1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * tscan1.c: driver for Technologic Systems TS-CAN1 PC104 boards |
4 | * |
5 | * Copyright 2010 Andre B. Oliveira |
6 | */ |
7 | |
8 | /* References: |
9 | * - Getting started with TS-CAN1, Technologic Systems, Feb 2022 |
10 | * https://docs.embeddedts.com/TS-CAN1 |
11 | */ |
12 | |
13 | #include <linux/init.h> |
14 | #include <linux/io.h> |
15 | #include <linux/ioport.h> |
16 | #include <linux/isa.h> |
17 | #include <linux/module.h> |
18 | #include <linux/netdevice.h> |
19 | #include "sja1000.h" |
20 | |
21 | MODULE_DESCRIPTION("Driver for Technologic Systems TS-CAN1 PC104 boards" ); |
22 | MODULE_AUTHOR("Andre B. Oliveira <anbadeol@gmail.com>" ); |
23 | MODULE_LICENSE("GPL" ); |
24 | |
25 | /* Maximum number of boards (one in each JP1:JP2 setting of IO address) */ |
26 | #define TSCAN1_MAXDEV 4 |
27 | |
28 | /* PLD registers address offsets */ |
29 | #define TSCAN1_ID1 0 |
30 | #define TSCAN1_ID2 1 |
31 | #define TSCAN1_VERSION 2 |
32 | #define TSCAN1_LED 3 |
33 | #define TSCAN1_PAGE 4 |
34 | #define TSCAN1_MODE 5 |
35 | #define TSCAN1_JUMPERS 6 |
36 | |
37 | /* PLD board identifier registers magic values */ |
38 | #define TSCAN1_ID1_VALUE 0xf6 |
39 | #define TSCAN1_ID2_VALUE 0xb9 |
40 | |
41 | /* PLD mode register SJA1000 IO enable bit */ |
42 | #define TSCAN1_MODE_ENABLE 0x40 |
43 | |
44 | /* PLD jumpers register bits */ |
45 | #define TSCAN1_JP4 0x10 |
46 | #define TSCAN1_JP5 0x20 |
47 | |
48 | /* PLD IO base addresses start */ |
49 | #define TSCAN1_PLD_ADDRESS 0x150 |
50 | |
51 | /* PLD register space size */ |
52 | #define TSCAN1_PLD_SIZE 8 |
53 | |
54 | /* SJA1000 register space size */ |
55 | #define TSCAN1_SJA1000_SIZE 32 |
56 | |
57 | /* SJA1000 crystal frequency (16MHz) */ |
58 | #define TSCAN1_SJA1000_XTAL 16000000 |
59 | |
60 | /* SJA1000 IO base addresses */ |
61 | static const unsigned short tscan1_sja1000_addresses[] = { |
62 | 0x100, 0x120, 0x180, 0x1a0, 0x200, 0x240, 0x280, 0x320 |
63 | }; |
64 | |
65 | /* Read SJA1000 register */ |
66 | static u8 tscan1_read(const struct sja1000_priv *priv, int reg) |
67 | { |
68 | return inb(port: (unsigned long)priv->reg_base + reg); |
69 | } |
70 | |
71 | /* Write SJA1000 register */ |
72 | static void tscan1_write(const struct sja1000_priv *priv, int reg, u8 val) |
73 | { |
74 | outb(value: val, port: (unsigned long)priv->reg_base + reg); |
75 | } |
76 | |
77 | /* Probe for a TS-CAN1 board with JP2:JP1 jumper setting ID */ |
78 | static int tscan1_probe(struct device *dev, unsigned id) |
79 | { |
80 | struct net_device *netdev; |
81 | struct sja1000_priv *priv; |
82 | unsigned long pld_base, sja1000_base; |
83 | int irq, i; |
84 | |
85 | pld_base = TSCAN1_PLD_ADDRESS + id * TSCAN1_PLD_SIZE; |
86 | if (!request_region(pld_base, TSCAN1_PLD_SIZE, dev_name(dev))) |
87 | return -EBUSY; |
88 | |
89 | if (inb(port: pld_base + TSCAN1_ID1) != TSCAN1_ID1_VALUE || |
90 | inb(port: pld_base + TSCAN1_ID2) != TSCAN1_ID2_VALUE) { |
91 | release_region(pld_base, TSCAN1_PLD_SIZE); |
92 | return -ENODEV; |
93 | } |
94 | |
95 | switch (inb(port: pld_base + TSCAN1_JUMPERS) & (TSCAN1_JP4 | TSCAN1_JP5)) { |
96 | case TSCAN1_JP4: |
