diff mbox series

[v4,1/5] gpio: gxp: Add HPE GXP GPIO

Message ID 20230621213115.113266-2-nick.hawkins@hpe.com
State New
Headers show
Series ARM: Add GPIO support | expand

Commit Message

Hawkins, Nick June 21, 2023, 9:31 p.m. UTC
From: Nick Hawkins <nick.hawkins@hpe.com>

The GXP SoC supports GPIO on multiple interfaces. The interfaces are
CPLD and Host. The GPIOs is a combination of both physical and virtual
I/O across the interfaces. The gpio-gxp driver specifically covers the
CSM(physical), FN2(virtual), and VUHC(virtual) which are the host. The
driver supports interrupts from the host.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>

---

v4:
 *Moved gpio-gxp-pl.c to a separate commit.
 *Moved regmap_config out of function and made it static const
 *Removed unnecessary variables
 *Removed redundant conditional
 *Modified regmap_read switch statements to calculate offset and mask
  then read at end.
 *Removed use of -EOPNOTSUPP
 *Removed redundant casting
 *Switched generic_handle_irq -> generic_handle_domain_irq
 *Used GENMASK where applicable
 *Used bitmap_xor and for_each_bit_set
 *Made GPIO chip const and marked as a template (in the name)
 *Made irq_chip const and immutable
 *Removed casting in one case
 *Corrected check on devm_gpiochip_add_data
 *Remove dev_err_probe on platform_get_irq
 *Changed return 0 to devm_request_irq
v3:
 *Remove shared variables with gxp-fan-ctrl
v2:
 *Separated code into two files to keep size down: gpio-gxp.c and
  gpio-gxp-pl.c
 *Fixed Kconfig indentation as well as add new entry for gpio-gxp-pl
 *Removed use of linux/of.h and linux/of_device.h
 *Added mod_devicetable.h and property.h
 *Fixed indentation of defines and uses consistent number of digits
 *Corrected defines with improper GPIO_ namespace.
 *For masks now use BIT()
 *Added comment for PLREG offsets
 *Move gpio_chip to be first in structure
 *Calculate offset for high and low byte GPIO reads instead of having
  H(High) and L(Low) letters added to the variables.
 *Removed repeditive use of "? 1 : 0"
 *Switched to handle_bad_irq()
 *Removed improper bailout on gpiochip_add_data
 *Used GENMASK to arm interrupts
 *Removed use of of_match_device
 *fixed sizeof in devm_kzalloc
 *Added COMPILE_TEST to Kconfig
 *Added dev_err_probe
 *Removed unecessary parent and compatible checks
---
 drivers/gpio/Kconfig    |   9 +
 drivers/gpio/Makefile   |   1 +
 drivers/gpio/gpio-gxp.c | 573 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 583 insertions(+)
 create mode 100644 drivers/gpio/gpio-gxp.c

Comments

Andy Shevchenko June 22, 2023, 2:15 p.m. UTC | #1
On Thu, Jun 22, 2023 at 12:35 AM <nick.hawkins@hpe.com> wrote:
>
> From: Nick Hawkins <nick.hawkins@hpe.com>
>
> The GXP SoC supports GPIO on multiple interfaces. The interfaces are
> CPLD and Host. The GPIOs is a combination of both physical and virtual

GPIOs are

> I/O across the interfaces. The gpio-gxp driver specifically covers the
> CSM(physical), FN2(virtual), and VUHC(virtual) which are the host. The

"...are the host"?! hosts?

> driver supports interrupts from the host.

I will have some comments against the code, but I will try to review
it probably later on (next week or so). Taking into account the
approaching release date, I think we have a couple more months for
polishing this series.

--
With Best Regards,
Andy Shevchenko
Andy Shevchenko June 27, 2023, 1:36 p.m. UTC | #2
On Thu, Jun 22, 2023 at 12:35 AM <nick.hawkins@hpe.com> wrote:
>
> From: Nick Hawkins <nick.hawkins@hpe.com>
>
> The GXP SoC supports GPIO on multiple interfaces. The interfaces are
> CPLD and Host. The GPIOs is a combination of both physical and virtual

are a

> I/O across the interfaces. The gpio-gxp driver specifically covers the
> CSM(physical), FN2(virtual), and VUHC(virtual) which are the host. The

A bit of elaboration what the Host interface means and what is the
difference to the CPLD. Perhaps spell it here as "Host interface", so
it will be clear that above you mentioned it already.

> driver supports interrupts from the host.

...

> +#define GPIDAT         0x040
> +#define GPODAT         0x0b0
> +#define GPODAT2                0x0f8
> +#define GPOOWN         0x110
> +#define GPOOWN2                0x118
> +#define ASR_OFS                0x05c
> +#define VUHC_OFS       0x064

Hmm... No GPIDAT2? I'm wondering if you can drop all these *2
definitions. Let see below...

...

> +struct gxp_gpio_drvdata {
> +       struct gpio_chip chip;
> +       struct regmap *csm_map;

> +       void __iomem *fn2_vbtn;

Looking into the code I have no clue why this is in this driver. You
have regmaps and a separate resource for this. Why?! Is it in the
window of GPIO MMIO?

> +       struct regmap *fn2_stat;
> +       struct regmap *vuhc0_map;
> +       int irq;
> +};

...

