drivers/soc/renesas/rcar-mfis.c

Source file repositories/reference/linux-study-clean/drivers/soc/renesas/rcar-mfis.c

File Facts

System
Linux kernel
Corpus path
drivers/soc/renesas/rcar-mfis.c
Extension
.c
Size
9910 bytes
Lines
385
Domain
Driver Families
Bucket
drivers/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

struct mfis_reg {
	void __iomem *base;
	resource_size_t start;
	struct mfis_priv *priv;
};

struct mfis_info {
	u32 unprotect_mask;
	unsigned int mb_num_channels;
	unsigned int mb_reg_comes_from_dt:1;
	unsigned int mb_tx_uses_eicr:1;
	unsigned int mb_channels_are_unidir:1;
	u32 (*mb_calc_reg)(u32 chan_num, bool tx_uses_eicr, bool is_only_rx);
};

struct mfis_chan_priv {
	u32 reg;
	int irq;
};

struct mfis_priv {
	spinlock_t unprotect_lock; /* guards access to the unprotection reg */
	struct device *dev;
	struct mfis_reg common_reg;
	struct mfis_reg mbox_reg;
	const struct mfis_info *info;

	/* mailbox private data */
	struct mbox_controller mbox;
	struct mfis_chan_priv *chan_privs;
};

static u32 mfis_read(struct mfis_reg *mreg, unsigned int reg)
{
	return ioread32(mreg->base + reg);
}

static void mfis_write(struct mfis_reg *mreg, u32 reg, u32 val)
{
	struct mfis_priv *priv = mreg->priv;
	u32 unprotect_mask = priv->info->unprotect_mask;
	unsigned long flags;
	u32 unprotect_code;

	/*
	 * [Gen4] key: 0xACCE0000, mask: 0x0000FFFF
	 * [Gen5] key: 0xACC00000, mask: 0x000FFFFF
	 */
	unprotect_code = (MFIS_UNPROTECT_KEY & ~unprotect_mask) |
			 ((mreg->start + reg) & unprotect_mask);

	spin_lock_irqsave(&priv->unprotect_lock, flags);
	iowrite32(unprotect_code, priv->common_reg.base + MFISWACNTR);
	iowrite32(val, mreg->base + reg);
	spin_unlock_irqrestore(&priv->unprotect_lock, flags);
}

/********************************************************
 *			Mailbox				*
 ********************************************************/

#define mfis_mb_mbox_to_priv(_m) container_of((_m), struct mfis_priv, mbox)

static irqreturn_t mfis_mb_iicr_interrupt(int irq, void *data)
{
	struct mbox_chan *chan = data;
	struct mfis_priv *priv = mfis_mb_mbox_to_priv(chan->mbox);
	struct mfis_chan_priv *chan_priv = chan->con_priv;

	mbox_chan_received_data(chan, NULL);
	/* Stop remote(!) doorbell */
	mfis_write(&priv->mbox_reg, chan_priv->reg, 0);

	return IRQ_HANDLED;
}

static int mfis_mb_startup(struct mbox_chan *chan)
{
	struct mfis_chan_priv *chan_priv = chan->con_priv;

	if (!chan_priv->irq)
		return 0;

	return request_irq(chan_priv->irq, mfis_mb_iicr_interrupt, 0,
			   dev_name(chan->mbox->dev), chan);
}

static void mfis_mb_shutdown(struct mbox_chan *chan)
{
	struct mfis_chan_priv *chan_priv = chan->con_priv;

Annotation

Implementation Notes