From 7159dbdae3c58d0200ae2550fab977a19a3c497a Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Thu, 16 May 2019 23:13:08 +0200 Subject: i2c: core: improve return value handling of i2c_new_device and i2c_new_dummy Currently i2c_new_device and i2c_new_dummy return just NULL in error case although they have more error details internally. Therefore move the functionality into new functions returning detailed errors and add wrappers for compatibility with the current API. This allows to use these functions with detailed error codes within the i2c core or for API extensions. Signed-off-by: Heiner Kallweit [wsa: rename new functions and fix minor kdoc issues] Signed-off-by: Wolfram Sang Reviewed-by: Peter Rosin Reviewed-by: Kieran Bingham Reviewed-by: Bartosz Golaszewski Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core-base.c | 74 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 9732a81bb7dd..9c38dde73366 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -714,7 +714,7 @@ static int i2c_dev_irq_from_resources(const struct resource *resources, } /** - * i2c_new_device - instantiate an i2c device + * i2c_new_client_device - instantiate an i2c device * @adap: the adapter managing the device * @info: describes one I2C device; bus_num is ignored * Context: can sleep @@ -727,17 +727,17 @@ static int i2c_dev_irq_from_resources(const struct resource *resources, * before any i2c_adapter could exist. * * This returns the new i2c client, which may be saved for later use with - * i2c_unregister_device(); or NULL to indicate an error. + * i2c_unregister_device(); or an ERR_PTR to describe the error. */ -struct i2c_client * -i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) +static struct i2c_client * +i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info) { struct i2c_client *client; int status; client = kzalloc(sizeof *client, GFP_KERNEL); if (!client) - return NULL; + return ERR_PTR(-ENOMEM); client->adapter = adap; @@ -803,7 +803,31 @@ out_err: client->name, client->addr, status); out_err_silent: kfree(client); - return NULL; + return ERR_PTR(status); +} +EXPORT_SYMBOL_GPL(i2c_new_client_device); + +/** + * i2c_new_device - instantiate an i2c device + * @adap: the adapter managing the device + * @info: describes one I2C device; bus_num is ignored + * Context: can sleep + * + * This deprecated function has the same functionality as + * @i2c_new_client_device, it just returns NULL instead of an ERR_PTR in case of + * an error for compatibility with current I2C API. It will be removed once all + * users are converted. + * + * This returns the new i2c client, which may be saved for later use with + * i2c_unregister_device(); or NULL to indicate an error. + */ +struct i2c_client * +i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) +{ + struct i2c_client *ret; + + ret = i2c_new_client_device(adap, info); + return IS_ERR(ret) ? NULL : ret; } EXPORT_SYMBOL_GPL(i2c_new_device); @@ -854,7 +878,7 @@ static struct i2c_driver dummy_driver = { }; /** - * i2c_new_dummy - return a new i2c device bound to a dummy driver + * i2c_new_dummy_device - return a new i2c device bound to a dummy driver * @adapter: the adapter managing the device * @address: seven bit address to be used * Context: can sleep @@ -869,15 +893,39 @@ static struct i2c_driver dummy_driver = { * different driver. * * This returns the new i2c client, which should be saved for later use with - * i2c_unregister_device(); or NULL to indicate an error. + * i2c_unregister_device(); or an ERR_PTR to describe the error. */ -struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) +static struct i2c_client * +i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address) { struct i2c_board_info info = { I2C_BOARD_INFO("dummy", address), }; - return i2c_new_device(adapter, &info); + return i2c_new_client_device(adapter, &info); +} +EXPORT_SYMBOL_GPL(i2c_new_dummy_device); + +/** + * i2c_new_dummy - return a new i2c device bound to a dummy driver + * @adapter: the adapter managing the device + * @address: seven bit address to be used + * Context: can sleep + * + * This deprecated function has the same functionality as @i2c_new_dummy_device, + * it just returns NULL instead of an ERR_PTR in case of an error for + * compatibility with current I2C API. It will be removed once all users are + * converted. + * + * This returns the new i2c client, which should be saved for later use with + * i2c_unregister_device(); or NULL to indicate an error. + */ +struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) +{ + struct i2c_client *ret; + + ret = i2c_new_dummy_device(adapter, address); + return IS_ERR(ret) ? NULL : ret; } EXPORT_SYMBOL_GPL(i2c_new_dummy); @@ -1000,9 +1048,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, info.flags |= I2C_CLIENT_SLAVE; } - client = i2c_new_device(adap, &info); - if (!client) - return -EINVAL; + client = i2c_new_client_device(adap, &info); + if (IS_ERR(client)) + return PTR_ERR(client); /* Keep track of the added device */ mutex_lock(&adap->userspace_clients_lock); -- cgit v1.2.3-59-g8ed1b From b8f5fe3bc5b9318d95770a09a480c31aced20cd2 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Thu, 16 May 2019 23:13:09 +0200 Subject: i2c: core: add device-managed version of i2c_new_dummy 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_i2c_new_dummy_device returns an ERR_PTR. Signed-off-by: Heiner Kallweit [wsa: rename new functions and fix minor kdoc issues] Signed-off-by: Wolfram Sang Reviewed-by: Peter Rosin Reviewed-by: Kieran Bingham Reviewed-by: Bartosz Golaszewski Signed-off-by: Wolfram Sang --- Documentation/driver-model/devres.txt | 3 +++ drivers/i2c/i2c-core-base.c | 44 +++++++++++++++++++++++++++++++++++ include/linux/i2c.h | 3 +++ 3 files changed, 50 insertions(+) diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 99994a461359..69c7fa7f616c 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -271,6 +271,9 @@ GPIO devm_gpio_request_one() devm_gpio_free() +I2C + devm_i2c_new_dummy_device() + 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 9c38dde73366..d389d4fb0623 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -929,6 +929,50 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) } EXPORT_SYMBOL_GPL(i2c_new_dummy); +struct i2c_dummy_devres { + struct i2c_client *client; +}; + +static void devm_i2c_release_dummy(struct device *dev, void *res) +{ + struct i2c_dummy_devres *this = res; + + i2c_unregister_device(this->client); +} + +/** + * devm_i2c_new_dummy_device - 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_device. It returns the + * new i2c client or an ERR_PTR in case of an error. + */ +struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, + struct i2c_adapter *adapter, + u16 address) +{ + struct i2c_dummy_devres *dr; + struct i2c_client *client; + + dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + client = i2c_new_dummy_device(adapter, address); + if (IS_ERR(client)) { + devres_free(dr); + } else { + dr->client = client; + devres_add(dev, dr); + } + + return client; +} +EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device); + /** * 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 be27062f8ed1..6c4db54714f6 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -469,6 +469,9 @@ 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_device(struct device *dev, struct i2c_adapter *adap, u16 address); + extern struct i2c_client * i2c_new_secondary_device(struct i2c_client *client, const char *name, -- cgit v1.2.3-59-g8ed1b