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/dev.h>
  42
  43 #include <linux/of_platform.h>
  44 #include <asm/prom.h>
  45
  46 #include "sja1000.h"
  47
  48 #define DRV_NAME "sja1000_of_platform"
  49
  50 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  51 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");
  52 MODULE_LICENSE("GPL v2");
  53
  54 #define SJA1000_OFP_CAN_CLOCK  (16000000 / 2)
  55
  56 #define SJA1000_OFP_OCR        OCR_TX0_PULLDOWN
  57 #define SJA1000_OFP_CDR        (CDR_CBP | CDR_CLK_OFF)
  58
  59 static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)
  60 {
  61         return in_8(priv->reg_base + reg);
  62 }
  63
  64 static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,
  65                                   int reg, u8 val)
  66 {
  67         out_8(priv->reg_base + reg, val);
  68 }
  69
  70 static int __devexit sja1000_ofp_remove(struct of_device *ofdev)
  71 {
  72         struct net_device *dev = dev_get_drvdata(&ofdev->dev);
  73         struct sja1000_priv *priv = netdev_priv(dev);
  74         struct device_node *np = ofdev->dev.of_node;
  75         struct resource res;
  76
  77         dev_set_drvdata(&ofdev->dev, NULL);
  78
  79         unregister_sja1000dev(dev);
  80         free_sja1000dev(dev);
  81         iounmap(priv->reg_base);
  82         irq_dispose_mapping(dev->irq);
  83
  84         of_address_to_resource(np, 0, &res);
  85         release_mem_region(res.start, resource_size(&res));
  86
  87         return 0;
  88 }
  89
  90 static int __devinit sja1000_ofp_probe(struct of_device *ofdev,
  91                                        const struct of_device_id *id)
  92 {
  93         struct device_node *np = ofdev->dev.of_node;
  94         struct net_device *dev;
  95         struct sja1000_priv *priv;
  96         struct resource res;
  97         const u32 *prop;
  98         int err, irq, res_size, prop_size;
  99         void __iomem *base;
 100
 101         err = of_address_to_resource(np, 0, &res);
 102         if (err) {
 103                 dev_err(&ofdev->dev, "invalid address\n");
 104                 return err;
 105         }
 106
 107         res_size = resource_size(&res);
 108
 109         if (!request_mem_region(res.start, res_size, DRV_NAME)) {
 110                 dev_err(&ofdev->dev, "couldn't request %#llx..%#llx\n",
 111                         (unsigned long long)res.start,
 112                         (unsigned long long)res.end);
 113                 return -EBUSY;
 114         }
 115
 116         base = ioremap_nocache(res.start, res_size);
 117         if (!base) {
 118                 dev_err(&ofdev->dev, "couldn't ioremap %#llx..%#llx\n",
 119                         (unsigned long long)res.start,
 120                         (unsigned long long)res.end);
 121                 err = -ENOMEM;
 122                 goto exit_release_mem;
 123         }
 124
 125         irq = irq_of_parse_and_map(np, 0);
 126         if (irq == NO_IRQ) {
 127                 dev_err(&ofdev->dev, "no irq found\n");
 128                 err = -ENODEV;
 129                 goto exit_unmap_mem;
 130         }
 131
 132         dev = alloc_sja1000dev(0);
 133         if (!dev) {
 134                 err = -ENOMEM;
 135                 goto exit_dispose_irq;
 136         }
 137
 138         priv = netdev_priv(dev);
 139
 140         priv->read_reg = sja1000_ofp_read_reg;
 141         priv->write_reg = sja1000_ofp_write_reg;
 142
 143         prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
 144         if (prop && (prop_size ==  sizeof(u32)))
 145                 priv->can.clock.freq = *prop / 2;
 146         else
 147                 priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
 148
 149         prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
 150         if (prop && (prop_size == sizeof(u32)))
 151                 priv->ocr |= *prop & OCR_MODE_MASK;
 152         else
 153                 priv->ocr |= OCR_MODE_NORMAL; /* default */
 154
 155         prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
 156         if (prop && (prop_size == sizeof(u32)))
 157                 priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 158         else
 159                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 160
 161         prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
 162         if (prop && (prop_size == sizeof(u32)) && *prop) {
 163                 u32 divider = priv->can.clock.freq * 2 / *prop;
 164
 165                 if (divider > 1)
 166                         priv->cdr |= divider / 2 - 1;
 167                 else
 168                         priv->cdr |= CDR_CLKOUT_MASK;
 169         } else {
 170                 priv->cdr |= CDR_CLK_OFF; /* default */
 171         }
 172
 173         prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
 174         if (!prop)
 175                 priv->cdr |= CDR_CBP; /* default */
 176
 177         priv->irq_flags = IRQF_SHARED;
 178         priv->reg_base = base;
 179
 180         dev->irq = irq;
 181
 182         dev_info(&ofdev->dev,
 183                  "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
 184                  priv->reg_base, dev->irq, priv->can.clock.freq,
 185                  priv->ocr, priv->cdr);
 186
 187         dev_set_drvdata(&ofdev->dev, dev);
 188         SET_NETDEV_DEV(dev, &ofdev->dev);
 189
 190         err = register_sja1000dev(dev);
 191         if (err) {
 192                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
 193                         DRV_NAME, err);
 194                 goto exit_free_sja1000;
 195         }
 196
 197         return 0;
 198
 199 exit_free_sja1000:
 200         free_sja1000dev(dev);
 201 exit_dispose_irq:
 202         irq_dispose_mapping(irq);
 203 exit_unmap_mem:
 204         iounmap(base);
 205 exit_release_mem:
 206         release_mem_region(res.start, res_size);
 207
 208         return err;
 209 }
 210
 211 static struct of_device_id __devinitdata sja1000_ofp_table[] = {
 212         {.compatible = "nxp,sja1000"},
 213         {},
 214 };
 215 MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
 216
 217 static struct of_platform_driver sja1000_ofp_driver = {
 218         .driver = {
 219                 .owner = THIS_MODULE,
 220                 .name = DRV_NAME,
 221                 .of_match_table = sja1000_ofp_table,
 222         },
 223         .probe = sja1000_ofp_probe,
 224         .remove = __devexit_p(sja1000_ofp_remove),
 225 };
 226
 227 static int __init sja1000_ofp_init(void)
 228 {
 229         return of_register_platform_driver(&sja1000_ofp_driver);
 230 }
 231 module_init(sja1000_ofp_init);
 232
 233 static void __exit sja1000_ofp_exit(void)
 234 {
 235         return of_unregister_platform_driver(&sja1000_ofp_driver);
 236 };
 237 module_exit(sja1000_ofp_exit);