// SPDX-License-Identifier: GPL-2.0-only
//
// CS35L56 ALSA SoC audio driver SoundWire binding
//
// Copyright (C) 2023 Cirrus Logic, Inc. and
//                    Cirrus Logic International Semiconductor Ltd.

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/soundwire/sdw.h>
#include <linux/soundwire/sdw_registers.h>
#include <linux/soundwire/sdw_type.h>
#include <linux/swab.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#include "cs35l56.h"

/* Register addresses are offset when sent over SoundWire */
#define CS35L56_SDW_ADDR_OFFSET         0x8000

/* Cirrus bus bridge registers */
#define CS35L56_SDW_MEM_ACCESS_STATUS   0xd0
#define CS35L56_SDW_MEM_READ_DATA       0xd8

#define CS35L56_SDW_LAST_LATE           BIT(3)
#define CS35L56_SDW_CMD_IN_PROGRESS     BIT(2)
#define CS35L56_SDW_RDATA_RDY           BIT(0)

#define CS35L56_LATE_READ_POLL_US       10
#define CS35L56_LATE_READ_TIMEOUT_US    1000

static int cs35l56_sdw_poll_mem_status(struct sdw_slave *peripheral,
                                       unsigned int mask,
                                       unsigned int match)
{
        int ret, val;

        ret = read_poll_timeout(sdw_read_no_pm, val,
                                (val < 0) || ((val & mask) == match),
                                CS35L56_LATE_READ_POLL_US, CS35L56_LATE_READ_TIMEOUT_US,
                                false, peripheral, CS35L56_SDW_MEM_ACCESS_STATUS);
        if (ret < 0)
                return ret;

        if (val < 0)
                return val;

        return 0;
}

static int cs35l56_sdw_slow_read(struct sdw_slave *peripheral, unsigned int reg,
                                 u8 *buf, size_t val_size)
{
        int ret, i;

        reg += CS35L56_SDW_ADDR_OFFSET;

        for (i = 0; i < val_size; i += sizeof(u32)) {
                /* Poll for bus bridge idle */
                ret = cs35l56_sdw_poll_mem_status(peripheral,
                                                  CS35L56_SDW_CMD_IN_PROGRESS,
                                                  0);
                if (ret < 0) {
                        dev_err(&peripheral->dev, "!CMD_IN_PROGRESS fail: %d\n", ret);
                        return ret;
                }

                /* Reading LSByte triggers read of register to holding buffer */
                sdw_read_no_pm(peripheral, reg + i);

                /* Wait for data available */
                ret = cs35l56_sdw_poll_mem_status(peripheral,
                                                  CS35L56_SDW_RDATA_RDY,
                                                  CS35L56_SDW_RDATA_RDY);
                if (ret < 0) {
                        dev_err(&peripheral->dev, "RDATA_RDY fail: %d\n", ret);
                        return ret;
                }

                /* Read data from buffer */
                ret = sdw_nread_no_pm(peripheral, CS35L56_SDW_MEM_READ_DATA,
                                      sizeof(u32), &buf[i]);
                if (ret) {
                        dev_err(&peripheral->dev, "Late read @%#x failed: %d\n", reg + i, ret);
                        return ret;
                }

                swab32s((u32 *)&buf[i]);
        }

        return 0;
}

static int cs35l56_sdw_read_one(struct sdw_slave *peripheral, unsigned int reg, void *buf)
{
        int ret;

        ret = sdw_nread_no_pm(peripheral, reg, 4, (u8 *)buf);
        if (ret != 0) {
                dev_err(&peripheral->dev, "Read failed @%#x:%d\n", reg, ret);
                return ret;
        }

        swab32s((u32 *)buf);

        return 0;
}

static int cs35l56_sdw_read(void *context, const void *reg_buf,
                            const size_t reg_size, void *val_buf,
                            size_t val_size)
{
        struct sdw_slave *peripheral = context;
        u8 *buf8 = val_buf;
        unsigned int reg, bytes;
        int ret;

        reg = le32_to_cpu(*(const __le32 *)reg_buf);

        if (cs35l56_is_otp_register(reg))
                return cs35l56_sdw_slow_read(peripheral, reg, buf8, val_size);

