[v2,2/5] gpio: gxp: Add HPE GXP GPIO

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
gpio-gxp-pl driver covers the CPLD which takes physical I/O from the
board and shares it with GXP via a propriety interface that maps the I/O
onto a specific register area of the GXP. The drivers both support
interrupts but from different interrupt parents.

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

---

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       |  18 ++
 drivers/gpio/Makefile      |   2 +
 drivers/gpio/gpio-gxp-pl.c | 536 +++++++++++++++++++++++++++++++
 drivers/gpio/gpio-gxp.c    | 637 +++++++++++++++++++++++++++++++++++++
 4 files changed, 1193 insertions(+)
 create mode 100644 drivers/gpio/gpio-gxp-pl.c
 create mode 100644 drivers/gpio/gpio-gxp.c

On Wed, May 31, 2023 at 5:23 PM <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
> I/O across the interfaces. The gpio-gxp driver specifically covers the
> CSM(physical), FN2(virtual), and VUHC(virtual) which are the host. The
> gpio-gxp-pl driver covers the CPLD which takes physical I/O from the
> board and shares it with GXP via a propriety interface that maps the I/O
> onto a specific register area of the GXP. The drivers both support
> interrupts but from different interrupt parents.
>
> Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
>
> ---
>
> 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       |  18 ++
>  drivers/gpio/Makefile      |   2 +
>  drivers/gpio/gpio-gxp-pl.c | 536 +++++++++++++++++++++++++++++++
>  drivers/gpio/gpio-gxp.c    | 637 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 1193 insertions(+)
>  create mode 100644 drivers/gpio/gpio-gxp-pl.c
>  create mode 100644 drivers/gpio/gpio-gxp.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 13be729710f2..b0a24ef18392 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1235,6 +1235,24 @@ 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_GXP_PL
> +       tristate "GXP GPIO PL support"
> +       depends on ARCH_HPE_GXP || COMPILE_TEST
> +       select GPIOLIB_IRQCHIP
> +       help
> +         Say Y here to support GXP GPIO PL controller. It provides
> +         support for the GPIO PL interface 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..a401dd472c93 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -63,6 +63,8 @@ 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_GXP_PL)              += gpio-gxp-pl.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-pl.c b/drivers/gpio/gpio-gxp-pl.c
> new file mode 100644
> index 000000000000..3b27848d6bfc
> --- /dev/null
> +++ b/drivers/gpio/gpio-gxp-pl.c
> @@ -0,0 +1,536 @@
> +// 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>
> +
> +/* Specific offsets in CPLD registers for interrupts */
> +#define PLREG_INT_GRP_STAT_MASK        0x08
> +#define PLREG_INT_HI_PRI_EN    0x0C
> +#define PLREG_INT_GRP5_BASE    0x31
> +#define PLREG_INT_GRP6_BASE    0x35
> +#define PLREG_INT_GRP5_FLAG    0x30
> +#define PLREG_INT_GRP6_FLAG    0x34
> +
> +/* Specific bits to enable Group 4 and Group 5 interrupts */
> +#define PLREG_GRP4_GRP5_MASK   GENMASK(5, 4)
> +
> +/* Specific offsets in CPLD registers */
> +#define PLREG_IOP_LED          0x04
> +#define PLREG_IDENT_LED                0x05
> +#define PLREG_HEALTH_LED       0x0D
> +#define PLREG_PSU_INST         0x19
> +#define PLREG_PSU_AC           0x1B
> +#define PLREG_PSU_DC           0x1C
> +#define PLREG_FAN_INST         0x27
> +#define PLREG_FAN_FAIL         0x29
> +
> +#define GXP_GPIO_DIR_OUT        0x00
> +#define GXP_GPIO_DIR_IN         0x01
> +
> +enum pl_gpio_pn {
> +       IOP_LED1 = 0,
> +       IOP_LED2 = 1,
> +       IOP_LED3 = 2,
> +       IOP_LED4 = 3,
> +       IOP_LED5 = 4,
> +       IOP_LED6 = 5,
> +       IOP_LED7 = 6,
> +       IOP_LED8 = 7,
> +       FAN1_INST = 8,
> +       FAN2_INST = 9,
> +       FAN3_INST = 10,
> +       FAN4_INST = 11,
> +       FAN5_INST = 12,
> +       FAN6_INST = 13,
> +       FAN7_INST = 14,
> +       FAN8_INST = 15,
> +       FAN1_FAIL = 16,
> +       FAN2_FAIL = 17,
> +       FAN3_FAIL = 18,
> +       FAN4_FAIL = 19,
> +       FAN5_FAIL = 20,
> +       FAN6_FAIL = 21,
> +       FAN7_FAIL = 22,
> +       FAN8_FAIL = 23,
> +       LED_IDENTIFY = 24,
> +       LED_HEALTH_RED = 25,
> +       LED_HEALTH_AMBER = 26,
> +       PWR_BTN_INT = 27,
> +       UID_PRESS_INT = 28,
> +       SLP_INT = 29,
> +       ACM_FORCE_OFF = 30,
> +       ACM_REMOVED = 31,
> +       ACM_REQ_N = 32,
> +       PSU1_INST = 33,
> +       PSU2_INST = 34,
> +       PSU3_INST = 35,
> +       PSU4_INST = 36,
> +       PSU5_INST = 37,
> +       PSU6_INST = 38,
> +       PSU7_INST = 39,
> +       PSU8_INST = 40,
> +       PSU1_AC = 41,
> +       PSU2_AC = 42,
> +       PSU3_AC = 43,
> +       PSU4_AC = 44,
> +       PSU5_AC = 45,
> +       PSU6_AC = 46,
> +       PSU7_AC = 47,
> +       PSU8_AC = 48,
> +       PSU1_DC = 49,
> +       PSU2_DC = 50,
> +       PSU3_DC = 51,
> +       PSU4_DC = 52,
> +       PSU5_DC = 53,
> +       PSU6_DC = 54,
> +       PSU7_DC = 55,
> +       PSU8_DC = 56,
> +       RESET = 57,
> +       NMI_OUT = 58,
> +       VPBTN = 59,
> +       PGOOD = 60,
> +       PERST = 61,
> +       POST_COMPLETE = 62,
> +};
> +
> +/* Provide info for fan driver */
> +u8 fan_presence;
> +EXPORT_SYMBOL(fan_presence);
> +

