1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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 22 MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>"); 23 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards"); 24 MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card"); 25 MODULE_LICENSE("GPL v2"); 26 27 #define EMS_PCMCIA_MAX_CHAN 2 28 29 struct ems_pcmcia_card { 30 int channels; 31 struct pcmcia_device *pcmcia_dev; 32 struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN]; 33 void __iomem *base_addr; 34 }; 35 36 #define EMS_PCMCIA_CAN_CLOCK (16000000 / 2) 37 38 /* 39 * The board configuration is probably following: 40 * RX1 is connected to ground. 41 * TX1 is not connected. 42 * CLKO is not connected. 43 * Setting the OCR register to 0xDA is a good idea. 44 * This means normal output mode , push-pull and the correct polarity. 45 */ 46 #define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL) 47 48 /* 49 * In the CDR register, you should set CBP to 1. 50 * You will probably also want to set the clock divider value to 7 51 * (meaning direct oscillator output) because the second SJA1000 chip 52 * is driven by the first one CLKOUT output. 53 */ 54 #define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK) 55 #define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */ 56 #define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */ 57 #define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */ 58 59 #define EMS_CMD_RESET 0x00 /* Perform a reset of the card */ 60 #define EMS_CMD_MAP 0x03 /* Map CAN controllers into card' memory */ 61 #define EMS_CMD_UMAP 0x02 /* Unmap CAN controllers from card' memory */ 62 63 static struct pcmcia_device_id ems_pcmcia_tbl[] = { 64 PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23, 65 0xa338573f, 0xe4575800), 66 PCMCIA_DEVICE_NULL, 67 }; 68 69 MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl); 70 71 static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port) 72 { 73 return readb(priv->reg_base + port); 74 } 75 76 static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port, 77 u8 val) 78 { 79 writeb(val, priv->reg_base + port); 80 } 81 82 static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id) 83 { 84 struct ems_pcmcia_card *card = dev_id; 85 struct net_device *dev; 86 irqreturn_t retval = IRQ_NONE; 87 int i, again; 88 89 /* Card not present */ 90 if (readw(card->base_addr) != 0xAA55) 91 return IRQ_HANDLED; 92 93 do { 94 again = 0; 95 96 /* Check interrupt for each channel */ 97 for (i = 0; i < card->channels; i++) { 98 dev = card->net_dev[i]; 99 if (!dev) 100 continue; 101 102 if (sja1000_interrupt(irq, dev) == IRQ_HANDLED) 103 again = 1; 104 } 105 /* At least one channel handled the interrupt */ 106 if (again) 107 retval = IRQ_HANDLED; 108 109 } while (again); 110 111 return retval; 112 } 113 114 /* 115 * Check if a CAN controller is present at the specified location 116 * by trying to set 'em into the PeliCAN mode 117 */ 118 static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv) 119 { 120 /* Make sure SJA1000 is in reset mode */ 121 ems_pcmcia_write_reg(priv, SJA1000_MOD, 1); 122 ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN); 123 124 /* read reset-values */ 125 if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN) 126 return 1; 127 128 return 0; 129 } 130 131 static void ems_pcmcia_del_card(struct pcmcia_device *pdev) 132 { 133 struct ems_pcmcia_card *card = pdev->priv; 134 struct net_device *dev; 135 int i; 136 137 free_irq(pdev->irq, card); 138 139 for (i = 0; i < card->channels; i++) { 140 dev = card->net_dev[i]; 141 if (!dev) 142 continue; 143 144 printk(KERN_INFO "%s: removing %s on channel #%d\n", 145 DRV_NAME, dev->name, i); 146 unregister_sja1000dev(dev); 147 free_sja1000dev(dev); 148 } 149 150 writeb(EMS_CMD_UMAP, card->base_addr); 151 iounmap(card->base_addr); 152 kfree(card); 153 154 pdev->priv = NULL; 155 } 156 157 /* 158 * Probe PCI device for EMS CAN signature and register each available 159 * CAN channel to SJA1000 Socket-CAN subsystem. 160 */ 161 static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base) 162 { 163 struct sja1000_priv *priv; 164 struct net_device *dev; 165 struct ems_pcmcia_card *card; 166 int err, i; 167 168 /* Allocating card structures to hold addresses, ... */ 169 card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL); 170 if (!card) 171 return -ENOMEM; 172 173 pdev->priv = card; 174 card->channels = 0; 175 176 card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE); 177 if (!card->base_addr) { 178 err = -ENOMEM; 179 goto failure_cleanup; 180 } 181 182 /* Check for unique EMS CAN signature */ 183 if (readw(card->base_addr) != 0xAA55) { 184 err = -ENODEV; 185 goto failure_cleanup; 186 } 187 188 /* Request board reset */ 189 writeb(EMS_CMD_RESET, card->base_addr); 190 191 /* Make sure CAN controllers are mapped into card's memory space */ 192 writeb(EMS_CMD_MAP, card->base_addr); 193 194 /* Detect available channels */ 195 for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) { 196 dev = alloc_sja1000dev(0); 197 if (!dev) { 198 err = -ENOMEM; 199 goto failure_cleanup; 200 } 201 202 card->net_dev[i] = dev; 203 priv = netdev_priv(dev); 204 priv->priv = card; 205 SET_NETDEV_DEV(dev, &pdev->dev); 206 dev->dev_id = i; 207 208 priv->irq_flags = IRQF_SHARED; 209 dev->irq = pdev->irq; 210 priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET + 211 (i * EMS_PCMCIA_CAN_CTRL_SIZE); 212 213 /* Check if channel is present */ 214 if (ems_pcmcia_check_chan(priv)) { 215 priv->read_reg = ems_pcmcia_read_reg; 216 priv->write_reg = ems_pcmcia_write_reg; 217 priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK; 218 priv->ocr = EMS_PCMCIA_OCR; 219 priv->cdr = EMS_PCMCIA_CDR; 220 priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER; 221 222 /* Register SJA1000 device */ 223 err = register_sja1000dev(dev); 224 if (err) { 225 free_sja1000dev(dev); 226 goto failure_cleanup; 227 } 228 229 card->channels++; 230 231 printk(KERN_INFO "%s: registered %s on channel " 232 "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name, 233 i, priv->reg_base, dev->irq); 234 } else 235 free_sja1000dev(dev); 236 } 237 238 err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED, 239 DRV_NAME, card); 240 if (!err) 241 return 0; 242 243 failure_cleanup: 244 ems_pcmcia_del_card(pdev); 245 return err; 246 } 247 248 /* 249 * Setup PCMCIA socket and probe for EMS CPC-CARD 250 */ 251 static int ems_pcmcia_probe(struct pcmcia_device *dev) 252 { 253 int csval; 254 255 /* General socket configuration */ 256 dev->config_flags |= CONF_ENABLE_IRQ; 257 dev->config_index = 1; 258 dev->config_regs = PRESENT_OPTION; 259 260 /* The io structure describes IO port mapping */ 261 dev->resource[0]->end = 16; 262 dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8; 263 dev->resource[1]->end = 16; 264 dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16; 265 dev->io_lines = 5; 266 267 /* Allocate a memory window */ 268 dev->resource[2]->flags = 269 (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE); 270 dev->resource[2]->start = dev->resource[2]->end = 0; 271 272 csval = pcmcia_request_window(dev, dev->resource[2], 0); 273 if (csval) { 274 dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n", 275 csval); 276 return 0; 277 } 278 279 csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base); 280 if (csval) { 281 dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n", 282 csval); 283 return 0; 284 } 285 286 csval = pcmcia_enable_device(dev); 287 if (csval) { 288 dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n", 289 csval); 290 return 0; 291 } 292 293 ems_pcmcia_add_card(dev, dev->resource[2]->start); 294 return 0; 295 } 296 297 /* 298 * Release claimed resources 299 */ 300 static void ems_pcmcia_remove(struct pcmcia_device *dev) 301 { 302 ems_pcmcia_del_card(dev); 303 pcmcia_disable_device(dev); 304 } 305 306 static struct pcmcia_driver ems_pcmcia_driver = { 307 .name = DRV_NAME, 308 .probe = ems_pcmcia_probe, 309 .remove = ems_pcmcia_remove, 310 .id_table = ems_pcmcia_tbl, 311 }; 312 module_pcmcia_driver(ems_pcmcia_driver); 313