can: sja1000: generic OF platform bus driver
[linux-2.6.git] / drivers / net / can / sja1000 / sja1000_of_platform.c
1 /*
2  * Driver for SJA1000 CAN controllers on the OpenFirmware platform bus
3  *
4  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the version 2 of the GNU General Public License
8  * as published by the Free Software Foundation
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software Foundation,
17  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19
20 /* This is a generic driver for SJA1000 chips on the OpenFirmware platform
21  * bus found on embedded PowerPC systems. You need a SJA1000 CAN node
22  * definition in your flattened device tree source (DTS) file similar to:
23  *
24  *   can@3,100 {
25  *           compatible = "nxp,sja1000";
26  *           reg = <3 0x100 0x80>;
27  *           interrupts = <2 0>;
28  *           interrupt-parent = <&mpic>;
29  *           nxp,external-clock-frequency = <16000000>;
30  *   };
31  *
32  * See "Documentation/powerpc/dts-bindings/can/sja1000.txt" for further
33  * information.
34  */
35
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/interrupt.h>
39 #include <linux/netdevice.h>
40 #include <linux/delay.h>
41 #include <linux/can.h>
42 #include <linux/can/dev.h>
43
44 #include <linux/of_platform.h>
45 #include <asm/prom.h>
46
47 #include "sja1000.h"
48
49 #define DRV_NAME "sja1000_of_platform"
50
51 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
52 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");
53 MODULE_LICENSE("GPL v2");
54
55 #define SJA1000_OFP_CAN_CLOCK  (16000000 / 2)
56
57 #define SJA1000_OFP_OCR        OCR_TX0_PULLDOWN
58 #define SJA1000_OFP_CDR        (CDR_CBP | CDR_CLK_OFF)
59
60 static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)
61 {
62         return in_8(priv->reg_base + reg);
63 }
64
65 static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,
66                                   int reg, u8 val)
67 {
68         out_8(priv->reg_base + reg, val);
69 }
70
71 static int __devexit sja1000_ofp_remove(struct of_device *ofdev)
72 {
73         struct net_device *dev = dev_get_drvdata(&ofdev->dev);
74         struct sja1000_priv *priv = netdev_priv(dev);
75         struct device_node *np = ofdev->node;
76         struct resource res;
77
78         dev_set_drvdata(&ofdev->dev, NULL);
79
80         unregister_sja1000dev(dev);
81         free_sja1000dev(dev);
82         iounmap(priv->reg_base);
83         irq_dispose_mapping(dev->irq);
84
85         of_address_to_resource(np, 0, &res);
86         release_mem_region(res.start, resource_size(&res));
87
88         return 0;
89 }
90
91 static int __devinit sja1000_ofp_probe(struct of_device *ofdev,
92                                        const struct of_device_id *id)
93 {
94         struct device_node *np = ofdev->node;
95         struct net_device *dev;
96         struct sja1000_priv *priv;
97         struct resource res;
98         const u32 *prop;
99         int err, irq, res_size, prop_size;
100         void __iomem *base;
101
102         err = of_address_to_resource(np, 0, &res);
103         if (err) {
104                 dev_err(&ofdev->dev, "invalid address\n");
105                 return err;
106         }
107
108         res_size = resource_size(&res);
109
110         if (!request_mem_region(res.start, res_size, DRV_NAME)) {
111                 dev_err(&ofdev->dev, "couldn't request %#x..%#x\n",
112                         res.start, res.end);
113                 return -EBUSY;
114         }
115
116         base = ioremap_nocache(res.start, res_size);
117         if (!base) {
118                 dev_err(&ofdev->dev, "couldn't ioremap %#x..%#x\n",
119                         res.start, res.end);
120                 err = -ENOMEM;
121                 goto exit_release_mem;
122         }
123
124         irq = irq_of_parse_and_map(np, 0);
125         if (irq == NO_IRQ) {
126                 dev_err(&ofdev->dev, "no irq found\n");
127                 err = -ENODEV;
128                 goto exit_unmap_mem;
129         }
130
131         dev = alloc_sja1000dev(0);
132         if (!dev) {
133                 err = -ENOMEM;
134                 goto exit_dispose_irq;
135         }
136
137         priv = netdev_priv(dev);
138
139         priv->read_reg = sja1000_ofp_read_reg;
140         priv->write_reg = sja1000_ofp_write_reg;
141
142         prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
143         if (prop && (prop_size ==  sizeof(u32)))
144                 priv->can.clock.freq = *prop / 2;
145         else
146                 priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
147
148         prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
149         if (prop && (prop_size == sizeof(u32)))
150                 priv->ocr |= *prop & OCR_MODE_MASK;
151         else
152                 priv->ocr |= OCR_MODE_NORMAL; /* default */
153
154         prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
155         if (prop && (prop_size == sizeof(u32)))
156                 priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
157         else
158                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
159
160         prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
161         if (prop && (prop_size == sizeof(u32)) && *prop) {
162                 u32 divider = priv->can.clock.freq * 2 / *prop;
163
164                 if (divider > 1)
165                         priv->cdr |= divider / 2 - 1;
166                 else
167                         priv->cdr |= CDR_CLKOUT_MASK;
168         } else {
169                 priv->cdr |= CDR_CLK_OFF; /* default */
170         }
171
172         prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
173         if (!prop)
174                 priv->cdr |= CDR_CBP; /* default */
175
176         priv->irq_flags = IRQF_SHARED;
177         priv->reg_base = base;
178
179         dev->irq = irq;
180
181         dev_info(&ofdev->dev,
182                  "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
183                  priv->reg_base, dev->irq, priv->can.clock.freq,
184                  priv->ocr, priv->cdr);
185
186         dev_set_drvdata(&ofdev->dev, dev);
187         SET_NETDEV_DEV(dev, &ofdev->dev);
188
189         err = register_sja1000dev(dev);
190         if (err) {
191                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
192                         DRV_NAME, err);
193                 goto exit_free_sja1000;
194         }
195
196         return 0;
197
198 exit_free_sja1000:
199         free_sja1000dev(dev);
200 exit_dispose_irq:
201         irq_dispose_mapping(irq);
202 exit_unmap_mem:
203         iounmap(base);
204 exit_release_mem:
205         release_mem_region(res.start, res_size);
206
207         return err;
208 }
209
210 static struct of_device_id __devinitdata sja1000_ofp_table[] = {
211         {.compatible = "nxp,sja1000"},
212         {},
213 };
214
215 static struct of_platform_driver sja1000_ofp_driver = {
216         .owner = THIS_MODULE,
217         .name = DRV_NAME,
218         .probe = sja1000_ofp_probe,
219         .remove = __devexit_p(sja1000_ofp_remove),
220         .match_table = sja1000_ofp_table,
221 };
222
223 static int __init sja1000_ofp_init(void)
224 {
225         return of_register_platform_driver(&sja1000_ofp_driver);
226 }
227 module_init(sja1000_ofp_init);
228
229 static void __exit sja1000_ofp_exit(void)
230 {
231         return of_unregister_platform_driver(&sja1000_ofp_driver);
232 };
233 module_exit(sja1000_ofp_exit);