root/drivers/pinctrl/pinctrl-as3722.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ams AS3722 pin control and GPIO driver.
 *
 * Copyright (c) 2013, NVIDIA Corporation.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 */

#include <linux/delay.h>
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mfd/as3722.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/property.h>
#include <linux/slab.h>

#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinmux.h>

#include "core.h"
#include "pinconf.h"
#include "pinctrl-utils.h"

#define AS3722_PIN_GPIO0                0
#define AS3722_PIN_GPIO1                1
#define AS3722_PIN_GPIO2                2
#define AS3722_PIN_GPIO3                3
#define AS3722_PIN_GPIO4                4
#define AS3722_PIN_GPIO5                5
#define AS3722_PIN_GPIO6                6
#define AS3722_PIN_GPIO7                7
#define AS3722_PIN_NUM                  (AS3722_PIN_GPIO7 + 1)

#define AS3722_GPIO_MODE_PULL_UP           BIT(PIN_CONFIG_BIAS_PULL_UP)
#define AS3722_GPIO_MODE_PULL_DOWN         BIT(PIN_CONFIG_BIAS_PULL_DOWN)
#define AS3722_GPIO_MODE_HIGH_IMPED        BIT(PIN_CONFIG_BIAS_HIGH_IMPEDANCE)
#define AS3722_GPIO_MODE_OPEN_DRAIN        BIT(PIN_CONFIG_DRIVE_OPEN_DRAIN)

struct as3722_pin_function {
        const char *name;
        const char * const *groups;
        unsigned ngroups;
        int mux_option;
};

struct as3722_gpio_pin_control {
        unsigned mode_prop;
        int io_function;
};

struct as3722_pingroup {
        const char *name;
        const unsigned pins[1];
        unsigned npins;
};

struct as3722_pctrl_info {
        struct device *dev;
        struct pinctrl_dev *pctl;
        struct as3722 *as3722;
        struct gpio_chip gpio_chip;
        int pins_current_opt[AS3722_PIN_NUM];
        const struct as3722_pin_function *functions;
        unsigned num_functions;
        const struct as3722_pingroup *pin_groups;
        int num_pin_groups;
        const struct pinctrl_pin_desc *pins;
        unsigned num_pins;
        struct as3722_gpio_pin_control gpio_control[AS3722_PIN_NUM];
};

static const struct pinctrl_pin_desc as3722_pins_desc[] = {
        PINCTRL_PIN(AS3722_PIN_GPIO0, "gpio0"),
        PINCTRL_PIN(AS3722_PIN_GPIO1, "gpio1"),
        PINCTRL_PIN(AS3722_PIN_GPIO2, "gpio2"),
        PINCTRL_PIN(AS3722_PIN_GPIO3, "gpio3"),
        PINCTRL_PIN(AS3722_PIN_GPIO4, "gpio4"),
        PINCTRL_PIN(AS3722_PIN_GPIO5, "gpio5"),
        PINCTRL_PIN(AS3722_PIN_GPIO6, "gpio6"),
        PINCTRL_PIN(AS3722_PIN_GPIO7, "gpio7"),
};

static const char * const gpio_groups[] = {
        "gpio0",
        "gpio1",
        "gpio2",
        "gpio3",
        "gpio4",
        "gpio5",
        "gpio6",
        "gpio7",
};

enum as3722_pinmux_option {
        AS3722_PINMUX_GPIO                      = 0,
        AS3722_PINMUX_INTERRUPT_OUT             = 1,
        AS3722_PINMUX_VSUB_VBAT_UNDEB_LOW_OUT   = 2,
        AS3722_PINMUX_GPIO_INTERRUPT            = 3,
        AS3722_PINMUX_PWM_INPUT                 = 4,
        AS3722_PINMUX_VOLTAGE_IN_STBY           = 5,
        AS3722_PINMUX_OC_PG_SD0                 = 6,
        AS3722_PINMUX_PG_OUT                    = 7,
        AS3722_PINMUX_CLK32K_OUT                = 8,
        AS3722_PINMUX_WATCHDOG_INPUT            = 9,
        AS3722_PINMUX_SOFT_RESET_IN             = 11,
        AS3722_PINMUX_PWM_OUTPUT                = 12,
        AS3722_PINMUX_VSUB_VBAT_LOW_DEB_OUT     = 13,
        AS3722_PINMUX_OC_PG_SD6                 = 14,
};

