drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

Source file repositories/reference/linux-study-clean/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

File Facts

System
Linux kernel
Corpus path
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
Extension
.c
Size
64365 bytes
Lines
2455
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern 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

static const struct net_device_ops mcp251xfd_netdev_ops = {
	.ndo_open = mcp251xfd_open,
	.ndo_stop = mcp251xfd_stop,
	.ndo_start_xmit	= mcp251xfd_start_xmit,
	.ndo_hwtstamp_get = can_hwtstamp_get,
	.ndo_hwtstamp_set = can_hwtstamp_set,
};

static void
mcp251xfd_register_quirks(struct mcp251xfd_priv *priv)
{
	const struct spi_device *spi = priv->spi;
	const struct spi_controller *ctlr = spi->controller;

	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
		priv->devtype_data.quirks |= MCP251XFD_QUIRK_HALF_DUPLEX;
}

static int mcp251xfd_register_chip_detect(struct mcp251xfd_priv *priv)
{
	const struct net_device *ndev = priv->ndev;
	const struct mcp251xfd_devtype_data *devtype_data;
	u32 osc;
	int err;

	/* The OSC_LPMEN is only supported on MCP2518FD and MCP251863,
	 * so use it to autodetect the model.
	 */
	err = regmap_update_bits(priv->map_reg, MCP251XFD_REG_OSC,
				 MCP251XFD_REG_OSC_LPMEN,
				 MCP251XFD_REG_OSC_LPMEN);
	if (err)
		return err;

	err = regmap_read(priv->map_reg, MCP251XFD_REG_OSC, &osc);
	if (err)
		return err;

	if (osc & MCP251XFD_REG_OSC_LPMEN) {
		/* We cannot distinguish between MCP2518FD and
		 * MCP251863. If firmware specifies MCP251863, keep
		 * it, otherwise set to MCP2518FD.
		 */
		if (mcp251xfd_is_251863(priv))
			devtype_data = &mcp251xfd_devtype_data_mcp251863;
		else
			devtype_data = &mcp251xfd_devtype_data_mcp2518fd;
	} else {
		devtype_data = &mcp251xfd_devtype_data_mcp2517fd;
	}

	if (!mcp251xfd_is_251XFD(priv) &&
	    priv->devtype_data.model != devtype_data->model) {
		netdev_info(ndev,
			    "Detected %s, but firmware specifies a %s. Fixing up.\n",
			    __mcp251xfd_get_model_str(devtype_data->model),
			    mcp251xfd_get_model_str(priv));
	}
	priv->devtype_data = *devtype_data;

	/* We need to preserve the Half Duplex Quirk. */
	mcp251xfd_register_quirks(priv);

	/* Re-init regmap with quirks of detected model. */
	return mcp251xfd_regmap_init(priv);
}

static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
{
	int err, rx_pending;

	if (!priv->rx_int)
		return 0;

	err = mcp251xfd_chip_rx_int_enable(priv);
	if (err)
		return err;

	/* Check if RX_INT is properly working. The RX_INT should not
	 * be active after a softreset.
	 */
	rx_pending = gpiod_get_value_cansleep(priv->rx_int);

	err = mcp251xfd_chip_rx_int_disable(priv);
	if (err)
		return err;

	if (!rx_pending)
		return 0;

Annotation

Implementation Notes