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Commit 7b053842 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'regmap-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap 

Pull regmap updates from Mark Brown:
 "In user visible terms just a couple of enhancements here, though there
  was a moderate amount of refactoring required in order to support the
  register cache sync performance improvements.

   - Support for block and asynchronous I/O during register cache
     syncing; this provides a use case dependant performance
     improvement.
   - Additional debugfs information on the memory consuption and
     register set"

* tag 'regmap-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap: (23 commits)
  regmap: don't corrupt work buffer in _regmap_raw_write()
  regmap: cache: Fix format specifier in dev_dbg
  regmap: cache: Make regcache_sync_block_raw static
  regmap: cache: Write consecutive registers in a single block write
  regmap: cache: Split raw and non-raw syncs
  regmap: cache: Factor out block sync
  regmap: cache: Factor out reg_present support from rbtree cache
  regmap: cache: Use raw I/O to sync rbtrees if we can
  regmap: core: Provide regmap_can_raw_write() operation
  regmap: cache: Provide a get address of value operation
  regmap: Cut down on the average # of nodes in the rbtree cache
  regmap: core: Make raw write available to regcache
  regmap: core: Warn on invalid operation combinations
  regmap: irq: Clarify error message when we fail to request primary IRQ
  regmap: rbtree Expose total memory consumption in the rbtree debugfs entry
  regmap: debugfs: Add a registers `range' file
  regmap: debugfs: Simplify calculation of `c->max_reg'
  regmap: cache: Store caches in native register format where possible
  regmap: core: Split out in place value parsing
  regmap: cache: Use regcache_get_value() to check if we updated
  ...
parents 5415ba99 38a81796

drivers/base/regmap/internal.h

+34 −6
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ struct regmap_format { 
			     unsigned int reg, unsigned int val);

	void (*format_reg)(void *buf, unsigned int reg, unsigned int shift);

	void (*format_val)(void *buf, unsigned int val, unsigned int shift);

	unsigned int (*parse_val)(void *buf);

	unsigned int (*parse_val)(const void *buf);

	void (*parse_inplace)(void *buf);

};



struct regmap_async {
@@ -76,6 +77,7 @@ struct regmap { 
	unsigned int debugfs_tot_len;



	struct list_head debugfs_off_cache;

	struct mutex cache_lock;

#endif



	unsigned int max_register;
@@ -125,6 +127,9 @@ struct regmap { 
	void *cache;

	u32 cache_dirty;



	unsigned long *cache_present;

	unsigned int cache_present_nbits;



	struct reg_default *patch;

	int patch_regs;
@@ -187,12 +192,35 @@ int regcache_read(struct regmap *map, 
int regcache_write(struct regmap *map,

			unsigned int reg, unsigned int value);

int regcache_sync(struct regmap *map);



unsigned int regcache_get_val(const void *base, unsigned int idx,

			      unsigned int word_size);

bool regcache_set_val(void *base, unsigned int idx,

		      unsigned int val, unsigned int word_size);

int regcache_sync_block(struct regmap *map, void *block,

			unsigned int block_base, unsigned int start,

			unsigned int end);



static inline const void *regcache_get_val_addr(struct regmap *map,

						const void *base,

						unsigned int idx)

{

	return base + (map->cache_word_size * idx);

}



unsigned int regcache_get_val(struct regmap *map, const void *base,

			      unsigned int idx);

bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,

		      unsigned int val);

int regcache_lookup_reg(struct regmap *map, unsigned int reg);

int regcache_set_reg_present(struct regmap *map, unsigned int reg);



static inline bool regcache_reg_present(struct regmap *map, unsigned int reg)

{

	if (!map->cache_present)

		return true;

	if (reg > map->cache_present_nbits)

		return false;

	return map->cache_present[BIT_WORD(reg)] & BIT_MASK(reg);

}



int _regmap_raw_write(struct regmap *map, unsigned int reg,

		      const void *val, size_t val_len, bool async);



void regmap_async_complete_cb(struct regmap_async *async, int ret);

drivers/base/regmap/regcache-lzo.c

+2 −4
Original line number Diff line number Diff line
@@ -260,8 +260,7 @@ static int regcache_lzo_read(struct regmap *map, 
	ret = regcache_lzo_decompress_cache_block(map, lzo_block);

	if (ret >= 0)

