drivers/net/can/mscan/mpc5xxx_can.c

   1 /*
   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/dev.h>
  29 #include <linux/of_platform.h>
  30 #include <sysdev/fsl_soc.h>
  31 #include <linux/clk.h>
  32 #include <linux/io.h>
  33 #include <asm/mpc52xx.h>
  34
  35 #include "mscan.h"
  36
  37 #define DRV_NAME "mpc5xxx_can"
  38
  39 struct mpc5xxx_can_data {
  40         unsigned int type;
  41         u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name,
  42                          int *mscan_clksrc);
  43 };
  44
  45 #ifdef CONFIG_PPC_MPC52xx
  46 static struct of_device_id __devinitdata mpc52xx_cdm_ids[] = {
  47         { .compatible = "fsl,mpc5200-cdm", },
  48         {}
  49 };
  50
  51 static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
  52                                            const char *clock_name,
  53                                            int *mscan_clksrc)
  54 {
  55         unsigned int pvr;
  56         struct mpc52xx_cdm  __iomem *cdm;
  57         struct device_node *np_cdm;
  58         unsigned int freq;
  59         u32 val;
  60
  61         pvr = mfspr(SPRN_PVR);
  62
  63         /*
  64          * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
  65          * (IP_CLK) can be selected as MSCAN clock source. According to
  66          * the MPC5200 user's manual, the oscillator clock is the better
  67          * choice as it has less jitter. For this reason, it is selected
  68          * by default. Unfortunately, it can not be selected for the old
  69          * MPC5200 Rev. A chips due to a hardware bug (check errata).
  70          */
  71         if (clock_name && strcmp(clock_name, "ip") == 0)
  72                 *mscan_clksrc = MSCAN_CLKSRC_BUS;
  73         else
  74                 *mscan_clksrc = MSCAN_CLKSRC_XTAL;
  75
  76         freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
  77         if (!freq)
  78                 return 0;
  79
  80         if (*mscan_clksrc == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
  81                 return freq;
  82
  83         /* Determine SYS_XTAL_IN frequency from the clock domain settings */
  84         np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
  85         if (!np_cdm) {
  86                 dev_err(&ofdev->dev, "can't get clock node!\n");
  87                 return 0;
  88         }
  89         cdm = of_iomap(np_cdm, 0);
  90
  91         if (in_8(&cdm->ipb_clk_sel) & 0x1)
  92                 freq *= 2;
  93         val = in_be32(&cdm->rstcfg);
  94
  95         freq *= (val & (1 << 5)) ? 8 : 4;
  96         freq /= (val & (1 << 6)) ? 12 : 16;
  97
  98         of_node_put(np_cdm);
  99         iounmap(cdm);
 100
 101         return freq;
 102 }
 103 #else /* !CONFIG_PPC_MPC52xx */
 104 static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
 105                                            const char *clock_name,
 106                                            int *mscan_clksrc)
 107 {
 108         return 0;
 109 }
 110 #endif /* CONFIG_PPC_MPC52xx */
 111
 112 #ifdef CONFIG_PPC_MPC512x
 113 struct mpc512x_clockctl {
 114         u32 spmr;               /* System PLL Mode Reg */
 115         u32 sccr[2];            /* System Clk Ctrl Reg 1 & 2 */
 116         u32 scfr1;              /* System Clk Freq Reg 1 */
 117         u32 scfr2;              /* System Clk Freq Reg 2 */
 118         u32 reserved;
 119         u32 bcr;                /* Bread Crumb Reg */
 120         u32 pccr[12];           /* PSC Clk Ctrl Reg 0-11 */
 121         u32 spccr;              /* SPDIF Clk Ctrl Reg */
 122         u32 cccr;               /* CFM Clk Ctrl Reg */
 123         u32 dccr;               /* DIU Clk Cnfg Reg */
 124         u32 mccr[4];            /* MSCAN Clk Ctrl Reg 1-3 */
 125 };
 126
 127 static struct of_device_id __devinitdata mpc512x_clock_ids[] = {
 128         { .compatible = "fsl,mpc5121-clock", },
 129         {}
 130 };
 131
 132 static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 133                                            const char *clock_name,
 134                                            int *mscan_clksrc)
 135 {
 136         struct mpc512x_clockctl __iomem *clockctl;
 137         struct device_node *np_clock;
 138         struct clk *sys_clk, *ref_clk;
 139         int plen, clockidx, clocksrc = -1;
 140         u32 sys_freq, val, clockdiv = 1, freq = 0;
 141         const u32 *pval;
 142
 143         np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
 144         if (!np_clock) {
 145                 dev_err(&ofdev->dev, "couldn't find clock node\n");
 146                 return 0;
 147         }
 148         clockctl = of_iomap(np_clock, 0);
 149         if (!clockctl) {
 150                 dev_err(&ofdev->dev, "couldn't map clock registers\n");
 151                 goto exit_put;
 152         }
 153
 154         /* Determine the MSCAN device index from the physical address */
 155         pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
 156         BUG_ON(!pval || plen < sizeof(*pval));
 157         clockidx = (*pval & 0x80) ? 1 : 0;
 158         if (*pval & 0x2000)
 159                 clockidx += 2;
 160
 161         /*
 162          * Clock source and divider selection: 3 different clock sources
 163          * can be selected: "ip", "ref" or "sys". For the latter two, a
 164          * clock divider can be defined as well. If the clock source is
 165          * not specified by the device tree, we first try to find an
 166          * optimal CAN source clock based on the system clock. If that
 167          * is not posslible, the reference clock will be used.
