1/*
2 *  Probe for F81216A LPC to 4 UART
3 *
4 *  Based on drivers/tty/serial/8250_pnp.c, by Russell King, et al
5 *
6 *  Copyright (C) 2014 Ricardo Ribalda, Qtechnology A/S
7 *
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License.
12 */
13#include <linux/module.h>
14#include <linux/pci.h>
15#include <linux/pnp.h>
16#include <linux/kernel.h>
17#include <linux/serial_core.h>
18#include  "8250.h"
19
20#define ADDR_PORT 0
21#define DATA_PORT 1
22#define EXIT_KEY 0xAA
23#define CHIP_ID1  0x20
24#define CHIP_ID2  0x21
25#define CHIP_ID_0 0x1602
26#define CHIP_ID_1 0x0501
27#define VENDOR_ID1 0x23
28#define VENDOR_ID1_VAL 0x19
29#define VENDOR_ID2 0x24
30#define VENDOR_ID2_VAL 0x34
31#define IO_ADDR1 0x61
32#define IO_ADDR2 0x60
33#define LDN 0x7
34
35#define RS485  0xF0
36#define RTS_INVERT BIT(5)
37#define RS485_URA BIT(4)
38#define RXW4C_IRA BIT(3)
39#define TXW4C_IRA BIT(2)
40
41#define DRIVER_NAME "8250_fintek"
42
43struct fintek_8250 {
44	u16 base_port;
45	u8 index;
46	u8 key;
47	long line;
48};
49
50static int fintek_8250_enter_key(u16 base_port, u8 key)
51{
52
53	if (!request_muxed_region(base_port, 2, DRIVER_NAME))
54		return -EBUSY;
55
56	outb(key, base_port + ADDR_PORT);
57	outb(key, base_port + ADDR_PORT);
58	return 0;
59}
60
61static void fintek_8250_exit_key(u16 base_port)
62{
63
64	outb(EXIT_KEY, base_port + ADDR_PORT);
65	release_region(base_port + ADDR_PORT, 2);
66}
67
68static int fintek_8250_check_id(u16 base_port)
69{
70	u16 chip;
71
72	outb(VENDOR_ID1, base_port + ADDR_PORT);
73	if (inb(base_port + DATA_PORT) != VENDOR_ID1_VAL)
74		return -ENODEV;
75
76	outb(VENDOR_ID2, base_port + ADDR_PORT);
77	if (inb(base_port + DATA_PORT) != VENDOR_ID2_VAL)
78		return -ENODEV;
79
80	outb(CHIP_ID1, base_port + ADDR_PORT);
81	chip = inb(base_port + DATA_PORT);
82	outb(CHIP_ID2, base_port + ADDR_PORT);
83	chip |= inb(base_port + DATA_PORT) << 8;
84
85	if (chip != CHIP_ID_0 && chip != CHIP_ID_1)
86		return -ENODEV;
87
88	return 0;
89}
90
91static int fintek_8250_rs485_config(struct uart_port *port,
92			      struct serial_rs485 *rs485)
93{
94	uint8_t config = 0;
95	struct fintek_8250 *pdata = port->private_data;
96
97	if (!pdata)
98		return -EINVAL;
99
100	if (rs485->flags & SER_RS485_ENABLED)
101		memset(rs485->padding, 0, sizeof(rs485->padding));
102	else
103		memset(rs485, 0, sizeof(*rs485));
104
105	rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
106			SER_RS485_RTS_AFTER_SEND;
107
108	if (rs485->delay_rts_before_send) {
109		rs485->delay_rts_before_send = 1;
110		config |= TXW4C_IRA;
111	}
112
113	if (rs485->delay_rts_after_send) {
114		rs485->delay_rts_after_send = 1;
115		config |= RXW4C_IRA;
116	}
117
118	if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) ==
119			(!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))
120		rs485->flags &= SER_RS485_ENABLED;
121	else
122		config |= RS485_URA;
123
124	if (rs485->flags & SER_RS485_RTS_ON_SEND)
125		config |= RTS_INVERT;
126
127	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
128		return -EBUSY;
129
130	outb(LDN, pdata->base_port + ADDR_PORT);
131	outb(pdata->index, pdata->base_port + DATA_PORT);
132	outb(RS485, pdata->base_port + ADDR_PORT);
133	outb(config, pdata->base_port + DATA_PORT);
134	fintek_8250_exit_key(pdata->base_port);
135
136	port->rs485 = *rs485;
137
138	return 0;
139}
140
141static int fintek_8250_base_port(u16 io_address, u8 *key, u8 *index)
142{
143	static const u16 addr[] = {0x4e, 0x2e};
144	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