This is awful. Not only do you export a random global variable with no
namespace prefix - that's also not declared in any header - but you
then set this singular global variable from per-device probe().

There's no other mention of this anywhere, so please explain who needs
that and I'm sure we can find a better solution.

Bart

> +u8 fan_fail;
> +EXPORT_SYMBOL(fan_fail);
> +
> +/* Remember last PSU config */
> +u8 psu_presence;
> +
> +struct gxp_gpio_drvdata {
> +       struct regmap *base;
> +       struct regmap *interrupt;
> +       struct gpio_chip chip;
> +       int irq;
> +};
> +
> +static struct regmap *gxp_gpio_init_regmap(struct platform_device *pdev,
> +                                          char *reg_name, u8 bits)
> +{
> +       struct regmap_config regmap_config = {
> +               .reg_bits = 32,
> +               .reg_stride = 4,
> +               .val_bits = 32,
> +       };
> +       void __iomem *base;
> +
> +       if (bits == 8) {
> +               regmap_config.reg_bits = 8;
> +               regmap_config.reg_stride = 1;
> +               regmap_config.val_bits = 8;
> +               regmap_config.max_register = 0xff;
> +       }
> +
> +       base = devm_platform_ioremap_resource_byname(pdev, reg_name);
> +       if (IS_ERR(base))
> +               return ERR_CAST(base);
> +
> +       regmap_config.name = reg_name;
> +
> +       return devm_regmap_init_mmio(&pdev->dev, base, &regmap_config);
> +}
> +
> +static int gxp_gpio_pl_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +       unsigned int val;
> +       int ret = 0;
> +
> +       switch (offset) {
> +       case IOP_LED1 ... IOP_LED8:
> +               regmap_read(drvdata->base, PLREG_IOP_LED, &val);
> +               ret = (val & BIT(offset)) ? 1 : 0;
> +               break;
> +       case FAN1_INST ...FAN8_INST:
> +               regmap_read(drvdata->base, PLREG_FAN_INST, &val);
> +               fan_presence = (u8)val;
> +               ret = (fan_presence & BIT((offset - FAN1_INST))) ? 1 : 0;
> +               break;
> +       case FAN1_FAIL ... FAN8_FAIL:
> +               regmap_read(drvdata->base, PLREG_FAN_FAIL, &val);
> +               fan_fail = (u8)val;
> +               ret = (fan_fail & BIT((offset - FAN1_FAIL))) ? 1 : 0;
> +               break;
> +       case PWR_BTN_INT ... SLP_INT:
> +               regmap_read(drvdata->base, PLREG_INT_GRP5_FLAG, &val);
> +               /* Active low */
> +               ret = (val & BIT((offset - PWR_BTN_INT) + 16)) ? 0 : 1;
> +               break;
> +       case  PSU1_INST ... PSU8_INST:
> +               regmap_read(drvdata->base, PLREG_PSU_INST, &val);
> +               psu_presence = (u8)val;
> +               ret = (psu_presence & BIT((offset - PSU1_INST))) ? 1 : 0;
> +               break;
> +       case PSU1_AC ... PSU8_AC:
> +               regmap_read(drvdata->base, PLREG_PSU_AC, &val);
> +               ret = (val & BIT((offset - PSU1_AC))) ? 1 : 0;
> +               break;
> +       case PSU1_DC ... PSU8_DC:
> +               regmap_read(drvdata->base, PLREG_PSU_DC, &val);
> +               ret = (val & BIT((offset - PSU1_DC))) ? 1 : 0;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static void gxp_gpio_pl_set(struct gpio_chip *chip,
> +                           unsigned int offset, int value)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +
> +       switch (offset) {
> +       case IOP_LED1 ... IOP_LED8:
> +               regmap_update_bits(drvdata->base,
> +                                  PLREG_IOP_LED,
> +                                  BIT(offset),
> +                                  value == 0 ? 0 : BIT(offset));
> +               break;
> +       case LED_IDENTIFY:
> +               regmap_update_bits(drvdata->base,
> +                                  PLREG_IDENT_LED,
> +                                  BIT(7) | BIT(6),
> +                                  value == 0 ? BIT(7) : BIT(7) | BIT(6));
> +               break;
> +       case LED_HEALTH_RED:
> +               regmap_update_bits(drvdata->base,
> +                                  PLREG_HEALTH_LED,
