1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for the 98626/98644/internal serial interface on hp300/hp400
4 * (based on the National Semiconductor INS8250/NS16550AF/WD16C552 UARTs)
5 *
6 * Ported from 2.2 and modified to use the normal 8250 driver
7 * by Kars de Jong <jongk@linux-m68k.org>, May 2004.
8 */
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/string.h>
12#include <linux/kernel.h>
13#include <linux/serial.h>
14#include <linux/serial_8250.h>
15#include <linux/delay.h>
16#include <linux/dio.h>
17#include <linux/console.h>
18#include <linux/slab.h>
19#include <asm/io.h>
20
21#include "8250.h"
22
23#if !defined(CONFIG_HPDCA) && !defined(CONFIG_HPAPCI) && !defined(CONFIG_COMPILE_TEST)
24#warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
25#endif
26
27#ifdef CONFIG_HPAPCI
28struct hp300_port {
29	struct hp300_port *next;	/* next port */
30	int line;			/* line (tty) number */
31};
32
33static struct hp300_port *hp300_ports;
34#endif
35
36#ifdef CONFIG_HPDCA
37
38static int hpdca_init_one(struct dio_dev *d,
39					const struct dio_device_id *ent);
40static void hpdca_remove_one(struct dio_dev *d);
41
42static struct dio_device_id hpdca_dio_tbl[] = {
43	{ DIO_ID_DCA0 },
44	{ DIO_ID_DCA0REM },
45	{ DIO_ID_DCA1 },
46	{ DIO_ID_DCA1REM },
47	{ 0 }
48};
49
50static struct dio_driver hpdca_driver = {
51	.name      = "hpdca",
52	.id_table  = hpdca_dio_tbl,
53	.probe     = hpdca_init_one,
54	.remove    = hpdca_remove_one,
55};
56
57#endif
58
59static unsigned int num_ports;
60
61extern int hp300_uart_scode;
62
63/* Offset to UART registers from base of DCA */
64#define UART_OFFSET	17
65
66#define DCA_ID		0x01	/* ID (read), reset (write) */
67#define DCA_IC		0x03	/* Interrupt control        */
68
69/* Interrupt control */
70#define DCA_IC_IE	0x80	/* Master interrupt enable  */
71
72#define HPDCA_BAUD_BASE 153600
73
74/* Base address of the Frodo part */
75#define FRODO_BASE	(0x41c000)
76
77/*
78 * Where we find the 8250-like APCI ports, and how far apart they are.
79 */
80#define FRODO_APCIBASE		0x0
81#define FRODO_APCISPACE		0x20
82#define FRODO_APCI_OFFSET(x)	(FRODO_APCIBASE + ((x) * FRODO_APCISPACE))
83
84#define HPAPCI_BAUD_BASE 500400
85
86#ifdef CONFIG_SERIAL_8250_CONSOLE
87/*
88 * Parse the bootinfo to find descriptions for headless console and
89 * debug serial ports and register them with the 8250 driver.
90 */
91int __init hp300_setup_serial_console(void)
92{
93	int scode;
94	struct uart_port port;
95
96	memset(&port, 0, sizeof(port));
97
98	if (hp300_uart_scode < 0 || hp300_uart_scode > DIO_SCMAX)
99		return 0;
100
101	if (DIO_SCINHOLE(hp300_uart_scode))
102		return 0;
103
104	scode = hp300_uart_scode;
105
106	/* Memory mapped I/O */
107	port.iotype = UPIO_MEM;
108	port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
109	port.type = PORT_UNKNOWN;
110
111	/* Check for APCI console */
112	if (scode == 256) {
113#ifdef CONFIG_HPAPCI
114		pr_info("Serial console is HP APCI 1\n");
115
116		port.uartclk = HPAPCI_BAUD_BASE * 16;
117		port.mapbase = (FRODO_BASE + FRODO_APCI_OFFSET(1));
118		port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
119		port.regshift = 2;
120		add_preferred_console("ttyS", port.line, "9600n8");
121#else
122		pr_warn("Serial console is APCI but support is disabled (CONFIG_HPAPCI)!\n");
123		return 0;
124#endif
125	} else {
126#ifdef CONFIG_HPDCA
127		unsigned long pa = dio_scodetophysaddr(scode);
128		if (!pa)
129			return 0;
130
131		pr_info("Serial console is HP DCA at select code %d\n", scode);
132
133		port.uartclk = HPDCA_BAUD_BASE * 16;
134		port.mapbase = (pa + UART_OFFSET);
135		port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
136		port.regshift = 1;
137		port.irq = DIO_IPL(pa + DIO_VIRADDRBASE);
138
139		/* Enable board-interrupts */
140		out_8(pa + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
141
142		if (DIO_ID(pa + DIO_VIRADDRBASE) & 0x80)
143			add_preferred_console("ttyS", port.line, "9600n8");
144#else
145		pr_warn("Serial console is DCA but support is disabled (CONFIG_HPDCA)!\n");
146		return 0;
147#endif
148	}
149
150	if (early_serial_setup(&port) < 0)
151		pr_warn("%s: early_serial_setup() failed.\n", __func__);
152	return 0;
153}
