regmap: Add the rbtree cache support (28644c80) · Commits · 戴 / test

drivers/base/regmap/Makefile

+1 −1

Original line number	Original line	Diff line number	Diff line
	obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o		obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o regcache-rbtree.o
	obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o		obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
	obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o		obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
	obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o		obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o

drivers/base/regmap/internal.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -119,4 +119,5 @@ int regcache_insert_reg(struct regmap *map, unsigned int reg,
	unsigned int val);		unsigned int val);

	extern struct regcache_ops regcache_indexed_ops;		extern struct regcache_ops regcache_indexed_ops;
			extern struct regcache_ops regcache_rbtree_ops;
	#endif		#endif

drivers/base/regmap/regcache-rbtree.c

0 → 100644

+399 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Register cache access API - rbtree caching support
			*
			* Copyright 2011 Wolfson Microelectronics plc
			*
			* Author: Dimitris Papastamos <dp@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/slab.h>
			#include <linux/rbtree.h>

			#include "internal.h"

			static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
			unsigned int value);

			struct regcache_rbtree_node {
			/* the actual rbtree node holding this block */
			struct rb_node node;
			/* base register handled by this block */
			unsigned int base_reg;
			/* number of bytes needed to represent the register index */
			unsigned int word_size;
			/* block of adjacent registers */
			void *block;
			/* number of registers available in the block */
			unsigned int blklen;
			} __attribute__ ((packed));

			struct regcache_rbtree_ctx {
			struct rb_root root;
			struct regcache_rbtree_node *cached_rbnode;
			};

			static inline void regcache_rbtree_get_base_top_reg(
			struct regcache_rbtree_node *rbnode,
			unsigned int base, unsigned int top)
			{
			*base = rbnode->base_reg;
			*top = rbnode->base_reg + rbnode->blklen - 1;
			}

			static unsigned int regcache_rbtree_get_register(
			struct regcache_rbtree_node *rbnode, unsigned int idx)
			{
			unsigned int val;

			switch (rbnode->word_size) {
			case 1: {
			u8 *p = rbnode->block;
			val = p[idx];
			return val;
			}
			case 2: {
			u16 *p = rbnode->block;
			val = p[idx];
			return val;
			}
			default:
			BUG();
			break;
			}
			return -1;
			}

			static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
			unsigned int idx, unsigned int val)
			{
			switch (rbnode->word_size) {
			case 1: {
			u8 *p = rbnode->block;
			p[idx] = val;
			break;
			}
			case 2: {
			u16 *p = rbnode->block;
			p[idx] = val;
			break;
			}
			default:
			BUG();
			break;
			}
			}

			static struct regcache_rbtree_node *regcache_rbtree_lookup(
			struct rb_root *root, unsigned int reg)
			{
			struct rb_node *node;
			struct regcache_rbtree_node *rbnode;
			unsigned int base_reg, top_reg;

			node = root->rb_node;
			while (node) {
			rbnode = container_of(node, struct regcache_rbtree_node, node);
			regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
			if (reg >= base_reg && reg <= top_reg)
			return rbnode;
			else if (reg > top_reg)
			node = node->rb_right;
			else if (reg < base_reg)
			node = node->rb_left;
			}

			return NULL;
			}

			static int regcache_rbtree_insert(struct rb_root *root,
			struct regcache_rbtree_node *rbnode)
			{
			struct rb_node *new, parent;
			struct regcache_rbtree_node *rbnode_tmp;
			unsigned int base_reg_tmp, top_reg_tmp;
			unsigned int base_reg;

			parent = NULL;
			new = &root->rb_node;
			while (*new) {
			rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
			node);
			/* base and top registers of the current rbnode */
			regcache_rbtree_get_base_top_reg(rbnode_tmp, &base_reg_tmp,
			&top_reg_tmp);
			/* base register of the rbnode to be added */
			base_reg = rbnode->base_reg;
			parent = *new;
			/* if this register has already been inserted, just return */
			if (base_reg >= base_reg_tmp &&
			base_reg <= top_reg_tmp)
			return 0;
			else if (base_reg > top_reg_tmp)
			new = &((*new)->rb_right);
			else if (base_reg < base_reg_tmp)
			new = &((*new)->rb_left);
			}