> +/*
> + * Note: Instead of definining all PINs here are the select few that

defining (I have a déjà vu of already showing you typos in the commit
message and comments and it looks like you ignored all of that. If so,
then why?)

> + * are specifically defined in DTS and offsets are used here.
> + */
> +enum gxp_gpio_pn {
> +       RESET = 192,
> +       VPBTN = 210, /* aka POWER_OK */
> +       PGOOD = 211, /* aka PS_PWROK */
> +       PERST = 212, /* aka PCIERST */
> +       POST_COMPLETE = 213,

So, vbtn is a GPIO? Why does it need a special treatment?

> +};

...

> +static int gxp_gpio_csm_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);

> +       int ret = 0;

Seems like a weird assignment.

> +       unsigned int reg_offset;
> +       unsigned int reg_mask;
> +
> +       switch (offset) {
> +       case 0 ... 31:
> +               reg_offset = GPIDAT;
> +               reg_mask = BIT(offset);
> +               break;
> +       case 32 ... 63:
> +               reg_offset = GPIDAT + 0x20;
> +               reg_mask = BIT(offset - 32);
> +               break;

So, here is the 0x20 offset shift...

> +       case 64 ... 95:
> +               reg_offset = GPODAT;
> +               reg_mask = BIT(offset - 64);
> +               break;
> +       case 96 ... 127:
> +               reg_offset = GPODAT + 0x04;
> +               reg_mask = BIT(offset - 96);
> +               break;

...and here (between two groups of GPO) is 0x48. Looks a bit weird.
Does this GPIO have more functions than simply being a GPIO? To me
looks like a PMIC-ish one. Is there any datasheet available?

> +       case 128 ...  159:
> +               reg_offset = GPODAT2;
> +               reg_mask = BIT(offset - 128);
> +               break;
> +       case 160 ... 191:
> +               reg_offset = GPODAT2 + 0x04;
> +               reg_mask = BIT(offset - 160);
> +               break;

These (64-192) are two groups of the sequential bits in the address
space. Why do you do this instead of the simplest calculus with bit
and offset?

> +       case RESET:
> +               /* SW_RESET */
> +               reg_offset = ASR_OFS;
> +               reg_mask = BIT(15);
> +               break;

Does it really belong to this driver? Maybe it should be an MFD with
GPIO and special functions with valid_mask properly assigned?

> +       default:
> +               break;
> +       }

> +       regmap_read(drvdata->csm_map, reg_offset, &ret);
> +       ret = (ret & reg_mask) ? 1 : 0;
> +
> +       return ret;


  ret = regmap_read(, &value);
  if (ret)
    return ret;

  return !!(value & mask);

> +}
> +
> +static void gxp_gpio_csm_set(struct gpio_chip *chip, unsigned int offset,
> +                            int value)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +       u32 tmp;

> +       switch (offset) {

You definitely don't need this. All bits are in the sequential addresses.

> +       case 64 ... 95:
> +               /* Keep ownership setting */
> +               regmap_read(drvdata->csm_map, GPOOWN, &tmp);
> +               tmp = (tmp & BIT(offset - 64)) ? 1 : 0;
> +
> +               regmap_update_bits(drvdata->csm_map, GPOOWN,
> +                                  BIT(offset - 64), BIT(offset - 64));
> +               regmap_update_bits(drvdata->csm_map, GPODAT,
> +                                  BIT(offset - 64), value ? BIT(offset - 64) : 0);
> +
> +               /* Restore ownership setting */
> +               regmap_update_bits(drvdata->csm_map, GPOOWN,
> +                                  BIT(offset - 64), tmp ? BIT(offset - 64) : 0);
> +               break;
> +       case 96 ... 127:
> +               /* Keep ownership setting */
> +               regmap_read(drvdata->csm_map, GPOOWN + 0x04, &tmp);
> +               tmp = (tmp & BIT(offset - 96)) ? 1 : 0;
> +
> +               regmap_update_bits(drvdata->csm_map, GPOOWN + 0x04,
> +                                  BIT(offset - 96), BIT(offset - 96));
> +               regmap_update_bits(drvdata->csm_map, GPODAT + 0x04,
> +                                  BIT(offset - 96), value ? BIT(offset - 96) : 0);
> +
> +               /* Restore ownership setting */
> +               regmap_update_bits(drvdata->csm_map, GPOOWN + 0x04,
> +                                  BIT(offset - 96), tmp ? BIT(offset - 96) : 0);
> +               break;
> +       case 128 ... 159:
> +               /* Keep ownership setting */
> +               regmap_read(drvdata->csm_map, GPOOWN2, &tmp);
> +               tmp = (tmp & BIT(offset - 128)) ? 1 : 0;
> +
> +               regmap_update_bits(drvdata->csm_map, GPOOWN2,
> +                                  BIT(offset - 128), BIT(offset - 128));
> +               regmap_update_bits(drvdata->csm_map, GPODAT2,
> +                                  BIT(offset - 128), value ? BIT(offset - 128) : 0);
> +
> +               /* Restore ownership setting */
> +               regmap_update_bits(drvdata->csm_map, GPOOWN2,
> +                                  BIT(offset - 128), tmp ? BIT(offset - 128) : 0);
> +               break;
> +       case 160 ... 191:
> +               /* Keep ownership setting */
> +               regmap_read(drvdata->csm_map, GPOOWN2 + 0x04,   &tmp);
> +               tmp = (tmp & BIT(offset - 160)) ? 1 : 0;
> +
> +               regmap_update_bits(drvdata->csm_map, GPOOWN2 + 0x04,
> +                                  BIT(offset - 160), BIT(offset - 160));
> +               regmap_update_bits(drvdata->csm_map, GPODAT2 + 0x04,
> +                                  BIT(offset - 160), value ? BIT(offset - 160) : 0);
> +
> +               /* Restore ownership setting */
> +               regmap_update_bits(drvdata->csm_map, GPOOWN2 + 0x04,
> +                                  BIT(offset - 160), tmp ? BIT(offset - 160) : 0);
> +               break;

