root/sound/soc/starfive/jh7110_pwmdac.c
// SPDX-License-Identifier: GPL-2.0
/*
 * jh7110_pwmdac.c -- StarFive JH7110 PWM-DAC driver
 *
 * Copyright (C) 2021-2023 StarFive Technology Co., Ltd.
 *
 * Authors: Jenny Zhang
 *          Curry Zhang
 *          Xingyu Wu <xingyu.wu@starfivetech.com>
 *          Hal Feng <hal.feng@starfivetech.com>
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#define JH7110_PWMDAC_WDATA                             0x00
#define JH7110_PWMDAC_CTRL                              0x04
        #define JH7110_PWMDAC_ENABLE                    BIT(0)
        #define JH7110_PWMDAC_SHIFT                     BIT(1)
        #define JH7110_PWMDAC_DUTY_CYCLE_SHIFT          2
        #define JH7110_PWMDAC_DUTY_CYCLE_MASK           GENMASK(3, 2)
        #define JH7110_PWMDAC_CNT_N_SHIFT               4
        #define JH7110_PWMDAC_CNT_N_MASK                GENMASK(12, 4)
        #define JH7110_PWMDAC_DATA_CHANGE               BIT(13)
        #define JH7110_PWMDAC_DATA_MODE                 BIT(14)
        #define JH7110_PWMDAC_DATA_SHIFT_SHIFT          15
        #define JH7110_PWMDAC_DATA_SHIFT_MASK           GENMASK(17, 15)

enum JH7110_PWMDAC_SHIFT_VAL {
        PWMDAC_SHIFT_8 = 0,
        PWMDAC_SHIFT_10,
};

enum JH7110_PWMDAC_DUTY_CYCLE_VAL {
        PWMDAC_CYCLE_LEFT = 0,
        PWMDAC_CYCLE_RIGHT,
        PWMDAC_CYCLE_CENTER,
};

enum JH7110_PWMDAC_CNT_N_VAL {
        PWMDAC_SAMPLE_CNT_1 = 1,
        PWMDAC_SAMPLE_CNT_2,
        PWMDAC_SAMPLE_CNT_3,
        PWMDAC_SAMPLE_CNT_512 = 512, /* max */
};

enum JH7110_PWMDAC_DATA_CHANGE_VAL {
        NO_CHANGE = 0,
        CHANGE,
};

enum JH7110_PWMDAC_DATA_MODE_VAL {
        UNSIGNED_DATA = 0,
        INVERTER_DATA_MSB,
};

enum JH7110_PWMDAC_DATA_SHIFT_VAL {
        PWMDAC_DATA_LEFT_SHIFT_BIT_0 = 0,
        PWMDAC_DATA_LEFT_SHIFT_BIT_1,
        PWMDAC_DATA_LEFT_SHIFT_BIT_2,
        PWMDAC_DATA_LEFT_SHIFT_BIT_3,
        PWMDAC_DATA_LEFT_SHIFT_BIT_4,
        PWMDAC_DATA_LEFT_SHIFT_BIT_5,
        PWMDAC_DATA_LEFT_SHIFT_BIT_6,
        PWMDAC_DATA_LEFT_SHIFT_BIT_7,
};

struct jh7110_pwmdac_cfg {
        enum JH7110_PWMDAC_SHIFT_VAL shift;
        enum JH7110_PWMDAC_DUTY_CYCLE_VAL duty_cycle;
        u16 cnt_n;
        enum JH7110_PWMDAC_DATA_CHANGE_VAL data_change;
        enum JH7110_PWMDAC_DATA_MODE_VAL data_mode;
        enum JH7110_PWMDAC_DATA_SHIFT_VAL data_shift;
};

struct jh7110_pwmdac_dev {
        void __iomem *base;
        resource_size_t mapbase;
        struct jh7110_pwmdac_cfg cfg;

        struct clk_bulk_data clks[2];
        struct reset_control *rst_apb;
        struct device *dev;
        struct snd_dmaengine_dai_dma_data play_dma_data;
        u32 saved_ctrl;
};

static inline void jh7110_pwmdac_write_reg(void __iomem *io_base, int reg, u32 val)
{
        writel(val, io_base + reg);
}

static inline u32 jh7110_pwmdac_read_reg(void __iomem *io_base, int reg)
{
        return readl(io_base + reg);
}

static void jh7110_pwmdac_set_enable(struct jh7110_pwmdac_dev *dev, bool enable)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        if (enable)
                value |= JH7110_PWMDAC_ENABLE;
        else
                value &= ~JH7110_PWMDAC_ENABLE;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_shift(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        if (dev->cfg.shift == PWMDAC_SHIFT_8)
                value &= ~JH7110_PWMDAC_SHIFT;
        else if (dev->cfg.shift == PWMDAC_SHIFT_10)
                value |= JH7110_PWMDAC_SHIFT;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_duty_cycle(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        value &= ~JH7110_PWMDAC_DUTY_CYCLE_MASK;
        value |= (dev->cfg.duty_cycle & 0x3) << JH7110_PWMDAC_DUTY_CYCLE_SHIFT;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_cnt_n(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        value &= ~JH7110_PWMDAC_CNT_N_MASK;
        value |= ((dev->cfg.cnt_n - 1) & 0x1ff) << JH7110_PWMDAC_CNT_N_SHIFT;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_data_change(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        if (dev->cfg.data_change == NO_CHANGE)
                value &= ~JH7110_PWMDAC_DATA_CHANGE;
        else if (dev->cfg.data_change == CHANGE)
                value |= JH7110_PWMDAC_DATA_CHANGE;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_data_mode(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        if (dev->cfg.data_mode == UNSIGNED_DATA)
                value &= ~JH7110_PWMDAC_DATA_MODE;
        else if (dev->cfg.data_mode == INVERTER_DATA_MSB)
                value |= JH7110_PWMDAC_DATA_MODE;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set_data_shift(struct jh7110_pwmdac_dev *dev)
{
        u32 value;

        value = jh7110_pwmdac_read_reg(dev->base, JH7110_PWMDAC_CTRL);
        value &= ~JH7110_PWMDAC_DATA_SHIFT_MASK;
        value |= (dev->cfg.data_shift & 0x7) << JH7110_PWMDAC_DATA_SHIFT_SHIFT;

        jh7110_pwmdac_write_reg(dev->base, JH7110_PWMDAC_CTRL, value);
}

static void jh7110_pwmdac_set(struct jh7110_pwmdac_dev *dev)
{
        jh7110_pwmdac_set_shift(dev);
        jh7110_pwmdac_set_duty_cycle(dev);
        jh7110_pwmdac_set_cnt_n(dev);
        jh7110_pwmdac_set_enable(dev, true);

        jh7110_pwmdac_set_data_change(dev);
        jh7110_pwmdac_set_data_mode(dev);
        jh7110_pwmdac_set_data_shift(dev);
}

static void jh7110_pwmdac_stop(struct jh7110_pwmdac_dev *dev)
{
        jh7110_pwmdac_set_enable(dev, false);
}

static int jh7110_pwmdac_startup(struct snd_pcm_substream *substream,
                                 struct snd_soc_dai *dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai_link *dai_link = rtd->dai_link;

        dai_link->trigger_stop = SND_SOC_TRIGGER_ORDER_LDC;

        return 0;
}

static int jh7110_pwmdac_hw_params(struct snd_pcm_substream *substream,
                                   struct snd_pcm_hw_params *params,
                                   struct snd_soc_dai *dai)
{
        struct jh7110_pwmdac_dev *dev = dev_get_drvdata(dai->dev);
        unsigned long core_clk_rate;
        int ret;

        switch (params_rate(params)) {
        case 8000:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_3;
                core_clk_rate = 6144000;
                break;
        case 11025:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_2;
                core_clk_rate = 5644800;
                break;
        case 16000:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_3;
                core_clk_rate = 12288000;
                break;
        case 22050:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_1;
                core_clk_rate = 5644800;
                break;
        case 32000:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_1;
                core_clk_rate = 8192000;
                break;
        case 44100:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_1;
                core_clk_rate = 11289600;
                break;
        case 48000:
                dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_1;
                core_clk_rate = 12288000;
                break;
        default:
                dev_err(dai->dev, "%d rate not supported\n",
                        params_rate(params));
                return -EINVAL;
        }

        switch (params_channels(params)) {
        case 1:
                dev->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
                break;
        case 2:
                dev->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
                break;
        default:
                dev_err(dai->dev, "%d channels not supported\n",
                        params_channels(params));
                return -EINVAL;
        }

