root/drivers/input/misc/sparcspkr.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Driver for PC-speaker like devices found on various Sparc systems.
 *
 *  Copyright (c) 2002 Vojtech Pavlik
 *  Copyright (c) 2002, 2006, 2008 David S. Miller (davem@davemloft.net)
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <asm/io.h>

MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
MODULE_DESCRIPTION("Sparc Speaker beeper driver");
MODULE_LICENSE("GPL");

struct grover_beep_info {
        void __iomem    *freq_regs;
        void __iomem    *enable_reg;
};

struct bbc_beep_info {
        u32             clock_freq;
        void __iomem    *regs;
};

struct sparcspkr_state {
        const char              *name;
        int (*event)(struct input_dev *dev, unsigned int type, unsigned int code, int value);
        spinlock_t              lock;
        struct input_dev        *input_dev;
        union {
                struct grover_beep_info grover;
                struct bbc_beep_info bbc;
        } u;
};

static u32 bbc_count_to_reg(struct bbc_beep_info *info, unsigned int count)
{
        u32 val, clock_freq = info->clock_freq;
        int i;

        if (!count)
                return 0;

        if (count <= clock_freq >> 20)
                return 1 << 18;

        if (count >= clock_freq >> 12)
                return 1 << 10;

        val = 1 << 18;
        for (i = 19; i >= 11; i--) {
                val >>= 1;
                if (count <= clock_freq >> i)
                        break;
        }

        return val;
}

static int bbc_spkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
{
        struct sparcspkr_state *state = dev_get_drvdata(dev->dev.parent);
        struct bbc_beep_info *info = &state->u.bbc;
        unsigned int count = 0;

        if (type != EV_SND)
                return -1;

        switch (code) {
        case SND_BELL:
                if (value)
                        value = 1000;
                break;
        case SND_TONE:
                break;
        default:
                return -1;
        }

        if (value > 20 && value < 32767)
                count = 1193182 / value;

        count = bbc_count_to_reg(info, count);

        guard(spinlock_irqsave)(&state->lock);

        if (count) {
                sbus_writeb(0x01,                 info->regs + 0);
                sbus_writeb(0x00,                 info->regs + 2);
                sbus_writeb((count >> 16) & 0xff, info->regs + 3);
                sbus_writeb((count >>  8) & 0xff, info->regs + 4);
                sbus_writeb(0x00,                 info->regs + 5);
        } else {
                sbus_writeb(0x00,                 info->regs + 0);
        }

        return 0;
}

static int grover_spkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
{
        struct sparcspkr_state *state = dev_get_drvdata(dev->dev.parent);
        struct grover_beep_info *info = &state->u.grover;
        unsigned int count = 0;

        if (type != EV_SND)
                return -1;

        switch (code) {
        case SND_BELL:
                if (value)
                        value = 1000;
                break;
        case SND_TONE:
                break;
        default:
                return -1;
        }

        if (value > 20 && value < 32767)
                count = 1193182 / value;

        guard(spinlock_irqsave)(&state->lock);

        if (count) {
                /* enable counter 2 */
                sbus_writeb(sbus_readb(info->enable_reg) | 3, info->enable_reg);
                /* set command for counter 2, 2 byte write */
                sbus_writeb(0xB6, info->freq_regs + 1);
                /* select desired HZ */
                sbus_writeb(count & 0xff, info->freq_regs + 0);
                sbus_writeb((count >> 8) & 0xff, info->freq_regs + 0);
        } else {
                /* disable counter 2 */
                sbus_writeb(sbus_readb(info->enable_reg) & 0xFC, info->enable_reg);
        }

        return 0;
}

static int sparcspkr_probe(struct device *dev)
{
        struct sparcspkr_state *state = dev_get_drvdata(dev);
        struct input_dev *input_dev;
        int error;

        input_dev = input_allocate_device();
        if (!input_dev)
                return -ENOMEM;

        input_dev->name = state->name;
        input_dev->phys = "sparc/input0";
        input_dev->id.bustype = BUS_ISA;
        input_dev->id.vendor = 0x001f;
        input_dev->id.product = 0x0001;
        input_dev->id.version = 0x0100;
        input_dev->dev.parent = dev;

        input_dev->evbit[0] = BIT_MASK(EV_SND);
        input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);

        input_dev->event = state->event;

        error = input_register_device(input_dev);
        if (error) {
                input_free_device(input_dev);
                return error;
        }

        state->input_dev = input_dev;

        return 0;
}

static void sparcspkr_shutdown(struct platform_device *dev)
{
        struct sparcspkr_state *state = platform_get_drvdata(dev);
        struct input_dev *input_dev = state->input_dev;

