Re: [PATCH v3 06/10] gpio: add QIXIS FPGA GPIO controller

[Frank Li <Frank.li@nxp.com>]

On Wed, Sep 17, 2025 at 12:04:18PM +0300, Ioana Ciornei wrote:
> Add support for the GPIO controller found on some QIXIS FPGAs in
> Layerscape boards such as LX2160ARDB and LS1046AQDS. This driver is
> using gpio-regmap.
>
> A GPIO controller has a maximum of 8 lines (all found in the same
> register). Even within the same controller, the GPIO lines' direction is
> fixed, which mean that both input and output lines are found in the same
> register. This is why the driver also passed to gpio-regmap the newly
> added .fixed_direction_output bitmap to represent the true direction of
> the lines.
>
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> ---
> Changes in v2:
> - Use the newly added .fixed_direction_output bitmap representing
>   the fixed direction of the GPIO lines.
> Changes in v3:
> - Remove 'drivers' from the commit title.
> - Remove the qixis_cpld_gpio_type enum since its not needed.
> - Remove the NULL check for device_get_match_data().
> - Use a bitmap declared on the stack as the config field passed to
>   gpio-regmap.
>
>  drivers/gpio/Kconfig           |   9 +++
>  drivers/gpio/Makefile          |   1 +
>  drivers/gpio/gpio-qixis-fpga.c | 107 +++++++++++++++++++++++++++++++++
>  3 files changed, 117 insertions(+)
>  create mode 100644 drivers/gpio/gpio-qixis-fpga.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 81fe3b085f7b..e963a7ee4ce1 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1962,6 +1962,15 @@ config GPIO_LATCH
>  	  Say yes here to enable a driver for GPIO multiplexers based on latches
>  	  connected to other GPIOs.
>
> +config GPIO_QIXIS_FPGA
> +	tristate "NXP QIXIS FPGA GPIO support"
> +	depends on MFD_SIMPLE_MFD_I2C || COMPILE_TEST
> +	select GPIO_REGMAP
> +	help
> +	  This enables support for the GPIOs found in the QIXIS FPGA which is
> +	  integrated on some NXP Layerscape boards such as LX2160ARDB and
> +	  LS1046AQDS.
> +
>  config GPIO_MOCKUP
>  	tristate "GPIO Testing Driver (DEPRECATED)"
>  	select IRQ_SIM
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index b1593ce92ebe..850c0e086c82 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -144,6 +144,7 @@ obj-$(CONFIG_GPIO_PL061)		+= gpio-pl061.o
>  obj-$(CONFIG_GPIO_PMIC_EIC_SPRD)	+= gpio-pmic-eic-sprd.o
>  obj-$(CONFIG_GPIO_POLARFIRE_SOC)	+= gpio-mpfs.o
>  obj-$(CONFIG_GPIO_PXA)			+= gpio-pxa.o
> +obj-$(CONFIG_GPIO_QIXIS_FPGA)		+= gpio-qixis-fpga.o
>  obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)	+= gpio-raspberrypi-exp.o
>  obj-$(CONFIG_GPIO_RC5T583)		+= gpio-rc5t583.o
>  obj-$(CONFIG_GPIO_RCAR)			+= gpio-rcar.o
> diff --git a/drivers/gpio/gpio-qixis-fpga.c b/drivers/gpio/gpio-qixis-fpga.c
> new file mode 100644
> index 000000000000..048a2cac4f0f
> --- /dev/null
> +++ b/drivers/gpio/gpio-qixis-fpga.c
> @@ -0,0 +1,107 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Layerscape GPIO QIXIS FPGA driver
> + *
> + * Copyright 2025 NXP
> + */
> +
> +#include <linux/device.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/gpio/regmap.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +struct qixis_cpld_gpio_config {
> +	u64 output_lines;
> +};
> +
> +static const struct qixis_cpld_gpio_config lx2160ardb_sfp_cfg = {
> +	.output_lines = BIT(0),
> +};
> +
> +static const struct qixis_cpld_gpio_config ls1046aqds_stat_pres2_cfg = {
> +	.output_lines = 0x0,
> +};
> +
> +static const struct regmap_config regmap_config_8r_8v = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +};
> +
> +static int qixis_cpld_gpio_probe(struct platform_device *pdev)
> +{
> +	DECLARE_BITMAP(fixed_direction_output, 8);
> +	const struct qixis_cpld_gpio_config *cfg;
> +	struct gpio_regmap_config config = {0};
> +	struct regmap *regmap;
> +	void __iomem *reg;
> +	u32 base;
> +	int ret;
> +
> +	if (!pdev->dev.parent)
> +		return -ENODEV;
> +
> +	cfg = device_get_match_data(&pdev->dev);
> +
> +	ret = device_property_read_u32(&pdev->dev, "reg", &base);
> +	if (ret)
> +		return ret;
> +
> +	regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!regmap) {
> +		/* In case there is no regmap configured by the parent device,
> +		 * create our own from the MMIO space.
> +		 */
> +		reg = devm_platform_ioremap_resource(pdev, 0);
> +		if (!reg)
> +			return -ENODEV;
> +
> +		regmap = devm_regmap_init_mmio(&pdev->dev, reg, &regmap_config_8r_8v);
> +		if (!regmap)
> +			return -ENODEV;
> +
> +		/* In this case, the offset of our register is 0 inside the
> +		 * regmap area that we just created.
> +		 */
> +		base = 0;
> +	}
> +	config.reg_dat_base = GPIO_REGMAP_ADDR(base);
> +	config.reg_set_base = GPIO_REGMAP_ADDR(base);
> +
> +	config.drvdata = (void *)cfg;
> +	config.regmap = regmap;
> +	config.parent = &pdev->dev;
> +	config.ngpio_per_reg = 8;
> +	config.ngpio = 8;
> +
> +	bitmap_from_u64(fixed_direction_output, cfg->output_lines);
> +	config.fixed_direction_output = fixed_direction_output;
> +
> +	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
> +}
> +
> +static const struct of_device_id qixis_cpld_gpio_of_match[] = {
> +	{
> +		.compatible = "fsl,lx2160ardb-fpga-gpio-sfp",
> +		.data = &lx2160ardb_sfp_cfg,
> +	},
> +	{
> +		.compatible = "fsl,ls1046aqds-fpga-gpio-stat-pres2",
> +		.data = &ls1046aqds_stat_pres2_cfg,
> +	},
> +
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, qixis_cpld_gpio_of_match);
> +
> +static struct platform_driver qixis_cpld_gpio_driver = {
> +	.probe = qixis_cpld_gpio_probe,
> +	.driver = {
> +		.name = "gpio-qixis-cpld",
> +		.of_match_table = qixis_cpld_gpio_of_match,
> +	},
> +};
> +module_platform_driver(qixis_cpld_gpio_driver);
> --
> 2.25.1
>