| Message ID | 1531756070-8560-2-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > This adds Serial Camera Control Bus (SCCB) support for regmap API that > is intended to be used by some of Omnivision sensor drivers. The following changes since commit ce397d215ccd07b8ae3f71db689aedb85d56ab40: Linux 4.18-rc1 (2018-06-17 08:04:49 +0900) are available in the Git repository at: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git tags/regmap-sccb for you to fetch changes up to bcf7eac3d97f49d8400ba52c71bee5934bf20093: regmap: add SCCB support (2018-07-18 15:45:23 +0100) ---------------------------------------------------------------- regmap: Add support for SCCB This is an I2C subset. ---------------------------------------------------------------- Akinobu Mita (1): regmap: add SCCB support drivers/base/regmap/Kconfig | 4 ++ drivers/base/regmap/Makefile | 1 + drivers/base/regmap/regmap-sccb.c | 128 ++++++++++++++++++++++++++++++++++++++ include/linux/regmap.h | 35 +++++++++++ 4 files changed, 168 insertions(+) create mode 100644 drivers/base/regmap/regmap-sccb.c
On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > 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. Cool, this series really gets better and better each time. Thank you for keeping at it! And thanks to everyone for their suggestions. I really like how we do not introduce a couple of i2c_sccb_* functions with a need to export them. And given the nature of regmap, I'd think it should be fairly easy to add support for ov2659 somewhen which has 16 bit registers? Only minor nits: > +#include <linux/regmap.h> > +#include <linux/i2c.h> > +#include <linux/module.h> Sort these? > +/** > + * regmap_sccb_read - Read data from SCCB slave device > + * @context: Device that will be interacted wit "with" > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); Mark: __i2c_smbus_xfer is a dependency on i2c/for-next. Do you want an immutable branch for that? > +/** > + * regmap_sccb_write - Write data to SCCB slave device > + * @context: Device that will be interacted wit "with" But in general (especially for the I2C parts): Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
On Wed, Jul 18, 2018 at 05:28:32PM +0200, Wolfram Sang wrote: > On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > > + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); > Mark: __i2c_smbus_xfer is a dependency on i2c/for-next. Do you want an > immutable branch for that? Oh dear, that dependency wasn't mentioned anywhere I can see in the submissions and I already applied this and created a signed tag :( . I'll need a branch to pull in if I'm going to apply this (which I'd prefer, it tends to make life easier).
Hi, On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > 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 <broonie@kernel.org> > Cc: Peter Rosin <peda@axentia.se> > Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk> > Cc: Wolfram Sang <wsa@the-dreams.de> > Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> > Cc: Jacopo Mondi <jacopo+renesas@jmondi.org> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Cc: Hans Verkuil <hans.verkuil@cisco.com> > Cc: Sakari Ailus <sakari.ailus@linux.intel.com> > Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > --- Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> -- Sebastian > drivers/base/regmap/Kconfig | 4 ++ > drivers/base/regmap/Makefile | 1 + > drivers/base/regmap/regmap-sccb.c | 128 ++++++++++++++++++++++++++++++++++++++ > include/linux/regmap.h | 35 +++++++++++ > 4 files changed, 168 insertions(+) > create mode 100644 drivers/base/regmap/regmap-sccb.c > > diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig > index aff34c0..6ad5ef4 100644 > --- a/drivers/base/regmap/Kconfig > +++ b/drivers/base/regmap/Kconfig > @@ -45,3 +45,7 @@ config REGMAP_IRQ > config REGMAP_SOUNDWIRE > tristate > depends on SOUNDWIRE_BUS > + > +config REGMAP_SCCB > + tristate > + depends on I2C > diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile > index 5ed0023..f5b4e88 100644 > --- a/drivers/base/regmap/Makefile > +++ b/drivers/base/regmap/Makefile > @@ -15,3 +15,4 @@ obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o > obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o > obj-$(CONFIG_REGMAP_W1) += regmap-w1.o > obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o > +obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o > diff --git a/drivers/base/regmap/regmap-sccb.c b/drivers/base/regmap/regmap-sccb.c > new file mode 100644 > index 0000000..b6eb876 > --- /dev/null > +++ b/drivers/base/regmap/regmap-sccb.c > @@ -0,0 +1,128 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Register map access API - SCCB support > + > +#include <linux/regmap.