cregit-Linux how code gets into the kernel

Release 4.11 drivers/base/regmap/regcache.c

/*
 * 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 reg, 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_readable(map, i * map->reg_stride) && !regmap_volatile(map, i * map->reg_stride)) count++; /* all registers are unreadable or 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) { bool 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 = true; 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->cache_size_raw); map->cache_bypass = cache_bypass; if (ret == 0) { map->reg_defaults_raw = tmp_buf; map->cache_free = 1; } else { kfree(tmp_buf); } } /* fill the reg_defaults */ for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) { reg = i * map->reg_stride; if (!regmap_readable(map, reg)) continue; if (regmap_volatile(map, reg)) continue; if (map->reg_defaults_raw) { val = regcache_get_val(map, map->reg_defaults_raw, i); } else { bool cache_bypass = map->cache_bypass; map->cache_bypass = true; ret = regmap_read(map, reg, &val); map->cache_bypass = cache_bypass; if (ret != 0) { dev_err(map->dev, "Failed to read %d: %d\n", reg, ret); goto err_free; } } map->reg_defaults[j].reg = reg; map->reg_defaults[j].def = val; j++; } return 0; err_free: kfree(map->reg_defaults); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos15937.95%17.69%
Xiubo Li11026.25%323.08%
Mark Brown10124.11%215.38%
Laxman Dewangan174.06%17.69%
Lars-Peter Clausen153.58%215.38%
Maarten ter Huurne122.86%17.69%
Maciej S. Szmigiero20.48%17.69%
Viresh Kumar20.48%17.69%
Stephen Warren10.24%17.69%
Total419100.00%13100.00%


int regcache_init(struct regmap *map, const struct regmap_config *config) { int ret; int i; void *tmp_buf; if (map->cache_type == REGCACHE_NONE) { if (config->reg_defaults || config->num_reg_defaults_raw) dev_warn(map->dev, "No cache used with register defaults set!\n"); map->cache_bypass = true; return 0; } if (config->reg_defaults && !config->num_reg_defaults) { dev_err(map->dev, "Register defaults are set without the number!\n"); return -EINVAL; } for (i = 0; i < config->num_reg_defaults; i++) if (config->reg_defaults[i].reg % map->reg_stride) return -EINVAL; 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) { 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; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos23252.85%19.09%
Lars-Peter Clausen9220.96%436.36%
Xiubo Li7316.63%327.27%
Stephen Warren347.74%19.09%
Mark Brown81.82%218.18%
Total439100.00%11100.00%


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); } }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos81100.00%1100.00%
Total81100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos6671.74%150.00%
Mark Brown2628.26%150.00%
Total92100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos64100.00%1100.00%
Total64100.00%1100.00%


static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg, unsigned int val) { int ret; /* If we don't know the chip just got reset, then sync everything. */ if (!map->no_sync_defaults) return true; /* Is this the hardware default? If so skip. */ ret = regcache_lookup_reg(map, reg); if (ret >= 0 && val == map->reg_defaults[ret].def) return false; return true; }

Contributors

PersonTokensPropCommitsCommitProp
Kevin Cernekee66100.00%2100.00%
Total66100.00%2100.00%


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; if (!regcache_reg_needs_sync(map, reg, val)) continue; map->cache_bypass = true; ret = _regmap_write(map, reg, val); map->cache_bypass = false; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Maarten ter Huurne12477.99%116.67%
Jarkko Nikula159.43%116.67%
Dylan Reid127.55%233.33%
Kevin Cernekee63.77%116.67%
Viresh Kumar21.26%116.67%
Total159100.00%6100.00%

/** * 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; bool 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 = true; 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 = false; 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->no_sync_defaults = false; map->unlock(map->lock_arg); regmap_async_complete(map); trace_regcache_sync(map, name, "stop"); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown13144.86%635.29%
Dimitris Papastamos12141.44%635.29%
Maarten ter Huurne227.53%15.88%
Kevin Cernekee62.05%15.88%
Stephen Warren51.71%15.88%
Lars-Peter Clausen41.37%15.88%
Viresh Kumar31.03%15.88%
Total292100.00%17100.00%

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; bool 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->no_sync_defaults = false; map->unlock(map->lock_arg); regmap_async_complete(map); trace_regcache_sync(map, name, "stop region"); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown11863.78%218.18%
Dimitris Papastamos3116.76%436.36%
Maarten ter Huurne2010.81%19.09%
Kevin Cernekee63.24%19.09%
Stephen Warren52.70%19.09%
Lars-Peter Clausen42.16%19.09%
Viresh Kumar10.54%19.09%
Total185100.00%11100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown8093.02%133.33%
Lars-Peter Clausen66.98%266.67%
Total86100.00%3100.00%

