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/can.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 of_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 of_device *ofdev,
  92                                        const struct of_device_id *id)
  93 {
  94         struct device_node *np = ofdev->dev.of_node;
  95         struct net_device *dev;
  96         struct sja1000_priv *priv;
  97         struct resource res;
  98         const u32 *prop;
  99         int err, irq, res_size, prop_size;
 100         void __iomem *base;
 101
 102         err = of_address_to_resource(np, 0, &res);
 103         if (err) {
 104                 dev_err(&ofdev->dev, "invalid address\n");
 105                 return err;
 106         }
 107
 108         res_size = resource_size(&res);
 109
 110         if (!request_mem_region(res.start, res_size, DRV_NAME)) {
 111                 dev_err(&ofdev->dev, "couldn't request %#llx..%#llx\n",
 112                         (unsigned long long)res.start,
 113                         (unsigned long long)res.end);
 114                 return -EBUSY;
 115         }
 116
 117         base = ioremap_nocache(res.start, res_size);
 118         if (!base) {
 119                 dev_err(&ofdev->dev, "couldn't ioremap %#llx..%#llx\n",
 120                         (unsigned long long)res.start,
 121                         (unsigned long long)res.end);
 122                 err = -ENOMEM;
 123                 goto exit_release_mem;
 124         }
 125
 126         irq = irq_of_parse_and_map(np, 0);
 127         if (irq == NO_IRQ) {
 128                 dev_err(&ofdev->dev, "no irq found\n");
 129                 err = -ENODEV;
 130                 goto exit_unmap_mem;
 131         }
 132
 133         dev = alloc_sja1000dev(0);
 134         if (!dev) {
 135                 err = -ENOMEM;
 136                 goto exit_dispose_irq;
 137         }
 138
 139         priv = netdev_priv(dev);
 140
 141         priv->read_reg = sja1000_ofp_read_reg;
 142         priv->write_reg = sja1000_ofp_write_reg;
 143
 144         prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
 145         if (prop && (prop_size ==  sizeof(u32)))
 146                 priv->can.clock.freq = *prop / 2;
 147         else
 148                 priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
 149
 150         prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
 151         if (prop && (prop_size == sizeof(u32)))
 152                 priv->ocr |= *prop & OCR_MODE_MASK;
 153         else
 154                 priv->ocr |= OCR_MODE_NORMAL; /* default */
 155
 156         prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
 157         if (prop && (prop_size == sizeof(u32)))
 158                 priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 159         else
 160                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 161
 162         prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
 163         if (prop && (prop_size == sizeof(u32)) && *prop) {
 164                 u32 divider = priv->can.clock.freq * 2 / *prop;
 165
 166                 if (divider > 1)
 167                         priv->cdr |= divider / 2 - 1;
 168                 else
 169                         priv->cdr |= CDR_CLKOUT_MASK;
 170         } else {
 171                 priv->cdr |= CDR_CLK_OFF; /* default */
 172         }
 173
 174         prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
 175         if (!prop)
 176                 priv->cdr |= CDR_CBP; /* default */
 177
 178         priv->irq_flags = IRQF_SHARED;
 179         priv->reg_base = base;
 180
 181         dev->irq = irq;
 182
 183         dev_info(&ofdev->dev,
 184                  "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
 185                  priv->reg_base, dev->irq, priv->can.clock.freq,
 186                  priv->ocr, priv->cdr);
 187
 188         dev_set_drvdata(&ofdev->dev, dev);
 189         SET_NETDEV_DEV(dev, &ofdev->dev);
 190
 191         err = register_sja1000dev(dev);
 192         if (err) {
 193                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
 194                         DRV_NAME, err);
 195                 goto exit_free_sja1000;
 196         }
 197
 198         return 0;
 199
 200 exit_free_sja1000:
 201         free_sja1000dev(dev);
 202 exit_dispose_irq:
 203         irq_dispose_mapping(irq);
 204 exit_unmap_mem:
 205         iounmap(base);
 206 exit_release_mem:
 207         release_mem_region(res.start, res_size);
 208
 209         return err;
 210 }
 211
 212 static struct of_device_id __devinitdata sja1000_ofp_table[] = {
 213         {.compatible = "nxp,sja1000"},
 214         {},
 215 };
 216 MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
 217
 218 static struct of_platform_driver sja1000_ofp_driver = {
 219         .driver = {
 220                 .owner = THIS_MODULE,
 221                 .name = DRV_NAME,
 222                 .of_match_table = sja1000_ofp_table,
 223         },
 224         .probe = sja1000_ofp_probe,
 225         .remove = __devexit_p(sja1000_ofp_remove),
 226 };
 227
 228 static int __init sja1000_ofp_init(void)
 229 {
 230         return of_register_platform_driver(&sja1000_ofp_driver);
 231 }
 232 module_init(sja1000_ofp_init);
 233
 234 static void __exit sja1000_ofp_exit(void)
 235 {
 236         return of_unregister_platform_driver(&sja1000_ofp_driver);
 237 };
 238 module_exit(sja1000_ofp_exit);