Re: [PATCH 3/3] gpio: da9062: add driver support

[Bartosz Golaszewski <bgolaszewski@baylibre.com>]

wt., 17 wrz 2019 o 12:59 Marco Felsch <m.felsch@pengutronix.de> napisał(a):
>
> The DA9062 is a mfd pmic device which supports 5 GPIOs. The GPIOs can
> be used as input, output or have a special use-case.
>
> The patch adds the support for the normal input/output use-case.
>
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/gpio/Kconfig            |  11 ++
>  drivers/gpio/Makefile           |   1 +
>  drivers/gpio/gpio-da9062.c      | 265 ++++++++++++++++++++++++++++++++
>  include/linux/mfd/da9062/gpio.h |  13 ++
>  4 files changed, 290 insertions(+)
>  create mode 100644 drivers/gpio/gpio-da9062.c
>  create mode 100644 include/linux/mfd/da9062/gpio.h
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index bb13c266c329..b308ea549aaa 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1038,6 +1038,17 @@ config GPIO_DA9055
>
>           If driver is built as a module it will be called gpio-da9055.
>
> +config GPIO_DA9062
> +       tristate "Dialog Semiconductor DA9062 GPIO"
> +       depends on MFD_DA9062
> +       help
> +         Say yes here to enable the GPIO driver for the DA9062 chip.
> +
> +         The Dialog DA9062 PMIC chip has 5 GPIO pins that can be
> +         be controller by this driver.
> +
> +         If driver is built as a module it will be called gpio-da9062.
> +
>  config GPIO_DLN2
>         tristate "Diolan DLN2 GPIO support"
>         depends on MFD_DLN2
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index a4e91175c708..f29c8af2d096 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -45,6 +45,7 @@ obj-$(CONFIG_GPIO_CRYSTAL_COVE)               += gpio-crystalcove.o
>  obj-$(CONFIG_GPIO_CS5535)              += gpio-cs5535.o
>  obj-$(CONFIG_GPIO_DA9052)              += gpio-da9052.o
>  obj-$(CONFIG_GPIO_DA9055)              += gpio-da9055.o
> +obj-$(CONFIG_GPIO_DA9062)              += gpio-da9062.o
>  obj-$(CONFIG_GPIO_DAVINCI)             += gpio-davinci.o
>  obj-$(CONFIG_GPIO_DLN2)                        += gpio-dln2.o
>  obj-$(CONFIG_GPIO_DWAPB)               += gpio-dwapb.o
> diff --git a/drivers/gpio/gpio-da9062.c b/drivers/gpio/gpio-da9062.c
> new file mode 100644
> index 000000000000..6035963929a2
> --- /dev/null
> +++ b/drivers/gpio/gpio-da9062.c
> @@ -0,0 +1,265 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * GPIO Driver for Dialog DA9062 PMICs.
> + * Based on DA9055 GPIO driver.
> + *
> + * Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
> + */
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/gpio/driver.h>
> +#include <linux/gpio/consumer.h>
> +
> +#include <linux/mfd/da9062/core.h>
> +#include <linux/mfd/da9062/registers.h>
> +
> +#include "gpiolib.h"
> +
> +#define DA9062_TYPE(offset)            (4 * (offset % 2))
> +#define DA9062_PIN_SHIFT(offset)       (4 * (offset % 2))
> +#define DA9062_PIN_ALTERNATE           0x00 /* gpio alternate mode */
> +#define DA9062_PIN_GPI                 0x01 /* gpio in */
> +#define DA9062_PIN_GPO_OD              0x02 /* gpio out open-drain */
> +#define DA9062_PIN_GPO_PP              0x03 /* gpio out push-pull */
> +#define DA9062_GPIO_NUM                        5
> +
> +struct da9062_gpio {
> +       struct da9062 *da9062;
> +       struct gpio_chip gp;
> +};
> +
> +int da9062_gpio_get_hwgpio(struct gpio_desc *desc)
> +{
> +       return gpio_chip_hwgpio(desc);
> +}
> +EXPORT_SYMBOL_GPL(da9062_gpio_get_hwgpio);
> +

Is this going to be used anywhere? I'm not really a fan of adding new
APIs without users.

> +static int da9062_gpio_get_pin_mode(struct regmap *regmap, unsigned int offset)
> +{
> +       int ret;
> +       int val;

Nit: maybe put these two in a single line?