		/* fetch the value from the cache */

		*value = regcache_get_val(lzo_block->dst, blkpos,

					  map->cache_word_size);

		*value = regcache_get_val(map, lzo_block->dst, blkpos);



	kfree(lzo_block->dst);

	/* restore the pointer and length of the compressed block */
@@ -304,8 +303,7 @@ static int regcache_lzo_write(struct regmap *map, 
	}



	/* write the new value to the cache */

	if (regcache_set_val(lzo_block->dst, blkpos, value,

			     map->cache_word_size)) {

	if (regcache_set_val(map, lzo_block->dst, blkpos, value)) {

		kfree(lzo_block->dst);

		goto out;

	}

drivers/base/regmap/regcache-rbtree.c

+46 −54
Original line number Diff line number Diff line
@@ -47,18 +47,17 @@ static inline void regcache_rbtree_get_base_top_reg( 
	*top = rbnode->base_reg + ((rbnode->blklen - 1) * map->reg_stride);

}



static unsigned int regcache_rbtree_get_register(

	struct regcache_rbtree_node *rbnode, unsigned int idx,

	unsigned int word_size)

static unsigned int regcache_rbtree_get_register(struct regmap *map,

	struct regcache_rbtree_node *rbnode, unsigned int idx)

{

	return regcache_get_val(rbnode->block, idx, word_size);

	return regcache_get_val(map, rbnode->block, idx);

}



static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,

					 unsigned int idx, unsigned int val,

					 unsigned int word_size)

static void regcache_rbtree_set_register(struct regmap *map,

					 struct regcache_rbtree_node *rbnode,

					 unsigned int idx, unsigned int val)

{

	regcache_set_val(rbnode->block, idx, val, word_size);

	regcache_set_val(map, rbnode->block, idx, val);

}



static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
@@ -139,15 +138,21 @@ static int rbtree_show(struct seq_file *s, void *ignored) 
	struct regcache_rbtree_node *n;

	struct rb_node *node;

	unsigned int base, top;

	size_t mem_size;

	int nodes = 0;

	int registers = 0;

	int this_registers, average;



	map->lock(map);



	mem_size = sizeof(*rbtree_ctx);

	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);



	for (node = rb_first(&rbtree_ctx->root); node != NULL;

	     node = rb_next(node)) {

		n = container_of(node, struct regcache_rbtree_node, node);

		mem_size += sizeof(*n);

		mem_size += (n->blklen * map->cache_word_size);



		regcache_rbtree_get_base_top_reg(map, n, &base, &top);

		this_registers = ((top - base) / map->reg_stride) + 1;
@@ -162,8 +167,8 @@ static int rbtree_show(struct seq_file *s, void *ignored) 
	else

		average = 0;



	seq_printf(s, "%d nodes, %d registers, average %d registers\n",

		   nodes, registers, average);

	seq_printf(s, "%d nodes, %d registers, average %d registers, used %zu bytes\n",

		   nodes, registers, average, mem_size);



	map->unlock(map);
@@ -260,8 +265,9 @@ static int regcache_rbtree_read(struct regmap *map, 
	rbnode = regcache_rbtree_lookup(map, reg);

	if (rbnode) {

		reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;

		*value = regcache_rbtree_get_register(rbnode, reg_tmp,

						      map->cache_word_size);

		if (!regcache_reg_present(map, reg))

			return -ENOENT;

		*value = regcache_rbtree_get_register(map, rbnode, reg_tmp);

	} else {

		return -ENOENT;

	}
@@ -270,21 +276,23 @@ static int regcache_rbtree_read(struct regmap *map, 
}





static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,

static int regcache_rbtree_insert_to_block(struct regmap *map,

					   struct regcache_rbtree_node *rbnode,

					   unsigned int pos, unsigned int reg,

					   unsigned int value, unsigned int word_size)

					   unsigned int value)

{

	u8 *blk;



	blk = krealloc(rbnode->block,

		       (rbnode->blklen + 1) * word_size, GFP_KERNEL);

		       (rbnode->blklen + 1) * map->cache_word_size,

		       GFP_KERNEL);

	if (!blk)

		return -ENOMEM;



	/* insert the register value in the correct place in the rbnode block */

	memmove(blk + (pos + 1) * word_size,

		blk + pos * word_size,

		(rbnode->blklen - pos) * word_size);

	memmove(blk + (pos + 1) * map->cache_word_size,

		blk + pos * map->cache_word_size,

		(rbnode->blklen - pos) * map->cache_word_size);



