// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
* Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>
* Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include "sja1000.h"
#define DRV_NAME
"ems_pcmcia"
MODULE_AUTHOR(
"Markus Plessing <plessing@ems-wuensche.com>");
MODULE_DESCRIPTION(
"Socket-CAN driver for EMS CPC-CARD cards");
MODULE_LICENSE(
"GPL v2");
#define EMS_PCMCIA_MAX_CHAN 2
struct ems_pcmcia_card {
int channels;
struct pcmcia_device *pcmcia_dev;
struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
void __iomem *base_addr;
};
#define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)
/*
* The board configuration is probably following:
* RX1 is connected to ground.
* TX1 is not connected.
* CLKO is not connected.
* Setting the OCR register to 0xDA is a good idea.
* This means normal output mode , push-pull and the correct polarity.
*/
#define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
/*
* In the CDR register, you should set CBP to 1.
* You will probably also want to set the clock divider value to 7
* (meaning direct oscillator output) because the second SJA1000 chip
* is driven by the first one CLKOUT output.
*/
#define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
#define EMS_PCMCIA_MEM_SIZE 4096
/* Size of the remapped io-memory */
#define EMS_PCMCIA_CAN_BASE_OFFSET 0x100
/* Offset where controllers starts */
#define EMS_PCMCIA_CAN_CTRL_SIZE 0x80
/* Memory size for each controller */
#define EMS_CMD_RESET 0x00
/* Perform a reset of the card */
#define EMS_CMD_MAP 0x03
/* Map CAN controllers into card' memory */
#define EMS_CMD_UMAP 0x02
/* Unmap CAN controllers from card' memory */
static struct pcmcia_device_id ems_pcmcia_tbl[] = {
PCMCIA_DEVICE_PROD_ID123(
"EMS_T_W",
"CPC-Card",
"V2.0", 0xeab1ea23,
0xa338573f, 0xe4575800),
PCMCIA_DEVICE_NULL,
};
MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
static u8 ems_pcmcia_read_reg(
const struct sja1000_priv *priv,
int port)
{
return readb(priv->reg_base + port);
}
static void ems_pcmcia_write_reg(
const struct sja1000_priv *priv,
int port,
u8 val)
{
writeb(val, priv->reg_base + port);
}
static irqreturn_t ems_pcmcia_interrupt(
int irq,
void *dev_id)
{
struct ems_pcmcia_card *card = dev_id;
struct net_device *dev;
irqreturn_t retval = IRQ_NONE;
int i, again;
/* Card not present */
if (readw(card->base_addr) != 0xAA55)
return IRQ_HANDLED;
do {
again = 0;
/* Check interrupt for each channel */
for (i = 0; i < card->channels; i++) {
dev = card->net_dev[i];
if (!dev)
continue;
if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
again = 1;
}
/* At least one channel handled the interrupt */
if (again)
retval = IRQ_HANDLED;
}
while (again);
return retval;
}
/*
* Check if a CAN controller is present at the specified location
* by trying to set 'em into the PeliCAN mode
*/
static inline int ems_pcmcia_check_chan(
struct sja1000_priv *priv)
{
/* Make sure SJA1000 is in reset mode */
ems_pcmcia_write_reg(priv, SJA1000_MOD, 1);
ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN);
/* read reset-values */
if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN)
return 1;
return 0;
}
static void ems_pcmcia_del_card(
struct pcmcia_device *pdev)
{
struct ems_pcmcia_card *card = pdev->priv;
struct net_device *dev;
int i;
free_irq(pdev->irq, card);
for (i = 0; i < card->channels; i++) {
dev = card->net_dev[i];
if (!dev)
continue;
printk(KERN_INFO
"%s: removing %s on channel #%d\n",
DRV_NAME, dev->name, i);
unregister_sja1000dev(dev);
free_sja1000dev(dev);
}
writeb(EMS_CMD_UMAP, card->base_addr);
iounmap(card->base_addr);
kfree(card);
pdev->priv = NULL;
}
/*
* Probe PCI device for EMS CAN signature and register each available
* CAN channel to SJA1000 Socket-CAN subsystem.
