From bcf7eac3d97f49d8400ba52c71bee5934bf20093 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Tue, 17 Jul 2018 00:47:48 +0900 Subject: regmap: add SCCB support This adds Serial Camera Control Bus (SCCB) support for regmap API that is intended to be used by some of Omnivision sensor drivers. The ov772x and ov9650 drivers are going to use this SCCB regmap API. The ov772x driver was previously only worked with the i2c controller drivers that support I2C_FUNC_PROTOCOL_MANGLING, because the ov772x device doesn't support repeated starts. After commit 0b964d183cbf ("media: ov772x: allow i2c controllers without I2C_FUNC_PROTOCOL_MANGLING"), reading ov772x register is replaced with issuing two separated i2c messages in order to avoid repeated start. Using this SCCB regmap hides the implementation detail. The ov9650 driver also issues two separated i2c messages to read the registers as the device doesn't support repeated start. So it can make use of this SCCB regmap. Cc: Mark Brown Cc: Peter Rosin Cc: Sebastian Reichel Cc: Wolfram Sang Cc: Sylwester Nawrocki Cc: Jacopo Mondi Cc: Laurent Pinchart Cc: Hans Verkuil Cc: Sakari Ailus Cc: Mauro Carvalho Chehab Signed-off-by: Akinobu Mita Signed-off-by: Mark Brown --- include/linux/regmap.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include') diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4f38068ffb71..52bf358e2c73 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -514,6 +514,10 @@ struct regmap *__regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); +struct regmap *__regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name); struct regmap *__regmap_init_slimbus(struct slim_device *slimbus, const struct regmap_config *config, struct lock_class_key *lock_key, @@ -558,6 +562,10 @@ struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); +struct regmap *__devm_regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name); struct regmap *__devm_regmap_init_spi(struct spi_device *dev, const struct regmap_config *config, struct lock_class_key *lock_key, @@ -645,6 +653,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, __regmap_lockdep_wrapper(__regmap_init_i2c, #config, \ i2c, config) +/** + * regmap_init_sccb() - Initialise register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer to + * a struct regmap. + */ +#define regmap_init_sccb(i2c, config) \ + __regmap_lockdep_wrapper(__regmap_init_sccb, #config, \ + i2c, config) + /** * regmap_init_slimbus() - Initialise register map * @@ -797,6 +818,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); __regmap_lockdep_wrapper(__devm_regmap_init_i2c, #config, \ i2c, config) +/** + * devm_regmap_init_sccb() - Initialise managed register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer + * to a struct regmap. The regmap will be automatically freed by the + * device management code. + */ +#define devm_regmap_init_sccb(i2c, config) \ + __regmap_lockdep_wrapper(__devm_regmap_init_sccb, #config, \ + i2c, config) + /** * devm_regmap_init_spi() - Initialise register map * -- cgit v1.2.3 From eef5ba1aa148ca5e6deb1e0aa1de797fa4e12cb7 Mon Sep 17 00:00:00 2001 From: Peter Rosin Date: Wed, 20 Jun 2018 10:51:53 +0200 Subject: i2c: smbus: add unlocked __i2c_smbus_xfer variant Removes all locking from i2c_smbus_xfer and renames it to __i2c_smbus_xfer, then adds a new i2c_smbus_xfer function that simply grabs the lock while calling the unlocked variant. This is not perfectly equivalent, since i2c_smbus_xfer was callable from atomic/irq context if you happened to end up emulating SMBus with an I2C transfer, and that is no longer the case with this patch. It is unknown (to me) if anything depends on that quirk, but it seems fragile enough to simply break those cases and require them to call i2c_transfer directly instead. While at it, for consistency rename the 2nd to last argument (size) of the i2c_smbus_xfer declaration to protocol and remove the surplus extern marker. Signed-off-by: Peter Rosin Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core-smbus.c | 28 ++++++++++++++++++++-------- include/linux/i2c.h | 11 ++++++++--- 2 files changed, 28 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 51970bae3c4a..9cd66cabb84f 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -463,7 +463,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, msg[num-1].len++; } - status = i2c_transfer(adapter, msg, num); + status = __i2c_transfer(adapter, msg, num); if (status < 0) goto cleanup; if (status != num) { @@ -524,9 +524,24 @@ cleanup: * This executes an SMBus protocol operation, and returns a negative * errno code else zero on success. */ -s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, - char read_write, u8 command, int protocol, - union i2c_smbus_data *data) +s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int protocol, union i2c_smbus_data *data) +{ + s32 res; + + i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); + res = __i2c_smbus_xfer(adapter, addr, flags, read_write, + command, protocol, data); + i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); + + return res; +} +EXPORT_SYMBOL(i2c_smbus_xfer); + +s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int