drivers/mmc/host/dw_mmc-hi3798cv200.c

Source file repositories/reference/linux-study-clean/drivers/mmc/host/dw_mmc-hi3798cv200.c

File Facts

System
Linux kernel
Corpus path
drivers/mmc/host/dw_mmc-hi3798cv200.c
Extension
.c
Size
5009 bytes
Lines
201
Domain
Driver Families
Bucket
drivers/mmc
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 hi3798cv200_priv {
	struct clk *sample_clk;
	struct clk *drive_clk;
};

static void dw_mci_hi3798cv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
	struct hi3798cv200_priv *priv = host->priv;
	u32 val;

	val = mci_readl(host, UHS_REG);
	if (ios->timing == MMC_TIMING_MMC_DDR52 ||
	    ios->timing == MMC_TIMING_UHS_DDR50)
		val |= SDMMC_UHS_DDR;
	else
		val &= ~SDMMC_UHS_DDR;
	mci_writel(host, UHS_REG, val);

	val = mci_readl(host, ENABLE_SHIFT);
	if (ios->timing == MMC_TIMING_MMC_DDR52)
		val |= SDMMC_ENABLE_PHASE;
	else
		val &= ~SDMMC_ENABLE_PHASE;
	mci_writel(host, ENABLE_SHIFT, val);

	val = mci_readl(host, DDR_REG);
	if (ios->timing == MMC_TIMING_MMC_HS400)
		val |= SDMMC_DDR_HS400;
	else
		val &= ~SDMMC_DDR_HS400;
	mci_writel(host, DDR_REG, val);

	if (ios->timing == MMC_TIMING_MMC_HS ||
	    ios->timing == MMC_TIMING_LEGACY)
		clk_set_phase(priv->drive_clk, 180);
	else if (ios->timing == MMC_TIMING_MMC_HS200)
		clk_set_phase(priv->drive_clk, 135);
}

static int dw_mci_hi3798cv200_execute_tuning(struct dw_mci *host, u32 opcode)
{
	static const int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
	struct hi3798cv200_priv *priv = host->priv;
	int raise_point = -1, fall_point = -1;
	int err, prev_err = -1;
	int found = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(degrees); i++) {
		clk_set_phase(priv->sample_clk, degrees[i]);
		mci_writel(host, RINTSTS, ALL_INT_CLR);

		err = mmc_send_tuning(host->mmc, opcode, NULL);
		if (!err)
			found = 1;

		if (i > 0) {
			if (err && !prev_err)
				fall_point = i - 1;
			if (!err && prev_err)
				raise_point = i;
		}

		if (raise_point != -1 && fall_point != -1)
			goto tuning_out;

		prev_err = err;
	}

tuning_out:
	if (found) {
		if (raise_point == -1)
			raise_point = 0;
		if (fall_point == -1)
			fall_point = ARRAY_SIZE(degrees) - 1;
		if (fall_point < raise_point) {
			if ((raise_point + fall_point) >
			    (ARRAY_SIZE(degrees) - 1))
				i = fall_point / 2;
			else
				i = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
		} else {
			i = (raise_point + fall_point) / 2;
		}

		clk_set_phase(priv->sample_clk, degrees[i]);
		dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
			raise_point, fall_point, degrees[i]);
	} else {
		dev_err(host->dev, "No valid clk_sample shift! use default\n");

Annotation

Implementation Notes