drivers/mailbox/exynos-mailbox.c

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

File Facts

System
Linux kernel
Corpus path
drivers/mailbox/exynos-mailbox.c
Extension
.c
Size
4413 bytes
Lines
153
Domain
Driver Families
Bucket
drivers/mailbox
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_mbox {
	void __iomem *regs;
	struct mbox_controller *mbox;
};

static int exynos_mbox_send_data(struct mbox_chan *chan, void *data)
{
	struct device *dev = chan->mbox->dev;
	struct exynos_mbox *exynos_mbox = dev_get_drvdata(dev);
	struct exynos_mbox_msg *msg = data;

	if (msg->chan_id >= exynos_mbox->mbox->num_chans) {
		dev_err(dev, "Invalid channel ID %d\n", msg->chan_id);
		return -EINVAL;
	}

	if (msg->chan_type != EXYNOS_MBOX_CHAN_TYPE_DOORBELL) {
		dev_err(dev, "Unsupported channel type [%d]\n", msg->chan_type);
		return -EINVAL;
	}

	writel(BIT(msg->chan_id), exynos_mbox->regs + EXYNOS_MBOX_INTGR1);

	return 0;
}

static const struct mbox_chan_ops exynos_mbox_chan_ops = {
	.send_data = exynos_mbox_send_data,
};

static struct mbox_chan *exynos_mbox_of_xlate(struct mbox_controller *mbox,
					      const struct of_phandle_args *sp)
{
	int i;

	if (sp->args_count != 0)
		return ERR_PTR(-EINVAL);

	/*
	 * Return the first available channel. When we don't pass the
	 * channel ID from device tree, each channel populated by the driver is
	 * just a software construct or a virtual channel. We use 'void *data'
	 * in send_data() to pass the channel identifiers.
	 */
	for (i = 0; i < mbox->num_chans; i++)
		if (mbox->chans[i].cl == NULL)
			return &mbox->chans[i];
	return ERR_PTR(-EINVAL);
}

static const struct of_device_id exynos_mbox_match[] = {
	{ .compatible = "google,gs101-mbox" },
	{},
};
MODULE_DEVICE_TABLE(of, exynos_mbox_match);

static int exynos_mbox_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct exynos_mbox *exynos_mbox;
	struct mbox_controller *mbox;
	struct mbox_chan *chans;
	struct clk *pclk;

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

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

	chans = devm_kcalloc(dev, EXYNOS_MBOX_CHAN_COUNT, sizeof(*chans),
			     GFP_KERNEL);
	if (!chans)
		return -ENOMEM;

	exynos_mbox->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(exynos_mbox->regs))
		return PTR_ERR(exynos_mbox->regs);

	pclk = devm_clk_get_enabled(dev, "pclk");
	if (IS_ERR(pclk))
		return dev_err_probe(dev, PTR_ERR(pclk),
				     "Failed to enable clock.\n");

	mbox->num_chans = EXYNOS_MBOX_CHAN_COUNT;
	mbox->chans = chans;
	mbox->dev = dev;
	mbox->ops = &exynos_mbox_chan_ops;

Annotation

Implementation Notes