	/* update the rbnode block, its size and the base register */

	rbnode->block = blk;
@@ -292,7 +300,7 @@ static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode, 
	if (!pos)

		rbnode->base_reg = reg;



	regcache_rbtree_set_register(rbnode, pos, value, word_size);

	regcache_rbtree_set_register(map, rbnode, pos, value);

	return 0;

}
@@ -302,25 +310,24 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg, 
	struct regcache_rbtree_ctx *rbtree_ctx;

	struct regcache_rbtree_node *rbnode, *rbnode_tmp;

	struct rb_node *node;

	unsigned int val;

	unsigned int reg_tmp;

	unsigned int pos;

	int i;

	int ret;



	rbtree_ctx = map->cache;

	/* update the reg_present bitmap, make space if necessary */

	ret = regcache_set_reg_present(map, reg);

	if (ret < 0)

		return ret;



	/* if we can't locate it in the cached rbnode we'll have

	 * to traverse the rbtree looking for it.

	 */

	rbnode = regcache_rbtree_lookup(map, reg);

	if (rbnode) {

		reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;

		val = regcache_rbtree_get_register(rbnode, reg_tmp,

						   map->cache_word_size);

		if (val == value)

			return 0;

		regcache_rbtree_set_register(rbnode, reg_tmp, value,

					     map->cache_word_size);

		regcache_rbtree_set_register(map, rbnode, reg_tmp, value);

	} else {

		/* look for an adjacent register to the one we are about to add */

		for (node = rb_first(&rbtree_ctx->root); node;
@@ -337,9 +344,10 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg, 
					pos = i + 1;

				else

					pos = i;

				ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,

								      reg, value,

								      map->cache_word_size);

				ret = regcache_rbtree_insert_to_block(map,

								      rbnode_tmp,

								      pos, reg,

								      value);

				if (ret)

					return ret;

				rbtree_ctx->cached_rbnode = rbnode_tmp;
@@ -354,7 +362,7 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg, 
		rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);

		if (!rbnode)

			return -ENOMEM;

		rbnode->blklen = 1;

		rbnode->blklen = sizeof(*rbnode);

		rbnode->base_reg = reg;

		rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,

					GFP_KERNEL);
@@ -362,7 +370,7 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg, 
			kfree(rbnode);

			return -ENOMEM;

		}

		regcache_rbtree_set_register(rbnode, 0, value, map->cache_word_size);

		regcache_rbtree_set_register(map, rbnode, 0, value);

		regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);

		rbtree_ctx->cached_rbnode = rbnode;

	}
@@ -376,10 +384,8 @@ static int regcache_rbtree_sync(struct regmap *map, unsigned int min, 
	struct regcache_rbtree_ctx *rbtree_ctx;

	struct rb_node *node;

	struct regcache_rbtree_node *rbnode;

	unsigned int regtmp;

	unsigned int val;

	int ret;

	int i, base, end;

	int base, end;



	rbtree_ctx = map->cache;

	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
@@ -402,27 +408,13 @@ static int regcache_rbtree_sync(struct regmap *map, unsigned int min, 
		else

			end = rbnode->blklen;



		for (i = base; i < end; i++) {

			regtmp = rbnode->base_reg + (i * map->reg_stride);

			val = regcache_rbtree_get_register(rbnode, i,

							   map->cache_word_size);



			/* Is this the hardware default?  If so skip. */

			ret = regcache_lookup_reg(map, regtmp);

			if (ret >= 0 && val == map->reg_defaults[ret].def)

				continue;



			map->cache_bypass = 1;

			ret = _regmap_write(map, regtmp, val);

			map->cache_bypass = 0;

			if (ret)

		ret = regcache_sync_block(map, rbnode->block, rbnode->base_reg,

					  base, end);

		if (ret != 0)

			return ret;

			dev_dbg(map->dev, "Synced register %#x, value %#x\n",

				regtmp, val);

		}

	}



	return 0;

	return regmap_async_complete(map);

}



struct regcache_ops regcache_rbtree_ops = {

drivers/base/regmap/regcache.c

+178 −18
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ static int regcache_hw_init(struct regmap *map) 
		tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);

		if (!tmp_buf)

			return -EINVAL;

		ret = regmap_bulk_read(map, 0, tmp_buf,

		ret = regmap_raw_read(map, 0, tmp_buf,

				      map->num_reg_defaults_raw);

		map->cache_bypass = cache_bypass;

		if (ret < 0) {
@@ -58,8 +58,7 @@ static int regcache_hw_init(struct regmap *map) 


