On 2021/3/16 16:56, Song Bao Hua (Barry Song) wrote: > > >> -----Original Message----- >> From: Yicong Yang [mailto:yangyicong@xxxxxxxxxxxxx] >> Sent: Wednesday, March 10, 2021 2:22 AM >> To: wsa@xxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx >> Cc: linuxarm@xxxxxxxxxxxxx; Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>; >> yangyicong <yangyicong@xxxxxxxxxx> >> Subject: [Linuxarm] [PATCH v2 1/3] i2c: core: add managed function for adding >> i2c adapters >> >> Some I2C controller drivers will only unregister the I2C >> adapter in their .remove() callback, which can be done >> by simply using a managed variant to add the I2C adapter. >> >> So add the managed functions for adding the I2C adapter. > > Sounds like a very useful wrapper. We are able to remove > some "remove" callbacks afterwards. > We have some similar wrappers like devm_hwrng_register > which is always helpful. devm_* are widely used for helping managing the resources and simplify the driver in other subsystems, so i think i2c core will also benefit from this. :) thanks for looking into this patch. Regards, Yicong > >> >> Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx> >> --- >> drivers/i2c/i2c-core-base.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/i2c.h | 1 + >> 2 files changed, 40 insertions(+) >> >> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c >> index 63ebf72..61486dc 100644 >> --- a/drivers/i2c/i2c-core-base.c >> +++ b/drivers/i2c/i2c-core-base.c >> @@ -1550,6 +1550,38 @@ int i2c_add_adapter(struct i2c_adapter *adapter) >> } >> EXPORT_SYMBOL(i2c_add_adapter); >> >> +static void devm_i2c_del_adapter(struct device *dev, void *ptr); >> + >> +/** >> + * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter() >> + * @dev: managing device for adding this I2C adapter >> + * @adapter: the adapter to add >> + * Context: can sleep >> + * >> + * Add adapter with dynamic bus number, same with i2c_add_adapter() >> + * but the adapter will be auto deleted on driver detach. >> + */ >> +int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter) >> +{ >> + struct i2c_adapter **ptr; >> + int ret; >> + >> + ptr = devres_alloc(devm_i2c_del_adapter, sizeof(*ptr), GFP_KERNEL); >> + if (!ptr) >> + return -ENOMEM; >> + >> + ret = i2c_add_adapter(adapter); >> + if (!ret) { >> + *ptr = adapter; >> + devres_add(dev, ptr); >> + } else { >> + devres_free(ptr); >> + } >> + >> + return ret; >> +} >> +EXPORT_SYMBOL(devm_i2c_add_adapter); >> + >> /** >> * i2c_add_numbered_adapter - declare i2c adapter, use static bus number >> * @adap: the adapter to register (with adap->nr initialized) >> @@ -1703,6 +1735,13 @@ void i2c_del_adapter(struct i2c_adapter *adap) >> } >> EXPORT_SYMBOL(i2c_del_adapter); >> >> +static void devm_i2c_del_adapter(struct device *dev, void *ptr) >> +{ >> + struct i2c_adapter *adapter = *((struct i2c_adapter **)ptr); >> + >> + i2c_del_adapter(adapter); >> +} >> + >> static void i2c_parse_timing(struct device *dev, char *prop_name, u32 >> *cur_val_p, >> u32 def_val, bool use_def) >> { >> diff --git a/include/linux/i2c.h b/include/linux/i2c.h >> index 5662265..10bd0b0 100644 >> --- a/include/linux/i2c.h >> +++ b/include/linux/i2c.h >> @@ -844,6 +844,7 @@ static inline void i2c_mark_adapter_resumed(struct >> i2c_adapter *adap) >> */ >> #if IS_ENABLED(CONFIG_I2C) >> int i2c_add_adapter(struct i2c_adapter *adap); >> +int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); >> void i2c_del_adapter(struct i2c_adapter *adap); >> int i2c_add_numbered_adapter(struct i2c_adapter *adap); >> >> -- >> 2.8.1 > > Thanks > Barry >
