Hi Wolfram: Sorry for the late reply. On Fri, Jan 20, 2023 at 5:08 PM Wolfram Sang <wsa@xxxxxxxxxx> wrote: > > Hi, > > the driver looks mostly good. Thank you for your hard work, and also > thanks to Andy for his great review efforts again! > > > +static unsigned int ls2x_i2c_func(struct i2c_adapter *adap) > > +{ > > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; > > +} > > Have you tried messages with zero-length or the SMBUS_QUICK transfer > which is basically the same? i2cdectect uses it by default, so if that > works, then we are good. Yes, I have tried this, and i2cdetect shows the following: [root@xxx ~]# ./i2c-tools-4.3/tools/i2cdetect -q -y 2 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- 18 -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: 30 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: 50 51 52 53 54 55 56 UU UU UU UU UU UU UU UU -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- [root@xxx ~]# ./i2c-tools-4.3/tools/i2cdetect -q -y 3 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- Do you mean this? > > > +/* The DC subsystem depends on it, we should initialize it earlier. */ > > +static int __init ls2x_i2c_init_driver(void) > > +{ > > + return platform_driver_register(&ls2x_i2c_driver); > > +} > > +subsys_initcall(ls2x_i2c_init_driver); > > Can't this be handled with deferred probing? Emm, I've been trying to register using the generic method before and deferred probing should be a better option. Also, I'll use module_platform_driver(ls2x_i2c_driver); instead in the next version. Thanks. Binbin > > Happy hacking, > > Wolfram >