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
28 struct pxa8250_data {
29 int line;
30 struct clk *clk;
31 };
32
serial_pxa_suspend(struct device * dev)33 static 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
serial_pxa_resume(struct device * dev)42 static 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
51 static const struct dev_pm_ops serial_pxa_pm_ops = {
52 SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
53 };
54
55 static const struct of_device_id serial_pxa_dt_ids[] = {
56 { .compatible = "mrvl,pxa-uart", },
57 { .compatible = "mrvl,mmp-uart", },
58 {}
59 };
60 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
61
62 /* Uart divisor latch write */
serial_pxa_dl_write(struct uart_8250_port * up,int value)63 static 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
serial_pxa_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)79 static 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
serial_pxa_probe(struct platform_device * pdev)90 static 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
serial_pxa_remove(struct platform_device * pdev)149 static 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
160 static 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
171 module_platform_driver(serial_pxa_driver);
172
173 #ifdef CONFIG_SERIAL_8250_CONSOLE
early_serial_pxa_setup(struct earlycon_device * device,const char * options)174 static 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 }
185 OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
186 #endif
187
188 MODULE_AUTHOR("Sergei Ianovich");
189 MODULE_LICENSE("GPL");
190 MODULE_ALIAS("platform:pxa2xx-uart");
191
