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