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	When regmap consists of single register, 'regmap' subsystem is unable to understand whether ->max_register is set or not, because in both cases it is equal to zero. It leads to that the logic based on value of ->max_register doesn't work. For example using of REGCACHE_FLAT fails. This patch introduces an extra parameter to regmap config, indicating that zero value in ->max_register is authentic. Signed-off-by: Jan Dakinevich <jan.dakinevich@salutedevices.com> Link: https://lore.kernel.org/r/20240126200836.1829995-1-jan.dakinevich@salutedevices.com Signed-off-by: Mark Brown <broonie@kernel.org>
		
			
				
	
	
		
			83 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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//
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// Register cache access API - flat caching support
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//
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// Copyright 2012 Wolfson Microelectronics plc
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//
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// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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#include <linux/device.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include "internal.h"
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static inline unsigned int regcache_flat_get_index(const struct regmap *map,
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						   unsigned int reg)
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{
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	return regcache_get_index_by_order(map, reg);
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}
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static int regcache_flat_init(struct regmap *map)
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{
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	int i;
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	unsigned int *cache;
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	if (!map || map->reg_stride_order < 0 || !map->max_register_is_set)
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		return -EINVAL;
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	map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
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			     + 1, sizeof(unsigned int), GFP_KERNEL);
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	if (!map->cache)
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		return -ENOMEM;
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	cache = map->cache;
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	for (i = 0; i < map->num_reg_defaults; i++) {
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		unsigned int reg = map->reg_defaults[i].reg;
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		unsigned int index = regcache_flat_get_index(map, reg);
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		cache[index] = map->reg_defaults[i].def;
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	}
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	return 0;
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}
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static int regcache_flat_exit(struct regmap *map)
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{
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	kfree(map->cache);
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	map->cache = NULL;
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	return 0;
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}
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static int regcache_flat_read(struct regmap *map,
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			      unsigned int reg, unsigned int *value)
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{
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	unsigned int *cache = map->cache;
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	unsigned int index = regcache_flat_get_index(map, reg);
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	*value = cache[index];
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	return 0;
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}
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static int regcache_flat_write(struct regmap *map, unsigned int reg,
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			       unsigned int value)
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{
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	unsigned int *cache = map->cache;
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	unsigned int index = regcache_flat_get_index(map, reg);
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	cache[index] = value;
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	return 0;
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}
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struct regcache_ops regcache_flat_ops = {
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	.type = REGCACHE_FLAT,
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	.name = "flat",
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	.init = regcache_flat_init,
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	.exit = regcache_flat_exit,
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	.read = regcache_flat_read,
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	.write = regcache_flat_write,
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};
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