cee6ba2b8b586bbc4b1f84b71fcc6785249d9547
[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/io.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 platform_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->dev.of_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 platform_device *ofdev)
92 {
93         struct device_node *np = ofdev->dev.of_node;
94         struct net_device *dev;
95         struct sja1000_priv *priv;
96         struct resource res;
97         const u32 *prop;
98         int err, irq, res_size, prop_size;
99         void __iomem *base;
100
101         err = of_address_to_resource(np, 0, &res);
102         if (err) {
103                 dev_err(&ofdev->dev, "invalid address\n");
104                 return err;
105         }
106
107         res_size = resource_size(&res);
108
109         if (!request_mem_region(res.start, res_size, DRV_NAME)) {
110                 dev_err(&ofdev->dev, "couldn't request %pR\n", &res);
111                 return -EBUSY;
112         }
113
114         base = ioremap_nocache(res.start, res_size);
115         if (!base) {
116                 dev_err(&ofdev->dev, "couldn't ioremap %pR\n", &res);
117                 err = -ENOMEM;
118                 goto exit_release_mem;
119         }
120
121         irq = irq_of_parse_and_map(np, 0);
122         if (irq == NO_IRQ) {
123                 dev_err(&ofdev->dev, "no irq found\n");
124                 err = -ENODEV;
125                 goto exit_unmap_mem;
126         }
127
128         dev = alloc_sja1000dev(0);
129         if (!dev) {
130                 err = -ENOMEM;
131                 goto exit_dispose_irq;
132         }
133
134         priv = netdev_priv(dev);
135
136         priv->read_reg = sja1000_ofp_read_reg;
137         priv->write_reg = sja1000_ofp_write_reg;
138
139         prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
140         if (prop && (prop_size ==  sizeof(u32)))
141                 priv->can.clock.freq = *prop / 2;
142         else
143                 priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
144
145         prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
146         if (prop && (prop_size == sizeof(u32)))
147                 priv->ocr |= *prop & OCR_MODE_MASK;
148         else
149                 priv->ocr |= OCR_MODE_NORMAL; /* default */
150
151         prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
152         if (prop && (prop_size == sizeof(u32)))
153                 priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
154         else
155                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
156
157         prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
158         if (prop && (prop_size == sizeof(u32)) && *prop) {
159                 u32 divider = priv->can.clock.freq * 2 / *prop;
160
161                 if (divider > 1)
162                         priv->cdr |= divider / 2 - 1;
163                 else
164                         priv->cdr |= CDR_CLKOUT_MASK;
165         } else {
166                 priv->cdr |= CDR_CLK_OFF; /* default */
167         }
168
169         prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
170         if (!prop)
171                 priv->cdr |= CDR_CBP; /* default */
172
173         priv->irq_flags = IRQF_SHARED;
174         priv->reg_base = base;
175
176         dev->irq = irq;
177
178         dev_info(&ofdev->dev,
179                  "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
180                  priv->reg_base, dev->irq, priv->can.clock.freq,
181                  priv->ocr, priv->cdr);
182
183         dev_set_drvdata(&ofdev->dev, dev);
184         SET_NETDEV_DEV(dev, &ofdev->dev);
185
186         err = register_sja1000dev(dev);
187         if (err) {
188                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
189                         DRV_NAME, err);
190                 goto exit_free_sja1000;
191         }
192
193         return 0;
194
195 exit_free_sja1000:
196         free_sja1000dev(dev);
197 exit_dispose_irq:
198         irq_dispose_mapping(irq);
199 exit_unmap_mem:
200         iounmap(base);
201 exit_release_mem:
202         release_mem_region(res.start, res_size);
203
204         return err;
205 }
206
207 static struct of_device_id __devinitdata sja1000_ofp_table[] = {
208         {.compatible = "nxp,sja1000"},
209         {},
210 };
211 MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
212
213 static struct platform_driver sja1000_ofp_driver = {
214         .driver = {
215                 .owner = THIS_MODULE,
216                 .name = DRV_NAME,
217                 .of_match_table = sja1000_ofp_table,
218         },
219         .probe = sja1000_ofp_probe,
220         .remove = __devexit_p(sja1000_ofp_remove),
221 };
222
223 static int __init sja1000_ofp_init(void)
224 {
225         return platform_driver_register(&sja1000_ofp_driver);
226 }
227 module_init(sja1000_ofp_init);
228
229 static void __exit sja1000_ofp_exit(void)
230 {
231         return platform_driver_unregister(&sja1000_ofp_driver);
232 };
233 module_exit(sja1000_ofp_exit);