1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * SGI IOC3 8250 UART driver |
4 | * |
5 | * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de> |
6 | * |
7 | * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org> |
8 | * Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org> |
9 | */ |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/errno.h> |
13 | #include <linux/io.h> |
14 | #include <linux/platform_device.h> |
15 | |
16 | #include "8250.h" |
17 | |
18 | #define IOC3_UARTCLK (22000000 / 3) |
19 | |
20 | struct ioc3_8250_data { |
21 | int line; |
22 | }; |
23 | |
24 | static unsigned int ioc3_serial_in(struct uart_port *p, int offset) |
25 | { |
26 | return readb(addr: p->membase + (offset ^ 3)); |
27 | } |
28 | |
29 | static void ioc3_serial_out(struct uart_port *p, int offset, int value) |
30 | { |
31 | writeb(val: value, addr: p->membase + (offset ^ 3)); |
32 | } |
33 | |
34 | static int serial8250_ioc3_probe(struct platform_device *pdev) |
35 | { |
36 | struct ioc3_8250_data *data; |
37 | struct uart_8250_port up; |
38 | struct resource *r; |
39 | void __iomem *membase; |
40 | int irq, line; |
41 | |
42 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
43 | if (!r) |
44 | return -ENODEV; |
45 | |
46 | data = devm_kzalloc(dev: &pdev->dev, size: sizeof(*data), GFP_KERNEL); |
47 | if (!data) |
48 | return -ENOMEM; |
49 | |
50 | membase = devm_ioremap(dev: &pdev->dev, offset: r->start, size: resource_size(res: r)); |
51 | if (!membase) |
52 | return -ENOMEM; |
53 | |
54 | irq = platform_get_irq(pdev, 0); |
55 | if (irq < 0) |
56 | irq = 0; /* no interrupt -> use polling */ |
57 | |
58 | /* Register serial ports with 8250.c */ |
59 | memset(&up, 0, sizeof(struct uart_8250_port)); |
60 | up.port.iotype = UPIO_MEM; |
61 | up.port.uartclk = IOC3_UARTCLK; |
62 | up.port.type = PORT_16550A; |
63 | up.port.irq = irq; |
64 | up.port.flags = (UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ); |
65 | up.port.dev = &pdev->dev; |
66 | up.port.membase = membase; |
67 | up.port.mapbase = r->start; |
68 | up.port.serial_in = ioc3_serial_in; |
69 | up.port.serial_out = ioc3_serial_out; |
70 | line = serial8250_register_8250_port(&up); |
71 | if (line < 0) |
72 | return line; |
73 | |
74 | platform_set_drvdata(pdev, data); |
75 | return 0; |
76 | } |
77 | |
78 | static void serial8250_ioc3_remove(struct platform_device *pdev) |
79 | { |
80 | struct ioc3_8250_data *data = platform_get_drvdata(pdev); |
81 | |
82 | serial8250_unregister_port(line: data->line); |
83 | } |
84 | |
85 | static struct platform_driver serial8250_ioc3_driver = { |
86 | .probe = serial8250_ioc3_probe, |
87 | .remove_new = serial8250_ioc3_remove, |
88 | .driver = { |
89 | .name = "ioc3-serial8250" , |
90 | } |
91 | }; |
92 | |
93 | module_platform_driver(serial8250_ioc3_driver); |
94 | |
95 | MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>" ); |
96 | MODULE_DESCRIPTION("SGI IOC3 8250 UART driver" ); |
97 | MODULE_LICENSE("GPL" ); |
98 | |