tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Probe for F81216A LPC to 4 UART
3 *
4 * Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License.
10 */
11#include <linux/module.h>
12#include <linux/pci.h>
13#include <linux/pnp.h>
14#include <linux/kernel.h>
15#include <linux/serial_core.h>
16#include "8250.h"
17
18#define ADDR_PORT 0
19#define DATA_PORT 1
20#define EXIT_KEY 0xAA
21#define CHIP_ID1 0x20
22#define CHIP_ID2 0x21
23#define CHIP_ID_0 0x1602
24#define CHIP_ID_1 0x0501
25#define VENDOR_ID1 0x23
26#define VENDOR_ID1_VAL 0x19
27#define VENDOR_ID2 0x24
28#define VENDOR_ID2_VAL 0x34
29#define IO_ADDR1 0x61
30#define IO_ADDR2 0x60
31#define LDN 0x7
32
33#define RS485 0xF0
34#define RTS_INVERT BIT(5)
35#define RS485_URA BIT(4)
36#define RXW4C_IRA BIT(3)
37#define TXW4C_IRA BIT(2)
38
39struct fintek_8250 {
40 u16 base_port;
41 u8 index;
42 u8 key;
43};
44
45static int fintek_8250_enter_key(u16 base_port, u8 key)
46{
47 if (!request_muxed_region(base_port, 2, "8250_fintek"))
48 return -EBUSY;
49
50 outb(key, base_port + ADDR_PORT);
51 outb(key, base_port + ADDR_PORT);
52 return 0;
53}
54
55static void fintek_8250_exit_key(u16 base_port)
56{
57
58 outb(EXIT_KEY, base_port + ADDR_PORT);
59 release_region(base_port + ADDR_PORT, 2);
60}
61
62static int fintek_8250_check_id(u16 base_port)
63{
64 u16 chip;
65
66 outb(VENDOR_ID1, base_port + ADDR_PORT);
67 if (inb(base_port + DATA_PORT) != VENDOR_ID1_VAL)
68 return -ENODEV;
69
70 outb(VENDOR_ID2, base_port + ADDR_PORT);
71 if (inb(base_port + DATA_PORT) != VENDOR_ID2_VAL)
72 return -ENODEV;
73
74 outb(CHIP_ID1, base_port + ADDR_PORT);
75 chip = inb(base_port + DATA_PORT);
76 outb(CHIP_ID2, base_port + ADDR_PORT);
77 chip |= inb(base_port + DATA_PORT) << 8;
78
79 if (chip != CHIP_ID_0 && chip != CHIP_ID_1)
80 return -ENODEV;
81
82 return 0;
83}
84
85static int fintek_8250_rs485_config(struct uart_port *port,
86 struct serial_rs485 *rs485)
87{
88 uint8_t config = 0;
89 struct fintek_8250 *pdata = port->private_data;
90
91 if (!pdata)
92 return -EINVAL;
93
94 if (rs485->flags & SER_RS485_ENABLED)
95 memset(rs485->padding, 0, sizeof(rs485->padding));
96 else
97 memset(rs485, 0, sizeof(*rs485));
98
99 rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
100 SER_RS485_RTS_AFTER_SEND;
101
102 if (rs485->delay_rts_before_send) {
103 rs485->delay_rts_before_send = 1;
104 config |= TXW4C_IRA;
105 }
106
107 if (rs485->delay_rts_after_send) {
108 rs485->delay_rts_after_send = 1;
109 config |= RXW4C_IRA;
110 }
111
112 if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) ==
113 (!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))
114 rs485->flags &= SER_RS485_ENABLED;
115 else
116 config |= RS485_URA;
117
118 if (rs485->flags & SER_RS485_RTS_ON_SEND)
119 config |= RTS_INVERT;
120
121 if (fintek_8250_enter_key(pdata->base_port, pdata->key))
122 return -EBUSY;
123
124 outb(LDN, pdata->base_port + ADDR_PORT);
125 outb(pdata->index, pdata->base_port + DATA_PORT);
126 outb(RS485, pdata->base_port + ADDR_PORT);
127 outb(config, pdata->base_port + DATA_PORT);
128 fintek_8250_exit_key(pdata->base_port);
129
130 port->rs485 = *rs485;
131
132 return 0;
133}
134
135static int find_base_port(struct fintek_8250 *pdata, u16 io_address)
136{
137 static const u16 addr[] = {0x4e, 0x2e};
138 static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
139 int i, j, k;
140
141 for (i = 0; i < ARRAY_SIZE(addr); i++) {
142 for (j = 0; j < ARRAY_SIZE(keys); j++) {
143
144 if (fintek_8250_enter_key(addr[i], keys[j]))
145 continue;
146 if (fintek_8250_check_id(addr[i])) {
147 fintek_8250_exit_key(addr[i]);
148 continue;
149 }
150
151 for (k = 0; k < 4; k++) {
152 u16 aux;
153
154 outb(LDN, addr[i] + ADDR_PORT);
155 outb(k, addr[i] + DATA_PORT);
156
157 outb(IO_ADDR1, addr[i] + ADDR_PORT);
158 aux = inb(addr[i] + DATA_PORT);
159 outb(IO_ADDR2, addr[i] + ADDR_PORT);
160 aux |= inb(addr[i] + DATA_PORT) << 8;
161 if (aux != io_address)
162 continue;
163
164 fintek_8250_exit_key(addr[i]);
165 pdata->key = keys[j];
166 pdata->base_port = addr[i];
167 pdata->index = k;
168
169 return 0;
170 }
171
172 fintek_8250_exit_key(addr[i]);
173 }
174 }
175
176 return -ENODEV;
177}
178
179int fintek_8250_probe(struct uart_8250_port *uart)
180{
181 struct fintek_8250 *pdata;
182 struct fintek_8250 probe_data;
183
184 if (find_base_port(&probe_data, uart->port.iobase))
185 return -ENODEV;
186
187 pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
188 if (!pdata)
189 return -ENOMEM;
190
191 memcpy(pdata, &probe_data, sizeof(probe_data));
192 uart->port.rs485_config = fintek_8250_rs485_config;
193 uart->port.private_data = pdata;
194
195 return 0;
196}