linux/drivers/net/can/sja1000/sja1000_platform.c
<<
>>
Prefs
   1/*
   2 * Copyright (C) 2005 Sascha Hauer, Pengutronix
   3 * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the version 2 of the GNU General Public License
   7 * as published by the Free Software Foundation
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/interrupt.h>
  21#include <linux/netdevice.h>
  22#include <linux/delay.h>
  23#include <linux/pci.h>
  24#include <linux/platform_device.h>
  25#include <linux/irq.h>
  26#include <linux/can/dev.h>
  27#include <linux/can/platform/sja1000.h>
  28#include <linux/io.h>
  29#include <linux/of.h>
  30#include <linux/of_irq.h>
  31
  32#include "sja1000.h"
  33
  34#define DRV_NAME "sja1000_platform"
  35#define SP_CAN_CLOCK  (16000000 / 2)
  36
  37MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
  38MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  39MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
  40MODULE_ALIAS("platform:" DRV_NAME);
  41MODULE_LICENSE("GPL v2");
  42
  43static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
  44{
  45        return ioread8(priv->reg_base + reg);
  46}
  47
  48static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
  49{
  50        iowrite8(val, priv->reg_base + reg);
  51}
  52
  53static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
  54{
  55        return ioread8(priv->reg_base + reg * 2);
  56}
  57
  58static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
  59{
  60        iowrite8(val, priv->reg_base + reg * 2);
  61}
  62
  63static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
  64{
  65        return ioread8(priv->reg_base + reg * 4);
  66}
  67
  68static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
  69{
  70        iowrite8(val, priv->reg_base + reg * 4);
  71}
  72
  73static void sp_populate(struct sja1000_priv *priv,
  74                        struct sja1000_platform_data *pdata,
  75                        unsigned long resource_mem_flags)
  76{
  77        /* The CAN clock frequency is half the oscillator clock frequency */
  78        priv->can.clock.freq = pdata->osc_freq / 2;
  79        priv->ocr = pdata->ocr;
  80        priv->cdr = pdata->cdr;
  81
  82        switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
  83        case IORESOURCE_MEM_32BIT:
  84                priv->read_reg = sp_read_reg32;
  85                priv->write_reg = sp_write_reg32;
  86                break;
  87        case IORESOURCE_MEM_16BIT:
  88                priv->read_reg = sp_read_reg16;
  89                priv->write_reg = sp_write_reg16;
  90                break;
  91        case IORESOURCE_MEM_8BIT:
  92        default:
  93                priv->read_reg = sp_read_reg8;
  94                priv->write_reg = sp_write_reg8;
  95                break;
  96        }
  97}
  98
  99static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
 100{
 101        int err;
 102        u32 prop;
 103
 104        err = of_property_read_u32(of, "reg-io-width", &prop);
 105        if (err)
 106                prop = 1; /* 8 bit is default */
 107
 108        switch (prop) {
 109        case 4:
 110                priv->read_reg = sp_read_reg32;
 111                priv->write_reg = sp_write_reg32;
 112                break;
 113        case 2:
 114                priv->read_reg = sp_read_reg16;
 115                priv->write_reg = sp_write_reg16;
 116                break;
 117        case 1: /* fallthrough */
 118        default:
 119                priv->read_reg = sp_read_reg8;
 120                priv->write_reg = sp_write_reg8;
 121        }
 122
 123        err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
 124        if (!err)
 125                priv->can.clock.freq = prop / 2;
 126        else
 127                priv->can.clock.freq = SP_CAN_CLOCK; /* default */
 128
 129        err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
 130        if (!err)
 131                priv->ocr |= prop & OCR_MODE_MASK;
 132        else
 133                priv->ocr |= OCR_MODE_NORMAL; /* default */
 134
 135        err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
 136        if (!err)
 137                priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 138        else
 139                priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 140
 141        err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
 142        if (!err && prop) {
 143                u32 divider = priv->can.clock.freq * 2 / prop;
 144
 145                if (divider > 1)
 146                        priv->cdr |= divider / 2 - 1;
 147                else
 148                        priv->cdr |= CDR_CLKOUT_MASK;
 149        } else {
 150                priv->cdr |= CDR_CLK_OFF; /* default */
 151        }
 152
 153        if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
 154                priv->cdr |= CDR_CBP; /* default */
 155}
 156
 157static int sp_probe(struct platform_device *pdev)
 158{
 159        int err, irq = 0;
 160        void __iomem *addr;
 161        struct net_device *dev;
 162        struct sja1000_priv *priv;
 163        struct resource *res_mem, *res_irq = NULL;
 164        struct sja1000_platform_data *pdata;
 165        struct device_node *of = pdev->dev.of_node;
 166
 167        pdata = dev_get_platdata(&pdev->dev);
 168        if (!pdata && !of) {
 169                dev_err(&pdev->dev, "No platform data provided!\n");
 170                return -ENODEV;
 171        }
 172
 173        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 174        if (!res_mem)
 175                return -ENODEV;
 176
 177        if (!devm_request_mem_region(&pdev->dev, res_mem->start,
 178                                     resource_size(res_mem), DRV_NAME))
 179                return -EBUSY;
 180
 181        addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
 182                                    resource_size(res_mem));
 183        if (!addr)
 184                return -ENOMEM;
 185
 186        if (of)
 187                irq = irq_of_parse_and_map(of, 0);
 188        else
 189                res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 190
 191        if (!irq && !res_irq)
 192                return -ENODEV;
 193
 194        dev = alloc_sja1000dev(0);
 195        if (!dev)
 196                return -ENOMEM;
 197        priv = netdev_priv(dev);
 198
 199        if (res_irq) {
 200                irq = res_irq->start;
 201                priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
 202                if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
 203                        priv->irq_flags |= IRQF_SHARED;
 204        } else {
 205                priv->irq_flags = IRQF_SHARED;
 206        }
 207
 208        dev->irq = irq;
 209        priv->reg_base = addr;
 210
 211        if (of)
 212                sp_populate_of(priv, of);
 213        else
 214                sp_populate(priv, pdata, res_mem->flags);
 215
 216        platform_set_drvdata(pdev, dev);
 217        SET_NETDEV_DEV(dev, &pdev->dev);
 218
 219        err = register_sja1000dev(dev);
 220        if (err) {
 221                dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 222                        DRV_NAME, err);
 223                goto exit_free;
 224        }
 225
 226        dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
 227                 DRV_NAME, priv->reg_base, dev->irq);
 228        return 0;
 229
 230 exit_free:
 231        free_sja1000dev(dev);
 232        return err;
 233}
 234
 235static int sp_remove(struct platform_device *pdev)
 236{
 237        struct net_device *dev = platform_get_drvdata(pdev);
 238
 239        unregister_sja1000dev(dev);
 240        free_sja1000dev(dev);
 241
 242        return 0;
 243}
 244
 245static struct of_device_id sp_of_table[] = {
 246        {.compatible = "nxp,sja1000"},
 247        {},
 248};
 249MODULE_DEVICE_TABLE(of, sp_of_table);
 250
 251static struct platform_driver sp_driver = {
 252        .probe = sp_probe,
 253        .remove = sp_remove,
 254        .driver = {
 255                .name = DRV_NAME,
 256                .owner = THIS_MODULE,
 257                .of_match_table = sp_of_table,
 258        },
 259};
 260
 261module_platform_driver(sp_driver);
 262
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.