        reg += CS35L56_SDW_ADDR_OFFSET;

        if (val_size == 4)
                return cs35l56_sdw_read_one(peripheral, reg, val_buf);

        while (val_size) {
                bytes = SDW_REG_NO_PAGE - (reg & SDW_REGADDR); /* to end of page */
                if (bytes > val_size)
                        bytes = val_size;

                ret = sdw_nread_no_pm(peripheral, reg, bytes, buf8);
                if (ret != 0) {
                        dev_err(&peripheral->dev, "Read failed @%#x..%#x:%d\n",
                                reg, reg + bytes - 1, ret);
                        return ret;
                }

                swab32_array((u32 *)buf8, bytes / 4);
                val_size -= bytes;
                reg += bytes;
                buf8 += bytes;
        }

        return 0;
}

static inline void cs35l56_swab_copy(void *dest, const void *src, size_t nbytes)
{
        u32 *dest32 = dest;
        const u32 *src32 = src;

        for (; nbytes > 0; nbytes -= 4)
                *dest32++ = swab32(*src32++);
}

static int cs35l56_sdw_write_one(struct sdw_slave *peripheral, unsigned int reg, const void *buf)
{
        u32 val_le = swab32(*(u32 *)buf);
        int ret;

        ret = sdw_nwrite_no_pm(peripheral, reg, 4, (u8 *)&val_le);
        if (ret != 0) {
                dev_err(&peripheral->dev, "Write failed @%#x:%d\n", reg, ret);
                return ret;
        }

        return 0;
}

static int cs35l56_sdw_gather_write(void *context,
                                    const void *reg_buf, size_t reg_size,
                                    const void *val_buf, size_t val_size)
{
        struct sdw_slave *peripheral = context;
        const u8 *src_be = val_buf;
        u32 val_le_buf[64];     /* Define u32 so it is 32-bit aligned */
        unsigned int reg, bytes;
        int ret;

        reg = le32_to_cpu(*(const __le32 *)reg_buf);
        reg += CS35L56_SDW_ADDR_OFFSET;

        if (val_size == 4)
                return cs35l56_sdw_write_one(peripheral, reg, src_be);

        while (val_size) {
                bytes = SDW_REG_NO_PAGE - (reg & SDW_REGADDR); /* to end of page */
                if (bytes > val_size)
                        bytes = val_size;
                if (bytes > sizeof(val_le_buf))
                        bytes = sizeof(val_le_buf);

                cs35l56_swab_copy(val_le_buf, src_be, bytes);

                ret = sdw_nwrite_no_pm(peripheral, reg, bytes, (u8 *)val_le_buf);
                if (ret != 0) {
                        dev_err(&peripheral->dev, "Write failed @%#x..%#x:%d\n",
                                reg, reg + bytes - 1, ret);
                        return ret;
                }

                val_size -= bytes;
                reg += bytes;
                src_be += bytes;
        }

        return 0;
}

static int cs35l56_sdw_write(void *context, const void *val_buf, size_t val_size)
{
        const u8 *src_buf = val_buf;

        /* First word of val_buf contains the destination address */
        return cs35l56_sdw_gather_write(context, &src_buf[0], 4, &src_buf[4], val_size - 4);
}

/*
 * Registers are big-endian on I2C and SPI but little-endian on SoundWire.
 * Exported firmware controls are big-endian on I2C/SPI but little-endian on
 * SoundWire. Firmware files are always big-endian and are opaque blobs.
 * Present a big-endian regmap and hide the endianness swap, so that the ALSA
 * byte controls always have the same byte order, and firmware file blobs
 * can be written verbatim.
 */
static const struct regmap_bus cs35l56_regmap_bus_sdw = {
        .read = cs35l56_sdw_read,
        .write = cs35l56_sdw_write,
        .gather_write = cs35l56_sdw_gather_write,
        .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
        .val_format_endian_default = REGMAP_ENDIAN_BIG,
};

static int cs35l56_sdw_get_unique_id(struct cs35l56_private *cs35l56)
{
        int ret;

        ret = sdw_read_no_pm(cs35l56->sdw_peripheral, SDW_SCP_DEVID_0);
        if (ret < 0)
                return ret;

        cs35l56->sdw_unique_id = ret & 0xf;

        return 0;
}

static void cs35l56_sdw_init(struct sdw_slave *peripheral)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);
        int ret;

        pm_runtime_get_noresume(cs35l56->base.dev);

        ret = cs35l56_sdw_get_unique_id(cs35l56);
        if (ret)
                goto out;