> +       case 192:
> +               if (value) {
> +                       regmap_update_bits(drvdata->csm_map, ASR_OFS,
> +                                          BIT(0), BIT(0));
> +                       regmap_update_bits(drvdata->csm_map, ASR_OFS,
> +                                          BIT(15), BIT(15));
> +               } else {
> +                       regmap_update_bits(drvdata->csm_map, ASR_OFS,
> +                                          BIT(15), 0);
> +               }
> +               break;

Again, seems like a special function of GPIO that should probably have
another driver that shares regmap with GPIO and GPIO marks this one is
not valid for the GPIO operations.

> +       default:
> +               break;
> +       }
> +}
> +
> +static int gxp_gpio_csm_get_direction(struct gpio_chip *chip,
> +                                     unsigned int offset)
> +{
> +       switch (offset) {

Why do you use your custom definitions for the direction? We already
have the generic ones for this. Please use them.

> +       case 0 ... 63:
> +               return GXP_GPIO_DIR_IN;
> +       case 64 ... 191:
> +               return GXP_GPIO_DIR_OUT;

> +       case 192 ... 193:
> +               return GXP_GPIO_DIR_OUT;
> +       case 194:
> +               return GXP_GPIO_DIR_IN;

These are special cases. Not sure if it's for the GPIO, but basically
you can check them separately and reduce switch-case to simple

  type = offset / 64;
  if (type)
    return OUT;
  return IN;

Something similar to the rest of the functions.

Note, that range operator in switch-case is non-standard.

> +       default:
> +               return -ENOTSUPP;
> +       }
> +}

...

> +static int gxp_gpio_vuhc_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +       unsigned int val;
> +       int ret = 0;
> +
> +       if (offset < 8) {
> +               regmap_read(drvdata->vuhc0_map, VUHC_OFS + 4 * offset,   &val);
> +               ret = (val & BIT(13)) ? 1 : 0;
> +       }
> +
> +       return ret;
> +}
> +
> +static void gxp_gpio_vuhc_set(struct gpio_chip *chip, unsigned int offset,
> +                             int value)
> +{
> +       /* Currently we are not supporting setting of these values yet */
> +       switch (offset) {
> +       default:
> +               break;
> +       }
> +}
> +
> +static int gxp_gpio_vuhc_get_direction(struct gpio_chip *chip,
> +                                      unsigned int offset)
> +{
> +       switch (offset) {
> +       case 0:
> +       case 1:
> +       case 2:
> +               return GXP_GPIO_DIR_IN;
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}
> +
> +static int gxp_gpio_vuhc_direction_input(struct gpio_chip *chip,
> +                                        unsigned int offset)
> +{
> +       switch (offset) {
> +       case 0:
> +       case 1:
> +       case 2:
> +               return 0;
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}
> +
> +static int gxp_gpio_vuhc_direction_output(struct gpio_chip *chip,
> +                                         unsigned int offset, int value)
> +{
> +       switch (offset) {
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}

I'm not sure this belongs to the GPIO driver.

