* [PATCH 0/2] i2c: introduce devm_i2c_new_dummy and use it in at24 driver @ 2017-12-05 19:40 Heiner Kallweit 2017-12-05 19:44 ` [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy Heiner Kallweit 2017-12-05 19:45 ` [PATCH resubmit 2/2] eeprom: at24: switch to " Heiner Kallweit 0 siblings, 2 replies; 5+ messages in thread From: Heiner Kallweit @ 2017-12-05 19:40 UTC (permalink / raw) To: Bartosz Golaszewski, Wolfram Sang, Peter Rosin Cc: linux-i2c@vger.kernel.org, Linux Kernel Mailing List i2c_new_dummy is typically called from the probe function of the driver for the primary i2c client. It requires calls to i2c_unregister_device in the error path of the probe function and in the remove function. This can be simplified by introducing a device-managed version. Make at24 driver the first user of the new function. Patch 1 has been submitted and reviewed some time ago, however it was waiting for a first user until now. Heiner Kallweit (2): i2c: core: add device-managed version of i2c_new_dummy eeprom: at24: switch to device-managed version of i2c_new_dummy Documentation/driver-model/devres.txt | 3 +++ drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++ drivers/misc/eeprom/at24.c | 7 +------ include/linux/i2c.h | 3 +++ 4 files changed, 46 insertions(+), 6 deletions(-) -- 2.15.1 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy 2017-12-05 19:40 [PATCH 0/2] i2c: introduce devm_i2c_new_dummy and use it in at24 driver Heiner Kallweit @ 2017-12-05 19:44 ` Heiner Kallweit 2017-12-06 10:36 ` Bartosz Golaszewski 2017-12-05 19:45 ` [PATCH resubmit 2/2] eeprom: at24: switch to " Heiner Kallweit 1 sibling, 1 reply; 5+ messages in thread From: Heiner Kallweit @ 2017-12-05 19:44 UTC (permalink / raw) To: Bartosz Golaszewski, Wolfram Sang, Peter Rosin Cc: linux-i2c@vger.kernel.org, Linux Kernel Mailing List i2c_new_dummy is typically called from the probe function of the driver for the primary i2c client. It requires calls to i2c_unregister_device in the error path of the probe function and in the remove function. This can be simplified by introducing a device-managed version. Note the changed error case return value type: i2c_new_dummy returns NULL whilst devm_new_i2c_dummy returns an ERR_PTR. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Peter Rosin <peda@axentia.se> --- Documentation/driver-model/devres.txt | 3 +++ drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++ include/linux/i2c.h | 3 +++ 3 files changed, 45 insertions(+) diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index c180045eb..6e2bccf85 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -259,6 +259,9 @@ GPIO devm_gpio_request_one() devm_gpio_free() +I2C + devm_i2c_new_dummy + IIO devm_iio_device_alloc() devm_iio_device_free() diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index bf52cca87..c1db67f9a 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -820,6 +820,45 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) } EXPORT_SYMBOL_GPL(i2c_new_dummy); +static void devm_i2c_release_dummy(struct device *dev, void *res) +{ + i2c_unregister_device(*(struct i2c_client **)res); +} + +/** + * devm_i2c_new_dummy - return a new i2c device bound to a dummy driver + * @dev: device the managed resource is bound to + * @adapter: the adapter managing the device + * @address: seven bit address to be used + * Context: can sleep + * + * This is the device-managed version of i2c_new_dummy. + * Note the changed return value type: It returns the new i2c client + * or an ERR_PTR in case of an error. + */ +struct i2c_client *devm_i2c_new_dummy(struct device *dev, + struct i2c_adapter *adapter, + u16 address) +{ + struct i2c_client *ret, **dr; + + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + ret = i2c_new_dummy(adapter, address); + if (!ret) { + devres_free(dr); + return ERR_PTR(-EBUSY); + } + + *dr = ret; + devres_add(dev, dr); + + return