nsi.c

can bus driver code.

/* nsi.c
 * Linux CAN-bus device driver.
 * Written by Arnaud Westenberg email:[e-mail]
 * This software is released under the GPL-License.
 * Version 0.7  6 Aug 2001
 */ 

#include <linux/autoconf.h>
#if defined (CONFIG_MODVERSIONS) && !defined (MODVERSIONS)
#define MODVERSIONS
#endif

#if defined (MODVERSIONS)
#include <linux/modversions.h>
#endif

#include <linux/ioport.h>
#include <linux/delay.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/irq.h>

#include "../include/main.h"
#include "../include/nsi.h"
#include "../include/i82527.h"

int nsican_irq=-1;
unsigned long nsican_base=0x0;

/* IO_RANGE is the io-memory range that gets reserved, please adjust according
 * your hardware. Example: #define IO_RANGE 0x100 for i82527 chips or
 * #define IO_RANGE 0x20 for sja1000 chips.
 */
#define IO_RANGE 0x04

/* The function template_request_io is used to reserve the io-memory. If your
 * hardware uses a dedicated memory range as hardware control registers you
 * will have to add the code to reserve this memory as well.
 * The reserved memory starts at io_addr, wich is the module parameter io.
 */
int nsi_request_io(unsigned long io_addr)
{

	if (check_region(io_addr,IO_RANGE)) {
		CANMSG("Unable to open port: 0x%lx\n",io_addr);
		return -ENODEV;
	}
	else {
		request_region(io_addr,IO_RANGE,DEVICE_NAME);
		DEBUGMSG("Registered IO-memory: 0x%lx - 0x%lx\n", io_addr, 
			 io_addr + IO_RANGE - 1);
	}
	return 0;
}

/* The function template_release_io is used to free the previously reserved 
 * io-memory. In case you reserved more memory, don't forget to free it here.
 */
int nsi_release_io(unsigned long io_addr)
{

	release_region(io_addr,IO_RANGE);

	return 0;
}

/* The function template_reset is used to give a hardware reset. This is rather
 * hardware specific so I haven't included example code. Don't forget to check
 * the reset status of the chip before returning.
 */
int nsi_reset(int card)
{
    int i; 

    DEBUGMSG("Resetting nsi hardware ...\n");
    /* we don't use template_write_register because we don't use the two first
       register of the card but the third in order to make a hard reset */
    outb (1, nsican_base + candevices_p[card]->res_addr);
    outb (0, nsican_base + candevices_p[card]->res_addr);
    for (i = 1; i < 1000; i++)
	udelay (1000);
    
    
    /* Check hardware reset status */ 
    i=0;
    while ( (nsi_read_register(nsican_base+iCPU) & iCPU_RST) && (i<=15)) {
	udelay(20000);
	i++;
    }
    if (i>=15) {
	CANMSG("Reset status timeout!\n");
	CANMSG("Please check your hardware.\n");
	return -ENODEV;
    }
    else
	DEBUGMSG("Chip0 reset status ok.\n");

    return 0;
}

/* The function template_init_hw_data is used to initialize the hardware
 * structure containing information about the installed CAN-board.
 * RESET_ADDR represents the io-address of the hardware reset register.
 * NR_82527 represents the number of intel 82527 chips on the board.
 * NR_SJA1000 represents the number of philips sja1000 chips on the board.
 * The flags entry can currently only be PROGRAMMABLE_IRQ to indicate that
 * the hardware uses programmable interrupts.
 */
#define RESET_ADDR 0x02
#define NR_82527 1
#define NR_SJA1000 0

int nsi_init_hw_data(int card) 
     {
	candevices_p[card]->res_addr=RESET_ADDR;
	candevices_p[card]->nr_82527_chips=1;
	candevices_p[card]->nr_sja1000_chips=0;
	candevices_p[card]->flags |= PROGRAMMABLE_IRQ;