EXPORT_SYMBOL_GPL(regcache_drop_region); /** * regcache_cache_only - Put a register map into cache only mode * * @map: map to configure * @enable: 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); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown2750.94%342.86%
Dimitris Papastamos1732.08%228.57%
Stephen Warren59.43%114.29%
Lars-Peter Clausen47.55%114.29%
Total53100.00%7100.00%

EXPORT_SYMBOL_GPL(regcache_cache_only); /** * regcache_mark_dirty - Indicate that HW registers were reset to default values * * @map: map to mark * * Inform regcache that the device has been powered down or reset, so that * on resume, regcache_sync() knows to write out all non-default values * stored in the cache. * * If this function is not called, regcache_sync() will assume that * the hardware state still matches the cache state, modulo any writes that * happened when cache_only was true. */
void regcache_mark_dirty(struct regmap *map) { map->lock(map->lock_arg); map->cache_dirty = true; map->no_sync_defaults = true; map->unlock(map->lock_arg); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown2562.50%125.00%
Kevin Cernekee615.00%125.00%
Stephen Warren512.50%125.00%
Lars-Peter Clausen410.00%125.00%
Total40100.00%4100.00%

EXPORT_SYMBOL_GPL(regcache_mark_dirty); /** * regcache_cache_bypass - Put a register map into cache bypass mode * * @map: map to configure * @enable: flag if changes should not be written to the cache * * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos3769.81%240.00%
Mark Brown713.21%120.00%
Stephen Warren59.43%120.00%
Lars-Peter Clausen47.55%120.00%
Total53100.00%5100.00%

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; } #ifdef CONFIG_64BIT case 8: { u64 *cache = base; cache[idx] = val; break; } #endif default: BUG(); } return false; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown7846.15%466.67%
Dimitris Papastamos6739.64%116.67%
Xiubo Li2414.20%116.67%
Total169100.00%6100.00%


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]; } #ifdef CONFIG_64BIT case 8: { const u64 *cache = base; return cache[idx]; } #endif default: BUG(); } /* unreachable */ return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos7449.66%116.67%
Mark Brown5234.90%466.67%
Xiubo Li2315.44%116.67%
Total149100.00%6100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Dimitris Papastamos4097.56%150.00%
Mark Brown12.44%150.00%
Total41100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown75100.00%2100.00%
Total75100.00%2100.00%


static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx) { if (!cache_present) return true; return test_bit(idx, cache_present); }

Contributors

PersonTokensPropCommitsCommitProp
Lars-Peter Clausen31100.00%1100.00%
Total31100.00%1100.00%


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); if (!regcache_reg_needs_sync(map, regtmp, val)) continue; map->cache_bypass = true; ret = _regmap_write(map, regtmp, val); map->cache_bypass = false; 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; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown13878.41%228.57%
Jarkko Nikula158.52%114.29%
Takashi Iwai84.55%114.29%
Lars-Peter Clausen73.98%114.29%
Kevin Cernekee63.41%114.29%
Viresh Kumar21.14%114.29%
Total176100.00%7100.00%


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 = true; 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 = false; *data = NULL; return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown10875.52%120.00%
Jarkko Nikula2316.08%120.00%
Dylan Reid96.29%120.00%
Viresh Kumar21.40%120.00%
Stratos Karafotis10.70%120.00%
Total143100.00%5100.00%


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); if (!regcache_reg_needs_sync(map, regtmp, val)) { 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); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown19388.13%337.50%
Lars-Peter Clausen115.02%225.00%
Takashi Iwai83.65%112.50%
Kevin Cernekee62.74%112.50%
Sachin Kamat10.46%112.50%
Total219100.00%8100.00%


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_write) 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); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Brown6686.84%250.00%
Lars-Peter Clausen911.84%125.00%
Markus Pargmann11.32%125.00%
Total76100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Mark Brown125939.50%2835.90%
Dimitris Papastamos102532.16%1316.67%
Xiubo Li2357.37%78.97%
Lars-Peter Clausen1915.99%911.54%
Maarten ter Huurne1785.59%22.56%
Kevin Cernekee1023.20%22.56%
Stephen Warren601.88%22.56%
Jarkko Nikula531.66%11.28%
Dylan Reid210.66%33.85%
Laxman Dewangan170.53%11.28%
Takashi Iwai160.50%11.28%
Viresh Kumar120.38%11.28%
Charles Keepax80.25%11.28%
Paul Gortmaker40.13%22.56%
Maciej S. Szmigiero20.06%11.28%
Markus Pargmann10.03%11.28%
Stratos Karafotis10.03%11.28%
Sachin Kamat10.03%11.28%
Steven Rostedt10.03%11.28%
Total3187100.00%78100.00%
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