Messages in this thread | | | From | "Bedel, Alban" <> | Subject | Re: [PATCH v2] gpio: pca953x: add support for open drain pins on PCAL6524 | Date | Tue, 16 Feb 2021 16:37:49 +0000 |
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On Mon, 2021-02-15 at 14:53 +0200, Andy Shevchenko wrote: > Hint: don't forget to include reviewers from previous version
I added you to the CC list for the new patch, did I miss someone else?
> On Thu, Feb 11, 2021 at 7:52 PM Alban Bedel <alban.bedel@aerq.com> > wrote: > > From a quick glance at various datasheets the PCAL6524 and the > > PCAL6534 seems to be the only chips in this family that support > > setting the drive mode of single pins. Other chips either don't > > support it at all, or can only set the drive mode of whole banks, > > which doesn't map to the GPIO API. > > > > Add a new flag, PCAL65xx_REGS, to mark chips that have the extra > > registers needed for this feature. Then mark the needed register > > banks > > as readable and writable, here we don't set OUT_CONF as writable, > > although it is, as we only need to read it. Finally add a function > > that configures the OUT_INDCONF register when the GPIO API sets the > > drive mode of the pins. > > ... > > > +#define PCAL65xx_REGS BIT(10) > > Can we have it as a _TYPE, please?
Let's please take a closer look at these macros and what they mean. Currently we have 3 possible set of functions that are indicated by setting bits in driver_data using the PCA_xxx macros:
- Basic register only: 0 - With interrupt support: PCA_INT - With latching interrupt regs: PCA_INT | PCA_PCAL = PCA_LATCH_INT
This patch then add a forth case:
- With pin config regs: PCA_INT | PCA_PCAL | $MACRO_WE_ARE_DICUSSING
Then there is the PCA953X_TYPE and PCA957X_TYPE macros which indicate the need for a different regmap config and register layout. These are accessed using the PCA_CHIP_TYPE() and are used as an integer value, not as bit-field like the above ones. If we had a struct instead of a packed integer that would be a different field.
I'll change it to PCAL65xx_TYPE if you insist, but that seems very wrong to me to use the same naming convention for macros meant for different fields.
> > > +#define PCAL65xx_BANK_INDOUT_CONF BIT(8 + 12) > > IND is a bit ambiguous based on the description below. > After you elaborate, I probably can propose better naming.
It's derived from the register name in the datasheet which is "Individual pin output port X configuration register".
> > + * - PCAL65xx with individual pin configuration > > + * Individual pin output config 0x40 + 12 * bank_size RW > > Not sure I understand what "individual" means here (no, I haven't > looked into the datasheet).
"individual" mean that each pin can be configured individually as opposed to other chips that only allow to configure a whole bank of pins.
> > + if (config == PIN_CONFIG_DRIVE_OPEN_DRAIN) > > + val = mask; > > + else if (config == PIN_CONFIG_DRIVE_PUSH_PULL) > > + val = 0; > > + else > > + return -EINVAL; > > Switch-case will look more naturally here (despite being longer in > terms of LOCs).
Ok.
> > +exit: > > exit_unlock:
Will do.
> > + mutex_unlock(&chip->i2c_lock); > > + return ret; > > ... > > > +#define OF_L65XX(__nrgpio) OF_953X(__nrgpio, PCA_LATCH_INT | > > PCAL65xx_REGS) > > When you change to the type, it will go accordingly. Don't add > LATCH_INT to the macro.
As explained above all chips with these registers also have the registers indicated by PCA_LATCH_INT.
Alban [unhandled content-type:application/pgp-signature] | |