> +
> +       ret = regmap_read(regmap, DA9062AA_GPIO_0_1 + (offset >> 1), &val);
> +       if (ret < 0)
> +               return ret;
> +
> +       val >>= DA9062_PIN_SHIFT(offset);
> +       val &= DA9062AA_GPIO0_PIN_MASK;
> +
> +       return val;
> +}
> +
> +static int da9062_gpio_set_pin_mode(struct regmap *regmap, unsigned int offset,
> +                                   unsigned int mode)
> +{
> +       unsigned int mask;
> +
> +       mode &= DA9062AA_GPIO0_PIN_MASK;
> +       mode <<= DA9062_PIN_SHIFT(offset);
> +       mask = DA9062AA_GPIO0_PIN_MASK << DA9062_PIN_SHIFT(offset);
> +
> +       return regmap_update_bits(regmap, DA9062AA_GPIO_0_1 + (offset >> 1),
> +                                 mask, mode);
> +}
> +
> +static int da9062_gpio_get(struct gpio_chip *gc, unsigned int offset)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct regmap *regmap = gpio->da9062->regmap;
> +       int gpio_dir, val;
> +       int ret;
> +
> +       gpio_dir = da9062_gpio_get_pin_mode(regmap, offset);
> +       if (gpio_dir < 0)
> +               return gpio_dir;
> +
> +       switch (gpio_dir) {
> +       case DA9062_PIN_ALTERNATE:
> +               return -ENOTSUPP;
> +       case DA9062_PIN_GPI:
> +               ret = regmap_read(regmap, DA9062AA_STATUS_B, &val);
> +               if (ret < 0)
> +                       return ret;
> +               break;
> +       case DA9062_PIN_GPO_OD:
> +               /* falltrough */
> +       case DA9062_PIN_GPO_PP:
> +               ret = regmap_read(regmap, DA9062AA_GPIO_MODE0_4, &val);
> +               if (ret < 0)
> +                       return ret;
> +       }
> +
> +       return val & BIT(offset);
> +}
> +
> +static void da9062_gpio_set(struct gpio_chip *gc, unsigned int offset,
> +                           int value)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct regmap *regmap = gpio->da9062->regmap;
> +
> +       regmap_update_bits(regmap, DA9062AA_GPIO_MODE0_4, BIT(offset),
> +                          value << offset);
> +}
> +
> +static int da9062_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct regmap *regmap = gpio->da9062->regmap;
> +       int gpio_dir;
> +
> +       gpio_dir = da9062_gpio_get_pin_mode(regmap, offset);
> +       if (gpio_dir < 0)
> +               return gpio_dir;
> +
> +       switch (gpio_dir) {
> +       case DA9062_PIN_ALTERNATE:
> +               return -ENOTSUPP;
> +       case DA9062_PIN_GPI:
> +               return 1;
> +       case DA9062_PIN_GPO_OD:
> +               /* falltrough */
> +       case DA9062_PIN_GPO_PP:
> +               return 0;
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +static int da9062_gpio_direction_input(struct gpio_chip *gc,
> +                                      unsigned int offset)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct regmap *regmap = gpio->da9062->regmap;
> +       struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
> +       unsigned int gpi_type;
> +       int ret;
> +
> +       ret = da9062_gpio_set_pin_mode(regmap, offset, DA9062_PIN_GPI);
> +       if (ret)
> +               return ret;
> +
> +       /*
> +        * If the gpio is active low we should set it in hw too. No worries
> +        * about gpio_get() because we read and return the gpio-level. So the
> +        * gpiolob active_low handling is still correct.
> +        *
> +        * 0 - active low, 1 - active high
> +        */
> +       gpi_type = !gpiod_is_active_low(desc);
> +       return regmap_update_bits(regmap, DA9062AA_GPIO_0_1 + (offset >> 1),
> +                               DA9062AA_GPIO0_TYPE_MASK << DA9062_TYPE(offset),
> +                               gpi_type << DA9062_TYPE(offset));
> +}
> +
> +static int da9062_gpio_direction_output(struct gpio_chip *gc,
> +                                       unsigned int offset, int value)
> +{
> +       /* Push-Pull / Open-Drain options are configured during set_config */
> +       da9062_gpio_set(gc, offset, value);
> +
> +       return 0;
> +}
> +
> +static int da9062_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
> +                                 unsigned long config)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct regmap *regmap = gpio->da9062->regmap;
> +       int gpio_dir;
> +
> +       switch (pinconf_to_config_param(config)) {
> +       case PIN_CONFIG_BIAS_PULL_DOWN:
> +               /* PD only if pin is input */
> +               gpio_dir = da9062_gpio_get_pin_mode(regmap, offset);
> +               if (gpio_dir < 0)
> +                       return -EINVAL;
> +               else if (gpio_dir != DA9062_PIN_GPI)
> +                       return -ENOTSUPP;
> +               return regmap_update_bits(regmap, DA9062AA_CONFIG_K,
> +                                         BIT(offset), BIT(offset));
> +       case PIN_CONFIG_BIAS_PULL_UP:
> +               /* PU only if pin is output open-drain */
> +               gpio_dir = da9062_gpio_get_pin_mode(regmap, offset);
> +               if (gpio_dir < 0)
> +                       return -EINVAL;
> +               else if (gpio_dir != DA9062_PIN_GPO_OD)
> +                       return -ENOTSUPP;
> +               return regmap_update_bits(regmap, DA9062AA_CONFIG_K,
> +                                         BIT(offset), BIT(offset));
> +       case PIN_CONFIG_DRIVE_OPEN_DRAIN:
> +               return da9062_gpio_set_pin_mode(regmap, offset,
> +                                               DA9062_PIN_GPO_OD);
> +       case PIN_CONFIG_DRIVE_PUSH_PULL:
> +               return da9062_gpio_set_pin_mode(regmap, offset,
> +                                               DA9062_PIN_GPO_PP);
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}
> +
> +static int da9062_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
> +{
> +       struct da9062_gpio *gpio = gpiochip_get_data(gc);
> +       struct da9062 *da9062 = gpio->da9062;
> +
> +       return regmap_irq_get_virq(da9062->regmap_irq,
> +                                  DA9062_IRQ_GPI0 + offset);
> +}
> +