        /* SoundWire UniqueId is used to index the calibration array */
        if (cs35l56->base.cal_index < 0)
                cs35l56->base.cal_index = cs35l56->sdw_unique_id;

        ret = cs35l56_init(cs35l56);
        if (ret < 0) {
                regcache_cache_only(cs35l56->base.regmap, true);
                goto out;
        }

        /*
         * cs35l56_init can return with !init_done if it triggered
         * a soft reset.
         */
        if (cs35l56->base.init_done) {
                /* Enable SoundWire interrupts */
                sdw_write_no_pm(peripheral, CS35L56_SDW_GEN_INT_MASK_1,
                                CS35L56_SDW_INT_MASK_CODEC_IRQ);
        }

out:
        pm_runtime_put_autosuspend(cs35l56->base.dev);
}

static int cs35l56_sdw_interrupt(struct sdw_slave *peripheral,
                                 struct sdw_slave_intr_status *status)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);

        /* SoundWire core holds our pm_runtime when calling this function. */

        dev_dbg(cs35l56->base.dev, "int control_port=%#x\n", status->control_port);

        if ((status->control_port & SDW_SCP_INT1_IMPL_DEF) == 0)
                return 0;

        /*
         * Prevent bus manager suspending and possibly issuing a
         * bus-reset before the queued work has run.
         */
        pm_runtime_get_noresume(cs35l56->base.dev);

        /*
         * Mask and clear until it has been handled. The read of GEN_INT_STAT_1
         * is required as per the SoundWire spec for interrupt status bits
         * to clear. GEN_INT_MASK_1 masks the _inputs_ to GEN_INT_STAT1.
         * None of the interrupts are time-critical so use the
         * power-efficient queue.
         */
        sdw_write_no_pm(peripheral, CS35L56_SDW_GEN_INT_MASK_1, 0);
        sdw_read_no_pm(peripheral, CS35L56_SDW_GEN_INT_STAT_1);
        sdw_write_no_pm(peripheral, CS35L56_SDW_GEN_INT_STAT_1, 0xFF);
        queue_work(system_power_efficient_wq, &cs35l56->sdw_irq_work);

        return 0;
}

static void cs35l56_sdw_irq_work(struct work_struct *work)
{
        struct cs35l56_private *cs35l56 = container_of(work,
                                                       struct cs35l56_private,
                                                       sdw_irq_work);

        cs35l56_irq(-1, &cs35l56->base);

        /* unmask interrupts */
        if (!cs35l56->sdw_irq_no_unmask)
                sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_MASK_1,
                                CS35L56_SDW_INT_MASK_CODEC_IRQ);

        pm_runtime_put_autosuspend(cs35l56->base.dev);
}

static int cs35l56_sdw_read_prop(struct sdw_slave *peripheral)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);
        struct sdw_slave_prop *prop = &peripheral->prop;
        struct sdw_dpn_prop *ports;

        ports = devm_kcalloc(cs35l56->base.dev, 2, sizeof(*ports), GFP_KERNEL);
        if (!ports)
                return -ENOMEM;

        prop->source_ports = BIT(CS35L56_SDW1_CAPTURE_PORT);
        prop->sink_ports = BIT(CS35L56_SDW1_PLAYBACK_PORT);
        prop->paging_support = true;
        prop->quirks = SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY;
        prop->scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY | SDW_SCP_INT1_IMPL_DEF;

        /* DP1 - playback */
        ports[0].num = CS35L56_SDW1_PLAYBACK_PORT;
        ports[0].type = SDW_DPN_FULL;
        ports[0].ch_prep_timeout = 10;
        prop->sink_dpn_prop = &ports[0];

