// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Implementation of primary ALSA driver code base for NVIDIA Tegra HDA.
 */

#include <linux/clk.h>
#include <linux/clocksource.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/pm_runtime.h>

#include <sound/core.h>
#include <sound/initval.h>

#include <sound/hda_codec.h>
#include "hda_controller.h"

/* Defines for Nvidia Tegra HDA support */
#define HDA_BAR0           0x8000

#define HDA_CFG_CMD        0x1004
#define HDA_CFG_BAR0       0x1010

#define HDA_ENABLE_IO_SPACE       (1 << 0)
#define HDA_ENABLE_MEM_SPACE      (1 << 1)
#define HDA_ENABLE_BUS_MASTER     (1 << 2)
#define HDA_ENABLE_SERR           (1 << 8)
#define HDA_DISABLE_INTR          (1 << 10)
#define HDA_BAR0_INIT_PROGRAM     0xFFFFFFFF
#define HDA_BAR0_FINAL_PROGRAM    (1 << 14)

/* IPFS */
#define HDA_IPFS_CONFIG           0x180
#define HDA_IPFS_EN_FPCI          0x1

#define HDA_IPFS_FPCI_BAR0        0x80
#define HDA_FPCI_BAR0_START       0x40

#define HDA_IPFS_INTR_MASK        0x188
#define HDA_IPFS_EN_INTR          (1 << 16)

/* FPCI */
#define FPCI_DBG_CFG_2            0x10F4
#define FPCI_GCAP_NSDO_SHIFT      18
#define FPCI_GCAP_NSDO_MASK       (0x3 << FPCI_GCAP_NSDO_SHIFT)

/* max number of SDs */
#define NUM_CAPTURE_SD 1
#define NUM_PLAYBACK_SD 1

/*
 * Tegra194 does not reflect correct number of SDO lines. Below macro
 * is used to update the GCAP register to workaround the issue.
 */
#define TEGRA194_NUM_SDO_LINES    4

struct hda_tegra {
        struct azx chip;
        struct device *dev;
        struct reset_control *reset;
        struct clk_bulk_data clocks[3];
        unsigned int nclocks;
        void __iomem *regs;
        struct work_struct probe_work;
};

#ifdef CONFIG_PM
static int power_save = CONFIG_SND_HDA_POWER_SAVE_DEFAULT;
module_param(power_save, bint, 0644);
MODULE_PARM_DESC(power_save,
                 "Automatic power-saving timeout (in seconds, 0 = disable).");
#else
#define power_save      0
#endif

static const struct hda_controller_ops hda_tegra_ops; /* nothing special */

static void hda_tegra_init(struct hda_tegra *hda)
{
        u32 v;

        /* Enable PCI access */
        v = readl(hda->regs + HDA_IPFS_CONFIG);
        v |= HDA_IPFS_EN_FPCI;
        writel(v, hda->regs + HDA_IPFS_CONFIG);

        /* Enable MEM/IO space and bus master */
        v = readl(hda->regs + HDA_CFG_CMD);
        v &= ~HDA_DISABLE_INTR;
        v |= HDA_ENABLE_MEM_SPACE | HDA_ENABLE_IO_SPACE |
                HDA_ENABLE_BUS_MASTER | HDA_ENABLE_SERR;
        writel(v, hda->regs + HDA_CFG_CMD);

        writel(HDA_BAR0_INIT_PROGRAM, hda->regs + HDA_CFG_BAR0);
        writel(HDA_BAR0_FINAL_PROGRAM, hda->regs + HDA_CFG_BAR0);
        writel(HDA_FPCI_BAR0_START, hda->regs + HDA_IPFS_FPCI_BAR0);

        v = readl(hda->regs + HDA_IPFS_INTR_MASK);
        v |= HDA_IPFS_EN_INTR;
        writel(v, hda->regs + HDA_IPFS_INTR_MASK);
}

