Re: [PATCH 06/13] gpio: add AD24xx GPIO driver

Bartosz Golaszewski
2024-05-22T15:31:14Z

On Fri, May 17, 2024 at 2:58 PM Alvin Šipraga <alvin@pqrs.dk> wrote:
>
> From: Alvin Šipraga <alsi@bang-olufsen.dk>
>
> This driver adds GPIO function support for AD24xx A2B transceiver chips.
> When a GPIO is requested, the relevant pin is automatically muxed to
> GPIO mode. The device tree property gpio-reserved-ranges can be used to
> protect certain pins which are reserved for other functionality such as
> I2S/TDM data.
>
> Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
> ---
> drivers/a2b/Kconfig | 1 +
> drivers/gpio/Kconfig | 6 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-ad24xx.c | 302 +++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 310 insertions(+)
>
> diff --git a/drivers/a2b/Kconfig b/drivers/a2b/Kconfig
> index 1f6d836463f3..8c894579e2fc 100644
> --- a/drivers/a2b/Kconfig
> +++ b/drivers/a2b/Kconfig
> @@ -32,6 +32,7 @@ config A2B_AD24XX_I2C
> config A2B_AD24XX_NODE
> tristate "Analog Devices Inc. AD24xx node support"
> select REGMAP_A2B
> + imply GPIO_AD24XX
> help
> Say Y here to enable support for AD24xx A2B transceiver nodes. This
> applies to both main nodes and subordinate nodes. Supported models
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 3dbddec07028..72bd0d88d6b3 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1241,6 +1241,12 @@ config GPIO_ALTERA_A10SR
> includes reads of pushbuttons and DIP switches as well
> as writes to LEDs.
>
> +config GPIO_AD24XX
> + tristate "Analog Devies Inc. AD24xx GPIO support"
> + depends on A2B_AD24XX_NODE
> + help
> + Say Y here to enable GPIO support for AD24xx A2B transceivers.
> +
> config GPIO_ARIZONA
> tristate "Wolfson Microelectronics Arizona class devices"
> depends on MFD_ARIZONA
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index e2a53013780e..f625bb140143 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_GPIO_104_IDI_48) += gpio-104-idi-48.o
> obj-$(CONFIG_GPIO_104_IDIO_16) += gpio-104-idio-16.o
> obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o
> obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o
> +obj-$(CONFIG_GPIO_AD24XX) += gpio-ad24xx.o
> obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o
> obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
> obj-$(CONFIG_GPIO_AGGREGATOR) += gpio-aggregator.o
> diff --git a/drivers/gpio/gpio-ad24xx.c b/drivers/gpio/gpio-ad24xx.c
> new file mode 100644
> index 000000000000..097ea9e2d629
> --- /dev/null
> +++ b/drivers/gpio/gpio-ad24xx.c
> @@ -0,0 +1,302 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * AD24xx GPIO driver
> + *
> + * Copyright (c) 2023-2024 Alvin Šipraga <alsi@bang-olufsen.dk>
> + */
> +
> +#include <linux/a2b/a2b.h>
> +#include <linux/a2b/ad24xx.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of_irq.h>
> +#include <linux/regmap.h>
> +
> +struct ad24xx_gpio {
> + struct device *dev;

You only use this once to emit a log message. You should probably drop
it and use the parent pointer in gpio_chip.

Otherwise looks pretty good to me.

With the above addressed:

Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Bart

> + struct a2b_func *func;
> + struct a2b_node *node;
> + struct regmap *regmap;
> + int irqs[AD24XX_MAX_GPIOS];
> + struct gpio_chip gpio_chip;
> + struct irq_chip irq_chip;
> + struct mutex mutex;
> + unsigned int irq_invert : AD24XX_MAX_GPIOS;
> + unsigned int irq_enable : AD24XX_MAX_GPIOS;
> +};
> +
> +static int ad24xx_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
> +{
> + struct ad24xx_gpio *adg = gpiochip_get_data(gc);
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_read(adg->regmap, A2B_GPIOOEN, &val);
> + if (ret)
> + return ret;
> +
> + if (val & BIT(offset))
> + return 0; /* output */
> +
> + return 1; /* input */
> +}
> +
> +static int ad24xx_gpio_get(struct gpio_chip *gc, unsigned int offset)
> +{
> + struct ad24xx_gpio *adg = gpiochip_get_data(gc);
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_read(adg->regmap, A2B_GPIOIN, &val);
> + if (ret)
> + return ret;
> +
> + if (val & BIT(offset))
> + return 1; /* high */
> +
> + return 0; /* low */
> +}
> +
> +static void ad24xx_gpio_set(struct gpio_chip *gc, unsigned int offset,
> + int value)
> +{
> + struct ad24xx_gpio *adg = gpiochip_get_data(gc);
> + unsigned int reg = value ? A2B_GPIODATSET : A2B_GPIODATCLR;
> +
> + regmap_write(adg->regmap, reg, BIT(offset));
> +}
> +
> +static int ad24xx_gpio_set_direction(struct ad24xx_gpio *adg,
> + unsigned int offset,
> + unsigned int direction)
> +{
> + unsigned int mask = BIT(offset);
> + unsigned int ival = direction ? BIT(offset) : 0;
> + int ret;
> +
> + ret = regmap_update_bits(adg->regmap, A2B_GPIOIEN, mask, ival);
> + if (ret)
> + return ret;
> +
> + ret = regmap_update_bits(adg->regmap, A2B_GPIOOEN, mask, ~ival);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int ad24xx_gpio_direction_input(struct gpio_chip *gc,
> + unsigned int offset)
> +{
> + struct ad24xx_gpio *adg = gpiochip_get_data(gc);
> +
> + return ad24xx_gpio_set_direction(adg, offset, 1);
> +}
> +
> +static int ad24xx_gpio_direction_output(struct gpio_chip *gc,
> + unsigned int offset, int value)
> +{
> + struct ad24xx_gpio *adg = gpiochip_get_data(gc);
> +
> + /* For atomicity, write the output value before setting the direction */
> + ad24xx_gpio_set(gc, offset, value);
> +
> + return ad24xx_gpio_set_direction(adg, offset, 0);
> +}
> +
> +static int ad24xx_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
> + unsigned int child,
> + unsigned int child_type,
> + unsigned int *parent,
> + unsigned int *parent_type)
> +{
> + *parent = child;
> + return 0;
> +}
> +
> +static void ad24xx_gpio_irq_mask(struct irq_data *d)
> +{
> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
> + struct ad24xx_gpio *adg = gpiochip_get_data(gpio_chip);
> + irq_hw_number_t hwirq = irqd_to_hwirq(d);
> +
> + adg->irq_enable &= ~BIT(hwirq);
> + gpiochip_disable_irq(gpio_chip, hwirq);
> +}
> +
> +static void ad24xx_gpio_irq_unmask(struct irq_data *d)
> +{
> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
> + struct ad24xx_gpio *adg = gpiochip_get_data(gpio_chip);
> + irq_hw_number_t hwirq = irqd_to_hwirq(d);
> +
> + gpiochip_disable_irq(gpio_chip, hwirq);
> + adg->irq_enable |= BIT(hwirq);
> +}
> +
> +static int ad24xx_gpio_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
> + struct ad24xx_gpio *adg = gpiochip_get_data(gpio_chip);
> + irq_hw_number_t hwirq = irqd_to_hwirq(d);
> +
> + switch (type) {
> + case IRQ_TYPE_EDGE_RISING:
> + adg->irq_invert &= ~BIT(hwirq);
> + break;
> + case IRQ_TYPE_EDGE_FALLING:
> + adg->irq_invert |= BIT(hwirq);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static void ad24xx_gpio_irq_bus_lock(struct irq_data *d)
> +{
> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
> + struct ad24xx_gpio *adg = gpiochip_get_data(gpio_chip);
> +
> + mutex_lock(&adg->mutex);
> +}
> +
> +static void ad24xx_gpio_irq_bus_sync_unlock(struct irq_data *d)
> +{
> + struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(d);
> + struct ad24xx_gpio *adg = gpiochip_get_data(gpio_chip);
