drivers/tty/serial/8250/8250_pxa.c

Source file repositories/reference/linux-study-clean/drivers/tty/serial/8250/8250_pxa.c

File Facts

System
Linux kernel
Corpus path
drivers/tty/serial/8250/8250_pxa.c
Extension
.c
Size
3856 bytes
Lines
172
Domain
Driver Families
Bucket
drivers/tty
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 pxa8250_data {
	int			line;
	struct clk		*clk;
};

static int __maybe_unused serial_pxa_suspend(struct device *dev)
{
	struct pxa8250_data *data = dev_get_drvdata(dev);

	serial8250_suspend_port(data->line);

	return 0;
}

static int __maybe_unused serial_pxa_resume(struct device *dev)
{
	struct pxa8250_data *data = dev_get_drvdata(dev);

	serial8250_resume_port(data->line);

	return 0;
}

static const struct dev_pm_ops serial_pxa_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
};

static const struct of_device_id serial_pxa_dt_ids[] = {
	{ .compatible = "mrvl,pxa-uart", },
	{ .compatible = "mrvl,mmp-uart", },
	{}
};
MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);

/* Uart divisor latch write */
static void serial_pxa_dl_write(struct uart_8250_port *up, u32 value)
{
	unsigned int dll;

	serial_out(up, UART_DLL, value & 0xff);
	/*
	 * work around Erratum #74 according to Marvel(R) PXA270M Processor
	 * Specification Update (April 19, 2010)
	 */
	dll = serial_in(up, UART_DLL);
	WARN_ON(dll != (value & 0xff));

	serial_out(up, UART_DLM, value >> 8 & 0xff);
}


static void serial_pxa_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	struct pxa8250_data *data = port->private_data;

	if (!state)
		clk_prepare_enable(data->clk);
	else
		clk_disable_unprepare(data->clk);
}

static int serial_pxa_probe(struct platform_device *pdev)
{
	struct uart_8250_port uart = {};
	struct pxa8250_data *data;
	struct resource *mmres;
	int ret;

	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mmres)
		return -ENODEV;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(data->clk))
		return PTR_ERR(data->clk);

	ret = clk_prepare(data->clk);
	if (ret)
		return ret;

	uart.port.type = PORT_XSCALE;
	uart.port.mapbase = mmres->start;
	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
	uart.port.dev = &pdev->dev;
	uart.port.uartclk = clk_get_rate(data->clk);

Annotation

Implementation Notes