Initial import

1 files changed, 723 insertions, 0 deletions

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
new file mode 100644
index 000000000..7eb7b3b98
--- /dev/null
+++ b/drivers/base/regmap/regcache.c
@@ -0,0 +1,723 @@
+/*
+ * Register cache access API
+ *
+ * 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/bsearch.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+
+#include "trace.h"
+#include "internal.h"
+
+static const struct regcache_ops *cache_types[] = {
+	&regcache_rbtree_ops,
+	&regcache_lzo_ops,
+	&regcache_flat_ops,
+};
+
+static int regcache_hw_init(struct regmap *map)
+{
+	int i, j;
+	int ret;
+	int count;
+	unsigned int val;
+	void *tmp_buf;
+
+	if (!map->num_reg_defaults_raw)
+		return -EINVAL;
+
+	/* calculate the size of reg_defaults */
+	for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++)
+		if (!regmap_volatile(map, i * map->reg_stride))
+			count++;
+
+	/* all registers are volatile, so just bypass */
+	if (!count) {
+		map->cache_bypass = true;
+		return 0;
+	}
+
+	map->num_reg_defaults = count;
+	map->reg_defaults = kmalloc_array(count, sizeof(struct reg_default),
+					  GFP_KERNEL);
+	if (!map->reg_defaults)
+		return -ENOMEM;
+
+	if (!map->reg_defaults_raw) {
+		u32 cache_bypass = map->cache_bypass;
+		dev_warn(map->dev, "No cache defaults, reading back from HW\n");
+
+		/* Bypass the cache access till data read from HW*/
+		map->cache_bypass = 1;
+		tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
+		if (!tmp_buf) {
+			ret = -ENOMEM;
+			goto err_free;
+		}
+		ret = regmap_raw_read(map, 0, tmp_buf,
+				      map->num_reg_defaults_raw);
+		map->cache_bypass = cache_bypass;
+		if (ret < 0)
+			goto err_cache_free;
+
+		map->reg_defaults_raw = tmp_buf;
+		map->cache_free = 1;
+	}
+
+	/* fill the reg_defaults */
+	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
+		if (regmap_volatile(map, i * map->reg_stride))
+			continue;
+		val = regcache_get_val(map, map->reg_defaults_raw, i);
+		map->reg_defaults[j].reg = i * map->reg_stride;
+		map->reg_defaults[j].def = val;
+		j++;
+	}
+
+	return 0;
+
+err_cache_free:
+	kfree(tmp_buf);
+err_free:
+	kfree(map->reg_defaults);
+
+	return ret;
+}
+
+int regcache_init(struct regmap *map, const struct regmap_config *config)
+{
+	int ret;
+	int i;
+	void *tmp_buf;
+
+	for (i = 0; i < config->num_reg_defaults; i++)
+		if (config->reg_defaults[i].reg % map->reg_stride)
+			return -EINVAL;
+
+	if (map->cache_type == REGCACHE_NONE) {
+		map->cache_bypass = true;
+		return 0;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(cache_types); i++)
+		if (cache_types[i]->type == map->cache_type)
+			break;
+
+	if (i == ARRAY_SIZE(cache_types)) {
+		dev_err(map->dev, "Could not match compress type: %d\n",
+			map->cache_type);
+		return -EINVAL;
+	}
+
+	map->num_reg_defaults = config->num_reg_defaults;
+	map->num_reg_defaults_raw = config->num_reg_defaults_raw;
+	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 = NULL;
+	map->cache_ops = cache_types[i];
+
+	if (!map->cache_ops->read ||
+	    !map->cache_ops->write ||
+	    !map->cache_ops->name)
+		return -EINVAL;
+
+	/* We still need to ensure that the reg_defaults
+	 * won't vanish from under us.  We'll need to make
+	 * a copy of it.
+	 */
+	if (config->reg_defaults) {
+		if (!map->num_reg_defaults)
+			return -EINVAL;
+		tmp_buf = kmemdup(config->reg_defaults, map->num_reg_defaults *
+				  sizeof(struct reg_default), GFP_KERNEL);
+		if (!tmp_buf)
+			return -ENOMEM;
+		map->reg_defaults = tmp_buf;
+	} else if (map->num_reg_defaults_raw) {
+		/* Some devices such as PMICs don't have cache defaults,
+		 * we cope with this by reading back the HW registers and
+		 * crafting the cache defaults by hand.