> +                                  BIT(7),
> +                                  value == 0 ? 0 : BIT(7));
> +               break;
> +       case LED_HEALTH_AMBER:
> +               regmap_update_bits(drvdata->base,
> +                                  PLREG_HEALTH_LED,
> +                                  BIT(6),
> +                                  value == 0 ? 0 : BIT(6));
> +               break;
> +       default:
> +               break;
> +       }
> +}
> +
> +static int gxp_gpio_pl_get_direction(struct gpio_chip *chip, unsigned int offset)
> +{
> +       int ret = GXP_GPIO_DIR_IN;
> +
> +       switch (offset) {
> +       case IOP_LED1 ... IOP_LED8:
> +       case LED_IDENTIFY ... LED_HEALTH_AMBER:
> +       case ACM_FORCE_OFF:
> +       case ACM_REQ_N:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_pl_direction_input(struct gpio_chip *chip,
> +                                      unsigned int offset)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case 8 ... 55:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       case 59 ... 65:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_pl_direction_output(struct gpio_chip *chip,
> +                                       unsigned int offset, int value)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case IOP_LED1 ... IOP_LED8:
> +       case LED_IDENTIFY ... LED_HEALTH_AMBER:
> +       case ACM_FORCE_OFF:
> +       case ACM_REQ_N:
> +               gxp_gpio_pl_set(chip, offset, value);
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static void gxp_gpio_pl_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 for group 5 */
> +       regmap_read(drvdata->interrupt, PLREG_INT_GRP5_FLAG, &val);
> +       /* Clear latched interrupt */
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP5_FLAG,
> +                          0xFF, 0xFF);
> +
> +       /* Read latched interrupt for group 6 */
> +       regmap_read(drvdata->interrupt, PLREG_INT_GRP6_FLAG, &val);
> +       /* Clear latched interrupt */
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP6_FLAG,
> +                          0xFF, 0xFF);
> +}
> +
> +static void gxp_gpio_pl_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->interrupt, PLREG_INT_GRP5_BASE,
> +                          BIT(0) | BIT(2), set ? 0 : BIT(0) | BIT(2));
> +
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP6_BASE,
> +                          BIT(2), set ? 0 : BIT(2));
> +}
> +
> +static void gxp_gpio_pl_irq_mask(struct irq_data *d)
> +{
> +       gxp_gpio_pl_irq_set_mask(d, false);
> +}
> +
> +static void gxp_gpio_pl_irq_unmask(struct irq_data *d)
> +{
> +       gxp_gpio_pl_irq_set_mask(d, true);
> +}
> +
> +static int gxp_gpio_irq_init_hw(struct gpio_chip *chip)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(chip->parent);
> +
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP5_BASE,
> +                          BIT(0) | BIT(2), 0);
> +
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP6_BASE,
> +                          BIT(2), 0);
> +
> +       return 0;
> +}
> +
> +static int gxp_gpio_pl_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_pl_irq_handle(int irq, void *_drvdata)
> +{
> +       struct gxp_gpio_drvdata *drvdata = (struct gxp_gpio_drvdata *)_drvdata;
> +       unsigned int val, girq, i;
> +
> +       /* Check group 5 interrupts */
> +
> +       regmap_read(drvdata->base, PLREG_INT_GRP5_FLAG, &val);
> +
> +       if (val) {
> +               for_each_set_bit(i, (unsigned long *)&val, 3) {
> +                       girq = irq_find_mapping(drvdata->chip.irq.domain,
> +                                               i + PWR_BTN_INT);
> +                       generic_handle_irq(girq);
> +               }
> +
> +               /* Clear latched interrupt */
> +               regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP5_FLAG,
> +                                  0xFF, 0xFF);
> +               regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP5_BASE,
> +                                  BIT(0) | BIT(2), 0);
> +       }
> +
> +       /* Check group 6 interrupts */
> +
> +       regmap_read(drvdata->base, PLREG_INT_GRP6_FLAG, &val);