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > + > +#include "internal.h" > + > +/** > + * sccb_is_available - Check if the adapter supports SCCB protocol > + * @adap: I2C adapter > + * > + * Return true if the I2C adapter is capable of using SCCB helper functions, > + * false otherwise. > + */ > +static bool sccb_is_available(struct i2c_adapter *adap) > +{ > + u32 needed_funcs = I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; > + > + /* > + * If we ever want support for hardware doing SCCB natively, we will > + * introduce a sccb_xfer() callback to struct i2c_algorithm and check > + * for it here. > + */ > + > + return (i2c_get_functionality(adap) & needed_funcs) == needed_funcs; > +} > + > +/** > + * regmap_sccb_read - Read data from SCCB slave device > + * @context: Device that will be interacted wit > + * @reg: Register to be read from > + * @val: Pointer to store read value > + * > + * This executes the 2-phase write transmission cycle that is followed by a > + * 2-phase read transmission cycle, returning negative errno else zero on > + * success. > + */ > +static int regmap_sccb_read(void *context, unsigned int reg, unsigned int *val) > +{ > + struct device *dev = context; > + struct i2c_client *i2c = to_i2c_client(dev); > + int ret; > + union i2c_smbus_data data; > + > + i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT); > + > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); > + if (ret < 0) > + goto out; > + > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data); > + if (ret < 0) > + goto out; > + > + *val = data.byte; > +out: > + i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT); > + > + return ret; > +} > + > +/** > + * regmap_sccb_write - Write data to SCCB slave device > + * @context: Device that will be interacted wit > + * @reg: Register to write to > + * @val: Value to be written > + * > + * This executes the SCCB 3-phase write transmission cycle, returning negative > + * errno else zero on success. > + */ > +static int regmap_sccb_write(void *context, unsigned int reg, unsigned int val) > +{ > + struct device *dev = context; > + struct i2c_client *i2c = to_i2c_client(dev); > + > + return i2c_smbus_write_byte_data(i2c, reg, val); > +} > + > +static struct regmap_bus regmap_sccb_bus = { > + .reg_write = regmap_sccb_write, > + .reg_read = regmap_sccb_read, > +}; > + > +static const struct regmap_bus *regmap_get_sccb_bus(struct i2c_client *i2c, > + const struct regmap_config *config) > +{ > + if (config->val_bits == 8 && config->reg_bits == 8 && > + sccb_is_available(i2c->adapter)) > + return ®map_sccb_bus; > + > + return ERR_PTR(-ENOTSUPP); > +} > + > +struct regmap *__regmap_init_sccb(struct i2c_client *i2c, > + const struct regmap_config *config, > + struct lock_class_key *lock_key, > + const char *lock_name) > +{ > + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); > + > + if (IS_ERR(bus)) > + return ERR_CAST(bus); > + > + return __regmap_init(&i2c->dev, bus, &i2c->dev, config, > + lock_key, lock_name); > +} > +EXPORT_SYMBOL_GPL(__regmap_init_sccb); > + > +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) > +{ > + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); > + > + if (IS_ERR(bus)) > + return ERR_CAST(bus); > + > + return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config, > + lock_key, lock_name); > +} > +EXPORT_SYMBOL_GPL(__devm_regmap_init_sccb); > + > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/regmap.h b/include/linux/regmap.h > index 4f38068..52bf358 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, > @@ -646,6 +654,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, > 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 > * > * @slimbus: Device that will be interacted with > @@ -798,6 +819,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); > 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 > * > * @dev: Device that will be interacted with > -- > 2.7.4 >
2018年7月19日(木) 0:28 Wolfram Sang <wsa@the-dreams.de>: > > On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > > 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. > > Cool, this series really gets better and better each time. Thank you for > keeping at it! And thanks to everyone for their suggestions. I really > like how we do not introduce a couple of i2c_sccb_* functions with a > need to export them. And given the nature of regmap, I'd think it should > be fairly easy to add support for ov2659 somewhen which has 16 bit > registers? Only minor nits: I have an ov2659 sensor. The ov2659 driver works with i2c adapter that doesn't know I2C_FUNC_PROTOCOL_MANGLING, so it actually supports repeated start. But ov5645, ov5647, ov7251 drivers may want to use SCCB regmap API for 16-bit register. Because they use i2c_master_send + i2c_master_recv for reading register value. > > +#include <linux/regmap.h> > > +#include <linux/i2c.h> > > +#include <linux/module.h> > > Sort these? > > > +/** > > + * regmap_sccb_read - Read data from SCCB slave device > > + * @context: Device that will be interacted wit > > "with" > > > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > > + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); > > Mark: __i2c_smbus_xfer is a dependency on i2c/for-next. Do you want an > immutable branch for that? > > > +/** > > + * regmap_sccb_write - Write data to SCCB slave device > > + * @context: Device that will be interacted wit > > "with" > > But in general (especially for the I2C parts): > > Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Thank you for your reviewing.