#define FUNCTION_GROUP(fname, mux)                      \
        {                                               \
                .name = #fname,                         \
                .groups = gpio_groups,                  \
                .ngroups = ARRAY_SIZE(gpio_groups),     \
                .mux_option = AS3722_PINMUX_##mux,      \
        }

static const struct as3722_pin_function as3722_pin_function[] = {
        FUNCTION_GROUP(gpio, GPIO),
        FUNCTION_GROUP(interrupt-out, INTERRUPT_OUT),
        FUNCTION_GROUP(gpio-in-interrupt, GPIO_INTERRUPT),
        FUNCTION_GROUP(vsup-vbat-low-undebounce-out, VSUB_VBAT_UNDEB_LOW_OUT),
        FUNCTION_GROUP(vsup-vbat-low-debounce-out, VSUB_VBAT_LOW_DEB_OUT),
        FUNCTION_GROUP(voltage-in-standby, VOLTAGE_IN_STBY),
        FUNCTION_GROUP(oc-pg-sd0, OC_PG_SD0),
        FUNCTION_GROUP(oc-pg-sd6, OC_PG_SD6),
        FUNCTION_GROUP(powergood-out, PG_OUT),
        FUNCTION_GROUP(pwm-in, PWM_INPUT),
        FUNCTION_GROUP(pwm-out, PWM_OUTPUT),
        FUNCTION_GROUP(clk32k-out, CLK32K_OUT),
        FUNCTION_GROUP(watchdog-in, WATCHDOG_INPUT),
        FUNCTION_GROUP(soft-reset-in, SOFT_RESET_IN),
};

#define AS3722_PINGROUP(pg_name, pin_id) \
        {                                                               \
                .name = #pg_name,                                       \
                .pins = {AS3722_PIN_##pin_id},                          \
                .npins = 1,                                             \
        }

static const struct as3722_pingroup as3722_pingroups[] = {
        AS3722_PINGROUP(gpio0,  GPIO0),
        AS3722_PINGROUP(gpio1,  GPIO1),
        AS3722_PINGROUP(gpio2,  GPIO2),
        AS3722_PINGROUP(gpio3,  GPIO3),
        AS3722_PINGROUP(gpio4,  GPIO4),
        AS3722_PINGROUP(gpio5,  GPIO5),
        AS3722_PINGROUP(gpio6,  GPIO6),
        AS3722_PINGROUP(gpio7,  GPIO7),
};

static int as3722_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        return as_pci->num_pin_groups;
}

static const char *as3722_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
                unsigned group)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        return as_pci->pin_groups[group].name;
}

static int as3722_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
                unsigned group, const unsigned **pins, unsigned *num_pins)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        *pins = as_pci->pin_groups[group].pins;
        *num_pins = as_pci->pin_groups[group].npins;
        return 0;
}

static const struct pinctrl_ops as3722_pinctrl_ops = {
        .get_groups_count = as3722_pinctrl_get_groups_count,
        .get_group_name = as3722_pinctrl_get_group_name,
        .get_group_pins = as3722_pinctrl_get_group_pins,
        .dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
        .dt_free_map = pinctrl_utils_free_map,
};

static int as3722_pinctrl_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        return as_pci->num_functions;
}

static const char *as3722_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
                        unsigned function)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        return as_pci->functions[function].name;
}

static int as3722_pinctrl_get_func_groups(struct pinctrl_dev *pctldev,
                unsigned function, const char * const **groups,
                unsigned * const num_groups)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        *groups = as_pci->functions[function].groups;
        *num_groups = as_pci->functions[function].ngroups;
        return 0;
}

static int as3722_pinctrl_set(struct pinctrl_dev *pctldev, unsigned function,
                unsigned group)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);
        int gpio_cntr_reg = AS3722_GPIOn_CONTROL_REG(group);
        u8 val = AS3722_GPIO_IOSF_VAL(as_pci->functions[function].mux_option);
        int ret;

        dev_dbg(as_pci->dev, "%s(): GPIO %u pin to function %u and val %u\n",
                __func__, group, function, val);

        ret = as3722_update_bits(as_pci->as3722, gpio_cntr_reg,
                        AS3722_GPIO_IOSF_MASK, val);
        if (ret < 0) {
                dev_err(as_pci->dev, "GPIO%d_CTRL_REG update failed %d\n",
                        group, ret);
                return ret;
        }
        as_pci->gpio_control[group].io_function = function;