I'm afraid this won't fly anymore. We now have support for
hierarchical GPIO irqchips (take a look at
Documentation/driver-api/gpio/driver.rst) and Linus is quite strict on
enforcing its usage. What I did with a very simple mfd device with
GPIOs (where using hierarchical irqchips was clearly overkill) was to
put the gpio-controller on the same DT node as the core mfd device -
that way there's no need for a hierarchy.

Bart

> +static const struct gpio_chip reference_gp = {
> +       .label = "da9062-gpio",
> +       .owner = THIS_MODULE,
> +       .get = da9062_gpio_get,
> +       .set = da9062_gpio_set,
> +       .get_direction = da9062_gpio_get_direction,
> +       .direction_input = da9062_gpio_direction_input,
> +       .direction_output = da9062_gpio_direction_output,
> +       .set_config = da9062_gpio_set_config,
> +       .to_irq = da9062_gpio_to_irq,
> +       .can_sleep = true,
> +       .ngpio = DA9062_GPIO_NUM,
> +       .base = -1,
> +};
> +
> +static int da9062_gpio_probe(struct platform_device *pdev)
> +{
> +       struct da9062_gpio *gpio;
> +
> +       gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
> +       if (!gpio)
> +               return -ENOMEM;
> +
> +       gpio->da9062 = dev_get_drvdata(pdev->dev.parent);
> +       if (!gpio->da9062)
> +               return -EINVAL;
> +
> +       gpio->gp = reference_gp;
> +       gpio->gp.parent = &pdev->dev;
> +
> +       platform_set_drvdata(pdev, gpio);
> +
> +       return devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
> +}
> +
> +static const struct of_device_id da9062_compatible_id_table[] = {
> +       { .compatible = "dlg,da9062-gpio" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
> +
> +static struct platform_driver da9062_gpio_driver = {
> +       .probe = da9062_gpio_probe,
> +       .driver = {
> +               .name   = "da9062-gpio",
> +               .of_match_table = da9062_compatible_id_table,
> +       },
> +};
> +module_platform_driver(da9062_gpio_driver);
> +
> +MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
> +MODULE_DESCRIPTION("DA9062 GPIO Device Driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:da9062-gpio");
> diff --git a/include/linux/mfd/da9062/gpio.h b/include/linux/mfd/da9062/gpio.h
> new file mode 100644
> index 000000000000..67627ada1ad4
> --- /dev/null
> +++ b/include/linux/mfd/da9062/gpio.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
> + */
> +
> +#ifndef __MFD_DA9062_GPIO_H__
> +#define __MFD_DA9062_GPIO_H__
> +
> +struct gpio_desc;
> +
> +int da9062_gpio_get_hwgpio(struct gpio_desc *desc);
> +
> +#endif /* __MFD_DA9062_GPIO_H__ */
> --
> 2.20.1
>