root/drivers/gpio/gpio-wm8994.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * gpiolib support for Wolfson WM8994
 *
 * Copyright 2009 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 */

#include <linux/cleanup.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/mfd/core.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/regmap.h>

#include <linux/mfd/wm8994/core.h>
#include <linux/mfd/wm8994/pdata.h>
#include <linux/mfd/wm8994/gpio.h>
#include <linux/mfd/wm8994/registers.h>

struct wm8994_gpio {
        struct wm8994 *wm8994;
        struct gpio_chip gpio_chip;
};

static int wm8994_gpio_request(struct gpio_chip *chip, unsigned offset)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        switch (wm8994->type) {
        case WM8958:
                switch (offset) {
                case 1:
                case 2:
                case 3:
                case 4:
                case 6:
                        return -EINVAL;
                }
                break;
        default:
                break;
        }

        return 0;
}

static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
                               WM8994_GPN_DIR, WM8994_GPN_DIR);
}

static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
        int ret;

        ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
        if (ret < 0)
                return ret;

        if (ret & WM8994_GPN_LVL)
                return 1;
        else
                return 0;
}

static int wm8994_gpio_direction_out(struct gpio_chip *chip,
                                     unsigned offset, int value)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        if (value)
                value = WM8994_GPN_LVL;

        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
                               WM8994_GPN_DIR | WM8994_GPN_LVL, value);
}

static int wm8994_gpio_set(struct gpio_chip *chip, unsigned int offset,
                           int value)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        if (value)
                value = WM8994_GPN_LVL;

        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL,
                               value);
}

static int wm8994_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
                                  unsigned long config)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        switch (pinconf_to_config_param(config)) {
        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
                return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
                                       WM8994_GPN_OP_CFG_MASK,
                                       WM8994_GPN_OP_CFG);
        case PIN_CONFIG_DRIVE_PUSH_PULL:
                return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
                                       WM8994_GPN_OP_CFG_MASK, 0);
        default:
                break;
        }

        return -ENOTSUPP;
}

static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;

        return regmap_irq_get_virq(wm8994->irq_data, offset);
}


#ifdef CONFIG_DEBUG_FS
static const char *wm8994_gpio_fn(u16 fn)
{
        switch (fn) {
        case WM8994_GP_FN_PIN_SPECIFIC:
                return "pin-specific";
        case WM8994_GP_FN_GPIO:
                return "GPIO";
        case WM8994_GP_FN_SDOUT:
                return "SDOUT";
        case WM8994_GP_FN_IRQ:
                return "IRQ";
        case WM8994_GP_FN_TEMPERATURE:
                return "Temperature";
        case WM8994_GP_FN_MICBIAS1_DET:
                return "MICBIAS1 detect";
        case WM8994_GP_FN_MICBIAS1_SHORT:
                return "MICBIAS1 short";
        case WM8994_GP_FN_MICBIAS2_DET:
                return "MICBIAS2 detect";
        case WM8994_GP_FN_MICBIAS2_SHORT:
                return "MICBIAS2 short";
        case WM8994_GP_FN_FLL1_LOCK:
                return "FLL1 lock";
        case WM8994_GP_FN_FLL2_LOCK:
                return "FLL2 lock";
        case WM8994_GP_FN_SRC1_LOCK:
                return "SRC1 lock";
        case WM8994_GP_FN_SRC2_LOCK:
                return "SRC2 lock";
        case WM8994_GP_FN_DRC1_ACT:
                return "DRC1 activity";
        case WM8994_GP_FN_DRC2_ACT:
                return "DRC2 activity";
        case WM8994_GP_FN_DRC3_ACT:
                return "DRC3 activity";
        case WM8994_GP_FN_WSEQ_STATUS:
                return "Write sequencer";
        case WM8994_GP_FN_FIFO_ERROR:
                return "FIFO error";
        case WM8994_GP_FN_OPCLK:
                return "OPCLK";
        case WM8994_GP_FN_THW:
                return "Thermal warning";
        case WM8994_GP_FN_DCS_DONE:
                return "DC servo";
        case WM8994_GP_FN_FLL1_OUT:
                return "FLL1 output";
        case WM8994_GP_FN_FLL2_OUT:
                return "FLL1 output";
        default:
                return "Unknown";
        }
}

static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
        struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
        int i;

        for (i = 0; i < chip->ngpio; i++) {
                int reg;