        switch (val) {
        case AS3722_GPIO_IOSF_SD0_OUT:
        case AS3722_GPIO_IOSF_PWR_GOOD_OUT:
        case AS3722_GPIO_IOSF_Q32K_OUT:
        case AS3722_GPIO_IOSF_PWM_OUT:
        case AS3722_GPIO_IOSF_SD6_LOW_VOLT_LOW:
                ret = as3722_update_bits(as_pci->as3722, gpio_cntr_reg,
                        AS3722_GPIO_MODE_MASK, AS3722_GPIO_MODE_OUTPUT_VDDH);
                if (ret < 0) {
                        dev_err(as_pci->dev, "GPIO%d_CTRL update failed %d\n",
                                group, ret);
                        return ret;
                }
                as_pci->gpio_control[group].mode_prop =
                                AS3722_GPIO_MODE_OUTPUT_VDDH;
                break;
        default:
                break;
        }
        return ret;
}

static int as3722_pinctrl_gpio_get_mode(unsigned gpio_mode_prop, bool input)
{
        if (gpio_mode_prop & AS3722_GPIO_MODE_HIGH_IMPED)
                return -EINVAL;

        if (gpio_mode_prop & AS3722_GPIO_MODE_OPEN_DRAIN) {
                if (gpio_mode_prop & AS3722_GPIO_MODE_PULL_UP)
                        return AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP;
                return AS3722_GPIO_MODE_IO_OPEN_DRAIN;
        }
        if (input) {
                if (gpio_mode_prop & AS3722_GPIO_MODE_PULL_UP)
                        return AS3722_GPIO_MODE_INPUT_PULL_UP;
                else if (gpio_mode_prop & AS3722_GPIO_MODE_PULL_DOWN)
                        return AS3722_GPIO_MODE_INPUT_PULL_DOWN;
                return AS3722_GPIO_MODE_INPUT;
        }
        if (gpio_mode_prop & AS3722_GPIO_MODE_PULL_DOWN)
                return AS3722_GPIO_MODE_OUTPUT_VDDL;
        return AS3722_GPIO_MODE_OUTPUT_VDDH;
}

static int as3722_pinctrl_gpio_request_enable(struct pinctrl_dev *pctldev,
                struct pinctrl_gpio_range *range, unsigned offset)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);

        if (as_pci->gpio_control[offset].io_function)
                return -EBUSY;
        return 0;
}

static int as3722_pinctrl_gpio_set_direction(struct pinctrl_dev *pctldev,
                struct pinctrl_gpio_range *range, unsigned offset, bool input)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);
        struct as3722 *as3722 = as_pci->as3722;
        int mode;

        mode = as3722_pinctrl_gpio_get_mode(
                        as_pci->gpio_control[offset].mode_prop, input);
        if (mode < 0) {
                dev_err(as_pci->dev, "%s direction for GPIO %d not supported\n",
                        (input) ? "Input" : "Output", offset);
                return mode;
        }

        return as3722_update_bits(as3722, AS3722_GPIOn_CONTROL_REG(offset),
                                AS3722_GPIO_MODE_MASK, mode);
}

static const struct pinmux_ops as3722_pinmux_ops = {
        .get_functions_count    = as3722_pinctrl_get_funcs_count,
        .get_function_name      = as3722_pinctrl_get_func_name,
        .get_function_groups    = as3722_pinctrl_get_func_groups,
        .set_mux                = as3722_pinctrl_set,
        .gpio_request_enable    = as3722_pinctrl_gpio_request_enable,
        .gpio_set_direction     = as3722_pinctrl_gpio_set_direction,
};

static int as3722_pinconf_get(struct pinctrl_dev *pctldev,
                        unsigned pin, unsigned long *config)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param param = pinconf_to_config_param(*config);
        int arg = 0;
        u16 prop;

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
                prop = AS3722_GPIO_MODE_PULL_UP |
                                AS3722_GPIO_MODE_PULL_DOWN;
                if (!(as_pci->gpio_control[pin].mode_prop & prop))
                        arg = 1;
                prop = 0;
                break;

        case PIN_CONFIG_BIAS_PULL_UP:
                prop = AS3722_GPIO_MODE_PULL_UP;
                break;

        case PIN_CONFIG_BIAS_PULL_DOWN:
                prop = AS3722_GPIO_MODE_PULL_DOWN;
                break;

