {
		return -ENOMEM;
	}

	map->lock(map->lock_arg);

	bypass = map->cache_bypass;

	map->cache_bypass = true;
	map->async = true;

	ret = _regmap_multi_reg_write(map, regs, num_regs);
	if (ret != 0)
		goto out;

out:
	map->async = false;
	map->cache_bypass = bypass;

	map->unlock(map->lock_arg);

	regmap_async_complete(map);

	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);

/**
 * regmap_get_max_register(): Report the max register value
 *
 * Report the max register value, mainly intended to for use by
 * generic infrastructure built on top of regmap.
 */
int regmap_get_max_register(struct regmap *map)
{
	return map->max_register ? map->max_register : -EINVAL;
}
EXPORT_SYMBOL_GPL(regmap_get_max_register);

int regmap_parse_val(struct regmap *map, const void *buf,
			unsigned int *val)
{
	if (!map->format.parse_val)
		return -EINVAL;

	*val = map->format.parse_val(buf);

	return 0;
}
EXPORT_SYMBOL_GPL(regmap_parse_val);

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

	return 0;
}
postcore_initcall(regmap_initcall);