			/* insert the node into the rbtree */
			rb_link_node(&rbnode->node, parent, new);
			rb_insert_color(&rbnode->node, root);

			return 1;
			}

			static int regcache_rbtree_init(struct regmap *map)
			{
			struct regcache_rbtree_ctx *rbtree_ctx;
			int i;
			int ret;

			map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
			if (!map->cache)
			return -ENOMEM;

			rbtree_ctx = map->cache;
			rbtree_ctx->root = RB_ROOT;
			rbtree_ctx->cached_rbnode = NULL;

			for (i = 0; i < map->num_reg_defaults; i++) {
			ret = regcache_rbtree_write(map,
			map->reg_defaults[i].reg,
			map->reg_defaults[i].def);
			if (ret)
			goto err;
			}

			return 0;

			err:
			regcache_exit(map);
			return ret;
			}

			static int regcache_rbtree_exit(struct regmap *map)
			{
			struct rb_node *next;
			struct regcache_rbtree_ctx *rbtree_ctx;
			struct regcache_rbtree_node *rbtree_node;

			/* if we've already been called then just return */
			rbtree_ctx = map->cache;
			if (!rbtree_ctx)
			return 0;

			/* free up the rbtree */
			next = rb_first(&rbtree_ctx->root);
			while (next) {
			rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
			next = rb_next(&rbtree_node->node);
			rb_erase(&rbtree_node->node, &rbtree_ctx->root);
			kfree(rbtree_node->block);
			kfree(rbtree_node);
			}

			/* release the resources */
			kfree(map->cache);
			map->cache = NULL;

			return 0;
			}

			static int regcache_rbtree_read(struct regmap *map,
			unsigned int reg, unsigned int *value)
			{
			struct regcache_rbtree_ctx *rbtree_ctx;
			struct regcache_rbtree_node *rbnode;
			unsigned int base_reg, top_reg;
			unsigned int reg_tmp;

			rbtree_ctx = map->cache;
			/* look up the required register in the cached rbnode */
			rbnode = rbtree_ctx->cached_rbnode;
			if (rbnode) {
			regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
			if (reg >= base_reg && reg <= top_reg) {
			reg_tmp = reg - base_reg;
			*value = regcache_rbtree_get_register(rbnode, reg_tmp);
			return 0;
			}
			}
			/* if we can't locate it in the cached rbnode we'll have
			* to traverse the rbtree looking for it.
			*/
			rbnode = regcache_rbtree_lookup(&rbtree_ctx->root, reg);
			if (rbnode) {
			reg_tmp = reg - rbnode->base_reg;
			*value = regcache_rbtree_get_register(rbnode, reg_tmp);
			rbtree_ctx->cached_rbnode = rbnode;
			} else {
			/* uninitialized registers default to 0 */
			*value = 0;
			}

			return 0;
			}


			static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
			unsigned int pos, unsigned int reg,
			unsigned int value)
			{
			u8 *blk;

			blk = krealloc(rbnode->block,
			(rbnode->blklen + 1) * rbnode->word_size, GFP_KERNEL);
			if (!blk)
			return -ENOMEM;

			/* insert the register value in the correct place in the rbnode block */
			memmove(blk + (pos + 1) * rbnode->word_size,
			blk + pos * rbnode->word_size,
			(rbnode->blklen - pos) * rbnode->word_size);

			/* update the rbnode block, its size and the base register */
			rbnode->block = blk;
			rbnode->blklen++;
			if (!pos)
			rbnode->base_reg = reg;

			regcache_rbtree_set_register(rbnode, pos, value);
			return 0;
			}

			static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
			unsigned int value)
			{
			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 base_reg, top_reg;
			unsigned int pos;
			int i;
			int ret;