                /* We report the GPIO even if it's not requested since
                 * we're also reporting things like alternate
                 * functions which apply even when the GPIO is not in
                 * use as a GPIO.
                 */
                char *label __free(kfree) = gpiochip_dup_line_label(chip, i);
                if (IS_ERR(label)) {
                        dev_err(wm8994->dev, "Failed to duplicate label\n");
                        continue;
                }

                seq_printf(s, " gpio-%-3d (%-20.20s) ", i,
                           label ?: "Unrequested");

                reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
                if (reg < 0) {
                        dev_err(wm8994->dev,
                                "GPIO control %d read failed: %d\n", i, reg);
                        seq_printf(s, "\n");
                        continue;
                }

                if (reg & WM8994_GPN_DIR)
                        seq_printf(s, "in ");
                else
                        seq_printf(s, "out ");

                if (reg & WM8994_GPN_PU)
                        seq_printf(s, "pull up ");

                if (reg & WM8994_GPN_PD)
                        seq_printf(s, "pull down ");

                if (reg & WM8994_GPN_POL)
                        seq_printf(s, "inverted ");
                else
                        seq_printf(s, "noninverted ");

                if (reg & WM8994_GPN_OP_CFG)
                        seq_printf(s, "open drain ");
                else
                        seq_printf(s, "push-pull ");

                seq_printf(s, "%s (%x)\n",
                           wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), reg);
        }
}
#else
#define wm8994_gpio_dbg_show NULL
#endif

static const struct gpio_chip template_chip = {
        .label                  = "wm8994",
        .owner                  = THIS_MODULE,
        .request                = wm8994_gpio_request,
        .direction_input        = wm8994_gpio_direction_in,
        .get                    = wm8994_gpio_get,
        .direction_output       = wm8994_gpio_direction_out,
        .set                    = wm8994_gpio_set,
        .set_config             = wm8994_gpio_set_config,
        .to_irq                 = wm8994_gpio_to_irq,
        .dbg_show               = wm8994_gpio_dbg_show,
        .can_sleep              = true,
};

static int wm8994_gpio_probe(struct platform_device *pdev)
{
        struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
        struct wm8994_pdata *pdata = dev_get_platdata(wm8994->dev);
        struct wm8994_gpio *wm8994_gpio;

        wm8994_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm8994_gpio),
                                   GFP_KERNEL);
        if (wm8994_gpio == NULL)
                return -ENOMEM;

        wm8994_gpio->wm8994 = wm8994;
        wm8994_gpio->gpio_chip = template_chip;
        wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
        wm8994_gpio->gpio_chip.parent = &pdev->dev;
        if (pdata && pdata->gpio_base)
                wm8994_gpio->gpio_chip.base = pdata->gpio_base;
        else
                wm8994_gpio->gpio_chip.base = -1;

        return devm_gpiochip_add_data(&pdev->dev, &wm8994_gpio->gpio_chip, wm8994_gpio);
}

static struct platform_driver wm8994_gpio_driver = {
        .driver.name    = "wm8994-gpio",
        .probe          = wm8994_gpio_probe,
};

static int __init wm8994_gpio_init(void)
{
        return platform_driver_register(&wm8994_gpio_driver);
}
subsys_initcall(wm8994_gpio_init);

static void __exit wm8994_gpio_exit(void)
{
        platform_driver_unregister(&wm8994_gpio_driver);
}
module_exit(wm8994_gpio_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("GPIO interface for WM8994");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8994-gpio");