97 | irq = 6; |
98 | break; |
99 | case TSCAN1_JP5: |
100 | irq = 7; |
101 | break; |
102 | case TSCAN1_JP4 | TSCAN1_JP5: |
103 | irq = 5; |
104 | break; |
105 | default: |
106 | dev_err(dev, "invalid JP4:JP5 setting (no IRQ)\n" ); |
107 | release_region(pld_base, TSCAN1_PLD_SIZE); |
108 | return -EINVAL; |
109 | } |
110 | |
111 | netdev = alloc_sja1000dev(sizeof_priv: 0); |
112 | if (!netdev) { |
113 | release_region(pld_base, TSCAN1_PLD_SIZE); |
114 | return -ENOMEM; |
115 | } |
116 | |
117 | dev_set_drvdata(dev, data: netdev); |
118 | SET_NETDEV_DEV(netdev, dev); |
119 | |
120 | netdev->base_addr = pld_base; |
121 | netdev->irq = irq; |
122 | |
123 | priv = netdev_priv(dev: netdev); |
124 | priv->read_reg = tscan1_read; |
125 | priv->write_reg = tscan1_write; |
126 | priv->can.clock.freq = TSCAN1_SJA1000_XTAL / 2; |
127 | priv->cdr = CDR_CBP | CDR_CLK_OFF; |
128 | priv->ocr = OCR_TX0_PUSHPULL; |
129 | |
130 | /* Select the first SJA1000 IO address that is free and that works */ |
131 | for (i = 0; i < ARRAY_SIZE(tscan1_sja1000_addresses); i++) { |
132 | sja1000_base = tscan1_sja1000_addresses[i]; |
133 | if (!request_region(sja1000_base, TSCAN1_SJA1000_SIZE, |
134 | dev_name(dev))) |
135 | continue; |
136 | |
137 | /* Set SJA1000 IO base address and enable it */ |
138 | outb(TSCAN1_MODE_ENABLE | i, port: pld_base + TSCAN1_MODE); |
139 | |
140 | priv->reg_base = (void __iomem *)sja1000_base; |
141 | if (!register_sja1000dev(dev: netdev)) { |
142 | /* SJA1000 probe succeeded; turn LED off and return */ |
143 | outb(value: 0, port: pld_base + TSCAN1_LED); |
144 | netdev_info(dev: netdev, format: "TS-CAN1 at 0x%lx 0x%lx irq %d\n" , |
145 | pld_base, sja1000_base, irq); |
146 | return 0; |
147 | } |
148 | |
149 | /* SJA1000 probe failed; release and try next address */ |
150 | outb(value: 0, port: pld_base + TSCAN1_MODE); |
151 | release_region(sja1000_base, TSCAN1_SJA1000_SIZE); |
152 | } |
153 | |
154 | dev_err(dev, "failed to assign SJA1000 IO address\n" ); |
155 | dev_set_drvdata(dev, NULL); |
156 | free_sja1000dev(dev: netdev); |
157 | release_region(pld_base, TSCAN1_PLD_SIZE); |
158 | return -ENXIO; |
159 | } |
160 | |
161 | static void tscan1_remove(struct device *dev, unsigned id /*unused*/) |
162 | { |
163 | struct net_device *netdev; |
164 | struct sja1000_priv *priv; |
165 | unsigned long pld_base, sja1000_base; |
166 | |
167 | netdev = dev_get_drvdata(dev); |
168 | unregister_sja1000dev(dev: netdev); |
169 | dev_set_drvdata(dev, NULL); |
170 | |
171 | priv = netdev_priv(dev: netdev); |
172 | pld_base = netdev->base_addr; |
173 | sja1000_base = (unsigned long)priv->reg_base; |
174 | |
175 | outb(value: 0, port: pld_base + TSCAN1_MODE); /* disable SJA1000 IO space */ |
176 | |
177 | release_region(sja1000_base, TSCAN1_SJA1000_SIZE); |
178 | release_region(pld_base, TSCAN1_PLD_SIZE); |
179 | |
180 | free_sja1000dev(dev: netdev); |
181 | } |
182 | |
183 | static struct isa_driver tscan1_isa_driver = { |
184 | .probe = tscan1_probe, |
185 | .remove = tscan1_remove, |
186 | .driver = { |
187 | .name = "tscan1" , |
188 | }, |
189 | }; |
190 | |
191 | module_isa_driver(tscan1_isa_driver, TSCAN1_MAXDEV); |
192 | |