> +
> +       if (val & BIT(2)) {
> +               u8 old_psu = psu_presence;
> +
> +               regmap_read(drvdata->base, PLREG_PSU_INST, &val);
> +               psu_presence = (u8)val;
> +
> +               if (old_psu != psu_presence) {
> +                       /* Identify all bits which differs */
> +                       u8 current_val = psu_presence;
> +                       u8 old_val = old_psu;
> +
> +                       for (i = 0 ; i < 8 ; i++) {
> +                               if ((current_val & 0x1) != (old_val & 0x1)) {
> +                               /* PSU state has changed */
> +                                       girq = irq_find_mapping(drvdata->chip.irq.domain,
> +                                                               i + PSU1_INST);
> +                                       if (girq)
> +                                               generic_handle_irq(girq);
> +                               }
> +                               current_val = current_val >> 1;
> +                               old_val = old_val >> 1;
> +                       }
> +               }
> +       }
> +
> +       /* Clear latched interrupt */
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP6_FLAG,
> +                          0xFF, 0xFF);
> +       regmap_update_bits(drvdata->interrupt, PLREG_INT_GRP6_BASE,
> +                          BIT(2), 0);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static struct gpio_chip plreg_chip = {
> +       .label                  = "gxp_gpio_plreg",
> +       .owner                  = THIS_MODULE,
> +       .get                    = gxp_gpio_pl_get,
> +       .set                    = gxp_gpio_pl_set,
> +       .get_direction = gxp_gpio_pl_get_direction,
> +       .direction_input = gxp_gpio_pl_direction_input,
> +       .direction_output = gxp_gpio_pl_direction_output,
> +       .base = -1,
> +};
> +
> +static struct irq_chip gxp_plreg_irqchip = {
> +       .name           = "gxp_plreg",
> +       .irq_ack        = gxp_gpio_pl_irq_ack,
> +       .irq_mask       = gxp_gpio_pl_irq_mask,
> +       .irq_unmask     = gxp_gpio_pl_irq_unmask,
> +       .irq_set_type   = gxp_gpio_pl_set_type,
> +};
> +
> +static int gxp_gpio_pl_init(struct platform_device *pdev)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> +       struct gpio_irq_chip *girq;
> +       int ret;
> +       unsigned int val;
> +
> +       drvdata->base = gxp_gpio_init_regmap(pdev, "base", 8);
> +       if (IS_ERR(drvdata->base))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->base),
> +                                    "failed to map base\n");
> +
> +       drvdata->interrupt = gxp_gpio_init_regmap(pdev, "interrupt", 8);
> +       if (IS_ERR(drvdata->interrupt))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->interrupt),
> +                                    "failed to map interrupt base\n");
> +
> +       regmap_read(drvdata->base, PLREG_FAN_INST, &val);
> +       fan_presence = (u8)val;
> +
> +       regmap_read(drvdata->base, PLREG_FAN_FAIL, &val);
> +       fan_fail = (u8)val;
> +
> +       regmap_read(drvdata->base, PLREG_PSU_INST, &val);
> +       psu_presence = (u8)val;
> +
> +       drvdata->chip = plreg_chip;
> +       drvdata->chip.ngpio = 57;
> +       drvdata->chip.parent = &pdev->dev;
> +
> +       girq = &drvdata->chip.irq;
> +       girq->chip = &gxp_plreg_irqchip;
> +       girq->parent_handler = NULL;
> +       girq->num_parents = 0;
> +       girq->parents = NULL;
> +       girq->default_type = IRQ_TYPE_NONE;
> +       girq->handler = handle_bad_irq;
> +
> +       girq->init_hw = gxp_gpio_irq_init_hw;
> +
> +       ret = devm_gpiochip_add_data(&pdev->dev, &drvdata->chip, drvdata);
> +       if (ret < 0)
> +               dev_err_probe(&pdev->dev, ret, "Could not register gpiochip for plreg\n");
> +
> +       regmap_update_bits(drvdata->base,
> +                          PLREG_INT_HI_PRI_EN,
> +                          PLREG_GRP4_GRP5_MASK,
> +                          PLREG_GRP4_GRP5_MASK);
> +       regmap_update_bits(drvdata->base,
