On Tue, 2018-07-17 at 13:48 +0200, Alexandre Belloni wrote: > Because some old designware IPs were not supporting setting an SDA > hold > time, vendors developed their own solution. Add a way for the final > driver > to provide its own SDA hold time handling. > Thanks for information you provided. See my comment below. After addressing it, Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > --- > drivers/i2c/busses/i2c-designware-common.c | 6 ++++++ > drivers/i2c/busses/i2c-designware-core.h | 1 + > 2 files changed, 7 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-designware-common.c > b/drivers/i2c/busses/i2c-designware-common.c > index 9afc3e075b33..545b69d6be3c 100644 > --- a/drivers/i2c/busses/i2c-designware-common.c > +++ b/drivers/i2c/busses/i2c-designware-common.c > @@ -297,6 +297,12 @@ void i2c_dw_set_sda_hold_time(struct dw_i2c_dev > *dev) > { > u32 reg; > > > + if (dev->set_sda_hold_time) { > + dev->set_sda_hold_time(dev); > + > + return; > + } I would rather inject this, for now (*), into if-else-if ladder, i.e. if (reg >= DW_IC_SDA_HOLD_MIN_VERS) { ... } else if (dev->set_sda_hold_time) { // <<< ... } else if (dev->sda_hold_time) { ... (*) Since your IP is of v1.10a I don't believe any new version of IP would shadow existing DW IP registers, thus version check is okay to have first in my opinion. > + > /* Configure SDA Hold Time if required. */ > reg = dw_readl(dev, DW_IC_COMP_VERSION); > if (reg >= DW_IC_SDA_HOLD_MIN_VERS) { > diff --git a/drivers/i2c/busses/i2c-designware-core.h > b/drivers/i2c/busses/i2c-designware-core.h > index bc43fb9ac1cf..b2778b6d8aca 100644 > --- a/drivers/i2c/busses/i2c-designware-core.h > +++ b/drivers/i2c/busses/i2c-designware-core.h > @@ -283,6 +283,7 @@ struct dw_i2c_dev { > void (*disable)(struct dw_i2c_dev > *dev); > void (*disable_int)(struct dw_i2c_dev > *dev); > int (*init)(struct dw_i2c_dev *dev); > + int (*set_sda_hold_time)(struct > dw_i2c_dev *dev); > int mode; > struct i2c_bus_recovery_info rinfo; > }; -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy