Quelle  loongson_i2s_plat.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
//
// Loongson I2S controller master mode dirver(platform device)
//
// Copyright (C) 2023-2024 Loongson Technology Corporation Limited
//
// Author: Yingkun Meng <mengyingkun@loongson.cn>
//         Binbin Zhou <zhoubinbin@loongson.cn>

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include "loongson_i2s.h"

#define LOONGSON_I2S_RX_DMA_OFFSET 21
#define LOONGSON_I2S_TX_DMA_OFFSET 18

#define LOONGSON_DMA0_CONF 0x0
#define LOONGSON_DMA1_CONF 0x1
#define LOONGSON_DMA2_CONF 0x2
#define LOONGSON_DMA3_CONF 0x3
#define LOONGSON_DMA4_CONF 0x4

/* periods_max = PAGE_SIZE / sizeof(struct ls_dma_chan_reg) */
static const struct snd_pcm_hardware loongson_pcm_hardware = {
 .info = SNDRV_PCM_INFO_MMAP |
  SNDRV_PCM_INFO_INTERLEAVED |
  SNDRV_PCM_INFO_MMAP_VALID |
  SNDRV_PCM_INFO_RESUME |
  SNDRV_PCM_INFO_PAUSE,
 .formats = SNDRV_PCM_FMTBIT_S16_LE |
     SNDRV_PCM_FMTBIT_S20_3LE |
     SNDRV_PCM_FMTBIT_S24_LE,
 .period_bytes_min = 128,
 .period_bytes_max = 128 * 1024,
 .periods_min = 1,
 .periods_max = 64,
 .buffer_bytes_max = 1024 * 1024,
};

static const struct snd_dmaengine_pcm_config loongson_dmaengine_pcm_config = {
 .pcm_hardware = &loongson_pcm_hardware,
 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
 .prealloc_buffer_size = 128 * 1024,
};

static int loongson_pcm_open(struct snd_soc_component *component,
        struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;

 if (substream->pcm->device & 1) {
  runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
  runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
 }

 if (substream->pcm->device & 2)
  runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
          SNDRV_PCM_INFO_MMAP_VALID);
 /*
 * For mysterious reasons (and despite what the manual says)
 * playback samples are lost if the DMA count is not a multiple
 * of the DMA burst size.  Let's add a rule to enforce that.
 */
 snd_pcm_hw_constraint_step(runtime, 0,
       SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
 snd_pcm_hw_constraint_step(runtime, 0,
       SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
 snd_pcm_hw_constraint_integer(substream->runtime,
          SNDRV_PCM_HW_PARAM_PERIODS);

 return 0;
}

static const struct snd_soc_component_driver loongson_i2s_component_driver = {
 .name   = LS_I2S_DRVNAME,
 .open = loongson_pcm_open,
};

static const struct regmap_config loongson_i2s_regmap_config = {
 .reg_bits = 32,
 .reg_stride = 4,
 .val_bits = 32,
 .max_register = 0x14,
 .cache_type = REGCACHE_FLAT,
};

static int loongson_i2s_apbdma_config(struct platform_device *pdev)
{
 int val;
 void __iomem *regs;

 regs = devm_platform_ioremap_resource(pdev, 1);
 if (IS_ERR(regs))
  return PTR_ERR(regs);

 val = readl(regs);
 val |= LOONGSON_DMA2_CONF << LOONGSON_I2S_TX_DMA_OFFSET;
 val |= LOONGSON_DMA3_CONF << LOONGSON_I2S_RX_DMA_OFFSET;
 writel(val, regs);

 return 0;
}

static int loongson_i2s_plat_probe(struct platform_device *pdev)
{
 struct device *dev = &pdev->dev;
 struct loongson_i2s *i2s;
 struct resource *res;
 struct clk *i2s_clk;
 int ret;

 i2s = devm_kzalloc(dev, sizeof(*i2s), GFP_KERNEL);
 if (!i2s)
  return -ENOMEM;

 ret = loongson_i2s_apbdma_config(pdev);
 if (ret)
  return ret;

 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 i2s->reg_base = devm_ioremap_resource(&pdev->dev, res);
 if (IS_ERR(i2s->reg_base))
  return dev_err_probe(dev, PTR_ERR(i2s->reg_base),
         "devm_ioremap_resource failed\n");

 i2s->regmap = devm_regmap_init_mmio(dev, i2s->reg_base,
         &loongson_i2s_regmap_config);
 if (IS_ERR(i2s->regmap))
  return dev_err_probe(dev, PTR_ERR(i2s->regmap),
         "devm_regmap_init_mmio failed\n");

 i2s->playback_dma_data.addr = res->start + LS_I2S_TX_DATA;
 i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 i2s->playback_dma_data.maxburst = 4;

 i2s->capture_dma_data.addr = res->start + LS_I2S_RX_DATA;
 i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 i2s->capture_dma_data.maxburst = 4;

 i2s_clk = devm_clk_get_enabled(dev, NULL);
 if (IS_ERR(i2s_clk))
  return dev_err_probe(dev, PTR_ERR(i2s_clk), "clock property invalid\n");
 i2s->clk_rate = clk_get_rate(i2s_clk);

 dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
 dev_set_name(dev, LS_I2S_DRVNAME);
 dev_set_drvdata(dev, i2s);

 ret = devm_snd_soc_register_component(dev, &loongson_i2s_component_driver,
           &loongson_i2s_dai, 1);
 if (ret)
  return dev_err_probe(dev, ret, "failed to register DAI\n");

 return devm_snd_dmaengine_pcm_register(dev, &loongson_dmaengine_pcm_config,
            SND_DMAENGINE_PCM_FLAG_COMPAT);
}

static const struct of_device_id loongson_i2s_ids[] = {
 { .compatible = "loongson,ls2k1000-i2s" },
 { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, loongson_i2s_ids);

static struct platform_driver loongson_i2s_driver = {
 .probe = loongson_i2s_plat_probe,
 .driver = {
  .name = "loongson-i2s-plat",
  .pm = pm_sleep_ptr(&loongson_i2s_pm),
  .of_match_table = loongson_i2s_ids,
 },
};
module_platform_driver(loongson_i2s_driver);

MODULE_DESCRIPTION("Loongson I2S Master Mode ASoC Driver");
MODULE_AUTHOR("Loongson Technology Corporation Limited");
MODULE_LICENSE("GPL");