> +                          PLREG_INT_GRP_STAT_MASK,
> +                          PLREG_GRP4_GRP5_MASK,
> +                          0x00);
> +       regmap_read(drvdata->base, PLREG_INT_HI_PRI_EN, &val);
> +       regmap_read(drvdata->base, PLREG_INT_GRP_STAT_MASK, &val);
> +
> +       ret = platform_get_irq(pdev, 0);
> +       if (ret < 0)
> +               return dev_err_probe(&pdev->dev, ret, "Get irq from platform fail\n");
> +
> +       drvdata->irq = ret;
> +
> +       ret = devm_request_irq(&pdev->dev, drvdata->irq, gxp_gpio_pl_irq_handle,
> +                              IRQF_SHARED, "gxp-pl", drvdata);
> +       if (ret < 0)
> +               return ret;
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id gxp_gpio_of_match[] = {
> +       { .compatible = "hpe,gxp-gpio-pl" },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(of, gxp_gpio_of_match);
> +
> +static int gxp_gpio_probe(struct platform_device *pdev)
> +{
> +       int ret;
> +       struct gxp_gpio_drvdata *drvdata;
> +
> +       /* Initialize global vars */
> +       fan_presence = 0;
> +       fan_fail = 0;
> +       psu_presence = 0;
> +
> +       drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> +       if (!drvdata)
> +               return -ENOMEM;
> +
> +       platform_set_drvdata(pdev, drvdata);
> +
> +       ret = gxp_gpio_pl_init(pdev);
> +
> +       return ret;
> +}
> +
> +static struct platform_driver gxp_gpio_driver = {
> +       .driver = {
> +               .name = "gxp-gpio-pl",
> +               .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 PL interface for GXP");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpio/gpio-gxp.c b/drivers/gpio/gpio-gxp.c
> new file mode 100644
> index 000000000000..ed6d8577e6b7
> --- /dev/null
> +++ b/drivers/gpio/gpio-gxp.c
> @@ -0,0 +1,637 @@
> +// 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 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;
> +
> +       switch (offset) {
> +       case 0 ... 31:
> +               regmap_read(drvdata->csm_map, GPIDAT, &ret);
> +               ret = (ret & BIT(offset));
> +               break;
> +       case 32 ... 63:
> +               regmap_read(drvdata->csm_map, GPIDAT + 0x20, &ret);
> +               ret = (ret & BIT(offset - 32));
> +               break;
> +       case 64 ... 95:
> +               regmap_read(drvdata->csm_map, GPODAT, &ret);
> +               ret = (ret & BIT(offset - 64));
> +               break;
> +       case 96 ... 127:
> +               regmap_read(drvdata->csm_map, GPODAT + 0x04, &ret);
> +               ret = (ret & BIT(offset - 96));
> +               break;
> +       case 128 ...  159:
> +               regmap_read(drvdata->csm_map, GPODAT2, &ret);
> +               ret = (ret & BIT(offset - 128));
> +               break;
> +       case 160 ... 191:
> +               regmap_read(drvdata->csm_map, GPODAT2 + 0x04, &ret);
> +               ret = (ret & BIT(offset - 160));
> +               break;
> +       case RESET:
> +               /* SW_RESET */
> +               regmap_read(drvdata->csm_map, ASR_OFS, &ret);
> +               ret = (ret & BIT(15));
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       /* Return either 1 or 0 */
> +       return (ret ? 1 : 0);
> +}
> +
> +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)
> +{
> +       int ret = 0;
> +
> +       switch (offset) {
> +       case 0 ... 63:
> +               ret = GXP_GPIO_DIR_IN;
> +               break;
> +       case 64 ... 191:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       case 192 ... 193:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       case 194:
> +               ret = GXP_GPIO_DIR_IN;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_csm_direction_input(struct gpio_chip *chip,
> +                                       unsigned int offset)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case 0 ... 63:
> +               ret = 0;
> +               break;
> +       case 194:
> +               ret = 0;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_csm_direction_output(struct gpio_chip *chip,
