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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)4 * Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>5 * Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>6 */7 8#include <linux/kernel.h>9#include <linux/module.h>10#include <linux/interrupt.h>11#include <linux/netdevice.h>12#include <linux/delay.h>13#include <linux/io.h>14#include <pcmcia/cistpl.h>15#include <pcmcia/ds.h>16#include <linux/can.h>17#include <linux/can/dev.h>18#include "sja1000.h"19 20#define DRV_NAME "ems_pcmcia"21 22MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");23MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");24MODULE_LICENSE("GPL v2");25 26#define EMS_PCMCIA_MAX_CHAN 227 28struct ems_pcmcia_card {29 int channels;30 struct pcmcia_device *pcmcia_dev;31 struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];32 void __iomem *base_addr;33};34 35#define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)36 37/*38 * The board configuration is probably following:39 * RX1 is connected to ground.40 * TX1 is not connected.41 * CLKO is not connected.42 * Setting the OCR register to 0xDA is a good idea.43 * This means normal output mode , push-pull and the correct polarity.44 */45#define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)46 47/*48 * In the CDR register, you should set CBP to 1.49 * You will probably also want to set the clock divider value to 750 * (meaning direct oscillator output) because the second SJA1000 chip51 * is driven by the first one CLKOUT output.52 */53#define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)54#define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */55#define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */56#define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */57 58#define EMS_CMD_RESET 0x00 /* Perform a reset of the card */59#define EMS_CMD_MAP 0x03 /* Map CAN controllers into card' memory */60#define EMS_CMD_UMAP 0x02 /* Unmap CAN controllers from card' memory */61 62static struct pcmcia_device_id ems_pcmcia_tbl[] = {63 PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,64 0xa338573f, 0xe4575800),65 PCMCIA_DEVICE_NULL,66};67 68MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);69 70static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)71{72 return readb(priv->reg_base + port);73}74 75static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,76 u8 val)77{78 writeb(val, priv->reg_base + port);79}80 81static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)82{83 struct ems_pcmcia_card *card = dev_id;84 struct net_device *dev;85 irqreturn_t retval = IRQ_NONE;86 int i, again;87 88 /* Card not present */89 if (readw(card->base_addr) != 0xAA55)90 return IRQ_HANDLED;91 92 do {93 again = 0;94 95 /* Check interrupt for each channel */96 for (i = 0; i < card->channels; i++) {97 dev = card->net_dev[i];98 if (!dev)99 continue;100 101 if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)102 again = 1;103 }104 /* At least one channel handled the interrupt */105 if (again)106 retval = IRQ_HANDLED;107 108 } while (again);109 110 return retval;111}112 113/*114 * Check if a CAN controller is present at the specified location115 * by trying to set 'em into the PeliCAN mode116 */117static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)118{119 /* Make sure SJA1000 is in reset mode */120 ems_pcmcia_write_reg(priv, SJA1000_MOD, 1);121 ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN);122 123 /* read reset-values */124 if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN)125 return 1;126 127 return 0;128}129 130static void ems_pcmcia_del_card(struct pcmcia_device *pdev)131{132 struct ems_pcmcia_card *card = pdev->priv;133 struct net_device *dev;134 int i;135 136 free_irq(pdev->irq, card);137 138 for (i = 0; i < card->channels; i++) {139 dev = card->net_dev[i];140 if (!dev)141 continue;142 143 printk(KERN_INFO "%s: removing %s on channel #%d\n",144 DRV_NAME, dev->name, i);145 unregister_sja1000dev(dev);146 free_sja1000dev(dev);147 }148 149 writeb(EMS_CMD_UMAP, card->base_addr);150 iounmap(card->base_addr);151 kfree(card);152 153 pdev->priv = NULL;154}155 156/*157 * Probe PCI device for EMS CAN signature and register each available158 * CAN channel to SJA1000 Socket-CAN subsystem.159 */160static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base)161{162 struct sja1000_priv *priv;163 struct net_device *dev;164 struct ems_pcmcia_card *card;165 int err, i;166 167 /* Allocating card structures to hold addresses, ... */168 card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);169 if (!card)170 return -ENOMEM;171 172 pdev->priv = card;173 card->channels = 0;174 175 card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);176 if (!card->base_addr) {177 err = -ENOMEM;178 goto failure_cleanup;179 }180 181 /* Check for unique EMS CAN signature */182 if (readw(card->base_addr) != 0xAA55) {183 err = -ENODEV;184 goto failure_cleanup;185 }186 187 /* Request board reset */188 writeb(EMS_CMD_RESET, card->base_addr);189 190 /* Make sure CAN controllers are mapped into card's memory space */191 writeb(EMS_CMD_MAP, card->base_addr);192 193 /* Detect available channels */194 for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {195 dev = alloc_sja1000dev(0);196 if (!dev) {197 err = -ENOMEM;198 goto failure_cleanup;199 }200 201 card->net_dev[i] = dev;202 priv = netdev_priv(dev);203 priv->priv = card;204 SET_NETDEV_DEV(dev, &pdev->dev);205 dev->dev_id = i;206 207 priv->irq_flags = IRQF_SHARED;208 dev->irq = pdev->irq;209 priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +210 (i * EMS_PCMCIA_CAN_CTRL_SIZE);211 212 /* Check if channel is present */213 if (ems_pcmcia_check_chan(priv)) {214 priv->read_reg = ems_pcmcia_read_reg;215 priv->write_reg = ems_pcmcia_write_reg;216 priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;217 priv->ocr = EMS_PCMCIA_OCR;218 priv->cdr = EMS_PCMCIA_CDR;219 priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;220 221 /* Register SJA1000 device */222 err = register_sja1000dev(dev);223 if (err) {224 free_sja1000dev(dev);225 goto failure_cleanup;226 }227 228 card->channels++;229 230 printk(KERN_INFO "%s: registered %s on channel "231 "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,232 i, priv->reg_base, dev->irq);233 } else234 free_sja1000dev(dev);235 }236 237 if (!card->channels) {238 err = -ENODEV;239 goto failure_cleanup;240 }241 242 err = request_irq(pdev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,243 DRV_NAME, card);244 if (!err)245 return 0;246 247failure_cleanup:248 ems_pcmcia_del_card(pdev);249 return err;250}251 252/*253 * Setup PCMCIA socket and probe for EMS CPC-CARD254 */255static int ems_pcmcia_probe(struct pcmcia_device *dev)256{257 int csval;258 259 /* General socket configuration */260 dev->config_flags |= CONF_ENABLE_IRQ;261 dev->config_index = 1;262 dev->config_regs = PRESENT_OPTION;263 264 /* The io structure describes IO port mapping */265 dev->resource[0]->end = 16;266 dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;267 dev->resource[1]->end = 16;268 dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;269 dev->io_lines = 5;270 271 /* Allocate a memory window */272 dev->resource[2]->flags =273 (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);274 dev->resource[2]->start = dev->resource[2]->end = 0;275 276 csval = pcmcia_request_window(dev, dev->resource[2], 0);277 if (csval) {278 dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",279 csval);280 return 0;281 }282 283 csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);284 if (csval) {285 dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",286 csval);287 return 0;288 }289 290 csval = pcmcia_enable_device(dev);291 if (csval) {292 dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",293 csval);294 return 0;295 }296 297 ems_pcmcia_add_card(dev, dev->resource[2]->start);298 return 0;299}300 301/*302 * Release claimed resources303 */304static void ems_pcmcia_remove(struct pcmcia_device *dev)305{306 ems_pcmcia_del_card(dev);307 pcmcia_disable_device(dev);308}309 310static struct pcmcia_driver ems_pcmcia_driver = {311 .name = DRV_NAME,312 .probe = ems_pcmcia_probe,313 .remove = ems_pcmcia_remove,314 .id_table = ems_pcmcia_tbl,315};316module_pcmcia_driver(ems_pcmcia_driver);317