	/* calculate the size of reg_defaults */

	for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) {

		val = regcache_get_val(map->reg_defaults_raw,

				       i, map->cache_word_size);

		val = regcache_get_val(map, map->reg_defaults_raw, i);

		if (regmap_volatile(map, i * map->reg_stride))

			continue;

		count++;
@@ -75,8 +74,7 @@ static int regcache_hw_init(struct regmap *map) 
	/* fill the reg_defaults */

	map->num_reg_defaults = count;

	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {

		val = regcache_get_val(map->reg_defaults_raw,

				       i, map->cache_word_size);

		val = regcache_get_val(map, map->reg_defaults_raw, i);

		if (regmap_volatile(map, i * map->reg_stride))

			continue;

		map->reg_defaults[j].reg = i * map->reg_stride;
@@ -123,6 +121,8 @@ int regcache_init(struct regmap *map, const struct regmap_config *config) 
	map->reg_defaults_raw = config->reg_defaults_raw;

	map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8);

	map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;

	map->cache_present = NULL;

	map->cache_present_nbits = 0;



	map->cache = NULL;

	map->cache_ops = cache_types[i];
@@ -181,6 +181,7 @@ void regcache_exit(struct regmap *map) 


	BUG_ON(!map->cache_ops);



	kfree(map->cache_present);

	kfree(map->reg_defaults);

	if (map->cache_free)

		kfree(map->reg_defaults_raw);
@@ -417,28 +418,68 @@ void regcache_cache_bypass(struct regmap *map, bool enable) 
}

EXPORT_SYMBOL_GPL(regcache_cache_bypass);



bool regcache_set_val(void *base, unsigned int idx,

		      unsigned int val, unsigned int word_size)

int regcache_set_reg_present(struct regmap *map, unsigned int reg)

{

	switch (word_size) {

	unsigned long *cache_present;

	unsigned int cache_present_size;

	unsigned int nregs;

	int i;



	nregs = reg + 1;

	cache_present_size = BITS_TO_LONGS(nregs);

	cache_present_size *= sizeof(long);



	if (!map->cache_present) {

		cache_present = kmalloc(cache_present_size, GFP_KERNEL);

		if (!cache_present)

			return -ENOMEM;

		bitmap_zero(cache_present, nregs);

		map->cache_present = cache_present;

		map->cache_present_nbits = nregs;

	}



	if (nregs > map->cache_present_nbits) {

		cache_present = krealloc(map->cache_present,

					 cache_present_size, GFP_KERNEL);

		if (!cache_present)

			return -ENOMEM;

		for (i = 0; i < nregs; i++)

			if (i >= map->cache_present_nbits)

				clear_bit(i, cache_present);

		map->cache_present = cache_present;

		map->cache_present_nbits = nregs;

	}



	set_bit(reg, map->cache_present);

	return 0;

}



bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,

		      unsigned int val)

{

	if (regcache_get_val(map, base, idx) == val)

		return true;



	/* Use device native format if possible */

	if (map->format.format_val) {

		map->format.format_val(base + (map->cache_word_size * idx),

				       val, 0);

		return false;

	}



	switch (map->cache_word_size) {

	case 1: {

		u8 *cache = base;

		if (cache[idx] == val)

			return true;

		cache[idx] = val;

		break;

	}

	case 2: {

		u16 *cache = base;

		if (cache[idx] == val)

			return true;

		cache[idx] = val;

		break;

	}

	case 4: {

		u32 *cache = base;

		if (cache[idx] == val)

			return true;

		cache[idx] = val;

		break;

	}
@@ -448,13 +489,18 @@ bool regcache_set_val(void *base, unsigned int idx, 
	return false;

}



unsigned int regcache_get_val(const void *base, unsigned int idx,

			      unsigned int word_size)

unsigned int regcache_get_val(struct regmap *map, const void *base,

			      unsigned int idx)

{

	if (!base)

		return -EINVAL;



	switch (word_size) {

	/* Use device native format if possible */

	if (map->format.parse_val)

		return map->format.parse_val(regcache_get_val_addr(map, base,

								   idx));



	switch (map->cache_word_size) {

	case 1: {

		const u8 *cache = base;

		return cache[idx];
@@ -498,3 +544,117 @@ int regcache_lookup_reg(struct regmap *map, unsigned int reg) 
	else

		return -ENOENT;

