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#include <linux/pm_runtime.h>
26
27#include "8250.h"
28
29struct pxa8250_data {
30	int			line;
31	struct clk		*clk;
32};
33
34static int __maybe_unused serial_pxa_suspend(struct device *dev)
35{
36	struct pxa8250_data *data = dev_get_drvdata(dev);
37
38	serial8250_suspend_port(data->line);
39
40	return 0;
41}
42
43static int __maybe_unused serial_pxa_resume(struct device *dev)
44{
45	struct pxa8250_data *data = dev_get_drvdata(dev);
46
47	serial8250_resume_port(data->line);
48
49	return 0;
50}
51
52static const struct dev_pm_ops serial_pxa_pm_ops = {
53	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
54};
55
56static const struct of_device_id serial_pxa_dt_ids[] = {
57	{ .compatible = "mrvl,pxa-uart", },
58	{ .compatible = "mrvl,mmp-uart", },
59	{}
60};
61MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
62
63/* Uart divisor latch write */
64static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
65{
66	unsigned int dll;
67
68	serial_out(up, UART_DLL, value & 0xff);
69	/*
70	 * work around Erratum #74 according to Marvel(R) PXA270M Processor
71	 * Specification Update (April 19, 2010)
72	 */
73	dll = serial_in(up, UART_DLL);
74	WARN_ON(dll != (value & 0xff));
75
76	serial_out(up, UART_DLM, value >> 8 & 0xff);
77}
78
79
80static void serial_pxa_pm(struct uart_port *port, unsigned int state,
81	      unsigned int oldstate)
82{
83	struct pxa8250_data *data = port->private_data;
84
85	if (!state)
86		clk_prepare_enable(data->clk);
87	else
88		clk_disable_unprepare(data->clk);
89}
90
91static int serial_pxa_probe(struct platform_device *pdev)
92{
93	struct uart_8250_port uart = {};
94	struct pxa8250_data *data;
95	struct resource *mmres;
96	int irq, ret;
97
98	irq = platform_get_irq(pdev, 0);
99	if (irq < 0)
100		return irq;
101
102	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
103	if (!mmres)
104		return -ENODEV;
105
106	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
107	if (!data)
108		return -ENOMEM;
109
110	data->clk = devm_clk_get(&pdev->dev, NULL);
111	if (IS_ERR(data->clk))
112		return PTR_ERR(data->clk);
113
114	ret = clk_prepare(data->clk);
115	if (ret)
116		return ret;
117
118	ret = of_alias_get_id(pdev->dev.of_node, "serial");
119	if (ret >= 0)
120		uart.port.line = ret;
121
122	uart.port.type = PORT_XSCALE;
123	uart.port.iotype = UPIO_MEM32;
124	uart.port.mapbase = mmres->start;
125	uart.port.regshift = 2;
126	uart.port.irq = irq;
127	uart.port.fifosize = 64;
128	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
129	uart.port.dev = &pdev->dev;
130	uart.port.uartclk = clk_get_rate(data->clk);
131	uart.port.pm = serial_pxa_pm;
132	uart.port.private_data = data;
133	uart.dl_write = serial_pxa_dl_write;
134
135	ret = serial8250_register_8250_port(&uart);
136	if (ret < 0)
137		goto err_clk;
138
139	data->line = ret;
140
141	platform_set_drvdata(pdev, data);
142
143	return 0;
144
145 err_clk:
146	clk_unprepare(data->clk);
147	return ret;
148}
149
150static int serial_pxa_remove(struct platform_device *pdev)
151{
152	struct pxa8250_data *data = platform_get_drvdata(pdev);
153
154	serial8250_unregister_port(data->line);
155
156	clk_unprepare(data->clk);
157
158	return 0;
159}
160
161static struct platform_driver serial_pxa_driver = {
162	.probe          = serial_pxa_probe,
163	.remove         = serial_pxa_remove,
164
165	.driver		= {
166		.name	= "pxa2xx-uart",
167		.pm	= &serial_pxa_pm_ops,
168		.of_match_table = serial_pxa_dt_ids,
169	},
170};
171
172module_platform_driver(serial_pxa_driver);
173
174#ifdef CONFIG_SERIAL_8250_CONSOLE
175static int __init early_serial_pxa_setup(struct earlycon_device *device,
176				  const char *options)
177{
178	struct uart_port *port = &device->port;
179
180	if (!(device->port.membase || device->port.iobase))
181		return -ENODEV;
182
183	port->regshift = 2;
184	return early_serial8250_setup(device, NULL);
185}
186OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
187#endif
188
189MODULE_AUTHOR("Sergei Ianovich");
190MODULE_LICENSE("GPL");
191MODULE_ALIAS("platform:pxa2xx-uart");
192