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Wolfram Sangafa17a52009-11-13 06:14:52 +00001/*
2 * CAN bus driver for the Freescale MPC5xxx embedded CPU.
3 *
4 * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
5 * Varma Electronics Oy
6 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
7 * Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the version 2 of the GNU General Public License
11 * as published by the Free Software Foundation
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/interrupt.h>
26#include <linux/platform_device.h>
27#include <linux/netdevice.h>
28#include <linux/can.h>
29#include <linux/can/dev.h>
30#include <linux/of_platform.h>
31#include <sysdev/fsl_soc.h>
32#include <linux/io.h>
33#include <asm/mpc52xx.h>
34
35#include "mscan.h"
36
Wolfram Sangafa17a52009-11-13 06:14:52 +000037#define DRV_NAME "mpc5xxx_can"
38
39static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
40 { .compatible = "fsl,mpc5200-cdm", },
41 { .compatible = "fsl,mpc5200b-cdm", },
42 {}
43};
44
45/*
46 * Get the frequency of the external oscillator clock connected
47 * to the SYS_XTAL_IN pin, or return 0 if it cannot be determined.
48 */
49static unsigned int __devinit mpc52xx_can_xtal_freq(struct of_device *of)
50{
51 struct mpc52xx_cdm __iomem *cdm;
52 struct device_node *np_cdm;
53 unsigned int freq;
54 u32 val;
55
56 freq = mpc5xxx_get_bus_frequency(of->node);
57 if (!freq)
58 return 0;
59
60 /*
61 * Determine SYS_XTAL_IN frequency from the clock domain settings
62 */
63 np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
64 if (!np_cdm) {
65 dev_err(&of->dev, "can't get clock node!\n");
66 return 0;
67 }
68 cdm = of_iomap(np_cdm, 0);
69 of_node_put(np_cdm);
70
71 if (in_8(&cdm->ipb_clk_sel) & 0x1)
72 freq *= 2;
Wolfram Sang0285e7c2009-11-16 12:57:45 +000073 val = in_be32(&cdm->rstcfg);
74
75 freq *= (val & (1 << 5)) ? 8 : 4;
76 freq /= (val & (1 << 6)) ? 12 : 16;
Wolfram Sangafa17a52009-11-13 06:14:52 +000077
78 iounmap(cdm);
79
80 return freq;
81}
82
83/*
84 * Get frequency of the MSCAN clock source
85 *
86 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
87 * can be selected. According to the MPC5200 user's manual, the oscillator
88 * clock is the better choice as it has less jitter but due to a hardware
89 * bug, it can not be selected for the old MPC5200 Rev. A chips.
90 */
91
92static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of,
93 int clock_src)
94{
95 unsigned int pvr;
96
97 pvr = mfspr(SPRN_PVR);
98
99 if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
100 return mpc5xxx_get_bus_frequency(of->node);
101
102 return mpc52xx_can_xtal_freq(of);
103}
104
105static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
106 const struct of_device_id *id)
107{
108 struct device_node *np = ofdev->node;
109 struct net_device *dev;
110 struct mscan_priv *priv;
111 void __iomem *base;
112 const char *clk_src;
113 int err, irq, clock_src;
114
115 base = of_iomap(ofdev->node, 0);
116 if (!base) {
117 dev_err(&ofdev->dev, "couldn't ioremap\n");
118 err = -ENOMEM;
119 goto exit_release_mem;
120 }
121
122 irq = irq_of_parse_and_map(np, 0);
123 if (!irq) {
124 dev_err(&ofdev->dev, "no irq found\n");
125 err = -ENODEV;
126 goto exit_unmap_mem;
127 }
128
129 dev = alloc_mscandev();
130 if (!dev) {
131 err = -ENOMEM;
132 goto exit_dispose_irq;
133 }
134
135 priv = netdev_priv(dev);
136 priv->reg_base = base;
137 dev->irq = irq;
138
139 /*
140 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
141 * (IP_CLK) can be selected as MSCAN clock source. According to
142 * the MPC5200 user's manual, the oscillator clock is the better
143 * choice as it has less jitter. For this reason, it is selected
144 * by default.