}



static int regcache_sync_block_single(struct regmap *map, void *block,

				      unsigned int block_base,

				      unsigned int start, unsigned int end)

{

	unsigned int i, regtmp, val;

	int ret;



	for (i = start; i < end; i++) {

		regtmp = block_base + (i * map->reg_stride);



		if (!regcache_reg_present(map, regtmp))

			continue;



		val = regcache_get_val(map, block, i);



		/* Is this the hardware default?  If so skip. */

		ret = regcache_lookup_reg(map, regtmp);

		if (ret >= 0 && val == map->reg_defaults[ret].def)

			continue;



		map->cache_bypass = 1;



		ret = _regmap_write(map, regtmp, val);



		map->cache_bypass = 0;

		if (ret != 0)

			return ret;

		dev_dbg(map->dev, "Synced register %#x, value %#x\n",

			regtmp, val);

	}



	return 0;

}



static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,

					 unsigned int base, unsigned int cur)

{

	size_t val_bytes = map->format.val_bytes;

	int ret, count;



	if (*data == NULL)

		return 0;



	count = cur - base;



	dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n",

		count * val_bytes, count, base, cur - 1);



	map->cache_bypass = 1;



	ret = _regmap_raw_write(map, base, *data, count * val_bytes,

				false);



	map->cache_bypass = 0;



	*data = NULL;



	return ret;

}



static int regcache_sync_block_raw(struct regmap *map, void *block,

			    unsigned int block_base, unsigned int start,

			    unsigned int end)

{

	unsigned int i, val;

	unsigned int regtmp = 0;

	unsigned int base = 0;

	const void *data = NULL;

	int ret;



	for (i = start; i < end; i++) {

		regtmp = block_base + (i * map->reg_stride);



		if (!regcache_reg_present(map, regtmp)) {

			ret = regcache_sync_block_raw_flush(map, &data,

							    base, regtmp);

			if (ret != 0)

				return ret;

			continue;

		}



		val = regcache_get_val(map, block, i);



		/* Is this the hardware default?  If so skip. */

		ret = regcache_lookup_reg(map, regtmp);

		if (ret >= 0 && val == map->reg_defaults[ret].def) {

			ret = regcache_sync_block_raw_flush(map, &data,

							    base, regtmp);

			if (ret != 0)

				return ret;

			continue;

		}



		if (!data) {

			data = regcache_get_val_addr(map, block, i);

			base = regtmp;

		}

	}



	return regcache_sync_block_raw_flush(map, &data, base, regtmp);

}



int regcache_sync_block(struct regmap *map, void *block,

			unsigned int block_base, unsigned int start,

			unsigned int end)

{

	if (regmap_can_raw_write(map))

		return regcache_sync_block_raw(map, block, block_base,

					       start, end);

	else

		return regcache_sync_block_single(map, block, block_base,

						  start, end);

}

drivers/base/regmap/regmap-debugfs.c

+87 −7
Original line number Diff line number Diff line
@@ -88,16 +88,16 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, 
	 * If we don't have a cache build one so we don't have to do a

	 * linear scan each time.

	 */

	mutex_lock(&map->cache_lock);

	i = base;

	if (list_empty(&map->debugfs_off_cache)) {

		for (i = base; i <= map->max_register; i += map->reg_stride) {

		for (; i <= map->max_register; i += map->reg_stride) {

			/* Skip unprinted registers, closing off cache entry */

			if (!regmap_readable(map, i) ||

			    regmap_precious(map, i)) {

				if (c) {

					c->max = p - 1;

					fpos_offset = c->max - c->min;

					reg_offset = fpos_offset / map->debugfs_tot_len;

					c->max_reg = c->base_reg + reg_offset;

					c->max_reg = i - map->reg_stride;

					list_add_tail(&c->list,

						      &map->debugfs_off_cache);

					c = NULL;
@@ -111,6 +111,7 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, 
				c = kzalloc(sizeof(*c), GFP_KERNEL);

				if (!c) {

					regmap_debugfs_free_dump_cache(map);

					mutex_unlock(&map->cache_lock);

					return base;

