// SPDX-License-Identifier: GPL-2.0
/*
 * MAX1600 PCMCIA power switch library
 *
 * Copyright (C) 2016 Russell King
 */
#include <linux/device.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include "max1600.h"

static const char *max1600_gpio_name[2][MAX1600_GPIO_MAX] = {
        { "a0vcc", "a1vcc", "a0vpp", "a1vpp" },
        { "b0vcc", "b1vcc", "b0vpp", "b1vpp" },
};

int max1600_init(struct device *dev, struct max1600 **ptr,
        unsigned int channel, unsigned int code)
{
        struct max1600 *m;
        int chan;
        int i;

        switch (channel) {
        case MAX1600_CHAN_A:
                chan = 0;
                break;
        case MAX1600_CHAN_B:
                chan = 1;
                break;
        default:
                return -EINVAL;
        }

        if (code != MAX1600_CODE_LOW && code != MAX1600_CODE_HIGH)
                return -EINVAL;

        m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL);
        if (!m)
                return -ENOMEM;

        m->dev = dev;
        m->code = code;

        for (i = 0; i < MAX1600_GPIO_MAX; i++) {
                const char *name;

                name = max1600_gpio_name[chan][i];
                if (i != MAX1600_GPIO_0VPP) {
                        m->gpio[i] = devm_gpiod_get(dev, name, GPIOD_OUT_LOW);
                } else {
                        m->gpio[i] = devm_gpiod_get_optional(dev, name,
                                                             GPIOD_OUT_LOW);
                        if (!m->gpio[i])
                                break;
                }
                if (IS_ERR(m->gpio[i]))
                        return PTR_ERR(m->gpio[i]);
        }

        *ptr = m;

        return 0;
}
EXPORT_SYMBOL_GPL(max1600_init);

int max1600_configure(struct max1600 *m, unsigned int vcc, unsigned int vpp)
{
        DECLARE_BITMAP(values, MAX1600_GPIO_MAX) = { 0, };
        int n = MAX1600_GPIO_0VPP;

        if (m->gpio[MAX1600_GPIO_0VPP]) {
                if (vpp == 0) {
                        __assign_bit(MAX1600_GPIO_0VPP, values, 0);
                        __assign_bit(MAX1600_GPIO_1VPP, values, 0);
                } else if (vpp == 120) {
                        __assign_bit(MAX1600_GPIO_0VPP, values, 0);
                        __assign_bit(MAX1600_GPIO_1VPP, values, 1);
                } else if (vpp == vcc) {
                        __assign_bit(MAX1600_GPIO_0VPP, values, 1);
                        __assign_bit(MAX1600_GPIO_1VPP, values, 0);
                } else {
                        dev_err(m->dev, "unrecognised Vpp %u.%uV\n",
                                vpp / 10, vpp % 10);
                        return -EINVAL;
                }
                n = MAX1600_GPIO_MAX;
        } else if (vpp != vcc && vpp != 0) {
                dev_err(m->dev, "no VPP control\n");
                return -EINVAL;
        }

        if (vcc == 0) {
                __assign_bit(MAX1600_GPIO_0VCC, values, 0);
                __assign_bit(MAX1600_GPIO_1VCC, values, 0);
        } else if (vcc == 33) { /* VY */
                __assign_bit(MAX1600_GPIO_0VCC, values, 1);
                __assign_bit(MAX1600_GPIO_1VCC, values, 0);
        } else if (vcc == 50) { /* VX */
                __assign_bit(MAX1600_GPIO_0VCC, values, 0);
                __assign_bit(MAX1600_GPIO_1VCC, values, 1);
        } else {
                dev_err(m->dev, "unrecognised Vcc %u.%uV\n",
                        vcc / 10, vcc % 10);
                return -EINVAL;
        }

        if (m->code == MAX1600_CODE_HIGH) {
                /*
                 * Cirrus mode appears to be the same as Intel mode,
                 * except the VCC pins are inverted.
                 */
                __change_bit(MAX1600_GPIO_0VCC, values);
                __change_bit(MAX1600_GPIO_1VCC, values);
        }

        return gpiod_set_array_value_cansleep(n, m->gpio, NULL, values);
}
EXPORT_SYMBOL_GPL(max1600_configure);

MODULE_DESCRIPTION("MAX1600 PCMCIA power switch library");
MODULE_LICENSE("GPL v2");