> +static int gxp_gpio_fn2_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +       unsigned int val;
> +       int ret = 0;
> +       unsigned int reg_mask;
> +
> +       switch (offset) {
> +       case PGOOD:
> +               regmap_read(drvdata->fn2_stat, 0, &val);
> +               reg_mask = BIT(24);
> +
> +               break;
> +       case PERST:
> +               regmap_read(drvdata->fn2_stat, 0, &val);
> +               reg_mask = BIT(25);
> +
> +               break;
> +       default:
> +               return -ENOTSUPP;
> +       }
> +
> +       regmap_read(drvdata->fn2_stat, 0, &val);
> +       ret = (val & reg_mask);
> +       /* Return either 1 or 0 */
> +       return ret ? 1 : 0;
> +}
> +
> +static void gxp_gpio_fn2_set(struct gpio_chip *chip, unsigned int offset,
> +                            int value)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +
> +       switch (offset) {
> +       case VPBTN:
> +               writeb(1, drvdata->fn2_vbtn);
> +               break;
> +       default:
> +               break;
> +       }
> +}
> +
> +static int gxp_gpio_fn2_get_direction(struct gpio_chip *chip,
> +                                     unsigned int offset)
> +{
> +       switch (offset) {
> +       case VPBTN:
> +               return GXP_GPIO_DIR_OUT;
> +       default:
> +               return GXP_GPIO_DIR_IN;
> +       }
> +}
> +
> +static int gxp_gpio_fn2_direction_input(struct gpio_chip *chip,
> +                                       unsigned int offset)
> +{
> +       switch (offset) {
> +       case PGOOD:
> +       case PERST:
> +       case POST_COMPLETE:
> +               return 0;
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}
> +
> +static int gxp_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       if (offset < 200)
> +               return gxp_gpio_csm_get(chip, offset);
> +       else if (offset >= 200 && offset < 210)
> +               return gxp_gpio_vuhc_get(chip, offset - 200);
> +       else if (offset >= 210)
> +               return gxp_gpio_fn2_get(chip, offset);
> +
> +       return 0;
> +}
> +
> +static void gxp_gpio_set(struct gpio_chip *chip,
> +                        unsigned int offset, int value)
> +{
> +       if (offset < 200)
> +               gxp_gpio_csm_set(chip, offset, value);
> +       else if (offset >= 200 && offset < 210)
> +               gxp_gpio_vuhc_set(chip, offset - 200, value);
> +       else if (offset >= 210)
> +               gxp_gpio_fn2_set(chip, offset, value);
> +}
> +
> +static int gxp_gpio_get_direction(struct gpio_chip *chip,
> +                                 unsigned int offset)
> +{
> +       if (offset < 200)
> +               return gxp_gpio_csm_get_direction(chip, offset);
> +       else if (offset >= 200 && offset < 210)
> +               return gxp_gpio_vuhc_get_direction(chip, offset - 200);
> +       else if (offset >= 210)
> +               return gxp_gpio_fn2_get_direction(chip, offset);
> +
> +       return 0;
> +}
> +
> +static int gxp_gpio_direction_input(struct gpio_chip *chip,
> +                                   unsigned int offset)
> +{
> +       if (offset < 200)
> +               return gxp_gpio_csm_direction_input(chip, offset);
> +       else if (offset >= 200 && offset < 210)
> +               return gxp_gpio_vuhc_direction_input(chip, offset - 200);
> +       else if (offset >= 210)
> +               return gxp_gpio_fn2_direction_input(chip, offset);
> +
> +       return 0;
> +}
> +
> +static int gxp_gpio_direction_output(struct gpio_chip *chip,
> +                                    unsigned int offset, int value)
> +{
> +       if (offset < 200)
> +               return gxp_gpio_csm_direction_output(chip, offset, value);
> +       else if (offset >= 200 && offset < 210)
> +               return gxp_gpio_vuhc_direction_output(chip, offset - 200, value);
> +
> +       return 0;
> +}

...

> +       /* Clear latched interrupt */
> +       regmap_update_bits(drvdata->fn2_stat, 0,
> +                          GENMASK(15, 0), GENMASK(15, 0));

  unsigned int mask = GENMASK(...);
  unsigned int value = mask;
  regmap_update_bits(..., mask, value);

...

> +       regmap_update_bits(drvdata->fn2_stat, FN2_SEVMASK,
> +                          BIT(0), set ? BIT(0) : 0);

Ditto.

  unsigned int mask = BIT(0);
  unsigned int value = set ? mask : 0;

...

So, overall it looks to me like an MFD device which should be split to
GPIO, GPIO with IRQ (fh2), special cases and designated
functionalities (somelike ~5 drivers all together). Without having a
datasheet it's hard to say.


--
With Best Regards,
Andy Shevchenko
Hawkins, Nick June 27, 2023, 6:55 p.m. UTC | #3
> defining (I have a déjà vu of already showing you typos in the commit
> message and comments and it looks like you ignored all of that. If so,
> then why?)

Apologies Andy,

I somehow completely missed / lost your mention of a typo in both the
commit and comments. I have no intention of ignoring it. I will correct
this. Thank you for the input you have provided. I have several
questions and comments below.


> > + * are specifically defined in DTS and offsets are used here.
> > + */
> > +enum gxp_gpio_pn {
> > + RESET = 192,
> > + VPBTN = 210, /* aka POWER_OK */
> > + PGOOD = 211, /* aka PS_PWROK */
> > + PERST = 212, /* aka PCIERST */
> > + POST_COMPLETE = 213,


> So, vbtn is a GPIO? Why does it need a special treatment?

I was specifically grabbing the areas of memory that I needed instead of
mapping the entire fn2 area of memory. I believe I can map the entire
area instead.

...

> > + case 64 ... 95:
> > + reg_offset = GPODAT;
> > + reg_mask = BIT(offset - 64);
> > + break;
> > + case 96 ... 127:
> > + reg_offset = GPODAT + 0x04;
> > + reg_mask = BIT(offset - 96);
> > + break;


> ...and here (between two groups of GPO) is 0x48. Looks a bit weird.
> Does this GPIO have more functions than simply being a GPIO? To me
> looks like a PMIC-ish one. Is there any datasheet available?

Unfortunately, there is no public datasheet available currently. There
are however some special functions others than being a simple GPIO.
There are ownership bits as the same area is accessible VIA PCI.

> > + case RESET:
> > + /* SW_RESET */
> > + reg_offset = ASR_OFS;
> > + reg_mask = BIT(15);
> > + break;

> Does it really belong to this driver? Maybe it should be an MFD with
> GPIO and special functions with valid_mask properly assigned?

Unlike your suggestion I quote directly below are you implying that
My accesses to the CSM area of memory can be its own separate
driver that is MFD and provides GPIO lines to read?

> ... 

> > + case 192:
> > + if (value) {
> > + regmap_update_bits(drvdata->csm_map, ASR_OFS,
> > + BIT(0), BIT(0));
> > + regmap_update_bits(drvdata->csm_map, ASR_OFS,
> > + BIT(15), BIT(15));
> > + } else {
> > + regmap_update_bits(drvdata->csm_map, ASR_OFS,
> > + BIT(15), 0);
> > + }
> > + break;


> Again, seems like a special function of GPIO that should probably have
> another driver that shares regmap with GPIO and GPIO marks this one is
> not valid for the GPIO operations.