On Wed, Jul 18, 2018 at 04:31:40PM +0100, Mark Brown wrote: > On Wed, Jul 18, 2018 at 05:28:32PM +0200, Wolfram Sang wrote: > > On Tue, Jul 17, 2018 at 12:47:48AM +0900, Akinobu Mita wrote: > > > > + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, > > > + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); > > > Mark: __i2c_smbus_xfer is a dependency on i2c/for-next. Do you want an > > immutable branch for that? > > Oh dear, that dependency wasn't mentioned anywhere I can see in the > submissions and I already applied this and created a signed tag :( . > I'll need a branch to pull in if I'm going to apply this (which I'd > prefer, it tends to make life easier). Here is it: git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/smbus_xfer_unlock-immutable
On Fri, Jul 20, 2018 at 11:53:44PM +0200, Wolfram Sang wrote: > Here is it: > git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/smbus_xfer_unlock-immutable Thanks, pulled in now.
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig index aff34c0..6ad5ef4 100644 --- a/drivers/base/regmap/Kconfig +++ b/drivers/base/regmap/Kconfig @@ -45,3 +45,7 @@ config REGMAP_IRQ config REGMAP_SOUNDWIRE tristate depends on SOUNDWIRE_BUS + +config REGMAP_SCCB + tristate + depends on I2C diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile index 5ed0023..f5b4e88 100644 --- a/drivers/base/regmap/Makefile +++ b/drivers/base/regmap/Makefile @@ -15,3 +15,4 @@ obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o obj-$(CONFIG_REGMAP_W1) += regmap-w1.o obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o +obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o diff --git a/drivers/base/regmap/regmap-sccb.c b/drivers/base/regmap/regmap-sccb.c new file mode 100644 index 0000000..b6eb876 --- /dev/null +++ b/drivers/base/regmap/regmap-sccb.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0 +// Register map access API - SCCB support + +#include <linux/regmap.h> +#include <linux/i2c.h> +#include <linux/module.h> + +#include "internal.h" + +/** + * sccb_is_available - Check if the adapter supports SCCB protocol + * @adap: I2C adapter + * + * Return true if the I2C adapter is capable of using SCCB helper functions, + * false otherwise. + */ +static bool sccb_is_available(struct i2c_adapter *adap) +{ + u32 needed_funcs = I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; + + /* + * If we ever want support for hardware doing SCCB natively, we will + * introduce a sccb_xfer() callback to struct i2c_algorithm and check + * for it here. + */ + + return (i2c_get_functionality(adap) & needed_funcs) == needed_funcs; +} + +/** + * regmap_sccb_read - Read data from SCCB slave device + * @context: Device that will be interacted wit + * @reg: Register to be read from + * @val: Pointer to store read value + * + * This executes the 2-phase write transmission cycle that is followed by a + * 2-phase read transmission cycle, returning negative errno else zero on + * success. + */ +static int regmap_sccb_read(void *context, unsigned int reg, unsigned int *val) +{ + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + int ret; + union i2c_smbus_data data; + + i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT); + + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); + if (ret < 0) + goto out; + + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data); + if (ret < 0) + goto out; + + *val = data.byte; +out: + i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT); + + return ret; +} + +/** + * regmap_sccb_write - Write data to SCCB slave device + * @context: Device that will be interacted wit + * @reg: Register to write to + * @val: Value to be written + * + * This executes the SCCB 3-phase write transmission cycle, returning negative + * errno else zero on success. + */ +static int regmap_sccb_write(void *context, unsigned int reg, unsigned int val) +{ + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + + return i2c_smbus_write_byte_data(i2c, reg, val); +} + +static struct regmap_bus regmap_sccb_bus = { + .reg_write = regmap_sccb_write, + .reg_read = regmap_sccb_read, +}; + +static const struct regmap_bus *regmap_get_sccb_bus(struct i2c_client *i2c, + const struct regmap_config *config) +{ + if (config->val_bits == 8 && config->reg_bits == 8 && + sccb_is_available(i2c->adapter)) + return ®map_sccb_bus; + + return ERR_PTR(-ENOTSUPP); +} + +struct regmap *__regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __regmap_init(&i2c->dev, bus, &i2c->dev, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_sccb); + +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) +{ + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_sccb); + +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4f38068..52bf358 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, @@ -646,6 +654,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, 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 * * @slimbus: Device that will be interacted with @@ -798,6 +819,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); 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 * * @dev: Device that will be interacted with
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 <broonie@kernel.org> Cc: Peter Rosin <peda@axentia.se> Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Cc: Wolfram Sang <wsa@the-dreams.de> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Hans Verkuil <hans.verkuil@cisco.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> --- drivers/base/regmap/Kconfig | 4 ++ drivers/base/regmap/Makefile | 1 + drivers/base/regmap/regmap-sccb.c | 128 ++++++++++++++++++++++++++++++++++++++ include/linux/regmap.h | 35 +++++++++++ 4 files changed, 168 insertions(+) create mode 100644 drivers/base/regmap/regmap-sccb.c