// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tc3589x.h>
#include <linux/err.h>

/*
 * enum tc3589x_version - indicates the TC3589x version
 */
enum tc3589x_version {
        TC3589X_TC35890,
        TC3589X_TC35892,
        TC3589X_TC35893,
        TC3589X_TC35894,
        TC3589X_TC35895,
        TC3589X_TC35896,
        TC3589X_UNKNOWN,
};

#define TC3589x_CLKMODE_MODCTL_SLEEP            0x0
#define TC3589x_CLKMODE_MODCTL_OPERATION        (1 << 0)

/**
 * tc3589x_reg_read() - read a single TC3589x register
 * @tc3589x:    Device to read from
 * @reg:        Register to read
 */
int tc3589x_reg_read(struct tc3589x *tc3589x, u8 reg)
{
        int ret;

        ret = i2c_smbus_read_byte_data(tc3589x->i2c, reg);
        if (ret < 0)
                dev_err(tc3589x->dev, "failed to read reg %#x: %d\n",
                        reg, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(tc3589x_reg_read);

/**
 * tc3589x_reg_write() - write a single TC3589x register
 * @tc3589x:    Device to write to
 * @reg:        Register to read
 * @data:       Value to write
 */
int tc3589x_reg_write(struct tc3589x *tc3589x, u8 reg, u8 data)
{
        int ret;

        ret = i2c_smbus_write_byte_data(tc3589x->i2c, reg, data);
        if (ret < 0)
                dev_err(tc3589x->dev, "failed to write reg %#x: %d\n",
                        reg, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(tc3589x_reg_write);

/**
 * tc3589x_block_read() - read multiple TC3589x registers
 * @tc3589x:    Device to read from
 * @reg:        First register
 * @length:     Number of registers
 * @values:     Buffer to write to
 */
int tc3589x_block_read(struct tc3589x *tc3589x, u8 reg, u8 length, u8 *values)
{
        int ret;

        ret = i2c_smbus_read_i2c_block_data(tc3589x->i2c, reg, length, values);
        if (ret < 0)
                dev_err(tc3589x->dev, "failed to read regs %#x: %d\n",
                        reg, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(tc3589x_block_read);

/**
 * tc3589x_block_write() - write multiple TC3589x registers
 * @tc3589x:    Device to write to
 * @reg:        First register
 * @length:     Number of registers
 * @values:     Values to write
 */
int tc3589x_block_write(struct tc3589x *tc3589x, u8 reg, u8 length,
                        const u8 *values)
{
        int ret;

        ret = i2c_smbus_write_i2c_block_data(tc3589x->i2c, reg, length,
                                             values);
        if (ret < 0)
                dev_err(tc3589x->dev, "failed to write regs %#x: %d\n",
                        reg, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(tc3589x_block_write);

/**
 * tc3589x_set_bits() - set the value of a bitfield in a TC3589x register
 * @tc3589x:    Device to write to
 * @reg:        Register to write
 * @mask:       Mask of bits to set
 * @val:        Value to set
 */
int tc3589x_set_bits(struct tc3589x *tc3589x, u8 reg, u8 mask, u8 val)
{
        int ret;

        mutex_lock(&tc3589x->lock);

        ret = tc3589x_reg_read(tc3589x, reg);
        if (ret < 0)
                goto out;

        ret &= ~mask;
        ret |= val;

        ret = tc3589x_reg_write(tc3589x, reg, ret);

out:
        mutex_unlock(&tc3589x->lock);
        return ret;
}
EXPORT_SYMBOL_GPL(tc3589x_set_bits);

static const struct resource gpio_resources[] = {
        {
                .start  = TC3589x_INT_GPIIRQ,
                .end    = TC3589x_INT_GPIIRQ,
                .flags  = IORESOURCE_IRQ,
        },
};

static const struct resource keypad_resources[] = {
        {
                .start  = TC3589x_INT_KBDIRQ,
                .end    = TC3589x_INT_KBDIRQ,
                .flags  = IORESOURCE_IRQ,
        },
};

static const struct mfd_cell tc3589x_dev_gpio[] = {
        {
                .name           = "tc3589x-gpio",
                .num_resources  = ARRAY_SIZE(gpio_resources),
                .resources      = &gpio_resources[0],
                .of_compatible  = "toshiba,tc3589x-gpio",
        },
};

static const struct mfd_cell tc3589x_dev_keypad[] = {
        {
                .name           = "tc3589x-keypad",
                .num_resources  = ARRAY_SIZE(keypad_resources),
                .resources      = &keypad_resources[0],
                .of_compatible  = "toshiba,tc3589x-keypad",
        },
};

static irqreturn_t tc3589x_irq(int irq, void *data)
{
        struct tc3589x *tc3589x = data;
        int status;

again:
        status = tc3589x_reg_read(tc3589x, TC3589x_IRQST);
        if (status < 0)
                return IRQ_NONE;

        while (status) {
                int bit = __ffs(status);
                int virq = irq_find_mapping(tc3589x->domain, bit);