+		 */
+		ret = regcache_hw_init(map);
+		if (ret < 0)
+			return ret;
+		if (map->cache_bypass)
+			return 0;
+	}
+
+	if (!map->max_register)
+		map->max_register = map->num_reg_defaults_raw;
+
+	if (map->cache_ops->init) {
+		dev_dbg(map->dev, "Initializing %s cache\n",
+			map->cache_ops->name);
+		ret = map->cache_ops->init(map);
+		if (ret)
+			goto err_free;
+	}
+	return 0;
+
+err_free:
+	kfree(map->reg_defaults);
+	if (map->cache_free)
+		kfree(map->reg_defaults_raw);
+
+	return ret;
+}
+
+void regcache_exit(struct regmap *map)
+{
+	if (map->cache_type == REGCACHE_NONE)
+		return;
+
+	BUG_ON(!map->cache_ops);
+
+	kfree(map->reg_defaults);
+	if (map->cache_free)
+		kfree(map->reg_defaults_raw);
+
+	if (map->cache_ops->exit) {
+		dev_dbg(map->dev, "Destroying %s cache\n",
+			map->cache_ops->name);
+		map->cache_ops->exit(map);
+	}
+}
+
+/**
+ * regcache_read: Fetch the value of a given register from the cache.
+ *
+ * @map: map to configure.
+ * @reg: The register index.
+ * @value: The value to be returned.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_read(struct regmap *map,
+		  unsigned int reg, unsigned int *value)
+{
+	int ret;
+
+	if (map->cache_type == REGCACHE_NONE)
+		return -ENOSYS;
+
+	BUG_ON(!map->cache_ops);
+
+	if (!regmap_volatile(map, reg)) {
+		ret = map->cache_ops->read(map, reg, value);
+
+		if (ret == 0)
+			trace_regmap_reg_read_cache(map, reg, *value);
+
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * regcache_write: Set the value of a given register in the cache.
+ *
+ * @map: map to configure.
+ * @reg: The register index.
+ * @value: The new register value.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_write(struct regmap *map,
+		   unsigned int reg, unsigned int value)
+{
+	if (map->cache_type == REGCACHE_NONE)
+		return 0;
+
+	BUG_ON(!map->cache_ops);
+
+	if (!regmap_volatile(map, reg))
+		return map->cache_ops->write(map, reg, value);
+
+	return 0;
+}
+
+static int regcache_default_sync(struct regmap *map, unsigned int min,
+				 unsigned int max)
+{
+	unsigned int reg;
+
+	for (reg = min; reg <= max; reg += map->reg_stride) {
+		unsigned int val;
+		int ret;
+
+		if (regmap_volatile(map, reg) ||
+		    !regmap_writeable(map, reg))
+			continue;
+
+		ret = regcache_read(map, reg, &val);
+		if (ret)
+			return ret;
+
+		/* Is this the hardware default?  If so skip. */
+		ret = regcache_lookup_reg(map, reg);
+		if (ret >= 0 && val == map->reg_defaults[ret].def)
+			continue;
+
+		map->cache_bypass = 1;
+		ret = _regmap_write(map, reg, val);
+		map->cache_bypass = 0;
+		if (ret) {
+			dev_err(map->dev, "Unable to sync register %#x. %d\n",
+				reg, ret);
+			return ret;
+		}
+		dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
+	}
+
+	return 0;
+}
+
+/**
+ * regcache_sync: Sync the register cache with the hardware.
+ *
+ * @map: map to configure.