        /* turn off the speaker */
        state->event(input_dev, EV_SND, SND_BELL, 0);
}

static int bbc_beep_probe(struct platform_device *op)
{
        struct sparcspkr_state *state;
        struct bbc_beep_info *info;
        int err;

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

        state->name = "Sparc BBC Speaker";
        state->event = bbc_spkr_event;
        spin_lock_init(&state->lock);

        struct device_node *dp __free(device_node) = of_find_node_by_path("/");
        if (!dp)
                return -ENODEV;

        info = &state->u.bbc;
        info->clock_freq = of_getintprop_default(dp, "clock-frequency", 0);
        if (!info->clock_freq)
                return -ENODEV;

        info->regs = of_ioremap(&op->resource[0], 0, 6, "bbc beep");
        if (!info->regs)
                return -ENODEV;

        platform_set_drvdata(op, state);

        err = sparcspkr_probe(&op->dev);
        if (err) {
                of_iounmap(&op->resource[0], info->regs, 6);
                return err;
        }

        return 0;
}

static void bbc_remove(struct platform_device *op)
{
        struct sparcspkr_state *state = platform_get_drvdata(op);
        struct input_dev *input_dev = state->input_dev;
        struct bbc_beep_info *info = &state->u.bbc;

        /* turn off the speaker */
        state->event(input_dev, EV_SND, SND_BELL, 0);

        input_unregister_device(input_dev);

        of_iounmap(&op->resource[0], info->regs, 6);
}

static const struct of_device_id bbc_beep_match[] = {
        {
                .name = "beep",
                .compatible = "SUNW,bbc-beep",
        },
        {},
};
MODULE_DEVICE_TABLE(of, bbc_beep_match);

static struct platform_driver bbc_beep_driver = {
        .driver = {
                .name = "bbcbeep",
                .of_match_table = bbc_beep_match,
        },
        .probe          = bbc_beep_probe,
        .remove         = bbc_remove,
        .shutdown       = sparcspkr_shutdown,
};

static int grover_beep_probe(struct platform_device *op)
{
        struct sparcspkr_state *state;
        struct grover_beep_info *info;
        int err = -ENOMEM;

        state = devm_kzalloc(&op->dev, sizeof(*state), GFP_KERNEL);
        if (!state)
                return err;

        state->name = "Sparc Grover Speaker";
        state->event = grover_spkr_event;
        spin_lock_init(&state->lock);

        info = &state->u.grover;
        info->freq_regs = of_ioremap(&op->resource[2], 0, 2, "grover beep freq");
        if (!info->freq_regs)
                return err;

        info->enable_reg = of_ioremap(&op->resource[3], 0, 1, "grover beep enable");
        if (!info->enable_reg)
                goto out_unmap_freq_regs;

        platform_set_drvdata(op, state);

        err = sparcspkr_probe(&op->dev);
        if (err)
                goto out_clear_drvdata;

        return 0;

out_clear_drvdata:
        of_iounmap(&op->resource[3], info->enable_reg, 1);

out_unmap_freq_regs:
        of_iounmap(&op->resource[2], info->freq_regs, 2);

        return err;
}

static void grover_remove(struct platform_device *op)
{
        struct sparcspkr_state *state = platform_get_drvdata(op);
        struct grover_beep_info *info = &state->u.grover;
        struct input_dev *input_dev = state->input_dev;

        /* turn off the speaker */
        state->event(input_dev, EV_SND, SND_BELL, 0);

        input_unregister_device(input_dev);

        of_iounmap(&op->resource[3], info->enable_reg, 1);
        of_iounmap(&op->resource[2], info->freq_regs, 2);
}

static const struct of_device_id grover_beep_match[] = {
        {
                .name = "beep",
                .compatible = "SUNW,smbus-beep",
        },
        {},
};
MODULE_DEVICE_TABLE(of, grover_beep_match);

static struct platform_driver grover_beep_driver = {
        .driver = {
                .name = "groverbeep",
                .of_match_table = grover_beep_match,
        },
        .probe          = grover_beep_probe,
        .remove         = grover_remove,
        .shutdown       = sparcspkr_shutdown,
};

static struct platform_driver * const drivers[] = {
        &bbc_beep_driver,
        &grover_beep_driver,
};

static int __init sparcspkr_init(void)
{
        return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
}

static void __exit sparcspkr_exit(void)
{
        platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
}

module_init(sparcspkr_init);
module_exit(sparcspkr_exit);