What do you mean by GPIO marking this one as not valid for GPIO
operations?

...

> > +static int gxp_gpio_vuhc_get(struct gpio_chip *chip, unsigned int offset)
> > +{
> > + struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> > + unsigned int val;
> > + int ret = 0;
> > +
> > + if (offset < 8) {
> > + regmap_read(drvdata->vuhc0_map, VUHC_OFS + 4 * offset, &val);
> > + ret = (val & BIT(13)) ? 1 : 0;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static void gxp_gpio_vuhc_set(struct gpio_chip *chip, unsigned int offset,
> > + int value)
> > +{
> > + /* Currently we are not supporting setting of these values yet */
> > + switch (offset) {
> > + default:
> > + break;
> > + }
> > +}
> > +
> > +static int gxp_gpio_vuhc_get_direction(struct gpio_chip *chip,
> > + unsigned int offset)
> > +{
> > + switch (offset) {
> > + case 0:
> > + case 1:
> > + case 2:
> > + return GXP_GPIO_DIR_IN;
> > + default:
> > + return -ENOTSUPP;
> > + }
> > +}
> > +
> > +static int gxp_gpio_vuhc_direction_input(struct gpio_chip *chip,
> > + unsigned int offset)
> > +{
> > + switch (offset) {
> > + case 0:
> > + case 1:
> > + case 2:
> > + return 0;
> > + default:
> > + return -ENOTSUPP;
> > + }
> > +}
> > +
> > +static int gxp_gpio_vuhc_direction_output(struct gpio_chip *chip,
> > + unsigned int offset, int value)
> > +{
> > + switch (offset) {
> > + default:
> > + return -ENOTSUPP;
> > + }
> > +}


> I'm not sure this belongs to the GPIO driver.

By this do you mean that it needs to be in a separate non GPIO driver
that shares a regmap as suggested above?

...

> So, overall it looks to me like an MFD device which should be split to
> GPIO, GPIO with IRQ (fh2), special cases and designated
> functionalities (somelike ~5 drivers all together). Without having a
> datasheet it's hard to say.

Yes that sounds like a good plan to me I will see what I can work up.
I might end up removing thils file entirely and just sticking with
gpio-gxp-pl.c As for the gpio-gxp-pl.c are you okay with it?


Thank you for the assistance and review,

-Nick Hawkins
diff mbox series

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 13be729710f2..fa0c9fdbb50c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1235,6 +1235,15 @@  config HTC_EGPIO
 	  several HTC phones.  It provides basic support for input
 	  pins, output pins, and IRQs.
 