        /* DP3 - capture */
        ports[1].num = CS35L56_SDW1_CAPTURE_PORT;
        ports[1].type = SDW_DPN_FULL;
        ports[1].ch_prep_timeout = 10;
        prop->src_dpn_prop = &ports[1];

        return 0;
}

static int cs35l56_sdw_update_status(struct sdw_slave *peripheral,
                                     enum sdw_slave_status status)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);

        switch (status) {
        case SDW_SLAVE_ATTACHED:
                dev_dbg(cs35l56->base.dev, "%s: ATTACHED\n", __func__);
                if (cs35l56->sdw_attached)
                        break;

                if (!cs35l56->base.init_done || cs35l56->soft_resetting)
                        cs35l56_sdw_init(peripheral);

                cs35l56->sdw_attached = true;
                break;
        case SDW_SLAVE_UNATTACHED:
                dev_dbg(cs35l56->base.dev, "%s: UNATTACHED\n", __func__);
                cs35l56->sdw_attached = false;
                break;
        default:
                break;
        }

        return 0;
}

static int __maybe_unused cs35l56_sdw_clk_stop(struct sdw_slave *peripheral,
                                               enum sdw_clk_stop_mode mode,
                                               enum sdw_clk_stop_type type)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);

        dev_dbg(cs35l56->base.dev, "%s: mode:%d type:%d\n", __func__, mode, type);

        return 0;
}

static const struct sdw_slave_ops cs35l56_sdw_ops = {
        .read_prop = cs35l56_sdw_read_prop,
        .interrupt_callback = cs35l56_sdw_interrupt,
        .update_status = cs35l56_sdw_update_status,
#ifdef DEBUG
        .clk_stop = cs35l56_sdw_clk_stop,
#endif
};

static int __maybe_unused cs35l56_sdw_handle_unattach(struct cs35l56_private *cs35l56)
{
        struct sdw_slave *peripheral = cs35l56->sdw_peripheral;

        if (peripheral->unattach_request) {
                /* Cannot access registers until bus is re-initialized. */
                dev_dbg(cs35l56->base.dev, "Wait for initialization_complete\n");
                if (!wait_for_completion_timeout(&peripheral->initialization_complete,
                                                 msecs_to_jiffies(5000))) {
                        dev_err(cs35l56->base.dev, "initialization_complete timed out\n");
                        return -ETIMEDOUT;
                }

                peripheral->unattach_request = 0;

                /*
                 * Don't call regcache_mark_dirty(), we can't be sure that the
                 * Manager really did issue a Bus Reset.
                 */
        }

        return 0;
}

static int __maybe_unused cs35l56_sdw_runtime_suspend(struct device *dev)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);

        if (!cs35l56->base.init_done)
                return 0;

        return cs35l56_runtime_suspend_common(&cs35l56->base);
}

static int __maybe_unused cs35l56_sdw_runtime_resume(struct device *dev)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
        int ret;

        dev_dbg(dev, "Runtime resume\n");

        if (!cs35l56->base.init_done)
                return 0;

        ret = cs35l56_sdw_handle_unattach(cs35l56);
        if (ret < 0)
                return ret;

        ret = cs35l56_runtime_resume_common(&cs35l56->base, true);
        if (ret)
                return ret;

        /* Re-enable SoundWire interrupts */
        sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_MASK_1,
                        CS35L56_SDW_INT_MASK_CODEC_IRQ);

        return 0;
}

static int __maybe_unused cs35l56_sdw_system_suspend(struct device *dev)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);

        if (!cs35l56->base.init_done)
                return 0;

        /*
         * Disable SoundWire interrupts.
         * Flush - don't cancel because that could leave an unbalanced pm_runtime_get.
         */
        cs35l56->sdw_irq_no_unmask = true;
        flush_work(&cs35l56->sdw_irq_work);