ret; +} +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy); + /** * i2c_new_secondary_device - Helper to get the instantiated secondary address * and create the associated device diff --git a/include/linux/i2c.h b/include/linux/i2c.h index a556db976..c27eac1e1 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -383,6 +383,9 @@ extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); extern struct i2c_client * i2c_new_dummy(struct i2c_adapter *adap, u16 address); +extern struct i2c_client * +devm_i2c_new_dummy(struct device *dev, struct i2c_adapter *adap, u16 address); + extern struct i2c_client * i2c_new_secondary_device(struct i2c_client *client, const char *name, -- 2.15.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy 2017-12-05 19:44 ` [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy Heiner Kallweit @ 2017-12-06 10:36 ` Bartosz Golaszewski 2017-12-06 19:05 ` Heiner Kallweit 0 siblings, 1 reply; 5+ messages in thread From: Bartosz Golaszewski @ 2017-12-06 10:36 UTC (permalink / raw) To: Heiner Kallweit Cc: Wolfram Sang, Peter Rosin, linux-i2c@vger.kernel.org, Linux Kernel Mailing List 2017-12-05 20:44 GMT+01:00 Heiner Kallweit <hkallweit1@gmail.com>: > i2c_new_dummy is typically called from the probe function of the > driver for the primary i2c client. It requires calls to > i2c_unregister_device in the error path of the probe function and > in the remove function. > This can be simplified by introducing a device-managed version. > > Note the changed error case return value type: > i2c_new_dummy returns NULL whilst devm_new_i2c_dummy returns an ERR_PTR. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > Reviewed-by: Peter Rosin <peda@axentia.se> > --- > Documentation/driver-model/devres.txt | 3 +++ > drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++ > include/linux/i2c.h | 3 +++ > 3 files changed, 45 insertions(+) > > diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt > index c180045eb..6e2bccf85 100644 > --- a/Documentation/driver-model/devres.txt > +++ b/Documentation/driver-model/devres.txt > @@ -259,6 +259,9 @@ GPIO > devm_gpio_request_one() > devm_gpio_free() > > +I2C > + devm_i2c_new_dummy > + > IIO > devm_iio_device_alloc() > devm_iio_device_free() > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index bf52cca87..c1db67f9a 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -820,6 +820,45 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) > } > EXPORT_SYMBOL_GPL(i2c_new_dummy); > > +static void devm_i2c_release_dummy(struct device *dev, void *res) > +{ > + i2c_unregister_device(*(struct i2c_client **)res); > +} > + Wolfram will have the last word here, but I would really prefer that you wrap struct i2c_client in a separate devres (e.g. struct i2c_dummy_devres) structure and avoid the cast. I find it a lot more readable even if it only has a single member. > +/** > + * devm_i2c_new_dummy - return a new i2c device bound to a dummy driver > + * @dev: device the managed resource is bound to > + * @adapter: the adapter managing the device > + * @address: seven bit address to be used > + * Context: can sleep > + * > + * This is the device-managed version of i2c_new_dummy. > + * Note the changed return value type: It returns the new i2c client > + * or an ERR_PTR in case of an error. > + */ > +struct i2c_client *devm_i2c_new_dummy(struct device *dev, > + struct i2c_adapter *adapter, > + u16 address) > +{ > + struct i2c_client *ret, **dr; > + > + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); > + if (!dr) > + return ERR_PTR(-ENOMEM); > + > + ret = i2c_new_dummy(adapter, address); > + if (!ret) { > + devres_free(dr); > + return ERR_PTR(-EBUSY); This is misleading as EBUSY is not necessarily the error that cased i2c_new_device() to fail. Return NULL here and document that users need to use IS_ERR_OR_NULL() to check for errors. > + } > + > + *dr = ret; > + devres_add(dev, dr); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy); > + > /** > * i2c_new_secondary_device - Helper to get the instantiated secondary address > * and create the associated device > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index a556db976..c27eac1e1 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -383,6 +383,9 @@ extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); > extern struct i2c_client * > i2c_new_dummy(struct i2c_adapter *adap, u16 address); > > +extern struct i2c_client * > +devm_i2c_new_dummy(struct device *dev, struct i2c_adapter *adap, u16 address); > + > extern struct i2c_client * > i2c_new_secondary_device(struct i2c_client *client, > const char *name, > -- > 2.15.1 > > Thanks, Bartosz ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy 2017-12-06 10:36 ` Bartosz Golaszewski @ 2017-12-06 19:05 ` Heiner Kallweit 0 siblings, 0 replies; 5+ messages in thread From: Heiner Kallweit @ 2017-12-06 19:05 UTC (permalink / raw) To: Bartosz Golaszewski Cc: Wolfram Sang, Peter Rosin, linux-i2c@vger.kernel.org, Linux Kernel Mailing List Am 06.12.2017 um 11:36 schrieb Bartosz Golaszewski: > 2017-12-05 20:44 GMT+01:00 Heiner Kallweit <hkallweit1@gmail.com>: >> i2c_new_dummy is typically called from the probe function of the >> driver for the primary i2c client. It requires calls to >> i2c_unregister_device in the error path of the probe function and >> in the remove function. >> This can be simplified by introducing a device-managed version. >> >> Note the changed error case return value type: >> i2c_new_dummy returns NULL whilst devm_new_i2c_dummy returns an ERR_PTR. >> >> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >> Reviewed-by: Peter Rosin <peda@axentia.se> >> --- >> Documentation/driver-model/devres.txt | 3 +++ >> drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++ >> include/linux/i2c.h | 3 +++ >> 3 files changed, 45 insertions(+) >> >> diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt >> index c180045eb..6e2bccf85 100644 >> --- a/Documentation/driver-model/devres.txt >> +++ b/Documentation/driver-model/devres.txt >> @@ -259,6 +259,9 @@ GPIO >> devm_gpio_request_one() >> devm_gpio_free() >> >> +I2C >> + devm_i2c_new_dummy >> + >> IIO >> devm_iio_device_alloc() >> devm_iio_device_free() >> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c >> index bf52cca87..c1db67f9a 100644 >> --- a/drivers/i2c/i2c-core-base.c >> +++ b/drivers/i2c/i2c-core-base.c >> @@ -820,6 +820,45 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) >> } >> EXPORT_SYMBOL_GPL(i2c_new_dummy); >> >> +static void devm_i2c_release_dummy(struct device *dev, void *res) >> +{ >> + i2c_unregister_device(*(struct i2c_client **)res); >> +} >> + > > Wolfram will have the last word here, but I would really prefer that > you wrap struct i2c_client in a separate devres (e.g. struct > i2c_dummy_devres) structure and avoid the cast. I find it a lot more > readable even if it only has a single member. > This cast is a very common pattern in such release callbacks, see e.g. devm_spi_unregister. >> +/** >> + * devm_i2c_new_dummy - return a new i2c device bound to a dummy driver >> + * @dev: device the managed resource is bound to >> + * @adapter: the adapter managing the device >> + * @address: seven bit address to be used >> + * Context: can sleep >> + * >> + * This is the device-managed version of i2c_new_dummy. >> + * Note the changed return value type: It returns the new i2c client >> + * or an ERR_PTR in case of an error. >> + */ >> +struct i2c_client *devm_i2c_new_dummy(struct device *dev, >> + struct i2c_adapter *adapter, >> + u16 address) >> +{ >> + struct i2c_client *ret, **dr; >> + >> + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); >> + if (!dr) >> + return ERR_PTR(-ENOMEM); >> + >> + ret = i2c_new_dummy(adapter, address); >> + if (!ret) { >> + devres_free(dr); >> + return ERR_PTR(-EBUSY); > > This is misleading as EBUSY is not necessarily the error that cased > i2c_new_device() to fail. Return NULL here and document that users > need to use IS_ERR_OR_NULL() to check for errors. > Indeed returning a fixed error code -EBUSY may not be the best choice. I have another alternative in mind: i2c_new_device brings everything to return a detailed error code. I think of splitting this function into a main function returning a detailed error code and a compatibility wrapper which returns NULL in error case, thus keeping the API stable. I will submit a proposal. >> + } >> + >> + *dr = ret; >> + devres_add(dev, dr); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy); >> + >> /** >> * i2c_new_secondary_device - Helper to get the instantiated secondary address >> * and create the associated device >> diff --git a/include/linux/i2c.h b/include/linux/i2c.h >> index a556db976..c27eac1e1 100644 >> --- a/include/linux/i2c.h >> +++ b/include/linux/i2c.h >> @@ -383,6 +383,9 @@ extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); >> extern struct i2c_client * >> i2c_new_dummy(struct i2c_adapter *adap, u16 address); >> >> +extern struct i2c_client * >> +devm_i2c_new_dummy(struct device *dev, struct i2c_adapter *adap, u16 address); >> + >> extern struct i2c_client * >> i2c_new_secondary_device(struct i2c_client *client, >> const char *name, >> -- >> 2.15.1 >> >> > > Thanks, > Bartosz > ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH resubmit 2/2] eeprom: at24: switch to device-managed version of i2c_new_dummy 2017-12-05 19:40 [PATCH 0/2] i2c: introduce devm_i2c_new_dummy and use it in at24 driver Heiner Kallweit 2017-12-05 19:44 ` [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy Heiner Kallweit @ 2017-12-05 19:45 ` Heiner Kallweit 1 sibling, 0 replies; 5+ messages in thread From: Heiner Kallweit @ 2017-12-05 19:45 UTC (permalink / raw) To: Bartosz Golaszewski, Wolfram Sang, Peter Rosin Cc: linux-i2c@vger.kernel.org, Linux Kernel Mailing List Make use of recently introduced device-managed version of i2c_new_dummy to simplify the code. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/misc/eeprom/at24.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 625b00166..9e9fe69b4 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -621,9 +621,10 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) /* use dummy devices for multiple-address chips */ for (i = 1; i < num_addresses; i++) { - at24->client[i].client = i2c_new_dummy(client->adapter, - client->addr + i); - if (!at24->client[i].client) { + at24->client[i].client = devm_i2c_new_dummy(&client->dev, + client->adapter, + client->addr + i); + if (IS_ERR(at24->client[i].client)) { dev_err(&client->dev, "address 0x%02x unavailable\n", client->addr + i); err = -EADDRINUSE; @@ -686,10 +687,6 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) return 0; err_clients: - for (i = 1; i < num_addresses; i++) - if (at24->client[i].client) - i2c_unregister_device(at24->client[i].client); - pm_runtime_disable(&client->dev); return err; @@ -698,15 +695,11 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) static int at24_remove(struct i2c_client *client) { struct at24_data *at24; - int i; at24 = i2c_get_clientdata(client); nvmem_unregister(at24->nvmem); - for (i = 1; i < at24->num_addresses; i++) - i2c_unregister_device(at24->client[i].client); - pm_runtime_disable(&client->dev); pm_runtime_set_suspended(&client->dev); -- 2.15.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-12-06 19:06 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-12-05 19:40 [PATCH 0/2] i2c: introduce devm_i2c_new_dummy and use it in at24 driver Heiner Kallweit 2017-12-05 19:44 ` [PATCH resubmit 1/2] i2c: core: add device-managed version of i2c_new_dummy Heiner Kallweit 2017-12-06 10:36 ` Bartosz Golaszewski 2017-12-06 19:05 ` Heiner Kallweit 2017-12-05 19:45 ` [PATCH resubmit 2/2] eeprom: at24: switch to " Heiner Kallweit
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