        /*
         * The clock rate always rounds down when using clk_set_rate()
         * so increase the rate a bit
         */
        core_clk_rate += 64;
        jh7110_pwmdac_set(dev);

        ret = clk_set_rate(dev->clks[1].clk, core_clk_rate);
        if (ret)
                return dev_err_probe(dai->dev, ret,
                                     "failed to set rate %lu for core clock\n",
                                     core_clk_rate);

        return 0;
}

static int jh7110_pwmdac_trigger(struct snd_pcm_substream *substream, int cmd,
                                 struct snd_soc_dai *dai)
{
        struct jh7110_pwmdac_dev *dev = snd_soc_dai_get_drvdata(dai);
        int ret = 0;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                jh7110_pwmdac_set(dev);
                break;

        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                jh7110_pwmdac_stop(dev);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int jh7110_pwmdac_crg_enable(struct jh7110_pwmdac_dev *dev, bool enable)
{
        int ret;

        if (enable) {
                ret = clk_bulk_prepare_enable(ARRAY_SIZE(dev->clks), dev->clks);
                if (ret)
                        return dev_err_probe(dev->dev, ret,
                                             "failed to enable pwmdac clocks\n");

                ret = reset_control_deassert(dev->rst_apb);
                if (ret) {
                        dev_err(dev->dev, "failed to deassert pwmdac apb reset\n");
                        goto err_rst_apb;
                }
        } else {
                clk_bulk_disable_unprepare(ARRAY_SIZE(dev->clks), dev->clks);
        }

        return 0;

err_rst_apb:
        clk_bulk_disable_unprepare(ARRAY_SIZE(dev->clks), dev->clks);

        return ret;
}

static int jh7110_pwmdac_dai_probe(struct snd_soc_dai *dai)
{
        struct jh7110_pwmdac_dev *dev = dev_get_drvdata(dai->dev);

        snd_soc_dai_init_dma_data(dai, &dev->play_dma_data, NULL);
        snd_soc_dai_set_drvdata(dai, dev);

        return 0;
}

static const struct snd_soc_dai_ops jh7110_pwmdac_dai_ops = {
        .probe          = jh7110_pwmdac_dai_probe,
        .startup        = jh7110_pwmdac_startup,
        .hw_params      = jh7110_pwmdac_hw_params,
        .trigger        = jh7110_pwmdac_trigger,
};

static const struct snd_soc_component_driver jh7110_pwmdac_component = {
        .name           = "jh7110-pwmdac",
};

static struct snd_soc_dai_driver jh7110_pwmdac_dai = {
        .name           = "jh7110-pwmdac",
        .id             = 0,
        .playback = {
                .channels_min = 1,
                .channels_max = 2,
                .rates = SNDRV_PCM_RATE_8000_48000,
                .formats = SNDRV_PCM_FMTBIT_S16_LE,
        },
        .ops = &jh7110_pwmdac_dai_ops,
};

static int jh7110_pwmdac_runtime_suspend(struct device *dev)
{
        struct jh7110_pwmdac_dev *pwmdac = dev_get_drvdata(dev);

        return jh7110_pwmdac_crg_enable(pwmdac, false);
}

static int jh7110_pwmdac_runtime_resume(struct device *dev)
{
        struct jh7110_pwmdac_dev *pwmdac = dev_get_drvdata(dev);

        return jh7110_pwmdac_crg_enable(pwmdac, true);
}

static int jh7110_pwmdac_system_suspend(struct device *dev)
{
        struct jh7110_pwmdac_dev *pwmdac = dev_get_drvdata(dev);

        /* save the CTRL register value */
        pwmdac->saved_ctrl = jh7110_pwmdac_read_reg(pwmdac->base,
                                                    JH7110_PWMDAC_CTRL);
        return pm_runtime_force_suspend(dev);
}

static int jh7110_pwmdac_system_resume(struct device *dev)
{
        struct jh7110_pwmdac_dev *pwmdac = dev_get_drvdata(dev);
        int ret;

        ret = pm_runtime_force_resume(dev);
        if (ret)
                return ret;

