1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/*
* Driver for SJA1000 CAN controllers on the OpenFirmware platform bus
*
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* This is a generic driver for SJA1000 chips on the OpenFirmware platform
* bus found on embedded PowerPC systems. You need a SJA1000 CAN node
* definition in your flattened device tree source (DTS) file similar to:
*
* can@3,100 {
* compatible = "nxp,sja1000";
* reg = <3 0x100 0x80>;
* interrupts = <2 0>;
* interrupt-parent = <&mpic>;
* nxp,external-clock-frequency = <16000000>;
* };
*
* See "Documentation/devicetree/bindings/net/can/sja1000.txt" for further
* information.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/can/dev.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/prom.h>
#include "sja1000.h"
#define DRV_NAME "sja1000_of_platform"
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");
MODULE_LICENSE("GPL v2");
#define SJA1000_OFP_CAN_CLOCK (16000000 / 2)
#define SJA1000_OFP_OCR OCR_TX0_PULLDOWN
#define SJA1000_OFP_CDR (CDR_CBP | CDR_CLK_OFF)
static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)
{
return ioread8(priv->reg_base + reg);
}
static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,
int reg, u8 val)
{
iowrite8(val, priv->reg_base + reg);
}
static int sja1000_ofp_remove(struct platform_device *ofdev)
{
struct net_device *dev = dev_get_drvdata(&ofdev->dev);
struct sja1000_priv *priv = netdev_priv(dev);
struct device_node *np = ofdev->dev.of_node;
struct resource res;
dev_set_drvdata(&ofdev->dev, NULL);
unregister_sja1000dev(dev);
free_sja1000dev(dev);
iounmap(priv->reg_base);
irq_dispose_mapping(dev->irq);
of_address_to_resource(np, 0, &res);
release_mem_region(res.start, resource_size(&res));
return 0;
}
static int sja1000_ofp_probe(struct platform_device *ofdev)
{
struct device_node *np = ofdev->dev.of_node;
struct net_device *dev;
struct sja1000_priv *priv;
struct resource res;
u32 prop;
int err, irq, res_size;
void __iomem *base;
err = of_address_to_resource(np, 0, &res);
if (err) {
dev_err(&ofdev->dev, "invalid address\n");
return err;
}
res_size = resource_size(&res);
if (!request_mem_region(res.start, res_size, DRV_NAME)) {
dev_err(&ofdev->dev, "couldn't request %pR\n", &res);
return -EBUSY;
}
base = ioremap_nocache(res.start, res_size);
if (!base) {
dev_err(&ofdev->dev, "couldn't ioremap %pR\n", &res);
err = -ENOMEM;
goto exit_release_mem;
}
irq = irq_of_parse_and_map(np, 0);
if (irq == 0) {
dev_err(&ofdev->dev, "no irq found\n");
err = -ENODEV;
goto exit_unmap_mem;
}
dev = alloc_sja1000dev(0);
if (!dev) {
err = -ENOMEM;
goto exit_dispose_irq;
}
priv = netdev_priv(dev);
priv->read_reg = sja1000_ofp_read_reg;
priv->write_reg = sja1000_ofp_write_reg;
err = of_property_read_u32(np, "nxp,external-clock-frequency", &prop);
if (!err)
priv->can.clock.freq = prop / 2;
else
priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
err = of_property_read_u32(np, "nxp,tx-output-mode", &prop);
if (!err)
priv->ocr |= prop & OCR_MODE_MASK;
else
priv->ocr |= OCR_MODE_NORMAL; /* default */
err = of_property_read_u32(np, "nxp,tx-output-config", &prop);
if (!err)
priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
else
priv->ocr |= OCR_TX0_PULLDOWN; /* default */
err = of_property_read_u32(np, "nxp,clock-out-frequency", &prop);
if (!err && prop) {
u32 divider = priv->can.clock.freq * 2 / prop;
if (divider > 1)
priv->cdr |= divider / 2 - 1;
else
priv->cdr |= CDR_CLKOUT_MASK;
} else {
priv->cdr |= CDR_CLK_OFF; /* default */
}
if (!of_property_read_bool(np, "nxp,no-comparator-bypass"))
priv->cdr |= CDR_CBP; /* default */
priv->irq_flags = IRQF_SHARED;
priv->reg_base = base;
dev->irq = irq;
dev_info(&ofdev->dev,
"reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
priv->reg_base, dev->irq, priv->can.clock.freq,
priv->ocr, priv->cdr);
dev_set_drvdata(&ofdev->dev, dev);
SET_NETDEV_DEV(dev, &ofdev->dev);
err = register_sja1000dev(dev);
if (err) {
dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
DRV_NAME, err);
goto exit_free_sja1000;
}
return 0;
exit_free_sja1000:
free_sja1000dev(dev);
exit_dispose_irq:
irq_dispose_mapping(irq);
exit_unmap_mem:
iounmap(base);
exit_release_mem:
release_mem_region(res.start, res_size);
return err;
}
static struct of_device_id sja1000_ofp_table[] = {
{.compatible = "nxp,sja1000"},
{},
};
MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
static struct platform_driver sja1000_ofp_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
.of_match_table = sja1000_ofp_table,
},
.probe = sja1000_ofp_probe,
.remove = sja1000_ofp_remove,
};
module_platform_driver(sja1000_ofp_driver);
|