145 */
146 clk_src = of_get_property(np, "fsl,mscan-clk-src", NULL);
147 if (clk_src && strcmp(clk_src, "ip") == 0)
148 clock_src = MSCAN_CLKSRC_BUS;
149 else
150 clock_src = MSCAN_CLKSRC_XTAL;
151 priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
152 if (!priv->can.clock.freq) {
153 dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
154 err = -ENODEV;
155 goto exit_free_mscan;
156 }
157
158 SET_NETDEV_DEV(dev, &ofdev->dev);
159
160 err = register_mscandev(dev, clock_src);
161 if (err) {
162 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
163 DRV_NAME, err);
164 goto exit_free_mscan;
165 }
166
167 dev_set_drvdata(&ofdev->dev, dev);
168
169 dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
170 priv->reg_base, dev->irq, priv->can.clock.freq);
171
172 return 0;
173
174exit_free_mscan:
175 free_candev(dev);
176exit_dispose_irq:
177 irq_dispose_mapping(irq);
178exit_unmap_mem:
179 iounmap(base);
180exit_release_mem:
181 return err;
182}
183
184static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
185{
186 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
187 struct mscan_priv *priv = netdev_priv(dev);
188
189 dev_set_drvdata(&ofdev->dev, NULL);
190
191 unregister_mscandev(dev);
192 iounmap(priv->reg_base);
193 irq_dispose_mapping(dev->irq);
194 free_candev(dev);
195
196 return 0;
197}
198
199#ifdef CONFIG_PM
200static struct mscan_regs saved_regs;
201static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
202{
203 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
204 struct mscan_priv *priv = netdev_priv(dev);
205 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
206
207 _memcpy_fromio(&saved_regs, regs, sizeof(*regs));
208
209 return 0;
210}
211
212static int mpc5xxx_can_resume(struct of_device *ofdev)
213{
214 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
215 struct mscan_priv *priv = netdev_priv(dev);
216 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
217
218 regs->canctl0 |= MSCAN_INITRQ;
Wolfram Sang0285e7c2009-11-16 12:57:45 +0000219 while (!(regs->canctl1 & MSCAN_INITAK))
Wolfram Sangafa17a52009-11-13 06:14:52 +0000220 udelay(10);
221
222 regs->canctl1 = saved_regs.canctl1;
223 regs->canbtr0 = saved_regs.canbtr0;
224 regs->canbtr1 = saved_regs.canbtr1;
225 regs->canidac = saved_regs.canidac;
226
227 /* restore masks, buffers etc. */
228 _memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
229 sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
230
231 regs->canctl0 &= ~MSCAN_INITRQ;
232 regs->cantbsel = saved_regs.cantbsel;
233 regs->canrier = saved_regs.canrier;
234 regs->cantier = saved_regs.cantier;
235 regs->canctl0 = saved_regs.canctl0;
236
237 return 0;
238}
239#endif
240
241static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
242 {.compatible = "fsl,mpc5200-mscan"},
243 {.compatible = "fsl,mpc5200b-mscan"},
244 {},
245};
246
247static struct of_platform_driver mpc5xxx_can_driver = {
248 .owner = THIS_MODULE,
249 .name = "mpc5xxx_can",
250 .probe = mpc5xxx_can_probe,
251 .remove = __devexit_p(mpc5xxx_can_remove),
252#ifdef CONFIG_PM
253 .suspend = mpc5xxx_can_suspend,
254 .resume = mpc5xxx_can_resume,
255#endif
256 .match_table = mpc5xxx_can_table,
257};
258
259static int __init mpc5xxx_can_init(void)
260{
261 return of_register_platform_driver(&mpc5xxx_can_driver);
262}
263module_init(mpc5xxx_can_init);
264
265static void __exit mpc5xxx_can_exit(void)
266{
267 return of_unregister_platform_driver(&mpc5xxx_can_driver);
268};
269module_exit(mpc5xxx_can_exit);
270
271MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
272MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
273MODULE_LICENSE("GPL v2");