On 2016-11-24 20:52, Wolfram Sang wrote: >> Yes, I never liked that include, but I don't know how to get >> from struct gpio_desc * to the relevant struct device * >> without it... > > Looks to me like we should ask the GPIO maintainers if they are willing > to export this value? I am probably not as good as you in explaining the > details why, though... Right. Adding Linus, Alexandre and the gpio list. The background is that the gpio- and pinctrl-based i2c-mux drivers need to know if the device that is used to control the mux of the i2c-bus is also sitting on that very same i2c-bus. If it is, the locking has to be different and a bit more relaxed. This relaxed mode cannot be used always, as that would change the mux behavior in an unacceptable way for stuff expecting the (traditional) stricter locking. See Documentation/i2c/i2c-topology for more details if you need it. To check this, the i2c mux drivers dig out the device connected to each gpio-pin (or pinctrl-state) and walks up the device tree to see if the root i2c adapter that is muxed is in the loop. When I wrote this code, I could not find a clean way to go from a struct gpio_desc * to the relevant device, short of doing #include "../../gpio/gpiolib.h" gpio_dev = &gpio_desc->gdev->dev; And similarly for pinctrl: #include "../../pinctrl/core.h" struct pinctrl_setting *setting; pinctrl_dev = setting->pctldev->dev; I'm not very proud of that, and wonder if there is a better way to get at the needed struct device? If not, then perhaps there should be? Cheers, Peter -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