/*
 * power management
 */
static int __maybe_unused hda_tegra_suspend(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        int rc;

        rc = pm_runtime_force_suspend(dev);
        if (rc < 0)
                return rc;
        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);

        return 0;
}

static int __maybe_unused hda_tegra_resume(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        int rc;

        rc = pm_runtime_force_resume(dev);
        if (rc < 0)
                return rc;
        snd_power_change_state(card, SNDRV_CTL_POWER_D0);

        return 0;
}

static int __maybe_unused hda_tegra_runtime_suspend(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        struct azx *chip = card->private_data;
        struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);

        if (chip && chip->running) {
                /* enable controller wake up event */
                azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) |
                           STATESTS_INT_MASK);

                azx_stop_chip(chip);
                azx_enter_link_reset(chip);
        }
        clk_bulk_disable_unprepare(hda->nclocks, hda->clocks);

        return 0;
}

static int __maybe_unused hda_tegra_runtime_resume(struct device *dev)
{
        struct snd_card *card = dev_get_drvdata(dev);
        struct azx *chip = card->private_data;
        struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);
        int rc;

        if (!chip->running) {
                rc = reset_control_assert(hda->reset);
                if (rc)
                        return rc;
        }

        rc = clk_bulk_prepare_enable(hda->nclocks, hda->clocks);
        if (rc != 0)
                return rc;
        if (chip->running) {
                hda_tegra_init(hda);
                azx_init_chip(chip, 1);
                /* disable controller wake up event*/
                azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) &
                           ~STATESTS_INT_MASK);
        } else {
                usleep_range(10, 100);

                rc = reset_control_deassert(hda->reset);
                if (rc)
                        return rc;
        }

        return 0;
}

static const struct dev_pm_ops hda_tegra_pm = {
        SET_SYSTEM_SLEEP_PM_OPS(hda_tegra_suspend, hda_tegra_resume)
        SET_RUNTIME_PM_OPS(hda_tegra_runtime_suspend,
                           hda_tegra_runtime_resume,
                           NULL)
};

static int hda_tegra_dev_disconnect(struct snd_device *device)
{
        struct azx *chip = device->device_data;

        chip->bus.shutdown = 1;
        return 0;
}

/*
 * destructor
 */
static int hda_tegra_dev_free(struct snd_device *device)
{
        struct azx *chip = device->device_data;
        struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);

        cancel_work_sync(&hda->probe_work);
        if (azx_bus(chip)->chip_init) {
                azx_stop_all_streams(chip);
                azx_stop_chip(chip);
        }

        azx_free_stream_pages(chip);
        azx_free_streams(chip);
        snd_hdac_bus_exit(azx_bus(chip));

        return 0;
}

static int hda_tegra_init_chip(struct azx *chip, struct platform_device *pdev)
{
        struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);
        struct hdac_bus *bus = azx_bus(chip);
        struct resource *res;

        hda->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
        if (IS_ERR(hda->regs))
                return PTR_ERR(hda->regs);

        bus->remap_addr = hda->regs + HDA_BAR0;
        bus->addr = res->start + HDA_BAR0;

        hda_tegra_init(hda);

        return 0;
}

static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev)
{
        struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);
        struct hdac_bus *bus = azx_bus(chip);
        struct snd_card *card = chip->card;
        int err;
        unsigned short gcap;
        int irq_id = platform_get_irq(pdev, 0);
        const char *sname, *drv_name = "tegra-hda";
        struct device_node *np = pdev->dev.of_node;

        if (irq_id < 0)
                return irq_id;

        err = hda_tegra_init_chip(chip, pdev);
        if (err)
                return err;

        err = devm_request_irq(chip->card->dev, irq_id, azx_interrupt,
                             IRQF_SHARED, KBUILD_MODNAME, chip);
        if (err) {
                dev_err(chip->card->dev,
                        "unable to request IRQ %d, disabling device\n",
                        irq_id);
                return err;
        }
        bus->irq = irq_id;
        bus->dma_stop_delay = 100;
        card->sync_irq = bus->irq;