145	int i, j, k;
146
147	for (i = 0; i < ARRAY_SIZE(addr); i++) {
148		for (j = 0; j < ARRAY_SIZE(keys); j++) {
149
150			if (fintek_8250_enter_key(addr[i], keys[j]))
151				continue;
152			if (fintek_8250_check_id(addr[i])) {
153				fintek_8250_exit_key(addr[i]);
154				continue;
155			}
156
157			for (k = 0; k < 4; k++) {
158				u16 aux;
159
160				outb(LDN, addr[i] + ADDR_PORT);
161				outb(k, addr[i] + DATA_PORT);
162
163				outb(IO_ADDR1, addr[i] + ADDR_PORT);
164				aux = inb(addr[i] + DATA_PORT);
165				outb(IO_ADDR2, addr[i] + ADDR_PORT);
166				aux |= inb(addr[i] + DATA_PORT) << 8;
167				if (aux != io_address)
168					continue;
169
170				fintek_8250_exit_key(addr[i]);
171				*key = keys[j];
172				*index = k;
173				return addr[i];
174			}
175			fintek_8250_exit_key(addr[i]);
176		}
177	}
178
179	return -ENODEV;
180}
181
182static int
183fintek_8250_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
184{
185	struct uart_8250_port uart;
186	struct fintek_8250 *pdata;
187	int base_port;
188	u8 key;
189	u8 index;
190
191	if (!pnp_port_valid(dev, 0))
192		return -ENODEV;
193
194	base_port = fintek_8250_base_port(pnp_port_start(dev, 0), &key, &index);
195	if (base_port < 0)
196		return -ENODEV;
197
198	memset(&uart, 0, sizeof(uart));
199
200	pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
201	if (!pdata)
202		return -ENOMEM;
203	uart.port.private_data = pdata;
204
205	if (!pnp_irq_valid(dev, 0))
206		return -ENODEV;
207	uart.port.irq = pnp_irq(dev, 0);
208	uart.port.iobase = pnp_port_start(dev, 0);
209	uart.port.iotype = UPIO_PORT;
210	uart.port.rs485_config = fintek_8250_rs485_config;
211
212	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
213	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
214		uart.port.flags |= UPF_SHARE_IRQ;
215	uart.port.uartclk = 1843200;
216	uart.port.dev = &dev->dev;
217
218	pdata->key = key;
219	pdata->base_port = base_port;
220	pdata->index = index;
221	pdata->line = serial8250_register_8250_port(&uart);
222	if (pdata->line < 0)
223		return -ENODEV;
224
225	pnp_set_drvdata(dev, pdata);
226	return 0;
227}
228
229static void fintek_8250_remove(struct pnp_dev *dev)
230{
231	struct fintek_8250 *pdata = pnp_get_drvdata(dev);
232
233	if (pdata)
234		serial8250_unregister_port(pdata->line);
235}
236
237#ifdef CONFIG_PM
238static int fintek_8250_suspend(struct pnp_dev *dev, pm_message_t state)
239{
240	struct fintek_8250 *pdata = pnp_get_drvdata(dev);
241
242	if (!pdata)
243		return -ENODEV;
244	serial8250_suspend_port(pdata->line);
245	return 0;
246}
247
248static int fintek_8250_resume(struct pnp_dev *dev)
249{
250	struct fintek_8250 *pdata = pnp_get_drvdata(dev);
251
252	if (!pdata)
253		return -ENODEV;
254	serial8250_resume_port(pdata->line);
255	return 0;
256}
257#else
258#define fintek_8250_suspend NULL
259#define fintek_8250_resume NULL
260#endif /* CONFIG_PM */
261
262static const struct pnp_device_id fintek_dev_table[] = {
263	/* Qtechnology Panel PC / IO1000 */
264	{ "PNP0501"},
265	{}
266};
267
268MODULE_DEVICE_TABLE(pnp, fintek_dev_table);
269
270static struct pnp_driver fintek_8250_driver = {
271	.name		= DRIVER_NAME,
272	.probe		= fintek_8250_probe,
273	.remove		= fintek_8250_remove,
274	.suspend	= fintek_8250_suspend,
275	.resume		= fintek_8250_resume,
276	.id_table	= fintek_dev_table,
277};
278
279module_pnp_driver(fintek_8250_driver);
280MODULE_DESCRIPTION("Fintek F812164 module");
281MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>");
282MODULE_LICENSE("GPL");
283