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Wysocki" , CC: , Jan Dakinevich Subject: [RFC] regmap: rework ->max_register handling Date: Fri, 26 Jan 2024 23:08:36 +0300 Message-ID: <20240126200836.1829995-1-jan.dakinevich@salutedevices.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) To p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) X-KSMG-Rule-ID: 10 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 182973 [Jan 26 2024] X-KSMG-AntiSpam-Version: 6.1.0.3 X-KSMG-AntiSpam-Envelope-From: YVDakinevich@sberdevices.ru X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 7 0.3.7 6d6bf5bd8eea7373134f756a2fd73e9456bb7d1a, {Tracking_smtp_not_equal_from}, {Tracking_from_domain_doesnt_match_to}, smtp.sberdevices.ru:7.1.1,5.0.1;salutedevices.com:7.1.1;127.0.0.199:7.1.2;sberdevices.ru:7.1.1,5.0.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;100.64.160.123:7.1.2, FromAlignment: n, {Tracking_smtp_domain_mismatch}, {Tracking_smtp_domain_2level_mismatch}, {Tracking_white_helo}, ApMailHostAddress: 100.64.160.123 X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean X-KSMG-LinksScanning: Clean X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2024/01/26 14:25:00 #23442014 X-KSMG-AntiVirus-Status: Clean, skipped Content-Type: text/plain; charset="utf-8" ---- >8 ---- Indeed, it is an ugly workaround, but we need to pass an extra information to regmap. Another approach I'm thinking about is to introduce special macro for ->max_register initialization: #define REGMAP_MAX_REGISTER_IS_0 UINT_MAX #define REGMAP_MAX_REGISTER(_max) ((_max) ?: REGMAP_MAX_REGISTER_IS_0) and initialize regmap_config in the following way: struct regmap_config config =3D { ... .max_register =3D REGMAP_MAX_REGISTER(...), }; This will eliminate the need for an extra flag in the config. But this approach has another disadvantage, it imposes an extra requirement, that is not satisfied by existing code. ---- >8 ---- 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 --- drivers/base/regmap/internal.h | 1 + drivers/base/regmap/regcache-flat.c | 2 +- drivers/base/regmap/regcache.c | 4 +++- drivers/base/regmap/regmap.c | 10 ++++++---- include/linux/regmap.h | 5 +++++ 5 files changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 583dd5d7d46b..bcdb25bec77c 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -93,6 +93,7 @@ struct regmap { #endif =20 unsigned int max_register; + bool max_register_is_set; bool (*writeable_reg)(struct device *dev, unsigned int reg); bool (*readable_reg)(struct device *dev, unsigned int reg); bool (*volatile_reg)(struct device *dev, unsigned int reg); diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regc= ache-flat.c index b7e4b2464102..9b17c77dec9d 100644 --- a/drivers/base/regmap/regcache-flat.c +++ b/drivers/base/regmap/regcache-flat.c @@ -23,7 +23,7 @@ static int regcache_flat_init(struct regmap *map) int i; unsigned int *cache; =20 - if (!map || map->reg_stride_order < 0 || !map->max_register) + if (!map || map->reg_stride_order < 0 || !map->max_register_is_set) return -EINVAL; =20 map->cache =3D kcalloc(regcache_flat_get_index(map, map->max_register) diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index ac63a73ccdaa..2e41cb12b8e2 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -187,8 +187,10 @@ int regcache_init(struct regmap *map, const struct reg= map_config *config) return 0; } =20 - if (!map->max_register && map->num_reg_defaults_raw) + if (!map->max_register_is_set && map->num_reg_defaults_raw) { map->max_register =3D (map->num_reg_defaults_raw - 1) * map->reg_stride; + map->max_register_is_set =3D true; + } =20 if (map->cache_ops->init) { dev_dbg(map->dev, "Initializing %s cache\n", diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 6db77d8e45f9..5cb425f6f02d 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -89,7 +89,7 @@ EXPORT_SYMBOL_GPL(regmap_check_range_table); =20 bool regmap_writeable(struct regmap *map, unsigned int reg) { - if (map->max_register && reg > map->max_register) + if (map->max_register_is_set && reg > map->max_register) return false; =20 if (map->writeable_reg) @@ -112,7 +112,7 @@ bool regmap_cached(struct regmap *map, unsigned int reg) if (!map->cache_ops) return false; =20 - if (map->max_register && reg > map->max_register) + if (map->max_register_is_set && reg > map->max_register) return false; =20 map->lock(map->lock_arg); @@ -129,7 +129,7 @@ bool regmap_readable(struct regmap *map, unsigned int r= eg) if (!map->reg_read) return false; =20 - if (map->max_register && reg > map->max_register) + if (map->max_register_is_set && reg > map->max_register) return false; =20 if (map->format.format_write) @@ -787,6 +787,7 @@ struct regmap *__regmap_init(struct device *dev, map->bus =3D bus; map->bus_context =3D bus_context; map->max_register =3D config->max_register; + map->max_register_is_set =3D map->max_register ?: config->max_register_is= _0; map->wr_table =3D config->wr_table; map->rd_table =3D config->rd_table; map->volatile_table =3D config->volatile_table; @@ -1412,6 +1413,7 @@ int regmap_reinit_cache(struct regmap *map, const str= uct regmap_config *config) regmap_debugfs_exit(map); =20 map->max_register =3D config->max_register; + map->max_register_is_set =3D map->max_register ?: config->max_register_is= _0; map->writeable_reg =3D config->writeable_reg; map->readable_reg =3D config->readable_reg; map->volatile_reg =3D config->volatile_reg; @@ -3383,7 +3385,7 @@ EXPORT_SYMBOL_GPL(regmap_get_val_bytes); */ int regmap_get_max_register(struct regmap *map) { - return map->max_register ? map->max_register : -EINVAL; + return map->max_register_is_set ? map->max_register : -EINVAL; } EXPORT_SYMBOL_GPL(regmap_get_max_register); =20 diff --git a/include/linux/regmap.h b/include/linux/regmap.h index c9182a47736e..b743241cfb7c 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -332,6 +332,10 @@ typedef void (*regmap_unlock)(void *); * @io_port: Support IO port accessors. Makes sense only when MMIO vs. I= O port * access can be distinguished. * @max_register: Optional, specifies the maximum valid register address. + * @max_register_is_0: Optional, specifies that zero value in @max_register + * should be taken into account. This is a workaround = to + * apply handling of @max_register for regmap that con= tains + * only one register. * @wr_table: Optional, points to a struct regmap_access_table specify= ing * valid ranges for write access. * @rd_table: As above, for read access. @@ -422,6 +426,7 @@ struct regmap_config { bool io_port; =20 unsigned int max_register; + bool max_register_is_0; const struct regmap_access_table *wr_table; const struct regmap_access_table *rd_table; const struct regmap_access_table *volatile_table; --=20 2.34.1