protocol, union i2c_smbus_data *data) { unsigned long orig_jiffies; int try; @@ -543,8 +558,6 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; if (adapter->algo->smbus_xfer) { - i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); - /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; for (res = 0, try = 0; try <= adapter->retries; try++) { @@ -557,7 +570,6 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, orig_jiffies + adapter->timeout)) break; } - i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) goto trace; @@ -579,7 +591,7 @@ trace: return res; } -EXPORT_SYMBOL(i2c_smbus_xfer); +EXPORT_SYMBOL(__i2c_smbus_xfer); /** * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 254cd34eeae2..465afb092fa7 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -140,9 +140,14 @@ extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, and probably just as fast. Note that we use i2c_adapter here, because you do not need a specific smbus adapter to call this function. */ -extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, - unsigned short flags, char read_write, u8 command, - int size, union i2c_smbus_data *data); +s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, u8 command, + int protocol, union i2c_smbus_data *data); + +/* Unlocked flavor */ +s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, u8 command, + int protocol, union i2c_smbus_data *data); /* Now follow the 'nice' access routines. These also document the calling conventions of i2c_smbus_xfer. */ -- cgit v1.2.3 From 74fe7b551f3385fa585d92616c85b3a575b2b2cb Mon Sep 17 00:00:00 2001 From: Crestez Dan Leonard Date: Tue, 7 Aug 2018 17:52:17 +0300 Subject: regmap: Add regmap_noinc_read API The regmap API usually assumes that bulk read operations will read a range of registers but some I2C/SPI devices have certain registers for which a such a read operation will return data from an internal FIFO instead. Add an explicit API to support bulk read without range semantics. Some linux drivers use regmap_bulk_read or regmap_raw_read for such registers, for example mpu6050 or bmi150 from IIO. This only happens to work because when caching is disabled a single regmap read op will map to a single bus read op (as desired). This breaks if caching is enabled and reg+1 happens to be a cacheable register. Without regmap support refactoring a driver to enable regmap caching requires separate I2C and SPI paths. This is exactly what regmap is supposed to help avoid. Suggested-by: Jonathan Cameron Signed-off-by: Crestez Dan Leonard Signed-off-by: Stefan Popa Signed-off-by: Mark Brown --- drivers/base/regmap/internal.h | 3 ++ drivers/base/regmap/regmap.c | 79 +++++++++++++++++++++++++++++++++++++++++- include/linux/regmap.h | 19 ++++++++++ 3 files changed, 100 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 53785e0e297a..a6bf34d6394e 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -94,10 +94,12 @@ struct regmap { bool (*readable_reg)(struct device *dev, unsigned int reg); bool (*volatile_reg)(struct device *dev, unsigned int reg); bool (*precious_reg)(struct device *dev, unsigned int reg); + bool (*readable_noinc_reg)(struct device *dev, unsigned int reg); const struct regmap_access_table *wr_table; const struct regmap_access_table *rd_table; const struct regmap_access_table *volatile_table; const struct regmap_access_table *precious_table; + const struct regmap_access_table *rd_noinc_table; int (*reg_read)(void *context, unsigned int reg, unsigned int *val); int (*reg_write)(void *context, unsigned int reg, unsigned int val); @@ -181,6 +183,7 @@ bool regmap_writeable(struct regmap *map, unsigned int reg); bool regmap_readable(struct regmap *map, unsigned int reg); bool regmap_volatile(struct regmap *map, unsigned int reg); bool regmap_precious(struct regmap *map, unsigned int reg); +bool regmap_readable_noinc(struct regmap *map, unsigned int reg); int _regmap_write(struct regmap *map, unsigned int reg, unsigned int val); diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 3bc84885eb91..0360a90ad6b6 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -168,6 +168,17 @@ bool regmap_precious(struct regmap *map, unsigned int reg) return false; } +bool regmap_readable_noinc(struct regmap *map, unsigned int reg) +{ + if (map->readable_noinc_reg) + return map->readable_noinc_reg(map->dev, reg); + + if (map->rd_noinc_table) + return regmap_check_range_table(map, reg, map->rd_noinc_table); + + return true; +} + static bool regmap_volatile_range(struct regmap *map, unsigned int reg, size_t num) { @@ -766,10 +777,12 @@ struct regmap *__regmap_init(struct device *dev, map->rd_table = config->rd_table; map->volatile_table = config->volatile_table; map->precious_table = config->precious_table; + map->rd_noinc_table = config->rd_noinc_table; map->writeable_reg = config->writeable_reg; map->readable_reg = config->readable_reg; map->volatile_reg = config->volatile_reg; map->precious_reg = config->precious_reg; + map->readable_noinc_reg = config->readable_noinc_reg; map->cache_type = config->cache_type; spin_lock_init(&map->async_lock); @@ -1285,6 +1298,7 