sound/soc/loongson/loongson_i2s_plat.c

Source file repositories/reference/linux-study-clean/sound/soc/loongson/loongson_i2s_plat.c

File Facts

System
Linux kernel
Corpus path
sound/soc/loongson/loongson_i2s_plat.c
Extension
.c
Size
3494 bytes
Lines
123
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// 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"
#include "loongson_dma.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

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);

Annotation

Implementation Notes