drivers/media/pci/mantis/mantis_uart.c

Source file repositories/reference/linux-study-clean/drivers/media/pci/mantis/mantis_uart.c

File Facts

System
Linux kernel
Corpus path
drivers/media/pci/mantis/mantis_uart.c
Extension
.c
Size
4093 bytes
Lines
187
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 mantis_uart_params {
	enum mantis_baud	baud_rate;
	enum mantis_parity	parity;
};

static struct {
	char string[7];
} rates[5] = {
	{ "9600" },
	{ "19200" },
	{ "38400" },
	{ "57600" },
	{ "115200" }
};

static struct {
	char string[5];
} parity[3] = {
	{ "NONE" },
	{ "ODD" },
	{ "EVEN" }
};

static void mantis_uart_read(struct mantis_pci *mantis)
{
	struct mantis_hwconfig *config = mantis->hwconfig;
	int i, scancode = 0, err = 0;

	/* get data */
	dprintk(MANTIS_DEBUG, 1, "UART Reading ...");
	for (i = 0; i < (config->bytes + 1); i++) {
		int data = mmread(MANTIS_UART_RXD);

		dprintk(MANTIS_DEBUG, 0, " <%02x>", data);

		scancode = (scancode << 8) | (data & 0x3f);
		err |= data;

		if (data & (1 << 7))
			dprintk(MANTIS_ERROR, 1, "UART framing error");

		if (data & (1 << 6))
			dprintk(MANTIS_ERROR, 1, "UART parity error");
	}
	dprintk(MANTIS_DEBUG, 0, "\n");

	if ((err & 0xC0) == 0)
		mantis_input_process(mantis, scancode);
}

static void mantis_uart_work(struct work_struct *work)
{
	struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work);
	u32 stat;
	unsigned long timeout;

	stat = mmread(MANTIS_UART_STAT);

	if (stat & MANTIS_UART_RXFIFO_FULL)
		dprintk(MANTIS_ERROR, 1, "RX Fifo FULL");

	/*
	 * MANTIS_UART_RXFIFO_DATA is only set if at least
	 * config->bytes + 1 bytes are in the FIFO.
	 */

	/* FIXME: is 10ms good enough ? */
	timeout = jiffies +  msecs_to_jiffies(10);
	while (stat & MANTIS_UART_RXFIFO_DATA) {
		mantis_uart_read(mantis);
		stat = mmread(MANTIS_UART_STAT);

		if (!time_is_after_jiffies(timeout))
			break;
	}

	/* re-enable UART (RX) interrupt */
	mantis_unmask_ints(mantis, MANTIS_INT_IRQ1);
}

static int mantis_uart_setup(struct mantis_pci *mantis,
			     struct mantis_uart_params *params)
{
	u32 reg;

	mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL);

	reg = mmread(MANTIS_UART_BAUD);

	switch (params->baud_rate) {

Annotation

Implementation Notes