Re: [PATCH v2 2/4] gpio: Add Delta TN48M CPLD GPIO driver

From: Bartosz Golaszewski
Date: Tue May 25 2021 - 10:42:05 EST


On Mon, May 24, 2021 at 2:05 PM Robert Marko <robert.marko@xxxxxxxxxx> wrote:
>
> Delta TN48M CPLD is used as a GPIO expander for the SFP GPIOs.
>
> It is a mix of input only and output only pins.
>
> Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
> ---
> Changes in v2:
> * Rewrite to use simple I2C MFD and GPIO regmap
> * Drop DT bindings for pin numbering
>
> drivers/gpio/Kconfig | 12 ++++++
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-tn48m.c | 89 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 102 insertions(+)
> create mode 100644 drivers/gpio/gpio-tn48m.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 1dd0ec6727fd..46caf72960e6 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1332,6 +1332,18 @@ config GPIO_TIMBERDALE
> help
> Add support for the GPIO IP in the timberdale FPGA.
>
> +config GPIO_TN48M_CPLD
> + tristate "Delta Networks TN48M switch CPLD GPIO driver"
> + depends on MFD_TN48M_CPLD
> + select GPIO_REGMAP
> + help
> + This enables support for the GPIOs found on the Delta
> + Networks TN48M switch CPLD.
> + They are used for inputs and outputs on the SFP slots.
> +
> + This driver can also be built as a module. If so, the
> + module will be called gpio-tn48m.
> +
> config GPIO_TPS65086
> tristate "TI TPS65086 GPO"
> depends on MFD_TPS65086
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index d7c81e1611a4..07fa6419305f 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -147,6 +147,7 @@ obj-$(CONFIG_GPIO_TEGRA186) += gpio-tegra186.o
> obj-$(CONFIG_GPIO_TEGRA) += gpio-tegra.o
> obj-$(CONFIG_GPIO_THUNDERX) += gpio-thunderx.o
> obj-$(CONFIG_GPIO_TIMBERDALE) += gpio-timberdale.o
> +obj-$(CONFIG_GPIO_TN48M_CPLD) += gpio-tn48m.o
> obj-$(CONFIG_GPIO_TPIC2810) += gpio-tpic2810.o
> obj-$(CONFIG_GPIO_TPS65086) += gpio-tps65086.o
> obj-$(CONFIG_GPIO_TPS65218) += gpio-tps65218.o
> diff --git a/drivers/gpio/gpio-tn48m.c b/drivers/gpio/gpio-tn48m.c
> new file mode 100644
> index 000000000000..41484c002826
> --- /dev/null
> +++ b/drivers/gpio/gpio-tn48m.c
> @@ -0,0 +1,89 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Delta TN48M CPLD GPIO driver
> + *
> + * Copyright 2021 Sartura Ltd
> + *
> + * Author: Robert Marko <robert.marko@xxxxxxxxxx>
> + */
> +
> +#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>
> +
> +enum tn48m_gpio_type {
> + TN48M_SFP_TX_DISABLE = 1,
> + TN48M_SFP_PRESENT,
> + TN48M_SFP_LOS,
> +};
> +
> +static int tn48m_gpio_probe(struct platform_device *pdev)
> +{
> + struct gpio_regmap_config config = {0};
> + enum tn48m_gpio_type type;
> + struct regmap *regmap;
> + u32 base;
> + int ret;
> +
> + if (!pdev->dev.parent)
> + return -ENODEV;
> +
> + type = (uintptr_t)device_get_match_data(&pdev->dev);
> + if (!type)
> + return -ENODEV;
> +
> + ret = device_property_read_u32(&pdev->dev, "reg", &base);
> + if (ret)
> + return -EINVAL;
> +
> + regmap = dev_get_regmap(pdev->dev.parent, NULL);
> + if (!regmap)
> + return -ENODEV;
> +
> + config.regmap = regmap;
> + config.parent = &pdev->dev;
> + config.ngpio = 4;
> +
> + switch (type) {
> + case TN48M_SFP_TX_DISABLE:
> + config.reg_set_base = base;
> + break;
> + case TN48M_SFP_PRESENT:
> + config.reg_dat_base = base;
> + break;
> + case TN48M_SFP_LOS:
> + config.reg_dat_base = base;
> + break;
> + default:
> + dev_err(&pdev->dev, "unknown type %d\n", type);
> + return -ENODEV;
> + }
> +
> + return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
> +}
> +
> +static const struct of_device_id tn48m_gpio_of_match[] = {
> + { .compatible = "delta,tn48m-gpio-sfp-tx-disable", .data = (void *)TN48M_SFP_TX_DISABLE },
> + { .compatible = "delta,tn48m-gpio-sfp-present", .data = (void *)TN48M_SFP_PRESENT },
> + { .compatible = "delta,tn48m-gpio-sfp-los", .data = (void *)TN48M_SFP_LOS },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, tn48m_gpio_of_match);
> +
> +static struct platform_driver tn48m_gpio_driver = {
> + .driver = {
> + .name = "delta-tn48m-gpio",
> + .of_match_table = tn48m_gpio_of_match,
> + },
> + .probe = tn48m_gpio_probe,
> +};
> +module_platform_driver(tn48m_gpio_driver);
> +
> +MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Delta TN48M CPLD GPIO driver");
> +MODULE_LICENSE("GPL");
> --
> 2.31.1
>

Acked-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

I guess this will go through the MFD tree?

Bart