+config GPIO_GXP
+	tristate "GXP GPIO support"
+	depends on ARCH_HPE_GXP || COMPILE_TEST
+	select GPIOLIB_IRQCHIP
+	help
+	  Say Y here to support GXP GPIO controllers. It provides
+	  support for the multiple GPIO interfaces available to be
+	  available to the Host.
+
 config GPIO_JANZ_TTL
 	tristate "Janz VMOD-TTL Digital IO Module"
 	depends on MFD_JANZ_CMODIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c048ba003367..a7ce0ab097aa 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -63,6 +63,7 @@  obj-$(CONFIG_GPIO_FTGPIO010)		+= gpio-ftgpio010.o
 obj-$(CONFIG_GPIO_GE_FPGA)		+= gpio-ge.o
 obj-$(CONFIG_GPIO_GPIO_MM)		+= gpio-gpio-mm.o
 obj-$(CONFIG_GPIO_GRGPIO)		+= gpio-grgpio.o
+obj-$(CONFIG_GPIO_GXP)                  += gpio-gxp.o
 obj-$(CONFIG_GPIO_GW_PLD)		+= gpio-gw-pld.o
 obj-$(CONFIG_GPIO_HISI)                 += gpio-hisi.o
 obj-$(CONFIG_GPIO_HLWD)			+= gpio-hlwd.o
diff --git a/drivers/gpio/gpio-gxp.c b/drivers/gpio/gpio-gxp.c
new file mode 100644
index 000000000000..4fe086137e86
--- /dev/null
+++ b/drivers/gpio/gpio-gxp.c
@@ -0,0 +1,573 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2023 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define GPIDAT		0x040
+#define GPODAT		0x0b0
+#define GPODAT2		0x0f8
+#define GPOOWN		0x110
+#define GPOOWN2		0x118
+#define ASR_OFS		0x05c
+#define VUHC_OFS	0x064
+
+#define GXP_GPIO_DIR_OUT	0
+#define GXP_GPIO_DIR_IN		1
+
+#define PGOOD_MASK	BIT(0)
+
+struct gxp_gpio_drvdata {
+	struct gpio_chip chip;
+	struct regmap *csm_map;
+	void __iomem *fn2_vbtn;
+	struct regmap *fn2_stat;
+	struct regmap *vuhc0_map;
+	int irq;
+};
+
+/*
+ * Note: Instead of definining all PINs here are the select few that
+ * are specifically defined in DTS and offsets are used here.
+ */
+enum gxp_gpio_pn {
+	RESET = 192,
+	VPBTN = 210, /* aka POWER_OK */
+	PGOOD = 211, /* aka PS_PWROK */
+	PERST = 212, /* aka PCIERST */
+	POST_COMPLETE = 213,
+};
+
+static int gxp_gpio_csm_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+	int ret = 0;
+	unsigned int reg_offset;
+	unsigned int reg_mask;
+
+	switch (offset) {
+	case 0 ... 31:
+		reg_offset = GPIDAT;
+		reg_mask = BIT(offset);
+		break;
+	case 32 ... 63:
+		reg_offset = GPIDAT + 0x20;
+		reg_mask = BIT(offset - 32);
+		break;
+	case 64 ... 95:
+		reg_offset = GPODAT;
+		reg_mask = BIT(offset - 64);
+		break;
+	case 96 ... 127:
+		reg_offset = GPODAT + 0x04;
+		reg_mask = BIT(offset - 96);
+		break;
+	case 128 ...  159:
+		reg_offset = GPODAT2;
+		reg_mask = BIT(offset - 128);
+		break;
+	case 160 ... 191:
+		reg_offset = GPODAT2 + 0x04;
+		reg_mask = BIT(offset - 160);
+		break;
+	case RESET:
+		/* SW_RESET */
+		reg_offset = ASR_OFS;
+		reg_mask = BIT(15);
+		break;
+	default:
+		break;
+	}
+
+	regmap_read(drvdata->csm_map, reg_offset, &ret);
+	ret = (ret & reg_mask) ? 1 : 0;
+
+	return ret;
+}
+
+static void gxp_gpio_csm_set(struct gpio_chip *chip, unsigned int offset,
+			     int value)
+{
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+	u32 tmp;
+
+	switch (offset) {
+	case 64 ... 95:
+		/* Keep ownership setting */
+		regmap_read(drvdata->csm_map, GPOOWN, &tmp);
+		tmp = (tmp & BIT(offset - 64)) ? 1 : 0;
+
+		regmap_update_bits(drvdata->csm_map, GPOOWN,
+				   BIT(offset - 64), BIT(offset - 64));
+		regmap_update_bits(drvdata->csm_map, GPODAT,
+				   BIT(offset - 64), value ? BIT(offset - 64) : 0);
+
+		/* Restore ownership setting */
+		regmap_update_bits(drvdata->csm_map, GPOOWN,
+				   BIT(offset - 64), tmp ? BIT(offset - 64) : 0);
+		break;
+	case 96 ... 127:
+		/* Keep ownership setting */
+		regmap_read(drvdata->csm_map, GPOOWN + 0x04, &tmp);
+		tmp = (tmp & BIT(offset - 96)) ? 1 : 0;
+
+		regmap_update_bits(drvdata->csm_map, GPOOWN + 0x04,
+				   BIT(offset - 96), BIT(offset - 96));
+		regmap_update_bits(drvdata->csm_map, GPODAT + 0x04,
+				   BIT(offset - 96), value ? BIT(offset - 96) : 0);
+
+		/* Restore ownership setting */
+		regmap_update_bits(drvdata->csm_map, GPOOWN + 0x04,
+				   BIT(offset - 96), tmp ? BIT(offset - 96) : 0);
+		break;
+	case 128 ... 159:
+		/* Keep ownership setting */
+		regmap_read(drvdata->csm_map, GPOOWN2, &tmp);
+		tmp = (tmp & BIT(offset - 128)) ? 1 : 0;
+
+		regmap_update_bits(drvdata->csm_map, GPOOWN2,
+				   BIT(offset - 128), BIT(offset - 128));
+		regmap_update_bits(drvdata->csm_map, GPODAT2,
+				   BIT(offset - 128), value ? BIT(offset - 128) : 0);
+
+		/* Restore ownership setting */
+		regmap_update_bits(drvdata->csm_map, GPOOWN2,
+				   BIT(offset - 128), tmp ? BIT(offset - 128) : 0);
+		break;
+	case 160 ... 191:
+		/* Keep ownership setting */
+		regmap_read(drvdata->csm_map, GPOOWN2 + 0x04,	&tmp);
+		tmp = (tmp & BIT(offset - 160)) ? 1 : 0;
+
+		regmap_update_bits(drvdata->csm_map, GPOOWN2 + 0x04,
+				   BIT(offset - 160), BIT(offset - 160));
+		regmap_update_bits(drvdata->csm_map, GPODAT2 + 0x04,