        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
                prop = AS3722_GPIO_MODE_OPEN_DRAIN;
                break;

        case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
                prop = AS3722_GPIO_MODE_HIGH_IMPED;
                break;

        default:
                dev_err(as_pci->dev, "Properties not supported\n");
                return -ENOTSUPP;
        }

        if (as_pci->gpio_control[pin].mode_prop & prop)
                arg = 1;

        *config = pinconf_to_config_packed(param, (u16)arg);
        return 0;
}

static int as3722_pinconf_set(struct pinctrl_dev *pctldev,
                        unsigned pin, unsigned long *configs,
                        unsigned num_configs)
{
        struct as3722_pctrl_info *as_pci = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param param;
        int mode_prop;
        int i;

        for (i = 0; i < num_configs; i++) {
                param = pinconf_to_config_param(configs[i]);
                mode_prop = as_pci->gpio_control[pin].mode_prop;

                switch (param) {
                case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
                        break;

                case PIN_CONFIG_BIAS_DISABLE:
                        mode_prop &= ~(AS3722_GPIO_MODE_PULL_UP |
                                        AS3722_GPIO_MODE_PULL_DOWN);
                        break;
                case PIN_CONFIG_BIAS_PULL_UP:
                        mode_prop |= AS3722_GPIO_MODE_PULL_UP;
                        break;

                case PIN_CONFIG_BIAS_PULL_DOWN:
                        mode_prop |= AS3722_GPIO_MODE_PULL_DOWN;
                        break;

                case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
                        mode_prop |= AS3722_GPIO_MODE_HIGH_IMPED;
                        break;

                case PIN_CONFIG_DRIVE_OPEN_DRAIN:
                        mode_prop |= AS3722_GPIO_MODE_OPEN_DRAIN;
                        break;

                default:
                        dev_err(as_pci->dev, "Properties not supported\n");
                        return -ENOTSUPP;
                }

                as_pci->gpio_control[pin].mode_prop = mode_prop;
        }
        return 0;
}

static const struct pinconf_ops as3722_pinconf_ops = {
        .pin_config_get = as3722_pinconf_get,
        .pin_config_set = as3722_pinconf_set,
};

static struct pinctrl_desc as3722_pinctrl_desc = {
        .pctlops = &as3722_pinctrl_ops,
        .pmxops = &as3722_pinmux_ops,
        .confops = &as3722_pinconf_ops,
        .owner = THIS_MODULE,
        .pins = as3722_pins_desc,
        .npins = ARRAY_SIZE(as3722_pins_desc),
};

static int as3722_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct as3722_pctrl_info *as_pci = gpiochip_get_data(chip);
        struct as3722 *as3722 = as_pci->as3722;
        int ret;
        u32 reg;
        u32 control;
        u32 val;
        int mode;
        int invert_enable;

        ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &control);
        if (ret < 0) {
                dev_err(as_pci->dev,
                        "GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
                return ret;
        }

        invert_enable = !!(control & AS3722_GPIO_INV);
        mode = control & AS3722_GPIO_MODE_MASK;
        switch (mode) {
        case AS3722_GPIO_MODE_INPUT:
        case AS3722_GPIO_MODE_INPUT_PULL_UP:
        case AS3722_GPIO_MODE_INPUT_PULL_DOWN:
        case AS3722_GPIO_MODE_IO_OPEN_DRAIN:
        case AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP:
                reg = AS3722_GPIO_SIGNAL_IN_REG;
                break;
        case AS3722_GPIO_MODE_OUTPUT_VDDH:
        case AS3722_GPIO_MODE_OUTPUT_VDDL:
                reg = AS3722_GPIO_SIGNAL_OUT_REG;
                break;
        default:
                return -EINVAL;
        }

        ret = as3722_read(as3722, reg, &val);
        if (ret < 0) {
                dev_err(as_pci->dev,
                        "GPIO_SIGNAL_IN_REG read failed: %d\n", ret);
                return ret;
        }

        val = !!(val & AS3722_GPIOn_SIGNAL(offset));
        return (invert_enable) ? !val : val;
}

static int as3722_gpio_set(struct gpio_chip *chip, unsigned int offset,
                           int value)
{
        struct as3722_pctrl_info *as_pci = gpiochip_get_data(chip);
        struct as3722 *as3722 = as_pci->as3722;
        int en_invert;
        u32 val;
        int ret;

        ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &val);
        if (ret < 0) {
                dev_err(as_pci->dev,
                        "GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
                return ret;
        }
        en_invert = !!(val & AS3722_GPIO_INV);

        if (value)
                val = (en_invert) ? 0 : AS3722_GPIOn_SIGNAL(offset);
        else
                val = (en_invert) ? AS3722_GPIOn_SIGNAL(offset) : 0;

        ret = as3722_update_bits(as3722, AS3722_GPIO_SIGNAL_OUT_REG,
                        AS3722_GPIOn_SIGNAL(offset), val);
        if (ret < 0)
                dev_err(as_pci->dev,
                        "GPIO_SIGNAL_OUT_REG update failed: %d\n", ret);

        return ret;
}

static int as3722_gpio_direction_output(struct gpio_chip *chip,
                                        unsigned int offset, int value)
{
        int ret;

        ret = as3722_gpio_set(chip, offset, value);
        if (ret)
                return ret;

        return pinctrl_gpio_direction_output(chip, offset);
}

static int as3722_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
        struct as3722_pctrl_info *as_pci = gpiochip_get_data(chip);

        return as3722_irq_get_virq(as_pci->as3722, offset);
}

static const struct gpio_chip as3722_gpio_chip = {
        .label                  = "as3722-gpio",
        .owner                  = THIS_MODULE,
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .get                    = as3722_gpio_get,
        .set                    = as3722_gpio_set,
        .direction_input        = pinctrl_gpio_direction_input,
        .direction_output       = as3722_gpio_direction_output,
        .to_irq                 = as3722_gpio_to_irq,
        .can_sleep              = true,
        .ngpio                  = AS3722_PIN_NUM,
        .base                   = -1,
};

static int as3722_pinctrl_probe(struct platform_device *pdev)
{
        struct as3722_pctrl_info *as_pci;
        int ret;

        device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));

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

        as_pci->dev = &pdev->dev;
        as_pci->as3722 = dev_get_drvdata(pdev->dev.parent);

        as_pci->pins = as3722_pins_desc;
        as_pci->num_pins = ARRAY_SIZE(as3722_pins_desc);
        as_pci->functions = as3722_pin_function;
        as_pci->num_functions = ARRAY_SIZE(as3722_pin_function);
        as_pci->pin_groups = as3722_pingroups;
        as_pci->num_pin_groups = ARRAY_SIZE(as3722_pingroups);
        as3722_pinctrl_desc.name = dev_name(&pdev->dev);
        as_pci->pctl = devm_pinctrl_register(&pdev->dev, &as3722_pinctrl_desc,
                                             as_pci);
        if (IS_ERR(as_pci->pctl)) {
                dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
                return PTR_ERR(as_pci->pctl);
        }

        as_pci->gpio_chip = as3722_gpio_chip;
        as_pci->gpio_chip.parent = &pdev->dev;
        ret = devm_gpiochip_add_data(&pdev->dev, &as_pci->gpio_chip, as_pci);
        if (ret < 0) {
                dev_err(&pdev->dev, "Couldn't register gpiochip, %d\n", ret);
                return ret;
        }

        ret = gpiochip_add_pin_range(&as_pci->gpio_chip, dev_name(&pdev->dev),
                                0, 0, AS3722_PIN_NUM);
        if (ret < 0) {
                dev_err(&pdev->dev, "Couldn't add pin range, %d\n", ret);
                return ret;
        }

        return 0;
}

static const struct of_device_id as3722_pinctrl_of_match[] = {
        { .compatible = "ams,as3722-pinctrl", },
        { },
};
MODULE_DEVICE_TABLE(of, as3722_pinctrl_of_match);

static struct platform_driver as3722_pinctrl_driver = {
        .driver = {
                .name = "as3722-pinctrl",
                .of_match_table = as3722_pinctrl_of_match,
        },
        .probe = as3722_pinctrl_probe,
};
module_platform_driver(as3722_pinctrl_driver);

MODULE_ALIAS("platform:as3722-pinctrl");
MODULE_DESCRIPTION("AS3722 pin control and GPIO driver");
MODULE_AUTHOR("Laxman Dewangan<ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");