        /*
         * Tegra194 has 4 SDO lines and the STRIPE can be used to
         * indicate how many of the SDO lines the stream should be
         * striped. But GCAP register does not reflect the true
         * capability of HW. Below workaround helps to fix this.
         *
         * GCAP_NSDO is bits 19:18 in T_AZA_DBG_CFG_2,
         * 0 for 1 SDO, 1 for 2 SDO, 2 for 4 SDO lines.
         */
        if (of_device_is_compatible(np, "nvidia,tegra194-hda")) {
                u32 val;

                dev_info(card->dev, "Override SDO lines to %u\n",
                         TEGRA194_NUM_SDO_LINES);

                val = readl(hda->regs + FPCI_DBG_CFG_2) & ~FPCI_GCAP_NSDO_MASK;
                val |= (TEGRA194_NUM_SDO_LINES >> 1) << FPCI_GCAP_NSDO_SHIFT;
                writel(val, hda->regs + FPCI_DBG_CFG_2);
        }

        gcap = azx_readw(chip, GCAP);
        dev_dbg(card->dev, "chipset global capabilities = 0x%x\n", gcap);

        chip->align_buffer_size = 1;

        /* read number of streams from GCAP register instead of using
         * hardcoded value
         */
        chip->capture_streams = (gcap >> 8) & 0x0f;
        chip->playback_streams = (gcap >> 12) & 0x0f;
        if (!chip->playback_streams && !chip->capture_streams) {
                /* gcap didn't give any info, switching to old method */
                chip->playback_streams = NUM_PLAYBACK_SD;
                chip->capture_streams = NUM_CAPTURE_SD;
        }
        chip->capture_index_offset = 0;
        chip->playback_index_offset = chip->capture_streams;
        chip->num_streams = chip->playback_streams + chip->capture_streams;

        /* initialize streams */
        err = azx_init_streams(chip);
        if (err < 0) {
                dev_err(card->dev, "failed to initialize streams: %d\n", err);
                return err;
        }

        err = azx_alloc_stream_pages(chip);
        if (err < 0) {
                dev_err(card->dev, "failed to allocate stream pages: %d\n",
                        err);
                return err;
        }

        /* initialize chip */
        azx_init_chip(chip, 1);

        /*
         * Playback (for 44.1K/48K, 2-channel, 16-bps) fails with
         * 4 SDO lines due to legacy design limitation. Following
         * is, from HD Audio Specification (Revision 1.0a), used to
         * control striping of the stream across multiple SDO lines
         * for sample rates <= 48K.
         *
         * { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
         *
         * Due to legacy design issue it is recommended that above
         * ratio must be greater than 8. Since number of SDO lines is
         * in powers of 2, next available ratio is 16 which can be
         * used as a limiting factor here.
         */
        if (of_device_is_compatible(np, "nvidia,tegra30-hda"))
                chip->bus.core.sdo_limit = 16;

        /* codec detection */
        if (!bus->codec_mask) {
                dev_err(card->dev, "no codecs found!\n");
                return -ENODEV;
        }

        /* driver name */
        strncpy(card->driver, drv_name, sizeof(card->driver));
        /* shortname for card */
        sname = of_get_property(np, "nvidia,model", NULL);
        if (!sname)
                sname = drv_name;
        if (strlen(sname) > sizeof(card->shortname))
                dev_info(card->dev, "truncating shortname for card\n");
        strncpy(card->shortname, sname, sizeof(card->shortname));

        /* longname for card */
        snprintf(card->longname, sizeof(card->longname),
                 "%s at 0x%lx irq %i",
                 card->shortname, bus->addr, bus->irq);

        return 0;
}

/*
 * constructor
 */

static void hda_tegra_probe_work(struct work_struct *work);

static int hda_tegra_create(struct snd_card *card,
                            unsigned int driver_caps,
                            struct hda_tegra *hda)
{
        static const struct snd_device_ops ops = {
                .dev_disconnect = hda_tegra_dev_disconnect,
                .dev_free = hda_tegra_dev_free,
        };
        struct azx *chip;
        int err;

        chip = &hda->chip;

        mutex_init(&chip->open_mutex);
        chip->card = card;
        chip->ops = &hda_tegra_ops;
        chip->driver_caps = driver_caps;
        chip->driver_type = driver_caps & 0xff;
        chip->dev_index = 0;
        INIT_LIST_HEAD(&chip->pcm_list);

        chip->codec_probe_mask = -1;

        chip->single_cmd = false;
        chip->snoop = true;