+ *
+ * Any registers that should not be synced should be marked as
+ * volatile.  In general drivers can choose not to use the provided
+ * syncing functionality if they so require.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_sync(struct regmap *map)
+{
+	int ret = 0;
+	unsigned int i;
+	const char *name;
+	unsigned int bypass;
+
+	BUG_ON(!map->cache_ops);
+
+	map->lock(map->lock_arg);
+	/* Remember the initial bypass state */
+	bypass = map->cache_bypass;
+	dev_dbg(map->dev, "Syncing %s cache\n",
+		map->cache_ops->name);
+	name = map->cache_ops->name;
+	trace_regcache_sync(map, name, "start");
+
+	if (!map->cache_dirty)
+		goto out;
+
+	map->async = true;
+
+	/* Apply any patch first */
+	map->cache_bypass = 1;
+	for (i = 0; i < map->patch_regs; i++) {
+		ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to write %x = %x: %d\n",
+				map->patch[i].reg, map->patch[i].def, ret);
+			goto out;
+		}
+	}
+	map->cache_bypass = 0;
+
+	if (map->cache_ops->sync)
+		ret = map->cache_ops->sync(map, 0, map->max_register);
+	else
+		ret = regcache_default_sync(map, 0, map->max_register);
+
+	if (ret == 0)
+		map->cache_dirty = false;
+
+out:
+	/* Restore the bypass state */
+	map->async = false;
+	map->cache_bypass = bypass;
+	map->unlock(map->lock_arg);
+
+	regmap_async_complete(map);
+
+	trace_regcache_sync(map, name, "stop");
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_sync);
+
+/**
+ * regcache_sync_region: Sync part  of the register cache with the hardware.
+ *
+ * @map: map to sync.
+ * @min: first register to sync
+ * @max: last register to sync
+ *
+ * Write all non-default register values in the specified region to
+ * the hardware.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_sync_region(struct regmap *map, unsigned int min,
+			 unsigned int max)
+{
+	int ret = 0;
+	const char *name;
+	unsigned int bypass;
+
+	BUG_ON(!map->cache_ops);
+
+	map->lock(map->lock_arg);
+
+	/* Remember the initial bypass state */
+	bypass = map->cache_bypass;
+
+	name = map->cache_ops->name;
+	dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
+
+	trace_regcache_sync(map, name, "start region");
+
+	if (!map->cache_dirty)
+		goto out;
+
+	map->async = true;
+
+	if (map->cache_ops->sync)
+		ret = map->cache_ops->sync(map, min, max);
+	else
+		ret = regcache_default_sync(map, min, max);
+
+out:
+	/* Restore the bypass state */
+	map->cache_bypass = bypass;
+	map->async = false;
+	map->unlock(map->lock_arg);
+
+	regmap_async_complete(map);
+
+	trace_regcache_sync(map, name, "stop region");
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_sync_region);
+
+/**
+ * regcache_drop_region: Discard part of the register cache
+ *
+ * @map: map to operate on
+ * @min: first register to discard
+ * @max: last register to discard
+ *
+ * Discard part of the register cache.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_drop_region(struct regmap *map, unsigned int min,
+			 unsigned int max)
+{
+	int ret = 0;
+
+	if (!map->cache_ops || !map->cache_ops->drop)
+		return -EINVAL;
+
+	map->lock(map->lock_arg);
+
+	trace_regcache_drop_region(map, min, max);
+
+	ret = map->cache_ops->drop(map, min, max);
+
+	map->unlock(map->lock_arg);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_drop_region);
+
+/**
+ * regcache_cache_only: Put a register map into cache only mode
+ *
+ * @map: map to configure
+ * @cache_only: flag if changes should be written to the hardware
+ *
+ * When a register map is marked as cache only writes to the register
+ * map API will only update the register cache, they will not cause
+ * any hardware changes.  This is useful for allowing portions of
+ * drivers to act as though the device were functioning as normal when
+ * it is disabled for power saving reasons.
+ */
+void regcache_cache_only(struct regmap *map, bool enable)
+{
+	map->lock(map->lock_arg);
+	WARN_ON(map->cache_bypass && enable);
+	map->cache_only = enable;
+	trace_regmap_cache_only(map, enable);
+	map->unlock(map->lock_arg);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_only);
+
+/**
+ * regcache_mark_dirty: Mark the register cache as dirty
+ *
+ * @map: map to mark
+ *
+ * Mark the register cache as dirty, for example due to the device
+ * having been powered down for suspend.  If the cache is not marked
+ * as dirty then the cache sync will be suppressed.