> +                                        unsigned int offset, int value)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case 64 ... 191:
> +       case 192 ... 193:
> +               gxp_gpio_csm_set(chip, offset, value);
> +               ret = 0;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +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, 0x64 + 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)
> +{
> +       switch (offset) {
> +       default:
> +               break;
> +       }
> +}
> +
> +static int gxp_gpio_vuhc_get_direction(struct gpio_chip *chip,
> +                                      unsigned int offset)
> +{
> +       int ret = 0;
> +
> +       switch (offset) {
> +       case 0:
> +       case 1:
> +       case 2:
> +               ret = GXP_GPIO_DIR_IN;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_vuhc_direction_input(struct gpio_chip *chip,
> +                                        unsigned int offset)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case 0:
> +       case 1:
> +       case 2:
> +               ret = 0;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_vuhc_direction_output(struct gpio_chip *chip,
> +                                         unsigned int offset, int value)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +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;
> +
> +       switch (offset) {
> +       case PGOOD:
> +               regmap_read(drvdata->fn2_stat, 0, &val);
> +               ret = (val & BIT(24));
> +
> +               break;
> +       case PERST:
> +               regmap_read(drvdata->fn2_stat, 0, &val);
> +               ret = (val & BIT(25));
> +
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       /* 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)
> +{
> +       int ret = GXP_GPIO_DIR_IN;
> +
> +       switch (offset) {
> +       case VPBTN:
> +               ret = GXP_GPIO_DIR_OUT;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_fn2_direction_input(struct gpio_chip *chip,
> +                                       unsigned int offset)
> +{
> +       int ret = -EOPNOTSUPP;
> +
> +       switch (offset) {
> +       case PGOOD:
> +       case PERST:
> +       case POST_COMPLETE:
> +               ret = 0;
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       int ret = 0;
> +
> +       if (offset < 200)
> +               ret = gxp_gpio_csm_get(chip, offset);
> +       else if (offset >= 250 && offset < 300)
> +               ret = gxp_gpio_vuhc_get(chip, offset - 250);
> +       else if (offset >= 300)
> +               ret = gxp_gpio_fn2_get(chip, offset);
> +
> +       return ret;
> +}
> +
> +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 >= 250 && offset < 300)
> +               gxp_gpio_vuhc_set(chip, offset - 250, value);
> +       else if (offset >= 300)
> +               gxp_gpio_fn2_set(chip, offset, value);
> +}
> +
> +static int gxp_gpio_get_direction(struct gpio_chip *chip,
> +                                 unsigned int offset)
> +{
> +       int ret = 0;
> +
> +       if (offset < 200)
> +               ret = gxp_gpio_csm_get_direction(chip, offset);
> +       else if (offset >= 250 && offset < 300)
> +               ret = gxp_gpio_vuhc_get_direction(chip, offset - 250);
> +       else if (offset >= 300)
> +               ret = gxp_gpio_fn2_get_direction(chip, offset);
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_direction_input(struct gpio_chip *chip,
> +                                   unsigned int offset)
> +{
> +       int ret = 0;
> +
> +       if (offset < 200)
> +               ret = gxp_gpio_csm_direction_input(chip, offset);
> +       else if (offset >= 250 && offset < 300)
> +               ret = gxp_gpio_vuhc_direction_input(chip, offset - 250);
> +       else if (offset >= 300)
> +               ret = gxp_gpio_fn2_direction_input(chip, offset);
> +
> +       return ret;
> +}
> +
> +static int gxp_gpio_direction_output(struct gpio_chip *chip,
> +                                    unsigned int offset, int value)
> +{
> +       int ret = 0;
> +
> +       if (offset < 200)
> +               ret = gxp_gpio_csm_direction_output(chip, offset, value);
