--- /dev/null
+/*
+ * 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[] = {
+ ®cache_rbtree_ops,
+ ®cache_lzo_ops,
+ ®cache_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);
+}
Code Review / kvmfornfv.git / blobdiff