				}

				c->min = p;
@@ -124,9 +125,7 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, 
	/* Close the last entry off if we didn't scan beyond it */

	if (c) {

		c->max = p - 1;

		fpos_offset = c->max - c->min;

		reg_offset = fpos_offset / map->debugfs_tot_len;

		c->max_reg = c->base_reg + reg_offset;

		c->max_reg = i - map->reg_stride;

		list_add_tail(&c->list,

			      &map->debugfs_off_cache);

	}
@@ -145,12 +144,14 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, 
			fpos_offset = from - c->min;

			reg_offset = fpos_offset / map->debugfs_tot_len;

			*pos = c->min + (reg_offset * map->debugfs_tot_len);

			mutex_unlock(&map->cache_lock);

			return c->base_reg + reg_offset;

		}



		*pos = c->max;

		ret = c->max_reg;

	}

	mutex_unlock(&map->cache_lock);



	return ret;

}
@@ -311,6 +312,79 @@ static const struct file_operations regmap_range_fops = { 
	.llseek = default_llseek,

};



static ssize_t regmap_reg_ranges_read_file(struct file *file,

					   char __user *user_buf, size_t count,

					   loff_t *ppos)

{

	struct regmap *map = file->private_data;

	struct regmap_debugfs_off_cache *c;

	loff_t p = 0;

	size_t buf_pos = 0;

	char *buf;

	char *entry;

	int ret;



	if (*ppos < 0 || !count)

		return -EINVAL;



	buf = kmalloc(count, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	entry = kmalloc(PAGE_SIZE, GFP_KERNEL);

	if (!entry) {

		kfree(buf);

		return -ENOMEM;

	}



	/* While we are at it, build the register dump cache

	 * now so the read() operation on the `registers' file

	 * can benefit from using the cache.  We do not care

	 * about the file position information that is contained

	 * in the cache, just about the actual register blocks */

	regmap_calc_tot_len(map, buf, count);

	regmap_debugfs_get_dump_start(map, 0, *ppos, &p);



	/* Reset file pointer as the fixed-format of the `registers'

	 * file is not compatible with the `range' file */

	p = 0;

	mutex_lock(&map->cache_lock);

	list_for_each_entry(c, &map->debugfs_off_cache, list) {

		snprintf(entry, PAGE_SIZE, "%x-%x",

			 c->base_reg, c->max_reg);

		if (p >= *ppos) {

			if (buf_pos + 1 + strlen(entry) > count)

				break;

			snprintf(buf + buf_pos, count - buf_pos,

				 "%s", entry);

			buf_pos += strlen(entry);

			buf[buf_pos] = '\n';

			buf_pos++;

		}

		p += strlen(entry) + 1;

	}

	mutex_unlock(&map->cache_lock);



	kfree(entry);

	ret = buf_pos;



	if (copy_to_user(user_buf, buf, buf_pos)) {

		ret = -EFAULT;

		goto out_buf;

	}



	*ppos += buf_pos;

out_buf:

	kfree(buf);

	return ret;

}



static const struct file_operations regmap_reg_ranges_fops = {

	.open = simple_open,

	.read = regmap_reg_ranges_read_file,

	.llseek = default_llseek,

};



static ssize_t regmap_access_read_file(struct file *file,

				       char __user *user_buf, size_t count,

				       loff_t *ppos)
@@ -385,6 +459,7 @@ void regmap_debugfs_init(struct regmap *map, const char *name) 
	struct regmap_range_node *range_node;



	INIT_LIST_HEAD(&map->debugfs_off_cache);

	mutex_init(&map->cache_lock);



	if (name) {

		map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
@@ -403,6 +478,9 @@ void regmap_debugfs_init(struct regmap *map, const char *name) 
	debugfs_create_file("name", 0400, map->debugfs,

			    map, &regmap_name_fops);



	debugfs_create_file("range", 0400, map->debugfs,

			    map, &regmap_reg_ranges_fops);



	if (map->max_register) {

		debugfs_create_file("registers", 0400, map->debugfs,

				    map, &regmap_map_fops);
@@ -435,7 +513,9 @@ void regmap_debugfs_init(struct regmap *map, const char *name) 
void regmap_debugfs_exit(struct regmap *map)

{

	debugfs_remove_recursive(map->debugfs);

	mutex_lock(&map->cache_lock);

	regmap_debugfs_free_dump_cache(map);

	mutex_unlock(&map->cache_lock);

	kfree(map->debugfs_name);

}