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config) map->readable_reg = config->readable_reg; map->volatile_reg = config->volatile_reg; map->precious_reg = config->precious_reg; + map->readable_noinc_reg = config->readable_noinc_reg; map->cache_type = config->cache_type; regmap_debugfs_init(map, config->name); @@ -2564,7 +2578,70 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val, EXPORT_SYMBOL_GPL(regmap_raw_read); /** - * regmap_field_read() - Read a value to a single register field + * regmap_noinc_read(): Read data from a register without incrementing the + * register number + * + * @map: Register map to read from + * @reg: Register to read from + * @val: Pointer to data buffer + * @val_len: Length of output buffer in bytes. + * + * The regmap API usually assumes that bulk bus read operations will read a + * range of registers. Some devices have certain registers for which a read + * operation read will read from an internal FIFO. + * + * The target register must be volatile but registers after it can be + * completely unrelated cacheable registers. + * + * This will attempt multiple reads as required to read val_len bytes. + * + * A value of zero will be returned on success, a negative errno will be + * returned in error cases. + */ +int regmap_noinc_read(struct regmap *map, unsigned int reg, + void *val, size_t val_len) +{ + size_t read_len; + int ret; + + if (!map->bus) + return -EINVAL; + if (!map->bus->read) + return -ENOTSUPP; + if (val_len % map->format.val_bytes) + return -EINVAL; + if (!IS_ALIGNED(reg, map->reg_stride)) + return -EINVAL; + if (val_len == 0) + return -EINVAL; + + map->lock(map->lock_arg); + + if (!regmap_volatile(map, reg) || !regmap_readable_noinc(map, reg)) { + ret = -EINVAL; + goto out_unlock; + } + + while (val_len) { + if (map->max_raw_read && map->max_raw_read < val_len) + read_len = map->max_raw_read; + else + read_len = val_len; + ret = _regmap_raw_read(map, reg, val, read_len); + if (ret) + goto out_unlock; + val = ((u8 *)val) + read_len; + val_len -= read_len; + } + +out_unlock: + map->unlock(map->lock_arg); + return ret; +} +EXPORT_SYMBOL_GPL(regmap_noinc_read); + +/** + * regmap_field_read(): Read a value to a single register field * * @field: Register field to read from * @val: Pointer to store read value diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4f38068ffb71..19df946499d2 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -268,6 +268,13 @@ typedef void (*regmap_unlock)(void *); * field is NULL but precious_table (see below) is not, the * check is performed on such table (a register is precious if * it belongs to one of the ranges specified by precious_table). + * @readable_noinc_reg: Optional callback returning true if the register + * supports multiple read operations without incrementing + * the register number. If this field is NULL but + * rd_noinc_table (see below) is not, the check is + * performed on such table (a register is no increment + * readable if it belongs to one of the ranges specified + * by rd_noinc_table). * @disable_locking: This regmap is either protected by external means or * is guaranteed not be be accessed from multiple threads. * Don't use any locking mechanisms. @@ -295,6 +302,7 @@ typedef void (*regmap_unlock)(void *); * @rd_table: As above, for read access. * @volatile_table: As above, for volatile registers. * @precious_table: As above, for precious registers. + * @rd_noinc_table: As above, for no increment readable registers. * @reg_defaults: Power on reset values for registers (for use with * register cache support). * @num_reg_defaults: Number of elements in reg_defaults. @@ -344,6 +352,7 @@ struct regmap_config { bool (*readable_reg)(struct device *dev, unsigned int reg); bool (*volatile_reg)(struct device *dev, unsigned int reg); bool (*precious_reg)(struct device *dev, unsigned int reg); + bool (*readable_noinc_reg)(struct device *dev, unsigned int reg); bool disable_locking; regmap_lock lock; @@ -360,6 +369,7 @@ struct regmap_config { const struct regmap_access_table *rd_table; const struct regmap_access_table *volatile_table; const struct regmap_access_table *precious_table; + const struct regmap_access_table *rd_noinc_table; const struct reg_default *reg_defaults; unsigned int num_reg_defaults; enum regcache_type cache_type; @@ -946,6 +956,8 @@ int regmap_raw_write_async(struct regmap *map, unsigned int reg, int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val); int regmap_raw_read(struct regmap *map, unsigned int reg, void *val, size_t val_len); +int regmap_noinc_read(struct regmap *map, unsigned int reg, + void *val, size_t val_len); int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, size_t val_count); int regmap_update_bits_base(struct regmap *map, unsigned int reg, @@ -1196,6 +1208,13 @@ static inline int regmap_raw_read(struct regmap *map, unsigned int reg, return -EINVAL; } +static inline int regmap_noinc_read(struct regmap *map, unsigned int reg, + void *val, size_t val_len) +{ + WARN_ONCE(1, "regmap API is disabled"); + return -EINVAL; +} + static inline int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, size_t val_count) { -- cgit v1.2.3