summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/mscan/mpc5xxx_can.c
blob: 1de6f6349b16c914c9ad01dcbe05fa99f5562872 (plain)
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
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * CAN bus driver for the Freescale MPC5xxx embedded CPU.
 *
 * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
 *                         Varma Electronics Oy
 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
 * Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
 *
 * 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
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/of_platform.h>
#include <sysdev/fsl_soc.h>
#include <linux/io.h>
#include <asm/mpc52xx.h>

#include "mscan.h"

#define DRV_NAME "mpc5xxx_can"

static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
	{ .compatible = "fsl,mpc5200-cdm", },
	{}
};

/*
 * Get frequency of the MSCAN clock source
 *
 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
 * can be selected. According to the MPC5200 user's manual, the oscillator
 * clock is the better choice as it has less jitter but due to a hardware
 * bug, it can not be selected for the old MPC5200 Rev. A chips.
 */

static unsigned int  __devinit mpc52xx_can_clock_freq(struct of_device *of,
						      int clock_src)
{
	unsigned int pvr;
	struct mpc52xx_cdm  __iomem *cdm;
	struct device_node *np_cdm;
	unsigned int freq;
	u32 val;

	pvr = mfspr(SPRN_PVR);

	freq = mpc5xxx_get_bus_frequency(of->node);
	if (!freq)
		return 0;

	if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
		return freq;

	/* Determine SYS_XTAL_IN frequency from the clock domain settings */
	np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
	if (!np_cdm) {
		dev_err(&of->dev, "can't get clock node!\n");
		return 0;
	}
	cdm = of_iomap(np_cdm, 0);
	of_node_put(np_cdm);

	if (in_8(&cdm->ipb_clk_sel) & 0x1)
		freq *= 2;
	val = in_be32(&cdm->rstcfg);

	freq *= (val & (1 << 5)) ? 8 : 4;
	freq /= (val & (1 << 6)) ? 12 : 16;

	iounmap(cdm);

	return freq;
}

static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
				       const struct of_device_id *id)
{
	struct device_node *np = ofdev->node;
	struct net_device *dev;
	struct mscan_priv *priv;
	void __iomem *base;
	const char *clk_src;
	int err, irq, clock_src;

	base = of_iomap(ofdev->node, 0);
	if (!base) {
		dev_err(&ofdev->dev, "couldn't ioremap\n");
		err = -ENOMEM;
		goto exit_release_mem;
	}

	irq = irq_of_parse_and_map(np, 0);
	if (!irq) {
		dev_err(&ofdev->dev, "no irq found\n");
		err = -ENODEV;
		goto exit_unmap_mem;
	}

	dev = alloc_mscandev();
	if (!dev) {
		err = -ENOMEM;
		goto exit_dispose_irq;
	}

	priv = netdev_priv(dev);
	priv->reg_base = base;
	dev->irq = irq;

	/*
	 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
	 * (IP_CLK) can be selected as MSCAN clock source. According to
	 * the MPC5200 user's manual, the oscillator clock is the better
	 * choice as it has less jitter. For this reason, it is selected
	 * by default.
	 */
	clk_src = of_get_property(np, "fsl,mscan-clock-source", NULL);
	if (clk_src && strcmp(clk_src, "ip") == 0)
		clock_src = MSCAN_CLKSRC_BUS;
	else
		clock_src = MSCAN_CLKSRC_XTAL;
	priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
	if (!priv->can.clock.freq) {
		dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
		err = -ENODEV;
		goto exit_free_mscan;
	}

	SET_NETDEV_DEV(dev, &ofdev->dev);

	err = register_mscandev(dev, clock_src);
	if (err) {
		dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
			DRV_NAME, err);
		goto exit_free_mscan;
	}

	dev_set_drvdata(&ofdev->dev, dev);

	dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
		 priv->reg_base, dev->irq, priv->can.clock.freq);

	return 0;

exit_free_mscan:
	free_candev(dev);
exit_dispose_irq:
	irq_dispose_mapping(irq);
exit_unmap_mem:
	iounmap(base);
exit_release_mem:
	return err;
}

static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);

	dev_set_drvdata(&ofdev->dev, NULL);

	unregister_mscandev(dev);
	iounmap(priv->reg_base);
	irq_dispose_mapping(dev->irq);
	free_candev(dev);

	return 0;
}

#ifdef CONFIG_PM
static struct mscan_regs saved_regs;
static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);
	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;

	_memcpy_fromio(&saved_regs, regs, sizeof(*regs));

	return 0;
}

static int mpc5xxx_can_resume(struct of_device *ofdev)
{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);
	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;

	regs->canctl0 |= MSCAN_INITRQ;
	while (!(regs->canctl1 & MSCAN_INITAK))
		udelay(10);

	regs->canctl1 = saved_regs.canctl1;
	regs->canbtr0 = saved_regs.canbtr0;
	regs->canbtr1 = saved_regs.canbtr1;
	regs->canidac = saved_regs.canidac;

	/* restore masks, buffers etc. */
	_memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
		     sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));

	regs->canctl0 &= ~MSCAN_INITRQ;
	regs->cantbsel = saved_regs.cantbsel;
	regs->canrier = saved_regs.canrier;
	regs->cantier = saved_regs.cantier;
	regs->canctl0 = saved_regs.canctl0;

	return 0;
}
#endif

static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
	{.compatible = "fsl,mpc5200-mscan"},
	{},
};

static struct of_platform_driver mpc5xxx_can_driver = {
	.owner = THIS_MODULE,
	.name = "mpc5xxx_can",
	.probe = mpc5xxx_can_probe,
	.remove = __devexit_p(mpc5xxx_can_remove),
#ifdef CONFIG_PM
	.suspend = mpc5xxx_can_suspend,
	.resume = mpc5xxx_can_resume,
#endif
	.match_table = mpc5xxx_can_table,
};

static int __init mpc5xxx_can_init(void)
{
	return of_register_platform_driver(&mpc5xxx_can_driver);
}
module_init(mpc5xxx_can_init);

static void __exit mpc5xxx_can_exit(void)
{
	return of_unregister_platform_driver(&mpc5xxx_can_driver);
};
module_exit(mpc5xxx_can_exit);

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud