drivers/mfd/exynos-lpass.c

Source file repositories/reference/linux-study-clean/drivers/mfd/exynos-lpass.c

File Facts

System
Linux kernel
Corpus path
drivers/mfd/exynos-lpass.c
Extension
.c
Size
5235 bytes
Lines
196
Domain
Driver Families
Bucket
drivers/mfd
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

struct exynos_lpass {
	/* pointer to the LPASS TOP regmap */
	struct regmap *top;
	struct clk *sfr0_clk;
};

static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
{
	unsigned int val = 0;

	regmap_read(lpass->top, SFR_LPASS_CORE_SW_RESET, &val);

	val &= ~mask;
	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);

	usleep_range(100, 150);

	val |= mask;
	regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
}

static void exynos_lpass_enable(struct exynos_lpass *lpass)
{
	clk_prepare_enable(lpass->sfr0_clk);

	/* Unmask SFR, DMA and I2S interrupt */
	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);

	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK,
		     LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S |
		     LPASS_INTR_UART);

	exynos_lpass_core_sw_reset(lpass, LPASS_I2S_SW_RESET);
	exynos_lpass_core_sw_reset(lpass, LPASS_DMA_SW_RESET);
	exynos_lpass_core_sw_reset(lpass, LPASS_MEM_SW_RESET);
	exynos_lpass_core_sw_reset(lpass, LPASS_UART_SW_RESET);
}

static void exynos_lpass_disable(struct exynos_lpass *lpass)
{
	/* Mask any unmasked IP interrupt sources */
	regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
	regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);

	clk_disable_unprepare(lpass->sfr0_clk);
}

static const struct regmap_config exynos_lpass_reg_conf = {
	.reg_bits	= 32,
	.reg_stride	= 4,
	.val_bits	= 32,
	.max_register	= 0xfc,
};

static void exynos_lpass_disable_lpass(void *data)
{
	struct platform_device *pdev = data;
	struct exynos_lpass *lpass = platform_get_drvdata(pdev);

	pm_runtime_disable(&pdev->dev);
	if (!pm_runtime_status_suspended(&pdev->dev))
		exynos_lpass_disable(lpass);
}

static int exynos_lpass_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct exynos_lpass *lpass;
	void __iomem *base_top;
	int ret;

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

	base_top = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(base_top))
		return PTR_ERR(base_top);

	lpass->sfr0_clk = devm_clk_get(dev, "sfr0_ctrl");
	if (IS_ERR(lpass->sfr0_clk))
		return PTR_ERR(lpass->sfr0_clk);

	lpass->top = devm_regmap_init_mmio(dev, base_top,
					   &exynos_lpass_reg_conf);
	if (IS_ERR(lpass->top)) {
		dev_err(dev, "LPASS top regmap initialization failed\n");
		return PTR_ERR(lpass->top);
	}

Annotation

Implementation Notes