+				   BIT(offset - 160), value ? BIT(offset - 160) : 0);
+
+		/* Restore ownership setting */
+		regmap_update_bits(drvdata->csm_map, GPOOWN2 + 0x04,
+				   BIT(offset - 160), tmp ? BIT(offset - 160) : 0);
+		break;
+	case 192:
+		if (value) {
+			regmap_update_bits(drvdata->csm_map, ASR_OFS,
+					   BIT(0), BIT(0));
+			regmap_update_bits(drvdata->csm_map, ASR_OFS,
+					   BIT(15), BIT(15));
+		} else {
+			regmap_update_bits(drvdata->csm_map, ASR_OFS,
+					   BIT(15), 0);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static int gxp_gpio_csm_get_direction(struct gpio_chip *chip,
+				      unsigned int offset)
+{
+	switch (offset) {
+	case 0 ... 63:
+		return GXP_GPIO_DIR_IN;
+	case 64 ... 191:
+		return GXP_GPIO_DIR_OUT;
+	case 192 ... 193:
+		return GXP_GPIO_DIR_OUT;
+	case 194:
+		return GXP_GPIO_DIR_IN;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_csm_direction_input(struct gpio_chip *chip,
+					unsigned int offset)
+{
+	switch (offset) {
+	case 0 ... 63:
+		return 0;
+	case 194:
+		return 0;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_csm_direction_output(struct gpio_chip *chip,
+					 unsigned int offset, int value)
+{
+	switch (offset) {
+	case 64 ... 191:
+	case 192 ... 193:
+		gxp_gpio_csm_set(chip, offset, value);
+		return 0;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_vuhc_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+	unsigned int val;
+	int ret = 0;
+
+	if (offset < 8) {
+		regmap_read(drvdata->vuhc0_map, VUHC_OFS + 4 * offset,   &val);
+		ret = (val & BIT(13)) ? 1 : 0;
+	}
+
+	return ret;
+}
+
+static void gxp_gpio_vuhc_set(struct gpio_chip *chip, unsigned int offset,
+			      int value)
+{
+	/* Currently we are not supporting setting of these values yet */
+	switch (offset) {
+	default:
+		break;
+	}
+}
+
+static int gxp_gpio_vuhc_get_direction(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	switch (offset) {
+	case 0:
+	case 1:
+	case 2:
+		return GXP_GPIO_DIR_IN;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_vuhc_direction_input(struct gpio_chip *chip,
+					 unsigned int offset)
+{
+	switch (offset) {
+	case 0:
+	case 1:
+	case 2:
+		return 0;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_vuhc_direction_output(struct gpio_chip *chip,
+					  unsigned int offset, int value)
+{
+	switch (offset) {
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_fn2_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+	unsigned int val;
+	int ret = 0;
+	unsigned int reg_mask;
+
+	switch (offset) {
+	case PGOOD:
+		regmap_read(drvdata->fn2_stat, 0, &val);
+		reg_mask = BIT(24);
+
+		break;
+	case PERST:
+		regmap_read(drvdata->fn2_stat, 0, &val);
+		reg_mask = BIT(25);
+
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	regmap_read(drvdata->fn2_stat, 0, &val);
+	ret = (val & reg_mask);
+	/* Return either 1 or 0 */
+	return ret ? 1 : 0;
+}
+
+static void gxp_gpio_fn2_set(struct gpio_chip *chip, unsigned int offset,
+			     int value)
+{
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+
+	switch (offset) {
+	case VPBTN:
+		writeb(1, drvdata->fn2_vbtn);
+		break;
+	default:
+		break;
+	}
+}
+
+static int gxp_gpio_fn2_get_direction(struct gpio_chip *chip,
+				      unsigned int offset)
+{
+	switch (offset) {
+	case VPBTN:
+		return GXP_GPIO_DIR_OUT;
+	default:
+		return GXP_GPIO_DIR_IN;
+	}
+}
+
+static int gxp_gpio_fn2_direction_input(struct gpio_chip *chip,
+					unsigned int offset)
+{
+	switch (offset) {
+	case PGOOD:
+	case PERST:
+	case POST_COMPLETE:
+		return 0;
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int gxp_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset < 200)
+		return gxp_gpio_csm_get(chip, offset);
+	else if (offset >= 200 && offset < 210)
+		return gxp_gpio_vuhc_get(chip, offset - 200);
+	else if (offset >= 210)
+		return gxp_gpio_fn2_get(chip, offset);
+
+	return 0;
+}
+
+static void gxp_gpio_set(struct gpio_chip *chip,
+			 unsigned int offset, int value)
+{
+	if (offset < 200)
+		gxp_gpio_csm_set(chip, offset, value);
+	else if (offset >= 200 && offset < 210)
+		gxp_gpio_vuhc_set(chip, offset - 200, value);
+	else if (offset >= 210)
+		gxp_gpio_fn2_set(chip, offset, value);
+}
+
+static int gxp_gpio_get_direction(struct gpio_chip *chip,
+				  unsigned int offset)
+{
+	if (offset < 200)
+		return gxp_gpio_csm_get_direction(chip, offset);
+	else if (offset >= 200 && offset < 210)
+		return gxp_gpio_vuhc_get_direction(chip, offset - 200);
+	else if (offset >= 210)
+		return gxp_gpio_fn2_get_direction(chip, offset);
+
+	return 0;
+}
+
+static int gxp_gpio_direction_input(struct gpio_chip *chip,
+				    unsigned int offset)
+{
+	if (offset < 200)
+		return gxp_gpio_csm_direction_input(chip, offset);
+	else if (offset >= 200 && offset < 210)
+		return gxp_gpio_vuhc_direction_input(chip, offset - 200);
+	else if (offset >= 210)
