linux/drivers/net/can/sja1000/sja1000_platform.c
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   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_device.h>
  31#include <linux/of_irq.h>
  32
  33#include "sja1000.h"
  34
  35#define DRV_NAME "sja1000_platform"
  36#define SP_CAN_CLOCK  (16000000 / 2)
  37
  38MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
  39MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  40MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
  41MODULE_ALIAS("platform:" DRV_NAME);
  42MODULE_LICENSE("GPL v2");
  43
  44struct sja1000_of_data {
  45        size_t  priv_sz;
  46        int     (*init)(struct sja1000_priv *priv, struct device_node *of);
  47};
  48
  49struct technologic_priv {
  50        spinlock_t      io_lock;
  51};
  52
  53static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
  54{
  55        return ioread8(priv->reg_base + reg);
  56}
  57
  58static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
  59{
  60        iowrite8(val, priv->reg_base + reg);
  61}
  62
  63static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
  64{
  65        return ioread8(priv->reg_base + reg * 2);
  66}
  67
  68static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
  69{
  70        iowrite8(val, priv->reg_base + reg * 2);
  71}
  72
  73static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
  74{
  75        return ioread8(priv->reg_base + reg * 4);
  76}
  77
  78static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
  79{
  80        iowrite8(val, priv->reg_base + reg * 4);
  81}
  82
  83static u8 sp_technologic_read_reg16(const struct sja1000_priv *priv, int reg)
  84{
  85        struct technologic_priv *tp = priv->priv;
  86        unsigned long flags;
  87        u8 val;
  88
  89        spin_lock_irqsave(&tp->io_lock, flags);
  90        iowrite16(reg, priv->reg_base + 0);
  91        val = ioread16(priv->reg_base + 2);
  92        spin_unlock_irqrestore(&tp->io_lock, flags);
  93
  94        return val;
  95}
  96
  97static void sp_technologic_write_reg16(const struct sja1000_priv *priv,
  98                                       int reg, u8 val)
  99{
 100        struct technologic_priv *tp = priv->priv;
 101        unsigned long flags;
 102
 103        spin_lock_irqsave(&tp->io_lock, flags);
 104        iowrite16(reg, priv->reg_base + 0);
 105        iowrite16(val, priv->reg_base + 2);
 106        spin_unlock_irqrestore(&tp->io_lock, flags);
 107}
 108
 109static int sp_technologic_init(struct sja1000_priv *priv, struct device_node *of)
 110{
 111        struct technologic_priv *tp = priv->priv;
 112
 113        priv->read_reg = sp_technologic_read_reg16;
 114        priv->write_reg = sp_technologic_write_reg16;
 115        spin_lock_init(&tp->io_lock);
 116
 117        return 0;
 118}
 119
 120static void sp_populate(struct sja1000_priv *priv,
 121                        struct sja1000_platform_data *pdata,
 122                        unsigned long resource_mem_flags)
 123{
 124        /* The CAN clock frequency is half the oscillator clock frequency */
 125        priv->can.clock.freq = pdata->osc_freq / 2;
 126        priv->ocr = pdata->ocr;
 127        priv->cdr = pdata->cdr;
 128
 129        switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
 130        case IORESOURCE_MEM_32BIT:
 131                priv->read_reg = sp_read_reg32;
 132                priv->write_reg = sp_write_reg32;
 133                break;
 134        case IORESOURCE_MEM_16BIT:
 135                priv->read_reg = sp_read_reg16;
 136                priv->write_reg = sp_write_reg16;
 137                break;
 138        case IORESOURCE_MEM_8BIT:
 139        default:
 140                priv->read_reg = sp_read_reg8;
 141                priv->write_reg = sp_write_reg8;
 142                break;
 143        }
 144}
 145
 146static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
 147{
 148        int err;
 149        u32 prop;
 150
 151        err = of_property_read_u32(of, "reg-io-width", &prop);
 152        if (err)
 153                prop = 1; /* 8 bit is default */
 154
 155        switch (prop) {
 156        case 4:
 157                priv->read_reg = sp_read_reg32;
 158                priv->write_reg = sp_write_reg32;
 159                break;
 160        case 2:
 161                priv->read_reg = sp_read_reg16;
 162                priv->write_reg = sp_write_reg16;
 163                break;
 164        case 1: /* fallthrough */
 165        default:
 166                priv->read_reg = sp_read_reg8;
 167                priv->write_reg = sp_write_reg8;
 168        }
 169
 170        err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
 171        if (!err)
 172                priv->can.clock.freq = prop / 2;
 173        else
 174                priv->can.clock.freq = SP_CAN_CLOCK; /* default */
 175
 176        err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
 177        if (!err)
 178                priv->ocr |= prop & OCR_MODE_MASK;
 179        else
 180                priv->ocr |= OCR_MODE_NORMAL; /* default */
 181
 182        err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
 183        if (!err)
 184                priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
 185        else
 186                priv->ocr |= OCR_TX0_PULLDOWN; /* default */
 187
 188        err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
 189        if (!err && prop) {
 190                u32 divider = priv->can.clock.freq * 2 / prop;
 191
 192                if (divider > 1)
 193                        priv->cdr |= divider / 2 - 1;
 194                else
 195                        priv->cdr |= CDR_CLKOUT_MASK;
 196        } else {
 197                priv->cdr |= CDR_CLK_OFF; /* default */
 198        }
 199
 200        if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
 201                priv->cdr |= CDR_CBP; /* default */
 202}
 203
 204static struct sja1000_of_data technologic_data = {
 205        .priv_sz = sizeof(struct technologic_priv),
 206        .init = sp_technologic_init,
 207};
 208
 209static const struct of_device_id sp_of_table[] = {
 210        { .compatible = "nxp,sja1000", .data = NULL, },
 211        { .compatible = "technologic,sja1000", .data = &technologic_data, },
 212        { /* sentinel */ },
 213};
 214MODULE_DEVICE_TABLE(of, sp_of_table);
 215
 216static int sp_probe(struct platform_device *pdev)
 217{
 218        int err, irq = 0;
 219        void __iomem *addr;
 220        struct net_device *dev;
 221        struct sja1000_priv *priv;
 222        struct resource *res_mem, *res_irq = NULL;
 223        struct sja1000_platform_data *pdata;
 224        struct device_node *of = pdev->dev.of_node;
 225        const struct of_device_id *of_id;
 226        const struct sja1000_of_data *of_data = NULL;
 227        size_t priv_sz = 0;
 228
 229        pdata = dev_get_platdata(&pdev->dev);
 230        if (!pdata && !of) {
 231                dev_err(&pdev->dev, "No platform data provided!\n");
 232                return -ENODEV;
 233        }
 234
 235        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 236        if (!res_mem)
 237                return -ENODEV;
 238
 239        if (!devm_request_mem_region(&pdev->dev, res_mem->start,
 240                                     resource_size(res_mem), DRV_NAME))
 241                return -EBUSY;
 242
 243        addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
 244                                    resource_size(res_mem));
 245        if (!addr)
 246                return -ENOMEM;
 247
 248        if (of)
 249                irq = irq_of_parse_and_map(of, 0);
 250        else
 251                res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 252
 253        if (!irq && !res_irq)
 254                return -ENODEV;
 255
 256        of_id = of_match_device(sp_of_table, &pdev->dev);
 257        if (of_id && of_id->data) {
 258                of_data = of_id->data;
 259                priv_sz = of_data->priv_sz;
 260        }
 261
 262        dev = alloc_sja1000dev(priv_sz);
 263        if (!dev)
 264                return -ENOMEM;
 265        priv = netdev_priv(dev);
 266
 267        if (res_irq) {
 268                irq = res_irq->start;
 269                priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
 270                if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
 271                        priv->irq_flags |= IRQF_SHARED;
 272        } else {
 273                priv->irq_flags = IRQF_SHARED;
 274        }
 275
 276        dev->irq = irq;
 277        priv->reg_base = addr;
 278
 279        if (of) {
 280                sp_populate_of(priv, of);
 281
 282                if (of_data && of_data->init) {
 283                        err = of_data->init(priv, of);
 284                        if (err)
 285                                goto exit_free;
 286                }
 287        } else {
 288                sp_populate(priv, pdata, res_mem->flags);
 289        }
 290
 291        platform_set_drvdata(pdev, dev);
 292        SET_NETDEV_DEV(dev, &pdev->dev);
 293
 294        err = register_sja1000dev(dev);
 295        if (err) {
 296                dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
 297                        DRV_NAME, err);
 298                goto exit_free;
 299        }
 300
 301        dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
 302                 DRV_NAME, priv->reg_base, dev->irq);
 303        return 0;
 304
 305 exit_free:
 306        free_sja1000dev(dev);
 307        return err;
 308}
 309
 310static int sp_remove(struct platform_device *pdev)
 311{
 312        struct net_device *dev = platform_get_drvdata(pdev);
 313
 314        unregister_sja1000dev(dev);
 315        free_sja1000dev(dev);
 316
 317        return 0;
 318}
 319
 320static struct platform_driver sp_driver = {
 321        .probe = sp_probe,
 322        .remove = sp_remove,
 323        .driver = {
 324                .name = DRV_NAME,
 325                .of_match_table = sp_of_table,
 326        },
 327};
 328
 329module_platform_driver(sp_driver);
 330
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