        INIT_WORK(&hda->probe_work, hda_tegra_probe_work);

        err = azx_bus_init(chip, NULL);
        if (err < 0)
                return err;

        chip->bus.core.sync_write = 0;
        chip->bus.core.needs_damn_long_delay = 1;
        chip->bus.core.aligned_mmio = 1;

        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
        if (err < 0) {
                dev_err(card->dev, "Error creating device\n");
                return err;
        }

        return 0;
}

static const struct of_device_id hda_tegra_match[] = {
        { .compatible = "nvidia,tegra30-hda" },
        { .compatible = "nvidia,tegra194-hda" },
        {},
};
MODULE_DEVICE_TABLE(of, hda_tegra_match);

static int hda_tegra_probe(struct platform_device *pdev)
{
        const unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR |
                                          AZX_DCAPS_PM_RUNTIME;
        struct snd_card *card;
        struct azx *chip;
        struct hda_tegra *hda;
        int err;

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

        err = snd_card_new(&pdev->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
                           THIS_MODULE, 0, &card);
        if (err < 0) {
                dev_err(&pdev->dev, "Error creating card!\n");
                return err;
        }

        hda->reset = devm_reset_control_array_get_exclusive(&pdev->dev);
        if (IS_ERR(hda->reset)) {
                err = PTR_ERR(hda->reset);
                goto out_free;
        }

        hda->clocks[hda->nclocks++].id = "hda";
        hda->clocks[hda->nclocks++].id = "hda2hdmi";
        hda->clocks[hda->nclocks++].id = "hda2codec_2x";

        err = devm_clk_bulk_get(&pdev->dev, hda->nclocks, hda->clocks);
        if (err < 0)
                goto out_free;

        err = hda_tegra_create(card, driver_flags, hda);
        if (err < 0)
                goto out_free;
        card->private_data = chip;

        dev_set_drvdata(&pdev->dev, card);

        pm_runtime_enable(hda->dev);
        if (!azx_has_pm_runtime(chip))
                pm_runtime_forbid(hda->dev);

        schedule_work(&hda->probe_work);

        return 0;

out_free:
        snd_card_free(card);
        return err;
}

static void hda_tegra_probe_work(struct work_struct *work)
{
        struct hda_tegra *hda = container_of(work, struct hda_tegra, probe_work);
        struct azx *chip = &hda->chip;
        struct platform_device *pdev = to_platform_device(hda->dev);
        int err;

        pm_runtime_get_sync(hda->dev);
        err = hda_tegra_first_init(chip, pdev);
        if (err < 0)
                goto out_free;

        /* create codec instances */
        err = azx_probe_codecs(chip, 8);
        if (err < 0)
                goto out_free;

        err = azx_codec_configure(chip);
        if (err < 0)
                goto out_free;

        err = snd_card_register(chip->card);
        if (err < 0)
                goto out_free;

        chip->running = 1;
        snd_hda_set_power_save(&chip->bus, power_save * 1000);

 out_free:
        pm_runtime_put(hda->dev);
        return; /* no error return from async probe */
}

static int hda_tegra_remove(struct platform_device *pdev)
{
        int ret;

        ret = snd_card_free(dev_get_drvdata(&pdev->dev));
        pm_runtime_disable(&pdev->dev);

        return ret;
}

static void hda_tegra_shutdown(struct platform_device *pdev)
{
        struct snd_card *card = dev_get_drvdata(&pdev->dev);
        struct azx *chip;

        if (!card)
                return;
        chip = card->private_data;
        if (chip && chip->running)
                azx_stop_chip(chip);
}

static struct platform_driver tegra_platform_hda = {
        .driver = {
                .name = "tegra-hda",
                .pm = &hda_tegra_pm,
                .of_match_table = hda_tegra_match,
        },
        .probe = hda_tegra_probe,
        .remove = hda_tegra_remove,
        .shutdown = hda_tegra_shutdown,
};
module_platform_driver(tegra_platform_hda);

MODULE_DESCRIPTION("Tegra HDA bus driver");
MODULE_LICENSE("GPL v2");