 168          */
 169         if (clock_name && !strcmp(clock_name, "ip")) {
 170                 *mscan_clksrc = MSCAN_CLKSRC_IPS;
 171                 freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
 172         } else {
 173                 *mscan_clksrc = MSCAN_CLKSRC_BUS;
 174
 175                 pval = of_get_property(ofdev->dev.of_node,
 176                                        "fsl,mscan-clock-divider", &plen);
 177                 if (pval && plen == sizeof(*pval))
 178                         clockdiv = *pval;
 179                 if (!clockdiv)
 180                         clockdiv = 1;
 181
 182                 if (!clock_name || !strcmp(clock_name, "sys")) {
 183                         sys_clk = clk_get(&ofdev->dev, "sys_clk");
 184                         if (!sys_clk) {
 185                                 dev_err(&ofdev->dev, "couldn't get sys_clk\n");
 186                                 goto exit_unmap;
 187                         }
 188                         /* Get and round up/down sys clock rate */
 189                         sys_freq = 1000000 *
 190                                 ((clk_get_rate(sys_clk) + 499999) / 1000000);
 191
 192                         if (!clock_name) {
 193                                 /* A multiple of 16 MHz would be optimal */
 194                                 if ((sys_freq % 16000000) == 0) {
 195                                         clocksrc = 0;
 196                                         clockdiv = sys_freq / 16000000;
 197                                         freq = sys_freq / clockdiv;
 198                                 }
 199                         } else {
 200                                 clocksrc = 0;
 201                                 freq = sys_freq / clockdiv;
 202                         }
 203                 }
 204
 205                 if (clocksrc < 0) {
 206                         ref_clk = clk_get(&ofdev->dev, "ref_clk");
 207                         if (!ref_clk) {
 208                                 dev_err(&ofdev->dev, "couldn't get ref_clk\n");
 209                                 goto exit_unmap;
 210                         }
 211                         clocksrc = 1;
 212                         freq = clk_get_rate(ref_clk) / clockdiv;
 213                 }
 214         }
 215
 216         /* Disable clock */
 217         out_be32(&clockctl->mccr[clockidx], 0x0);
 218         if (clocksrc >= 0) {
 219                 /* Set source and divider */
 220                 val = (clocksrc << 14) | ((clockdiv - 1) << 17);
 221                 out_be32(&clockctl->mccr[clockidx], val);
 222                 /* Enable clock */
 223                 out_be32(&clockctl->mccr[clockidx], val | 0x10000);
 224         }
 225
 226         /* Enable MSCAN clock domain */
 227         val = in_be32(&clockctl->sccr[1]);
 228         if (!(val & (1 << 25)))
 229                 out_be32(&clockctl->sccr[1], val | (1 << 25));
 230
 231         dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
 232                 *mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
 233                 clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);
 234
 235 exit_unmap:
 236         iounmap(clockctl);
 237 exit_put:
 238         of_node_put(np_clock);
 239         return freq;
 240 }
 241 #else /* !CONFIG_PPC_MPC512x */
 242 static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 243                                            const char *clock_name,
 244                                            int *mscan_clksrc)
 245 {
 246         return 0;
 247 }
 248 #endif /* CONFIG_PPC_MPC512x */
 249
 250 static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 251 {
 252         struct mpc5xxx_can_data *data;
 253         struct device_node *np = ofdev->dev.of_node;
 254         struct net_device *dev;
 255         struct mscan_priv *priv;
 256         void __iomem *base;
 257         const char *clock_name = NULL;
 258         int irq, mscan_clksrc = 0;
 259         int err = -ENOMEM;
 260
 261         if (!ofdev->dev.of_match)
 262                 return -EINVAL;
 263         data = (struct mpc5xxx_can_data *)of_dev->dev.of_match->data;
 264
 265         base = of_iomap(np, 0);
 266         if (!base) {
 267                 dev_err(&ofdev->dev, "couldn't ioremap\n");
 268                 return err;
 269         }
 270
 271         irq = irq_of_parse_and_map(np, 0);
 272         if (!irq) {
 273                 dev_err(&ofdev->dev, "no irq found\n");
 274                 err = -ENODEV;
 275                 goto exit_unmap_mem;
 276         }
 277
 278         dev = alloc_mscandev();
 279         if (!dev)
 280                 goto exit_dispose_irq;
 281
 282         priv = netdev_priv(dev);
 283         priv->reg_base = base;
 284         dev->irq = irq;
 285
