Re: [PATCH v2 1/4] gpio-f7188x: Add GPIO support for Nuvoton NCT6116

From: Henning Schild
Date: Thu Aug 11 2022 - 09:52:58 EST


Am Thu, 11 Aug 2022 15:31:39 +0200
schrieb simon.guinot@xxxxxxxxxxxx:

> On Tue, Aug 09, 2022 at 05:04:39PM +0200, Henning Schild wrote:
> > Add GPIO support for Nuvoton NCT6116 chip. Nuvoton SuperIO chips are
> > very similar to the ones from Fintek. In other subsystems they also
> > share drivers and are called a family of drivers.
> >
> > For the GPIO subsystem the only difference is that the direction
> > bit is reversed and that there is only one data bit per pin. On the
> > SuperIO level the logical device is another one.
> >
> > Signed-off-by: Henning Schild <henning.schild@xxxxxxxxxxx>
>
> Hi Henning,
>
> This patch is looking good to me. I only have a couple of minor
> comments. Please see them below.
>
> > ---
> > drivers/gpio/gpio-f7188x.c | 70
> > +++++++++++++++++++++++++++----------- 1 file changed, 51
> > insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-f7188x.c b/drivers/gpio/gpio-f7188x.c
> > index 18a3147f5a42..4d8f38bc3b45 100644
> > --- a/drivers/gpio/gpio-f7188x.c
> > +++ b/drivers/gpio/gpio-f7188x.c
> > @@ -1,6 +1,7 @@
> > // SPDX-License-Identifier: GPL-2.0-or-later
> > /*
> > * GPIO driver for Fintek Super-I/O F71869, F71869A, F71882,
> > F71889 and F81866
> > + * and Nuvoton Super-I/O NCT6116D
> > *
> > * Copyright (C) 2010-2013 LaCie
> > *
> > @@ -22,13 +23,11 @@
> > #define SIO_LDSEL 0x07 /* Logical device
> > select */ #define SIO_DEVID 0x20 /* Device ID
> > (2 bytes) */ #define SIO_DEVREV 0x22 /*
> > Device revision */ -#define SIO_MANID 0x23 /*
> > Fintek ID (2 bytes) */
> > -#define SIO_LD_GPIO 0x06 /* GPIO logical
> > device */ #define SIO_UNLOCK_KEY 0x87 /* Key
> > to enable Super-I/O */ #define SIO_LOCK_KEY
> > 0xAA /* Key to disable Super-I/O */
> > -#define SIO_FINTEK_ID 0x1934 /* Manufacturer
> > ID */ +#define SIO_LD_GPIO_FINTEK 0x06 /* GPIO
> > logical device */ #define SIO_F71869_ID
> > 0x0814 /* F71869 chipset ID */ #define SIO_F71869A_ID
> > 0x1007 /* F71869A chipset ID */ #define
> > SIO_F71882_ID 0x0541 /* F71882 chipset ID */
> > @@ -38,6 +37,8 @@ #define SIO_F81804_ID 0x1502 /*
> > F81804 chipset ID, same for f81966 */ #define SIO_F81865_ID
> > 0x0704 /* F81865 chipset ID */
> > +#define SIO_LD_GPIO_NUVOTON 0x07 /* GPIO logical
> > device */ +#define SIO_NCT6116D_ID 0xD283 /*
> > NCT6116D chipset ID */
>
> Can we do better to make the definitions above more readable ? With
> the new additions I find it a little bit unclear.
>
> Maybe we could add a comment on the top of the Fintek and Nuvoton
> specific sections ? Or maybe we could group the LD_GPIO_ definitions
> in a dedicated section ? Or something else :)

Not sure what you mean. But i think i will put the two logical device
definitions under each other and simply add the chipset id at the end
of the list. It is all a matter of taste, when i wrote it it felt like
putting all the Nuvoton block ...

> >
> > enum chips {
> > f71869,
> > @@ -48,6 +49,7 @@ enum chips {
> > f81866,
> > f81804,
> > f81865,
> > + nct6116d,
> > };
> >
> > static const char * const f7188x_names[] = {
> > @@ -59,10 +61,12 @@ static const char * const f7188x_names[] = {
> > "f81866",
> > "f81804",
> > "f81865",
> > + "nct6116d",
> > };
> >
> > struct f7188x_sio {
> > int addr;
> > + int device;
> > enum chips type;
> > };
> >
> > @@ -170,6 +174,9 @@ static int f7188x_gpio_set_config(struct
> > gpio_chip *chip, unsigned offset, /* Output mode register (0:open
> > drain 1:push-pull). */ #define gpio_out_mode(base) (base + 3)
> >
> > +#define gpio_needs_invert(device) ((device) !=
> > SIO_LD_GPIO_FINTEK) +#define gpio_single_data(device)
> > ((device) != SIO_LD_GPIO_FINTEK)
>
> Since this macros are only used to get/set GPIO direction, then I
> think we should use the "gpio_dir_" prefix.

the first one yes, the second one is about data and not direction, but
i will go

gpio_dir_invert
gpio_data_single

> Also is there any reason to match the LD GPIO value rather than the
> chipset type ?
>
> I think we should enable this specific path only for a Nuvoton NCT6116
> device for now (by matching the NCT6116 chipset type). So if more
> devices are added later then we are sure they still go on the original
> path.

Right the chipset is which says how exactly that variant works, not the
device number on that multi-function chip. Will fix.

Thanks!
Henning