                handle_nested_irq(virq);
                status &= ~(1 << bit);
        }

        /*
         * A dummy read or write (to any register) appears to be necessary to
         * have the last interrupt clear (for example, GPIO IC write) take
         * effect. In such a case, recheck for any interrupt which is still
         * pending.
         */
        status = tc3589x_reg_read(tc3589x, TC3589x_IRQST);
        if (status)
                goto again;

        return IRQ_HANDLED;
}

static int tc3589x_irq_map(struct irq_domain *d, unsigned int virq,
                                irq_hw_number_t hwirq)
{
        struct tc3589x *tc3589x = d->host_data;

        irq_set_chip_data(virq, tc3589x);
        irq_set_chip_and_handler(virq, &dummy_irq_chip,
                                handle_edge_irq);
        irq_set_nested_thread(virq, 1);
        irq_set_noprobe(virq);

        return 0;
}

static void tc3589x_irq_unmap(struct irq_domain *d, unsigned int virq)
{
        irq_set_chip_and_handler(virq, NULL, NULL);
        irq_set_chip_data(virq, NULL);
}

static const struct irq_domain_ops tc3589x_irq_ops = {
        .map    = tc3589x_irq_map,
        .unmap  = tc3589x_irq_unmap,
        .xlate  = irq_domain_xlate_onecell,
};

static int tc3589x_irq_init(struct tc3589x *tc3589x, struct device_node *np)
{
        tc3589x->domain = irq_domain_create_simple(of_fwnode_handle(np),
                                                   TC3589x_NR_INTERNAL_IRQS, 0,
                                                   &tc3589x_irq_ops, tc3589x);

        if (!tc3589x->domain) {
                dev_err(tc3589x->dev, "Failed to create irqdomain\n");
                return -ENOSYS;
        }

        return 0;
}

static int tc3589x_chip_init(struct tc3589x *tc3589x)
{
        int manf, ver, ret;

        manf = tc3589x_reg_read(tc3589x, TC3589x_MANFCODE);
        if (manf < 0)
                return manf;

        ver = tc3589x_reg_read(tc3589x, TC3589x_VERSION);
        if (ver < 0)
                return ver;

        if (manf != TC3589x_MANFCODE_MAGIC) {
                dev_err(tc3589x->dev, "unknown manufacturer: %#x\n", manf);
                return -EINVAL;
        }

        dev_info(tc3589x->dev, "manufacturer: %#x, version: %#x\n", manf, ver);

        /*
         * Put everything except the IRQ module into reset;
         * also spare the GPIO module for any pin initialization
         * done during pre-kernel boot
         */
        ret = tc3589x_reg_write(tc3589x, TC3589x_RSTCTRL,
                                TC3589x_RSTCTRL_TIMRST
                                | TC3589x_RSTCTRL_ROTRST
                                | TC3589x_RSTCTRL_KBDRST);
        if (ret < 0)
                return ret;

        /* Clear the reset interrupt. */
        return tc3589x_reg_write(tc3589x, TC3589x_RSTINTCLR, 0x1);
}

static int tc3589x_device_init(struct tc3589x *tc3589x)
{
        int ret = 0;
        unsigned int blocks = tc3589x->pdata->block;

        if (blocks & TC3589x_BLOCK_GPIO) {
                ret = mfd_add_devices(tc3589x->dev, -1, tc3589x_dev_gpio,
                                      ARRAY_SIZE(tc3589x_dev_gpio), NULL,
                                      0, tc3589x->domain);
                if (ret) {
                        dev_err(tc3589x->dev, "failed to add gpio child\n");
                        return ret;
                }
                dev_info(tc3589x->dev, "added gpio block\n");
        }

        if (blocks & TC3589x_BLOCK_KEYPAD) {
                ret = mfd_add_devices(tc3589x->dev, -1, tc3589x_dev_keypad,
                                      ARRAY_SIZE(tc3589x_dev_keypad), NULL,
                                      0, tc3589x->domain);
                if (ret) {
                        dev_err(tc3589x->dev, "failed to keypad child\n");
                        return ret;
                }
                dev_info(tc3589x->dev, "added keypad block\n");
        }

        return ret;
}

static const struct of_device_id tc3589x_match[] = {
        { .compatible = "toshiba,tc35890", .data = (void *) TC3589X_TC35890 },
        { .compatible = "toshiba,tc35892", .data = (void *) TC3589X_TC35892 },
        { .compatible = "toshiba,tc35893", .data = (void *) TC3589X_TC35893 },
        { .compatible = "toshiba,tc35894", .data = (void *) TC3589X_TC35894 },
        { .compatible = "toshiba,tc35895", .data = (void *) TC3589X_TC35895 },
        { .compatible = "toshiba,tc35896", .data = (void *) TC3589X_TC35896 },
        { }
};

MODULE_DEVICE_TABLE(of, tc3589x_match);

static struct tc3589x_platform_data *
tc3589x_of_probe(struct device *dev, enum tc3589x_version *version)
{
        struct device_node *np = dev->of_node;
        struct tc3589x_platform_data *pdata;
        struct device_node *child;
        const struct of_device_id *of_id;

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

        of_id = of_match_device(tc3589x_match, dev);
        if (!of_id)
                return ERR_PTR(-ENODEV);
        *version = (uintptr_t) of_id->data;