	return 0;
}

/* The function template_init_chip_data is used to initialize the hardware
 * structure containing information about the CAN chips.
 * CHIP_TYPE represents the type of CAN chip. CHIP_TYPE can be "i82527" or
 * "sja1000".
 * The chip_base_addr entry represents the start of the 'official' memory map
 * of the installed chip. It's likely that this is the same as the io_addr
 * argument supplied at module loading time.
 * The clock argument holds the chip clock value in Hz.
 */
#define CHIP_TYPE "i82527"

int nsi_init_chip_data(int card, int chipnr)
{
	candevices_p[card]->chip[chipnr]->chip_type=CHIP_TYPE;
	candevices_p[card]->chip[chipnr]->chip_base_addr=
	    candevices_p[card]->io_addr;
	candevices_p[card]->chip[chipnr]->clock = 16000000;
	nsican_irq=candevices_p[card]->chip[chipnr]->chip_irq;	
        nsican_base=candevices_p[card]->chip[chipnr]->chip_base_addr;
	candevices_p[card]->chip[chipnr]->int_cpu_reg = iCPU_DSC;
	candevices_p[card]->chip[chipnr]->int_clk_reg = iCLK_SL1;
	candevices_p[card]->chip[chipnr]->int_bus_reg = iBUS_CBY;

	return 0;
}

 /* The function template_init_obj_data is used to initialize the hardware
 * structure containing information about the different message objects on the
 * CAN chip. In case of the sja1000 there's only one message object but on the
 * i82527 chip there are 15.
 * The code below is for a i82527 chip and initializes the object base addresses
 * The entry obj_base_addr represents the first memory address of the message 
 * object. In case of the sja1000 obj_base_addr is taken the same as the chips
 * base address.
 * Unless the hardware uses a segmented memory map, flags can be set zero.
 */
int nsi_init_obj_data(int chipnr, int objnr)
{

	chips_p[chipnr]->msgobj[objnr]->obj_base_addr=
	    chips_p[chipnr]->chip_base_addr+(objnr+1)*0x10;
	chips_p[chipnr]->msgobj[objnr]->flags=0;
	
	return 0;
}

/* The function template_program_irq is used for hardware that uses programmable
 * interrupts. If your hardware doesn't use programmable interrupts you should
 * not set the candevices_t->flags entry to PROGRAMMABLE_IRQ and leave this
 * function unedited. Again this function is hardware specific so there's no
 * example code.
 */
int nsi_program_irq(int card)
{
	return 0;
}

/* The function template_write_register is used to write to hardware registers
 * on the CAN chip. You should only have to edit this function if your hardware
 * uses some specific write process.
 */
void nsi_write_register(unsigned char data, unsigned long address)
{
    /* address is an absolute address */

    /* the nsi card has two registers, the address register at 0x0
       and the data register at 0x01 */

    /* write the relative address on the eight LSB bits 
       and the data on the eight MSB bits in one time */
    outw(address-nsican_base + (256 * data), nsican_base); 
}

/* The function template_read_register is used to read from hardware registers
 * on the CAN chip. You should only have to edit this function if your hardware
 * uses some specific read process.
 */
unsigned nsi_read_register(unsigned long address)
{
    /* this is the same thing that the function write_register.
       We use the two register, we write the address where we 
       want to read in a first time. In a second time we read the
       data */
    unsigned char ret;
    
    disable_irq(nsican_irq); 
    outb(address-nsican_base, nsican_base);
    ret=inb(nsican_base+1);
    enable_irq(nsican_irq); 
    return ret;
}


 /* !!! Don't change this function !!! */
int nsi_register(struct hwspecops_t *hwspecops)
{
	hwspecops->request_io = nsi_request_io;
	hwspecops->release_io = nsi_release_io;
	hwspecops->reset = nsi_reset;
	hwspecops->init_hw_data = nsi_init_hw_data;
	hwspecops->init_chip_data = nsi_init_chip_data;
	hwspecops->init_obj_data = nsi_init_obj_data;
	hwspecops->write_register = nsi_write_register;
	hwspecops->read_register = nsi_read_register;
	hwspecops->program_irq = nsi_program_irq;
	return 0;
}