+		return gxp_gpio_fn2_direction_input(chip, offset);
+
+	return 0;
+}
+
+static int gxp_gpio_direction_output(struct gpio_chip *chip,
+				     unsigned int offset, int value)
+{
+	if (offset < 200)
+		return gxp_gpio_csm_direction_output(chip, offset, value);
+	else if (offset >= 200 && offset < 210)
+		return gxp_gpio_vuhc_direction_output(chip, offset - 200, value);
+
+	return 0;
+}
+
+static const struct regmap_config gxp_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.name = "gxp",
+};
+
+static struct regmap *gxp_gpio_init_regmap(struct platform_device *pdev,
+					   char *reg_name)
+{
+	void __iomem *base;
+
+	base = devm_platform_ioremap_resource_byname(pdev, reg_name);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+
+	return devm_regmap_init_mmio(&pdev->dev, base, &gxp_regmap_config);
+}
+
+static void gxp_gpio_fn2_irq_ack(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+	unsigned int val;
+
+	/* Read latched interrupt */
+	regmap_read(drvdata->fn2_stat, 0, &val);
+	/* Clear latched interrupt */
+	regmap_update_bits(drvdata->fn2_stat, 0,
+			   GENMASK(15, 0), GENMASK(15, 0));
+}
+
+#define FN2_SEVMASK BIT(2)
+static void gxp_gpio_fn2_irq_set_mask(struct irq_data *d, bool set)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
+
+	regmap_update_bits(drvdata->fn2_stat, FN2_SEVMASK,
+			   BIT(0), set ? BIT(0) : 0);
+}
+
+static void gxp_gpio_fn2_irq_mask(struct irq_data *d)
+{
+	gxp_gpio_fn2_irq_set_mask(d, false);
+}
+
+static void gxp_gpio_fn2_irq_unmask(struct irq_data *d)
+{
+	gxp_gpio_fn2_irq_set_mask(d, true);
+}
+
+static int gxp_gpio_fn2_set_type(struct irq_data *d, unsigned int type)
+{
+	if (type & IRQ_TYPE_LEVEL_MASK)
+		irq_set_handler_locked(d, handle_level_irq);
+	else
+		irq_set_handler_locked(d, handle_edge_irq);
+
+	return 0;
+}
+
+static irqreturn_t gxp_gpio_fn2_irq_handle(int irq, void *_drvdata)
+{
+	struct gxp_gpio_drvdata *drvdata = (struct gxp_gpio_drvdata *)_drvdata;
+	unsigned int val;
+
+	regmap_read(drvdata->fn2_stat, 0, &val);
+
+	if (val & PGOOD_MASK)
+		generic_handle_domain_irq(drvdata->chip.irq.domain, PGOOD);
+
+	return IRQ_HANDLED;
+}
+
+static const struct irq_chip gxp_gpio_irqchip = {
+	.name		= "gxp_fn2",
+	.irq_ack	= gxp_gpio_fn2_irq_ack,
+	.irq_mask	= gxp_gpio_fn2_irq_mask,
+	.irq_unmask	= gxp_gpio_fn2_irq_unmask,
+	.irq_set_type	= gxp_gpio_fn2_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+};
+
+static const struct gpio_chip common_chip_template = {
+	.label			= "gxp_gpio",
+	.owner                  = THIS_MODULE,
+	.get                    = gxp_gpio_get,
+	.set                    = gxp_gpio_set,
+	.get_direction		= gxp_gpio_get_direction,
+	.direction_input	= gxp_gpio_direction_input,
+	.direction_output	= gxp_gpio_direction_output,
+	.base = 0,
+};
+
+static const struct of_device_id gxp_gpio_of_match[] = {
+	{ .compatible = "hpe,gxp-gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, gxp_gpio_of_match);
+
+static int gxp_gpio_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct gxp_gpio_drvdata *drvdata;
+	struct gpio_irq_chip *girq;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, drvdata);
+
+	drvdata->csm_map = gxp_gpio_init_regmap(pdev, "csm");
+	if (IS_ERR(drvdata->csm_map))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->csm_map),
+				     "failed to map csm_handle\n");
+
+	drvdata->fn2_vbtn = devm_platform_ioremap_resource_byname(pdev, "fn2-vbtn");
+	if (IS_ERR(drvdata->fn2_vbtn))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->fn2_vbtn),
+				     "failed to map fn2_vbtn\n");
+
+	drvdata->fn2_stat = gxp_gpio_init_regmap(pdev, "fn2-stat");
+	if (IS_ERR(drvdata->fn2_stat))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->fn2_stat),
+				     "failed to map fn2_stat\n");
+
+	drvdata->vuhc0_map = gxp_gpio_init_regmap(pdev, "vuhc");
+	if (IS_ERR(drvdata->vuhc0_map))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->vuhc0_map),
+				     "failed to map vuhc0_map\n");
+
+	girq = &drvdata->chip.irq;
+	gpio_irq_chip_set_chip(girq, &gxp_gpio_irqchip);
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_bad_irq;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+
+	drvdata->irq = ret;
+
+	ret = devm_request_irq(&pdev->dev, drvdata->irq, gxp_gpio_fn2_irq_handle,
+			       IRQF_SHARED, "gxp-fn2", drvdata);
+	if (ret < 0)
+		return ret;
+
+	drvdata->chip = common_chip_template;
+	drvdata->chip.ngpio = 220;
+
+	drvdata->chip.parent = &pdev->dev;
+
+	return devm_gpiochip_add_data(&pdev->dev, &drvdata->chip, NULL);
+}
+
+static struct platform_driver gxp_gpio_driver = {
+	.driver = {
+		.name = "gxp-gpio",
+		.of_match_table = gxp_gpio_of_match,
+	},
+	.probe = gxp_gpio_probe,
+};
+module_platform_driver(gxp_gpio_driver);
+
+MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
+MODULE_DESCRIPTION("GPIO interface for GXP");
+MODULE_LICENSE("GPL");