        /* Mask interrupts and flush in case sdw_irq_work was queued again */
        sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_MASK_1, 0);
        sdw_read_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_STAT_1);
        sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_STAT_1, 0xFF);
        flush_work(&cs35l56->sdw_irq_work);

        return cs35l56_system_suspend(dev);
}

static int __maybe_unused cs35l56_sdw_system_resume(struct device *dev)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);

        cs35l56->sdw_irq_no_unmask = false;
        /* runtime_resume re-enables the interrupt */

        return cs35l56_system_resume(dev);
}

static int cs35l56_sdw_probe(struct sdw_slave *peripheral, const struct sdw_device_id *id)
{
        struct device *dev = &peripheral->dev;
        struct cs35l56_private *cs35l56;
        const struct regmap_config *regmap_config;
        int ret;

        cs35l56 = devm_kzalloc(dev, sizeof(*cs35l56), GFP_KERNEL);
        if (!cs35l56)
                return -ENOMEM;

        cs35l56->base.dev = dev;
        cs35l56->sdw_peripheral = peripheral;
        cs35l56->sdw_link_num = peripheral->bus->link_id;
        INIT_WORK(&cs35l56->sdw_irq_work, cs35l56_sdw_irq_work);

        dev_set_drvdata(dev, cs35l56);

        switch ((unsigned int)id->driver_data) {
        case 0x3556:
        case 0x3557:
                regmap_config = &cs35l56_regmap_sdw;
                break;
        case 0x3563:
                regmap_config = &cs35l63_regmap_sdw;
                break;
        default:
                return -ENODEV;
        }

        cs35l56->base.type = ((unsigned int)id->driver_data) & 0xff;

        cs35l56->base.regmap = devm_regmap_init(dev, &cs35l56_regmap_bus_sdw,
                                           peripheral, regmap_config);
        if (IS_ERR(cs35l56->base.regmap)) {
                ret = PTR_ERR(cs35l56->base.regmap);
                return dev_err_probe(dev, ret, "Failed to allocate register map\n");
        }

        /* Start in cache-only until device is enumerated */
        regcache_cache_only(cs35l56->base.regmap, true);

        ret = cs35l56_common_probe(cs35l56);
        if (ret != 0)
                return ret;

        return 0;
}

static void cs35l56_sdw_remove(struct sdw_slave *peripheral)
{
        struct cs35l56_private *cs35l56 = dev_get_drvdata(&peripheral->dev);

        /* Disable SoundWire interrupts */
        cs35l56->sdw_irq_no_unmask = true;
        cancel_work_sync(&cs35l56->sdw_irq_work);
        sdw_write_no_pm(peripheral, CS35L56_SDW_GEN_INT_MASK_1, 0);
        sdw_read_no_pm(peripheral, CS35L56_SDW_GEN_INT_STAT_1);
        sdw_write_no_pm(peripheral, CS35L56_SDW_GEN_INT_STAT_1, 0xFF);

        cs35l56_remove(cs35l56);
}

static const struct dev_pm_ops cs35l56_sdw_pm = {
        SET_RUNTIME_PM_OPS(cs35l56_sdw_runtime_suspend, cs35l56_sdw_runtime_resume, NULL)
        SYSTEM_SLEEP_PM_OPS(cs35l56_sdw_system_suspend, cs35l56_sdw_system_resume)
        LATE_SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend_late, cs35l56_system_resume_early)
        /* NOIRQ stage not needed, SoundWire doesn't use a hard IRQ */
};

static const struct sdw_device_id cs35l56_sdw_id[] = {
        SDW_SLAVE_ENTRY(0x01FA, 0x3556, 0x3556),
        SDW_SLAVE_ENTRY(0x01FA, 0x3557, 0x3557),
        SDW_SLAVE_ENTRY(0x01FA, 0x3563, 0x3563),
        {},
};
MODULE_DEVICE_TABLE(sdw, cs35l56_sdw_id);

static struct sdw_driver cs35l56_sdw_driver = {
        .driver = {
                .name = "cs35l56",
                .pm = pm_ptr(&cs35l56_sdw_pm),
        },
        .probe = cs35l56_sdw_probe,
        .remove = cs35l56_sdw_remove,
        .ops = &cs35l56_sdw_ops,
        .id_table = cs35l56_sdw_id,
};

module_sdw_driver(cs35l56_sdw_driver);

MODULE_DESCRIPTION("ASoC CS35L56 SoundWire driver");
MODULE_IMPORT_NS("SND_SOC_CS35L56_CORE");
MODULE_IMPORT_NS("SND_SOC_CS35L56_SHARED");
MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
MODULE_AUTHOR("Simon Trimmer <simont@opensource.cirrus.com>");
MODULE_LICENSE("GPL");