        /* restore the CTRL register value */
        jh7110_pwmdac_write_reg(pwmdac->base, JH7110_PWMDAC_CTRL,
                                pwmdac->saved_ctrl);
        return 0;
}

static const struct dev_pm_ops jh7110_pwmdac_pm_ops = {
        RUNTIME_PM_OPS(jh7110_pwmdac_runtime_suspend,
                       jh7110_pwmdac_runtime_resume, NULL)
        SYSTEM_SLEEP_PM_OPS(jh7110_pwmdac_system_suspend,
                            jh7110_pwmdac_system_resume)
};

static void jh7110_pwmdac_init_params(struct jh7110_pwmdac_dev *dev)
{
        dev->cfg.shift = PWMDAC_SHIFT_8;
        dev->cfg.duty_cycle = PWMDAC_CYCLE_CENTER;
        dev->cfg.cnt_n = PWMDAC_SAMPLE_CNT_1;
        dev->cfg.data_change = NO_CHANGE;
        dev->cfg.data_mode = INVERTER_DATA_MSB;
        dev->cfg.data_shift = PWMDAC_DATA_LEFT_SHIFT_BIT_0;

        dev->play_dma_data.addr = dev->mapbase + JH7110_PWMDAC_WDATA;
        dev->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        dev->play_dma_data.fifo_size = 1;
        dev->play_dma_data.maxburst = 16;
}

static int jh7110_pwmdac_probe(struct platform_device *pdev)
{
        struct jh7110_pwmdac_dev *dev;
        struct resource *res;
        int ret;

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

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

        dev->mapbase = res->start;

        dev->clks[0].id = "apb";
        dev->clks[1].id = "core";

        ret = devm_clk_bulk_get(&pdev->dev, ARRAY_SIZE(dev->clks), dev->clks);
        if (ret)
                return dev_err_probe(&pdev->dev, ret,
                                     "failed to get pwmdac clocks\n");

        dev->rst_apb = devm_reset_control_get_exclusive(&pdev->dev, NULL);
        if (IS_ERR(dev->rst_apb))
                return dev_err_probe(&pdev->dev, PTR_ERR(dev->rst_apb),
                                     "failed to get pwmdac apb reset\n");

        jh7110_pwmdac_init_params(dev);

        dev->dev = &pdev->dev;
        dev_set_drvdata(&pdev->dev, dev);
        ret = devm_snd_soc_register_component(&pdev->dev,
                                              &jh7110_pwmdac_component,
                                              &jh7110_pwmdac_dai, 1);
        if (ret)
                return dev_err_probe(&pdev->dev, ret, "failed to register dai\n");

        ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
        if (ret)
                return dev_err_probe(&pdev->dev, ret, "failed to register pcm\n");

        pm_runtime_enable(dev->dev);
        if (!pm_runtime_enabled(&pdev->dev)) {
                ret = jh7110_pwmdac_runtime_resume(&pdev->dev);
                if (ret)
                        goto err_pm_disable;
        }

        return 0;

err_pm_disable:
        pm_runtime_disable(&pdev->dev);

        return ret;
}

static void jh7110_pwmdac_remove(struct platform_device *pdev)
{
        pm_runtime_disable(&pdev->dev);
}

static const struct of_device_id jh7110_pwmdac_of_match[] = {
        { .compatible = "starfive,jh7110-pwmdac" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, jh7110_pwmdac_of_match);

static struct platform_driver jh7110_pwmdac_driver = {
        .driver         = {
                .name   = "jh7110-pwmdac",
                .of_match_table = jh7110_pwmdac_of_match,
                .pm = pm_ptr(&jh7110_pwmdac_pm_ops),
        },
        .probe          = jh7110_pwmdac_probe,
        .remove         = jh7110_pwmdac_remove,
};
module_platform_driver(jh7110_pwmdac_driver);

MODULE_AUTHOR("Jenny Zhang");
MODULE_AUTHOR("Curry Zhang");
MODULE_AUTHOR("Xingyu Wu <xingyu.wu@starfivetech.com>");
MODULE_AUTHOR("Hal Feng <hal.feng@starfivetech.com>");
MODULE_DESCRIPTION("StarFive JH7110 PWM-DAC driver");
MODULE_LICENSE("GPL");