+ */
+void regcache_mark_dirty(struct regmap *map)
+{
+	map->lock(map->lock_arg);
+	map->cache_dirty = true;
+	map->unlock(map->lock_arg);
+}
+EXPORT_SYMBOL_GPL(regcache_mark_dirty);
+
+/**
+ * regcache_cache_bypass: Put a register map into cache bypass mode
+ *
+ * @map: map to configure
+ * @cache_bypass: flag if changes should not be written to the hardware
+ *
+ * When a register map is marked with the cache bypass option, writes
+ * to the register map API will only update the hardware and not the
+ * the cache directly.  This is useful when syncing the cache back to
+ * the hardware.
+ */
+void regcache_cache_bypass(struct regmap *map, bool enable)
+{
+	map->lock(map->lock_arg);
+	WARN_ON(map->cache_only && enable);
+	map->cache_bypass = enable;
+	trace_regmap_cache_bypass(map, enable);
+	map->unlock(map->lock_arg);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_bypass);
+
+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;
+		cache[idx] = val;
+		break;
+	}
+	case 2: {
+		u16 *cache = base;
+		cache[idx] = val;
+		break;
+	}
+	case 4: {
+		u32 *cache = base;
+		cache[idx] = val;
+		break;
+	}
+	default:
+		BUG();
+	}
+	return false;
+}
+
+unsigned int regcache_get_val(struct regmap *map, const void *base,
+			      unsigned int idx)
+{
+	if (!base)
+		return -EINVAL;
+
+	/* 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];
+	}
+	case 2: {
+		const u16 *cache = base;
+		return cache[idx];
+	}
+	case 4: {
+		const u32 *cache = base;
+		return cache[idx];
+	}
+	default:
+		BUG();
+	}
+	/* unreachable */
+	return -1;
+}
+
+static int regcache_default_cmp(const void *a, const void *b)
+{
+	const struct reg_default *_a = a;
+	const struct reg_default *_b = b;
+
+	return _a->reg - _b->reg;
+}
+
+int regcache_lookup_reg(struct regmap *map, unsigned int reg)
+{
+	struct reg_default key;
+	struct reg_default *r;
+
+	key.reg = reg;
+	key.def = 0;
+
+	r = bsearch(&key, map->reg_defaults, map->num_reg_defaults,
+		    sizeof(struct reg_default), regcache_default_cmp);
+
+	if (r)
+		return r - map->reg_defaults;
+	else
+		return -ENOENT;
+}
+
+static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx)
+{
+	if (!cache_present)
+		return true;
+
+	return test_bit(idx, cache_present);
+}
+
+static int regcache_sync_block_single(struct regmap *map, void *block,
+				      unsigned long *cache_present,
+				      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(cache_present, i) ||
+		    !regmap_writeable(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) {
+			dev_err(map->dev, "Unable to sync register %#x. %d\n",
+				regtmp, ret);
+			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) / map->reg_stride;
+
+	dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n",
+		count * val_bytes, count, base, cur - map->reg_stride);
+
+	map->cache_bypass = 1;
+
+	ret = _regmap_raw_write(map, base, *data, count * val_bytes);
+	if (ret)
+		dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
+			base, cur - map->reg_stride, ret);
+
+	map->cache_bypass = 0;
+
+	*data = NULL;
+
+	return ret;
+}
+
+static int regcache_sync_block_raw(struct regmap *map, void *block,
+			    unsigned long *cache_present,
+			    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(cache_present, i) ||
+		    !regmap_writeable(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 +
+			map->reg_stride);
+}
+
+int regcache_sync_block(struct regmap *map, void *block,
+			unsigned long *cache_present,
+			unsigned int block_base, unsigned int start,
+			unsigned int end)
+{
+	if (regmap_can_raw_write(map) && !map->use_single_rw)
+		return regcache_sync_block_raw(map, block, cache_present,
+					       block_base, start, end);
+	else
+		return regcache_sync_block_single(map, block, cache_present,
+						  block_base, start, end);
+}