        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, "toshiba,tc3589x-gpio"))
                        pdata->block |= TC3589x_BLOCK_GPIO;
                if (of_device_is_compatible(child, "toshiba,tc3589x-keypad"))
                        pdata->block |= TC3589x_BLOCK_KEYPAD;
        }

        return pdata;
}

static int tc3589x_probe(struct i2c_client *i2c)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
        struct device_node *np = i2c->dev.of_node;
        struct tc3589x_platform_data *pdata = dev_get_platdata(&i2c->dev);
        struct tc3589x *tc3589x;
        enum tc3589x_version version;
        int ret;

        if (!pdata) {
                pdata = tc3589x_of_probe(&i2c->dev, &version);
                if (IS_ERR(pdata)) {
                        dev_err(&i2c->dev, "No platform data or DT found\n");
                        return PTR_ERR(pdata);
                }
        } else {
                /* When not probing from device tree we have this ID */
                version = id->driver_data;
        }

        if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA
                                     | I2C_FUNC_SMBUS_I2C_BLOCK))
                return -EIO;

        tc3589x = devm_kzalloc(&i2c->dev, sizeof(struct tc3589x),
                                GFP_KERNEL);
        if (!tc3589x)
                return -ENOMEM;

        mutex_init(&tc3589x->lock);

        tc3589x->dev = &i2c->dev;
        tc3589x->i2c = i2c;
        tc3589x->pdata = pdata;

        switch (version) {
        case TC3589X_TC35893:
        case TC3589X_TC35895:
        case TC3589X_TC35896:
                tc3589x->num_gpio = 20;
                break;
        case TC3589X_TC35890:
        case TC3589X_TC35892:
        case TC3589X_TC35894:
        case TC3589X_UNKNOWN:
        default:
                tc3589x->num_gpio = 24;
                break;
        }

        i2c_set_clientdata(i2c, tc3589x);

        ret = tc3589x_chip_init(tc3589x);
        if (ret)
                return ret;

        ret = tc3589x_irq_init(tc3589x, np);
        if (ret)
                return ret;

        ret = request_threaded_irq(tc3589x->i2c->irq, NULL, tc3589x_irq,
                                   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                   "tc3589x", tc3589x);
        if (ret) {
                dev_err(tc3589x->dev, "failed to request IRQ: %d\n", ret);
                return ret;
        }

        ret = tc3589x_device_init(tc3589x);
        if (ret) {
                dev_err(tc3589x->dev, "failed to add child devices\n");
                return ret;
        }

        return 0;
}

static void tc3589x_remove(struct i2c_client *client)
{
        struct tc3589x *tc3589x = i2c_get_clientdata(client);

        mfd_remove_devices(tc3589x->dev);
}

static int tc3589x_suspend(struct device *dev)
{
        struct tc3589x *tc3589x = dev_get_drvdata(dev);
        struct i2c_client *client = tc3589x->i2c;
        int ret = 0;

        /* put the system to sleep mode */
        if (!device_may_wakeup(&client->dev))
                ret = tc3589x_reg_write(tc3589x, TC3589x_CLKMODE,
                                TC3589x_CLKMODE_MODCTL_SLEEP);

        return ret;
}

static int tc3589x_resume(struct device *dev)
{
        struct tc3589x *tc3589x = dev_get_drvdata(dev);
        struct i2c_client *client = tc3589x->i2c;
        int ret = 0;

        /* enable the system into operation */
        if (!device_may_wakeup(&client->dev))
                ret = tc3589x_reg_write(tc3589x, TC3589x_CLKMODE,
                                TC3589x_CLKMODE_MODCTL_OPERATION);

        return ret;
}

static DEFINE_SIMPLE_DEV_PM_OPS(tc3589x_dev_pm_ops,
                                tc3589x_suspend, tc3589x_resume);

static const struct i2c_device_id tc3589x_id[] = {
        { "tc35890", TC3589X_TC35890 },
        { "tc35892", TC3589X_TC35892 },
        { "tc35893", TC3589X_TC35893 },
        { "tc35894", TC3589X_TC35894 },
        { "tc35895", TC3589X_TC35895 },
        { "tc35896", TC3589X_TC35896 },
        { "tc3589x", TC3589X_UNKNOWN },
        { }
};
MODULE_DEVICE_TABLE(i2c, tc3589x_id);

static struct i2c_driver tc3589x_driver = {
        .driver = {
                .name   = "tc3589x",
                .pm     = pm_sleep_ptr(&tc3589x_dev_pm_ops),
                .of_match_table = tc3589x_match,
        },
        .probe          = tc3589x_probe,
        .remove         = tc3589x_remove,
        .id_table       = tc3589x_id,
};

static int __init tc3589x_init(void)
{
        return i2c_add_driver(&tc3589x_driver);
}
subsys_initcall(tc3589x_init);

static void __exit tc3589x_exit(void)
{
        i2c_del_driver(&tc3589x_driver);
}
module_exit(tc3589x_exit);

MODULE_DESCRIPTION("TC3589x MFD core driver");
MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");