154#endif /* CONFIG_SERIAL_8250_CONSOLE */
155
156#ifdef CONFIG_HPDCA
157static int hpdca_init_one(struct dio_dev *d,
158				const struct dio_device_id *ent)
159{
160	struct uart_8250_port uart;
161	int line;
162
163#ifdef CONFIG_SERIAL_8250_CONSOLE
164	if (hp300_uart_scode == d->scode) {
165		/* Already got it. */
166		return 0;
167	}
168#endif
169	memset(&uart, 0, sizeof(uart));
170
171	/* Memory mapped I/O */
172	uart.port.iotype = UPIO_MEM;
173	uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
174	uart.port.irq = d->ipl;
175	uart.port.uartclk = HPDCA_BAUD_BASE * 16;
176	uart.port.mapbase = (d->resource.start + UART_OFFSET);
177	uart.port.membase = (char *)(uart.port.mapbase + DIO_VIRADDRBASE);
178	uart.port.regshift = 1;
179	uart.port.dev = &d->dev;
180	line = serial8250_register_8250_port(&uart);
181
182	if (line < 0) {
183		dev_notice(&d->dev,
184			  "8250_hp300: register_serial() DCA scode %d irq %d failed\n",
185			  d->scode, uart.port.irq);
186		return -ENOMEM;
187	}
188
189	/* Enable board-interrupts */
190	out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
191	dio_set_drvdata(d, (void *)line);
192
193	/* Reset the DCA */
194	out_8(d->resource.start + DIO_VIRADDRBASE + DCA_ID, 0xff);
195	udelay(100);
196
197	num_ports++;
198
199	return 0;
200}
201#endif
202
203static int __init hp300_8250_init(void)
204{
205	static int called;
206#ifdef CONFIG_HPAPCI
207	int line;
208	unsigned long base;
209	struct uart_8250_port uart;
210	struct hp300_port *port;
211	int i;
212#endif
213	if (called)
214		return -ENODEV;
215	called = 1;
216
217	if (!MACH_IS_HP300)
218		return -ENODEV;
219
220#ifdef CONFIG_HPDCA
221	dio_register_driver(&hpdca_driver);
222#endif
223#ifdef CONFIG_HPAPCI
224	if (hp300_model < HP_400) {
225		if (!num_ports)
226			return -ENODEV;
227		return 0;
228	}
229	/* These models have the Frodo chip.
230	 * Port 0 is reserved for the Apollo Domain keyboard.
231	 * Port 1 is either the console or the DCA.
232	 */
233	for (i = 1; i < 4; i++) {
234		/* Port 1 is the console on a 425e, on other machines it's
235		 * mapped to DCA.
236		 */
237#ifdef CONFIG_SERIAL_8250_CONSOLE
238		if (i == 1)
239			continue;
240#endif
241
242		/* Create new serial device */
243		port = kmalloc(sizeof(struct hp300_port), GFP_KERNEL);
244		if (!port)
245			return -ENOMEM;
246
247		memset(&uart, 0, sizeof(uart));
248
249		base = (FRODO_BASE + FRODO_APCI_OFFSET(i));
250
251		/* Memory mapped I/O */
252		uart.port.iotype = UPIO_MEM;
253		uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ
254				| UPF_BOOT_AUTOCONF;
255		/* XXX - no interrupt support yet */
256		uart.port.irq = 0;
257		uart.port.uartclk = HPAPCI_BAUD_BASE * 16;
258		uart.port.mapbase = base;
259		uart.port.membase = (char *)(base + DIO_VIRADDRBASE);
260		uart.port.regshift = 2;
261
262		line = serial8250_register_8250_port(&uart);
263
264		if (line < 0) {
265			dev_notice(uart.port.dev,
266				   "8250_hp300: register_serial() APCI %d irq %d failed\n",
267				   i, uart.port.irq);
268			kfree(port);
269			continue;
270		}
271
272		port->line = line;
273		port->next = hp300_ports;
274		hp300_ports = port;
275
276		num_ports++;
277	}
278#endif
279
280	/* Any boards found? */
281	if (!num_ports)
282		return -ENODEV;
283
284	return 0;
285}
286
287#ifdef CONFIG_HPDCA
288static void hpdca_remove_one(struct dio_dev *d)
289{
290	int line;
291
292	line = (int) dio_get_drvdata(d);
293	if (d->resource.start) {
294		/* Disable board-interrupts */
295		out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, 0);
296	}
297	serial8250_unregister_port(line);
298}
299#endif
300
301static void __exit hp300_8250_exit(void)
302{
303#ifdef CONFIG_HPAPCI
304	struct hp300_port *port, *to_free;
305
306	for (port = hp300_ports; port; ) {
307		serial8250_unregister_port(port->line);
308		to_free = port;
309		port = port->next;
310		kfree(to_free);
311	}
312
313	hp300_ports = NULL;
314#endif
315#ifdef CONFIG_HPDCA
316	dio_unregister_driver(&hpdca_driver);
317#endif
318}
319
320module_init(hp300_8250_init);
321module_exit(hp300_8250_exit);
322MODULE_DESCRIPTION("HP DCA/APCI serial driver");
323MODULE_AUTHOR("Kars de Jong <jongk@linux-m68k.org>");
324MODULE_LICENSE("GPL");
325