 286         clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL);
 287
 288         BUG_ON(!data);
 289         priv->type = data->type;
 290         priv->can.clock.freq = data->get_clock(ofdev, clock_name,
 291                                                &mscan_clksrc);
 292         if (!priv->can.clock.freq) {
 293                 dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n");
 294                 goto exit_free_mscan;
 295         }
 296
 297         SET_NETDEV_DEV(dev, &ofdev->dev);
 298
 299         err = register_mscandev(dev, mscan_clksrc);
 300         if (err) {
 301                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
 302                         DRV_NAME, err);
 303                 goto exit_free_mscan;
 304         }
 305
 306         dev_set_drvdata(&ofdev->dev, dev);
 307
 308         dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
 309                  priv->reg_base, dev->irq, priv->can.clock.freq);
 310
 311         return 0;
 312
 313 exit_free_mscan:
 314         free_candev(dev);
 315 exit_dispose_irq:
 316         irq_dispose_mapping(irq);
 317 exit_unmap_mem:
 318         iounmap(base);
 319
 320         return err;
 321 }
 322
 323 static int __devexit mpc5xxx_can_remove(struct platform_device *ofdev)
 324 {
 325         struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 326         struct mscan_priv *priv = netdev_priv(dev);
 327
 328         dev_set_drvdata(&ofdev->dev, NULL);
 329
 330         unregister_mscandev(dev);
 331         iounmap(priv->reg_base);
 332         irq_dispose_mapping(dev->irq);
 333         free_candev(dev);
 334
 335         return 0;
 336 }
 337
 338 #ifdef CONFIG_PM
 339 static struct mscan_regs saved_regs;
 340 static int mpc5xxx_can_suspend(struct platform_device *ofdev, pm_message_t state)
 341 {
 342         struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 343         struct mscan_priv *priv = netdev_priv(dev);
 344         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 345
 346         _memcpy_fromio(&saved_regs, regs, sizeof(*regs));
 347
 348         return 0;
 349 }
 350
 351 static int mpc5xxx_can_resume(struct platform_device *ofdev)
 352 {
 353         struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 354         struct mscan_priv *priv = netdev_priv(dev);
 355         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 356
 357         regs->canctl0 |= MSCAN_INITRQ;
 358         while (!(regs->canctl1 & MSCAN_INITAK))
 359                 udelay(10);
 360
 361         regs->canctl1 = saved_regs.canctl1;
 362         regs->canbtr0 = saved_regs.canbtr0;
 363         regs->canbtr1 = saved_regs.canbtr1;
 364         regs->canidac = saved_regs.canidac;
 365
 366         /* restore masks, buffers etc. */
 367         _memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
 368                      sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
 369
 370         regs->canctl0 &= ~MSCAN_INITRQ;
 371         regs->cantbsel = saved_regs.cantbsel;
 372         regs->canrier = saved_regs.canrier;
 373         regs->cantier = saved_regs.cantier;
 374         regs->canctl0 = saved_regs.canctl0;
 375
 376         return 0;
 377 }
 378 #endif
 379
 380 static struct mpc5xxx_can_data __devinitdata mpc5200_can_data = {
 381         .type = MSCAN_TYPE_MPC5200,
 382         .get_clock = mpc52xx_can_get_clock,
 383 };
 384
 385 static struct mpc5xxx_can_data __devinitdata mpc5121_can_data = {
 386         .type = MSCAN_TYPE_MPC5121,
 387         .get_clock = mpc512x_can_get_clock,
 388 };
 389
 390 static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
 391         { .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, },
 392         /* Note that only MPC5121 Rev. 2 (and later) is supported */
 393         { .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, },
 394         {},
 395 };
 396
 397 static struct platform_driver mpc5xxx_can_driver = {
 398         .driver = {
 399                 .name = "mpc5xxx_can",
 400                 .owner = THIS_MODULE,
 401                 .of_match_table = mpc5xxx_can_table,
 402         },
 403         .probe = mpc5xxx_can_probe,
 404         .remove = __devexit_p(mpc5xxx_can_remove),
 405 #ifdef CONFIG_PM
 406         .suspend = mpc5xxx_can_suspend,
 407         .resume = mpc5xxx_can_resume,
 408 #endif
 409 };
 410
 411 static int __init mpc5xxx_can_init(void)
 412 {
 413         return platform_driver_register(&mpc5xxx_can_driver);
 414 }
 415 module_init(mpc5xxx_can_init);
 416
 417 static void __exit mpc5xxx_can_exit(void)
 418 {
 419         platform_driver_unregister(&mpc5xxx_can_driver);
 420 };
 421 module_exit(mpc5xxx_can_exit);
 422
 423 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 424 MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver");
 425 MODULE_LICENSE("GPL v2");