> + int ret;
> +
> + ret = regmap_write(adg->regmap, A2B_PINTINV, adg->irq_invert);
> + if (ret)
> + goto out;
> +
> + ret = regmap_write(adg->regmap, A2B_PINTEN, adg->irq_enable);
> + if (ret)
> + goto out;
> +
> +out:
> + mutex_unlock(&adg->mutex);
> +
> + if (ret)
> + dev_err(adg->dev,
> + "failed to update interrupt configuration: %d\n", ret);
> +}
> +
> +static const struct irq_chip ad24xx_gpio_irq_chip = {
> + .name = "ad24xx-gpio",
> + .flags = IRQCHIP_IMMUTABLE,
> + .irq_mask = ad24xx_gpio_irq_mask,
> + .irq_unmask = ad24xx_gpio_irq_unmask,
> + .irq_set_type = ad24xx_gpio_irq_set_type,
> + .irq_bus_lock = ad24xx_gpio_irq_bus_lock,
> + .irq_bus_sync_unlock = ad24xx_gpio_irq_bus_sync_unlock,
> + GPIOCHIP_IRQ_RESOURCE_HELPERS,
> +};
> +
> +static const struct regmap_config ad24xx_gpio_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
> +
> +static int ad24xx_gpio_probe(struct device *dev)
> +{
> + struct a2b_func *func = to_a2b_func(dev);
> + struct a2b_node *node = func->node;
> + struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node);
> + struct gpio_chip *gpio_chip;
> + struct gpio_irq_chip *irq_chip;
> + struct irq_domain *parent_domain;
> + struct ad24xx_gpio *adg;
> + struct device_node *np;
> + int ret;
> +
> + adg = devm_kzalloc(dev, sizeof(*adg), GFP_KERNEL);
> + if (!adg)
> + return -ENOMEM;
> +
> + adg->regmap =
> + devm_regmap_init_a2b_func(func, &ad24xx_gpio_regmap_config);
> + if (IS_ERR(adg->regmap))
> + return PTR_ERR(adg->regmap);
> +
> + adg->dev = dev;
> + adg->func = func;
> + adg->node = node;
> + mutex_init(&adg->mutex);
> +
> + np = of_irq_find_parent(dev->of_node);
> + if (!np)
> + return -ENOENT;
> +
> + parent_domain = irq_find_host(np);
> + of_node_put(np);
> + if (!parent_domain)
> + return -ENOENT;
> +
> + gpio_chip = &adg->gpio_chip;
> + gpio_chip->label = dev_name(dev);
> + gpio_chip->parent = dev;
> + gpio_chip->fwnode = fwnode;
> + gpio_chip->owner = THIS_MODULE;
> + gpio_chip->get_direction = ad24xx_gpio_get_direction;
> + gpio_chip->direction_input = ad24xx_gpio_direction_input;
> + gpio_chip->direction_output = ad24xx_gpio_direction_output;
> + gpio_chip->get = ad24xx_gpio_get;
> + gpio_chip->set = ad24xx_gpio_set;
> + gpio_chip->base = -1;
> + gpio_chip->ngpio = node->chip_info->max_gpios;
> + gpio_chip->can_sleep = true;
> +
> + irq_chip = &gpio_chip->irq;
> + gpio_irq_chip_set_chip(irq_chip, &ad24xx_gpio_irq_chip);
> + irq_chip->fwnode = fwnode;
> + irq_chip->parent_domain = parent_domain;
> + irq_chip->child_to_parent_hwirq = ad24xx_gpio_child_to_parent_hwirq;
> + irq_chip->handler = handle_bad_irq;
> + irq_chip->default_type = IRQ_TYPE_NONE;
> +
> + /* Initialize all GPIOs as inputs for high impedance state */
> + ret = regmap_write(adg->regmap, A2B_GPIOIEN, 0xFF);
> + if (ret)
> + return ret;
> +
> + ret = devm_gpiochip_add_data(dev, gpio_chip, adg);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static const struct of_device_id ad24xx_gpio_of_match_table[] = {
> + { .compatible = "adi,ad2401-gpio" },
> + { .compatible = "adi,ad2402-gpio" },
> + { .compatible = "adi,ad2403-gpio" },
> + { .compatible = "adi,ad2410-gpio" },
> + { .compatible = "adi,ad2420-gpio" },
> + { .compatible = "adi,ad2421-gpio" },
> + { .compatible = "adi,ad2422-gpio" },
> + { .compatible = "adi,ad2425-gpio" },
> + { .compatible = "adi,ad2426-gpio" },
> + { .compatible = "adi,ad2427-gpio" },
> + { .compatible = "adi,ad2428-gpio" },
> + { .compatible = "adi,ad2429-gpio" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, ad24xx_gpio_of_match_table);
> +
> +static struct a2b_driver ad24xx_gpio_driver = {
> + .driver = {
> + .name = "ad24xx-gpio",
> + .of_match_table = ad24xx_gpio_of_match_table,
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .probe = ad24xx_gpio_probe,
> +};
> +module_a2b_driver(ad24xx_gpio_driver);
> +
> +MODULE_AUTHOR("Alvin Šipraga <alsi@bang-olufsen.dk>");
> +MODULE_DESCRIPTION("AD24xx GPIO driver");
> +MODULE_LICENSE("GPL");
>
> --
> 2.44.0
>