mirror_ubuntu-kernels/drivers/tty/serial/8250/8250_pxa.c

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2024-07-02 00:48:40 +03:00
// SPDX-License-Identifier: GPL-2.0+
/*
* drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS
* Copyright: (C) 2013 Sergei Ianovich <ynvich@gmail.com>
*
* replaces drivers/serial/pxa.c by Nicolas Pitre
* Created: Feb 20, 2003
* Copyright: (C) 2003 Monta Vista Software, Inc.
*
* Based on drivers/serial/8250.c by Russell King.
*/
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include "8250.h"
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 irq, ret;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
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;
ret = of_alias_get_id(pdev->dev.of_node, "serial");
if (ret >= 0)
uart.port.line = ret;
uart.port.type = PORT_XSCALE;
uart.port.iotype = UPIO_MEM32;
uart.port.mapbase = mmres->start;
uart.port.regshift = 2;
uart.port.irq = irq;
uart.port.fifosize = 64;
uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
uart.port.dev = &pdev->dev;
uart.port.uartclk = clk_get_rate(data->clk);
uart.port.pm = serial_pxa_pm;
uart.port.private_data = data;
uart.dl_write = serial_pxa_dl_write;
ret = serial8250_register_8250_port(&uart);
if (ret < 0)
goto err_clk;
data->line = ret;
platform_set_drvdata(pdev, data);
return 0;
err_clk:
clk_unprepare(data->clk);
return ret;
}
static void serial_pxa_remove(struct platform_device *pdev)
{
struct pxa8250_data *data = platform_get_drvdata(pdev);
serial8250_unregister_port(data->line);
clk_unprepare(data->clk);
}
static struct platform_driver serial_pxa_driver = {
.probe = serial_pxa_probe,
.remove_new = serial_pxa_remove,
.driver = {
.name = "pxa2xx-uart",
.pm = &serial_pxa_pm_ops,
.of_match_table = serial_pxa_dt_ids,
},
};
module_platform_driver(serial_pxa_driver);
#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init early_serial_pxa_setup(struct earlycon_device *device,
const char *options)
{
struct uart_port *port = &device->port;
if (!(device->port.membase || device->port.iobase))
return -ENODEV;
port->regshift = 2;
return early_serial8250_setup(device, NULL);
}
OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup);
#endif
MODULE_AUTHOR("Sergei Ianovich");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pxa2xx-uart");