*/
static int ems_pcmcia_add_card(
struct pcmcia_device *pdev,
unsigned long base)
{
struct sja1000_priv *priv;
struct net_device *dev;
struct ems_pcmcia_card *card;
int err, i;
/* Allocating card structures to hold addresses, ... */
card = kzalloc(
sizeof(
struct ems_pcmcia_card), GFP_KERNEL);
if (!card)
return -ENOMEM;
pdev->priv = card;
card->channels = 0;
card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
if (!card->base_addr) {
err = -ENOMEM;
goto failure_cleanup;
}
/* Check for unique EMS CAN signature */
if (readw(card->base_addr) != 0xAA55) {
err = -ENODEV;
goto failure_cleanup;
}
/* Request board reset */
writeb(EMS_CMD_RESET, card->base_addr);
/* Make sure CAN controllers are mapped into card's memory space */
writeb(EMS_CMD_MAP, card->base_addr);
/* Detect available channels */
for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
dev = alloc_sja1000dev(0);
if (!dev) {
err = -ENOMEM;
goto failure_cleanup;
}
card->net_dev[i] = dev;
priv = netdev_priv(dev);
priv->priv = card;
SET_NETDEV_DEV(dev, &pdev->dev);
dev->dev_id = i;
priv->irq_flags = IRQF_SHARED;
dev->irq = pdev->irq;
priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
(i * EMS_PCMCIA_CAN_CTRL_SIZE);
/* Check if channel is present */
if (ems_pcmcia_check_chan(priv)) {
priv->read_reg = ems_pcmcia_read_reg;
priv->write_reg = ems_pcmcia_write_reg;
priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
priv->ocr = EMS_PCMCIA_OCR;
priv->cdr = EMS_PCMCIA_CDR;
priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
/* Register SJA1000 device */
err = register_sja1000dev(dev);
if (err) {
free_sja1000dev(dev);
goto failure_cleanup;
}
card->channels++;
printk(KERN_INFO
"%s: registered %s on channel "
"#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
i, priv->reg_base, dev->irq);
}
else
free_sja1000dev(dev);
}
if (!card->channels) {
err = -ENODEV;
goto failure_cleanup;
}
err = request_irq(pdev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
DRV_NAME, card);
if (!err)
return 0;
failure_cleanup:
ems_pcmcia_del_card(pdev);
return err;
}
/*
* Setup PCMCIA socket and probe for EMS CPC-CARD
*/
static int ems_pcmcia_probe(
struct pcmcia_device *dev)
{
int csval;
/* General socket configuration */
dev->config_flags |= CONF_ENABLE_IRQ;
dev->config_index = 1;
dev->config_regs = PRESENT_OPTION;
/* The io structure describes IO port mapping */
dev->resource[0]->end = 16;
dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
dev->resource[1]->end = 16;
dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
dev->io_lines = 5;
/* Allocate a memory window */
dev->resource[2]->flags =
(WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
dev->resource[2]->start = dev->resource[2]->end = 0;
csval = pcmcia_request_window(dev, dev->resource[2], 0);
if (csval) {
dev_err(&dev->dev,
"pcmcia_request_window failed (err=%d)\n",
csval);
return 0;
}
csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
if (csval) {
dev_err(&dev->dev,
"pcmcia_map_mem_page failed (err=%d)\n",
csval);
return 0;
}
csval = pcmcia_enable_device(dev);
if (csval) {
dev_err(&dev->dev,
"pcmcia_enable_device failed (err=%d)\n",
csval);
return 0;
}
ems_pcmcia_add_card(dev, dev->resource[2]->start);
return 0;
}
/*
* Release claimed resources
*/
static void ems_pcmcia_remove(
struct pcmcia_device *dev)
{
ems_pcmcia_del_card(dev);
pcmcia_disable_device(dev);
}
static struct pcmcia_driver ems_pcmcia_driver = {
.name = DRV_NAME,
.probe = ems_pcmcia_probe,
.remove = ems_pcmcia_remove,
.id_table = ems_pcmcia_tbl,
};
module_pcmcia_driver(ems_pcmcia_driver);