			rbtree_ctx = map->cache;
			/* look up the required register in the cached rbnode */
			rbnode = rbtree_ctx->cached_rbnode;
			if (rbnode) {
			regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
			if (reg >= base_reg && reg <= top_reg) {
			reg_tmp = reg - base_reg;
			val = regcache_rbtree_get_register(rbnode, reg_tmp);
			if (val == value)
			return 0;
			regcache_rbtree_set_register(rbnode, reg_tmp, value);
			return 0;
			}
			}
			/* if we can't locate it in the cached rbnode we'll have
			* to traverse the rbtree looking for it.
			*/
			rbnode = regcache_rbtree_lookup(&rbtree_ctx->root, reg);
			if (rbnode) {
			reg_tmp = reg - rbnode->base_reg;
			val = regcache_rbtree_get_register(rbnode, reg_tmp);
			if (val == value)
			return 0;
			regcache_rbtree_set_register(rbnode, reg_tmp, value);
			rbtree_ctx->cached_rbnode = rbnode;
			} else {
			/* bail out early, no need to create the rbnode yet */
			if (!value)
			return 0;
			/* look for an adjacent register to the one we are about to add */
			for (node = rb_first(&rbtree_ctx->root); node;
			node = rb_next(node)) {
			rbnode_tmp = rb_entry(node, struct regcache_rbtree_node, node);
			for (i = 0; i < rbnode_tmp->blklen; i++) {
			reg_tmp = rbnode_tmp->base_reg + i;
			if (abs(reg_tmp - reg) != 1)
			continue;
			/* decide where in the block to place our register */
			if (reg_tmp + 1 == reg)
			pos = i + 1;
			else
			pos = i;
			ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,
			reg, value);
			if (ret)
			return ret;
			rbtree_ctx->cached_rbnode = rbnode_tmp;
			return 0;
			}
			}
			/* we did not manage to find a place to insert it in an existing
			* block so create a new rbnode with a single register in its block.
			* This block will get populated further if any other adjacent
			* registers get modified in the future.
			*/
			rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
			if (!rbnode)
			return -ENOMEM;
			rbnode->blklen = 1;
			rbnode->base_reg = reg;
			rbnode->word_size = map->cache_word_size;
			rbnode->block = kmalloc(rbnode->blklen * rbnode->word_size,
			GFP_KERNEL);
			if (!rbnode->block) {
			kfree(rbnode);
			return -ENOMEM;
			}
			regcache_rbtree_set_register(rbnode, 0, value);
			regcache_rbtree_insert(&rbtree_ctx->root, rbnode);
			rbtree_ctx->cached_rbnode = rbnode;
			}

			return 0;
			}

			static int regcache_rbtree_sync(struct regmap *map)
			{
			struct regcache_rbtree_ctx *rbtree_ctx;
			struct rb_node *node;
			struct regcache_rbtree_node *rbnode;
			unsigned int regtmp;
			unsigned int val, def;
			int ret;
			int i;

			rbtree_ctx = map->cache;
			for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
			rbnode = rb_entry(node, struct regcache_rbtree_node, node);
			for (i = 0; i < rbnode->blklen; i++) {
			regtmp = rbnode->base_reg + i;
			val = regcache_rbtree_get_register(rbnode, i);
			ret = regcache_lookup_reg(map, i);
			if (ret < 0)
			def = 0;
			else
			def = map->reg_defaults[ret].def;
			if (val == def)
			continue;
			map->cache_bypass = 1;
			ret = regmap_write(map, regtmp, val);
			map->cache_bypass = 0;
			if (ret)
			return ret;
			dev_dbg(map->dev, "Synced register %#x, value %#x\n",
			regtmp, val);
			}
			}

			return 0;
			}

			struct regcache_ops regcache_rbtree_ops = {
			.type = REGCACHE_RBTREE,
			.name = "rbtree",
			.init = regcache_rbtree_init,
			.exit = regcache_rbtree_exit,
			.read = regcache_rbtree_read,
			.write = regcache_rbtree_write,
			.sync = regcache_rbtree_sync
			};

drivers/base/regmap/regcache.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -17,6 +17,7 @@

	static const struct regcache_ops *cache_types[] = {		static const struct regcache_ops *cache_types[] = {
	&regcache_indexed_ops,		&regcache_indexed_ops,
			&regcache_rbtree_ops,
	};		};

	static int regcache_hw_init(struct regmap *map)		static int regcache_hw_init(struct regmap *map)

include/linux/regmap.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -24,6 +24,7 @@ struct spi_device;
	enum regcache_type {		enum regcache_type {
	REGCACHE_NONE,		REGCACHE_NONE,
	REGCACHE_INDEXED,		REGCACHE_INDEXED,
			REGCACHE_RBTREE,
	};		};

	/**		/**

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