> +       else if (offset >= 250 && offset < 300)
> +               ret = gxp_gpio_vuhc_direction_output(chip, offset - 250, value);
> +       return ret;
> +}
> +
> +static struct regmap *gxp_gpio_init_regmap(struct platform_device *pdev,
> +                                          char *reg_name, u8 bits)
> +{
> +       struct regmap_config regmap_config = {
> +               .reg_bits = 32,
> +               .reg_stride = 4,
> +               .val_bits = 32,
> +       };
> +       void __iomem *base;
> +
> +       if (bits == 8) {
> +               regmap_config.reg_bits = 8;
> +               regmap_config.reg_stride = 1;
> +               regmap_config.val_bits = 8;
> +               regmap_config.max_register = 0xff;
> +       }
> +
> +       base = devm_platform_ioremap_resource_byname(pdev, reg_name);
> +       if (IS_ERR(base))
> +               return ERR_CAST(base);
> +
> +       regmap_config.name = reg_name;
> +
> +       return devm_regmap_init_mmio(&pdev->dev, base, &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,
> +                          0xFFFF, 0xFFFF);
> +}
> +
> +#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, girq;
> +
> +       regmap_read(drvdata->fn2_stat, 0, &val);
> +
> +       if (val & PGOOD_MASK) {
> +               girq = irq_find_mapping(drvdata->chip.irq.domain, PGOOD);
> +               generic_handle_irq(girq);
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static 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,
> +};
> +
> +static struct gpio_chip common_chip = {
> +       .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 int gxp_gpio_init(struct platform_device *pdev)
> +{
> +       struct gxp_gpio_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> +       struct gpio_irq_chip *girq;
> +       int ret;
> +
> +       drvdata->csm_map = gxp_gpio_init_regmap(pdev, "csm", 32);
> +       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", 32);
> +       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", 32);
> +       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;
> +       girq->chip = &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 dev_err_probe(&pdev->dev, ret,
> +                                    "Get irq from platform fail\n");
> +
> +       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;
> +       drvdata->chip.ngpio = 220;
> +
> +       drvdata->chip.parent = &pdev->dev;
> +       ret = devm_gpiochip_add_data(&pdev->dev, &drvdata->chip, NULL);
> +       if (ret < 0)
> +               return dev_err_probe(&pdev->dev, ret,
> +                       "Could not register gpiochip for fn2\n");
> +
> +       return 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;
> +
> +       drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> +       if (!drvdata)
> +               return -ENOMEM;
> +
> +       platform_set_drvdata(pdev, drvdata);
> +
> +       ret = gxp_gpio_init(pdev);
> +
> +       return ret;
> +}
> +
> +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");
> --
> 2.17.1
>

Hi Nick,

thanks for your patch!

On Wed, May 31, 2023 at 5:23 PM <nick.hawkins@hpe.com> wrote:

> +/* Provide info for fan driver */
> +u8 fan_presence;
> +EXPORT_SYMBOL(fan_presence);
> +
> +u8 fan_fail;
> +EXPORT_SYMBOL(fan_fail);
> +
> +/* Remember last PSU config */
> +u8 psu_presence;

As Bartosz said this doesn't work.

to me it looks like you should define a GPIO-controlled fan in the
device tree, similar to this:

       fan0: gpio-fan {
                compatible = "gpio-fan";
                gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>;
                gpio-fan,speed-map = <0 0>, <10000 1>;
                #cooling-cells = <2>;
        };

Then that cooling cell should be used by a thermal driver for the chassis
to keep the temperature reasonable. I bet you have a temperature sensor
as well, meaning they should form a thermal zone controlled by the fan.

Examples of chassis thermal zones in device tree:
arch/arm/boot/dts/gemini-dlink-dir-685.dts
arch/arm/boot/dts/gemini-dlink-dns-313.dts

Yours,
Linus Walleij