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/devicetree/bindings/net/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/io.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 platform_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 platform_device *ofdev)
  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 %pR\n", &res);
 111                 return -EBUSY;
 112         }
 113
 114         base = ioremap_nocache(res.start, res_size);
 115         if (!base) {
 116                 dev_err(&ofdev->dev, "couldn't ioremap %pR\n", &res);
 117                 err = -ENOMEM;
 118                 goto exit_release_mem;
 119         }
 120
 121         irq = irq_of_parse_and_map(np, 0);
 122         if (irq == NO_IRQ) {
 123                 dev_err(&ofdev->dev, "no irq found\n");
 124                 err = -ENODEV;
 125                 goto exit_unmap_mem;
 126         }
 127
 128         dev = alloc_sja1000dev(0);
 129         if (!dev) {
 130                 err = -ENOMEM;
 131                 goto exit_dispose_irq;
 132         }
 133
 134         priv = netdev_priv(dev);
 135
 136         priv->read_reg = sja1000_ofp_read_reg;
 137         priv->write_reg = sja1000_ofp_write_reg;
 138
 139         prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);
 140         if (prop && (prop_size ==  sizeof(u32)))
 141                 priv->can.clock.freq = *prop / 2;
 142         else
 143                 priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */
 144
 145         prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);
 146         if (prop && (prop_size == sizeof(u32)))
 147                 priv->ocr |= *prop & OCR_MODE_MASK;
 148         else
 149                 priv->ocr |= OCR_MODE_NORMAL; /* default */
 150
 151         prop = of_get_property(np, "nxp,tx-output-config", &prop_size);
 152         if (prop && (prop_size == sizeof(u32)))
 153                 priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 154         else
 155                 priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 156
 157         prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);
 158         if (prop && (prop_size == sizeof(u32)) && *prop) {
 159                 u32 divider = priv->can.clock.freq * 2 / *prop;
 160
 161                 if (divider > 1)
 162                         priv->cdr |= divider / 2 - 1;
 163                 else
 164                         priv->cdr |= CDR_CLKOUT_MASK;
 165         } else {
 166                 priv->cdr |= CDR_CLK_OFF; /* default */
 167         }
 168
 169         prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);
 170         if (!prop)
 171                 priv->cdr |= CDR_CBP; /* default */
 172
 173         priv->irq_flags = IRQF_SHARED;
 174         priv->reg_base = base;
 175
 176         dev->irq = irq;
 177
 178         dev_info(&ofdev->dev,
 179                  "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",
 180                  priv->reg_base, dev->irq, priv->can.clock.freq,
 181                  priv->ocr, priv->cdr);
 182
 183         dev_set_drvdata(&ofdev->dev, dev);
 184         SET_NETDEV_DEV(dev, &ofdev->dev);
 185
 186         err = register_sja1000dev(dev);
 187         if (err) {
 188                 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
 189                         DRV_NAME, err);
 190                 goto exit_free_sja1000;
 191         }
 192
 193         return 0;
 194
 195 exit_free_sja1000:
 196         free_sja1000dev(dev);
 197 exit_dispose_irq:
 198         irq_dispose_mapping(irq);
 199 exit_unmap_mem:
 200         iounmap(base);
 201 exit_release_mem:
 202         release_mem_region(res.start, res_size);
 203
 204         return err;
 205 }
 206
 207 static struct of_device_id __devinitdata sja1000_ofp_table[] = {
 208         {.compatible = "nxp,sja1000"},
 209         {},
 210 };
 211 MODULE_DEVICE_TABLE(of, sja1000_ofp_table);
 212
 213 static struct platform_driver sja1000_ofp_driver = {
 214         .driver = {
 215                 .owner = THIS_MODULE,
 216                 .name = DRV_NAME,
 217                 .of_match_table = sja1000_ofp_table,
 218         },
 219         .probe = sja1000_ofp_probe,
 220         .remove = __devexit_p(sja1000_ofp_remove),
 221 };
 222
 223 module_platform_driver(sja1000_ofp_driver);