cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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8250_pxa.c (4303B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 *  drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS
      4 *  Copyright:	(C) 2013 Sergei Ianovich <ynvich@gmail.com>
      5 *
      6 *  replaces drivers/serial/pxa.c by Nicolas Pitre
      7 *  Created:	Feb 20, 2003
      8 *  Copyright:	(C) 2003 Monta Vista Software, Inc.
      9 *
     10 *  Based on drivers/serial/8250.c by Russell King.
     11 */
     12
     13#include <linux/device.h>
     14#include <linux/init.h>
     15#include <linux/io.h>
     16#include <linux/module.h>
     17#include <linux/serial_8250.h>
     18#include <linux/serial_core.h>
     19#include <linux/serial_reg.h>
     20#include <linux/of.h>
     21#include <linux/of_platform.h>
     22#include <linux/platform_device.h>
     23#include <linux/slab.h>
     24#include <linux/clk.h>
     25
     26#include "8250.h"
     27
     28struct pxa8250_data {
     29	int			line;
     30	struct clk		*clk;
     31};
     32
     33static int __maybe_unused serial_pxa_suspend(struct device *dev)
     34{
     35	struct pxa8250_data *data = dev_get_drvdata(dev);
     36
     37	serial8250_suspend_port(data->line);
     38
     39	return 0;
     40}
     41
     42static int __maybe_unused serial_pxa_resume(struct device *dev)
     43{
     44	struct pxa8250_data *data = dev_get_drvdata(dev);
     45
     46	serial8250_resume_port(data->line);
     47
     48	return 0;
     49}
     50
     51static const struct dev_pm_ops serial_pxa_pm_ops = {
     52	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
     53};
     54
     55static const struct of_device_id serial_pxa_dt_ids[] = {
     56	{ .compatible = "mrvl,pxa-uart", },
     57	{ .compatible = "mrvl,mmp-uart", },
     58	{}
     59};
     60MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
     61
     62/* Uart divisor latch write */
     63static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
     64{
     65	unsigned int dll;
     66
     67	serial_out(up, UART_DLL, value & 0xff);
     68	/*
     69	 * work around Erratum #74 according to Marvel(R) PXA270M Processor
     70	 * Specification Update (April 19, 2010)
     71	 */
     72	dll = serial_in(up, UART_DLL);
     73	WARN_ON(dll != (value & 0xff));
     74
     75	serial_out(up, UART_DLM, value >> 8 & 0xff);
     76}
     77
     78
     79static void serial_pxa_pm(struct uart_port *port, unsigned int state,
     80	      unsigned int oldstate)
     81{
     82	struct pxa8250_data *data = port->private_data;
     83
     84	if (!state)
     85		clk_prepare_enable(data->clk);
     86	else
     87		clk_disable_unprepare(data->clk);
     88}
     89
     90static int serial_pxa_probe(struct platform_device *pdev)
     91{
     92	struct uart_8250_port uart = {};
     93	struct pxa8250_data *data;
     94	struct resource *mmres;
     95	int irq, ret;
     96
     97	irq = platform_get_irq(pdev, 0);
     98	if (irq < 0)
     99		return irq;
    100
    101	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    102	if (!mmres)
    103		return -ENODEV;
    104
    105	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
    106	if (!data)
    107		return -ENOMEM;
    108
    109	data->clk = devm_clk_get(&pdev->dev, NULL);
    110	if (IS_ERR(data->clk))
    111		return PTR_ERR(data->clk);
    112
    113	ret = clk_prepare(data->clk);
    114	if (ret)
    115		return ret;
    116
    117	ret = of_alias_get_id(pdev->dev.of_node, "serial");
    118	if (ret >= 0)
    119		uart.port.line = ret;
    120
    121	uart.port.type = PORT_XSCALE;
    122	uart.port.iotype = UPIO_MEM32;
    123	uart.port.mapbase = mmres->start;
    124	uart.port.regshift = 2;
    125	uart.port.irq = irq;
    126	uart.port.fifosize = 64;
    127	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
    128	uart.port.dev = &pdev->dev;
    129	uart.port.uartclk = clk_get_rate(data->clk);
    130	uart.port.pm = serial_pxa_pm;
    131	uart.port.private_data = data;
    132	uart.dl_write = serial_pxa_dl_write;
    133
    134	ret = serial8250_register_8250_port(&uart);
    135	if (ret < 0)
    136		goto err_clk;
    137
    138	data->line = ret;
    139
    140	platform_set_drvdata(pdev, data);
    141
    142	return 0;
    143
    144 err_clk:
    145	clk_unprepare(data->clk);
    146	return ret;
    147}
    148
    149static int serial_pxa_remove(struct platform_device *pdev)
    150{
    151	struct pxa8250_data *data = platform_get_drvdata(pdev);
    152
    153	serial8250_unregister_port(data->line);
    154
    155	clk_unprepare(data->clk);
    156
    157	return 0;
    158}
    159
    160static struct platform_driver serial_pxa_driver = {
    161	.probe          = serial_pxa_probe,
    162	.remove         = serial_pxa_remove,
    163
    164	.driver		= {
    165		.name	= "pxa2xx-uart",
    166		.pm	= &serial_pxa_pm_ops,
    167		.of_match_table = serial_pxa_dt_ids,
    168	},
    169};
    170
    171module_platform_driver(serial_pxa_driver);
    172
    173#ifdef CONFIG_SERIAL_8250_CONSOLE
    174static int __init early_serial_pxa_setup(struct earlycon_device *device,
    175				  const char *options)
    176{
    177	struct uart_port *port = &device->port;
    178
    179	if (!(device->port.membase || device->port.iobase))
    180		return -ENODEV;
    181
    182	port->regshift = 2;
    183	return early_serial8250_setup(device, NULL);
    184}
    185OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
    186#endif
    187
    188MODULE_AUTHOR("Sergei Ianovich");
    189MODULE_LICENSE("GPL");
    190MODULE_ALIAS("platform:pxa2xx-uart");