2 * CAN bus driver for the Freescale MPC5xxx embedded CPU.
4 * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
6 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
7 * Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
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
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.
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
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>
33 #include <asm/mpc52xx.h>
37 #define DRV_NAME "mpc5xxx_can"
39 static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
40 { .compatible = "fsl,mpc5200-cdm", },
45 * Get frequency of the MSCAN clock source
47 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
48 * can be selected. According to the MPC5200 user's manual, the oscillator
49 * clock is the better choice as it has less jitter but due to a hardware
50 * bug, it can not be selected for the old MPC5200 Rev. A chips.
53 static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of,
57 struct mpc52xx_cdm __iomem *cdm;
58 struct device_node *np_cdm;
62 pvr = mfspr(SPRN_PVR);
64 freq = mpc5xxx_get_bus_frequency(of->node);
68 if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
71 /* Determine SYS_XTAL_IN frequency from the clock domain settings */
72 np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
74 dev_err(&of->dev, "can't get clock node!\n");
77 cdm = of_iomap(np_cdm, 0);
80 if (in_8(&cdm->ipb_clk_sel) & 0x1)
82 val = in_be32(&cdm->rstcfg);
84 freq *= (val & (1 << 5)) ? 8 : 4;
85 freq /= (val & (1 << 6)) ? 12 : 16;
92 static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
93 const struct of_device_id *id)
95 struct device_node *np = ofdev->node;
96 struct net_device *dev;
97 struct mscan_priv *priv;
100 int err, irq, clock_src;
102 base = of_iomap(ofdev->node, 0);
104 dev_err(&ofdev->dev, "couldn't ioremap\n");
106 goto exit_release_mem;
109 irq = irq_of_parse_and_map(np, 0);
111 dev_err(&ofdev->dev, "no irq found\n");
116 dev = alloc_mscandev();
119 goto exit_dispose_irq;
122 priv = netdev_priv(dev);
123 priv->reg_base = base;
127 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
128 * (IP_CLK) can be selected as MSCAN clock source. According to
129 * the MPC5200 user's manual, the oscillator clock is the better
130 * choice as it has less jitter. For this reason, it is selected
133 clk_src = of_get_property(np, "fsl,mscan-clk-src", NULL);
134 if (clk_src && strcmp(clk_src, "ip") == 0)
135 clock_src = MSCAN_CLKSRC_BUS;
137 clock_src = MSCAN_CLKSRC_XTAL;
138 priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
139 if (!priv->can.clock.freq) {
140 dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
142 goto exit_free_mscan;
145 SET_NETDEV_DEV(dev, &ofdev->dev);
147 err = register_mscandev(dev, clock_src);
149 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
151 goto exit_free_mscan;
154 dev_set_drvdata(&ofdev->dev, dev);
156 dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
157 priv->reg_base, dev->irq, priv->can.clock.freq);
164 irq_dispose_mapping(irq);
171 static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
173 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
174 struct mscan_priv *priv = netdev_priv(dev);
176 dev_set_drvdata(&ofdev->dev, NULL);
178 unregister_mscandev(dev);
179 iounmap(priv->reg_base);
180 irq_dispose_mapping(dev->irq);
187 static struct mscan_regs saved_regs;
188 static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
190 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
191 struct mscan_priv *priv = netdev_priv(dev);
192 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
194 _memcpy_fromio(&saved_regs, regs, sizeof(*regs));
199 static int mpc5xxx_can_resume(struct of_device *ofdev)
201 struct net_device *dev = dev_get_drvdata(&ofdev->dev);
202 struct mscan_priv *priv = netdev_priv(dev);
203 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
205 regs->canctl0 |= MSCAN_INITRQ;
206 while (!(regs->canctl1 & MSCAN_INITAK))
209 regs->canctl1 = saved_regs.canctl1;
210 regs->canbtr0 = saved_regs.canbtr0;
211 regs->canbtr1 = saved_regs.canbtr1;
212 regs->canidac = saved_regs.canidac;
214 /* restore masks, buffers etc. */
215 _memcpy_toio(®s->canidar1_0, (void *)&saved_regs.canidar1_0,
216 sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
218 regs->canctl0 &= ~MSCAN_INITRQ;
219 regs->cantbsel = saved_regs.cantbsel;
220 regs->canrier = saved_regs.canrier;
221 regs->cantier = saved_regs.cantier;
222 regs->canctl0 = saved_regs.canctl0;
228 static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
229 {.compatible = "fsl,mpc5200-mscan"},
230 {.compatible = "fsl,mpc5200b-mscan"},
234 static struct of_platform_driver mpc5xxx_can_driver = {
235 .owner = THIS_MODULE,
236 .name = "mpc5xxx_can",
237 .probe = mpc5xxx_can_probe,
238 .remove = __devexit_p(mpc5xxx_can_remove),
240 .suspend = mpc5xxx_can_suspend,
241 .resume = mpc5xxx_can_resume,
243 .match_table = mpc5xxx_can_table,
246 static int __init mpc5xxx_can_init(void)
248 return of_register_platform_driver(&mpc5xxx_can_driver);
250 module_init(mpc5xxx_can_init);
252 static void __exit mpc5xxx_can_exit(void)
254 return of_unregister_platform_driver(&mpc5xxx_can_driver);
256 module_exit(mpc5xxx_can_exit);
258 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
259 MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
260 MODULE_LICENSE("GPL v2");