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, u32 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 void 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
158static struct platform_driver serial_pxa_driver = {
159	.probe          = serial_pxa_probe,
160	.remove_new     = serial_pxa_remove,
161
162	.driver		= {
163		.name	= "pxa2xx-uart",
164		.pm	= &serial_pxa_pm_ops,
165		.of_match_table = serial_pxa_dt_ids,
166	},
167};
168
169module_platform_driver(serial_pxa_driver);
170
171#ifdef CONFIG_SERIAL_8250_CONSOLE
172static int __init early_serial_pxa_setup(struct earlycon_device *device,
173				  const char *options)
174{
175	struct uart_port *port = &device->port;
176
177	if (!(device->port.membase || device->port.iobase))
178		return -ENODEV;
179
180	port->regshift = 2;
181	return early_serial8250_setup(device, NULL);
182}
183OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
184OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup);
185#endif
186
187MODULE_AUTHOR("Sergei Ianovich");
188MODULE_LICENSE("GPL");
189MODULE_ALIAS("platform:pxa2xx-uart");