pcccan.c

PCM9880是一块PC/104界面的双端口隔离CAN总线通讯卡

/* pcccan.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
 */ 

/* This file contains the low level functions for the pcccan-1 card from Gespac.
 * You can probably find more information at http://www.gespac.com
 */

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

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

int pcccan_irq=-1;
unsigned long pcccan_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 in basic CAN mode.
 */

/* The pcccan card uses indexed addressing hence the need to only reserve
 * eight bytes of memory.
 * base + 0 = Reset
 * base + 1 = Address loading
 * base + 2 = Read register
 * base + 3 = Read register + increment loaded address (saves a write operation
 * when accessing consecutive registers)
 * base + 4 = Unused
 * base + 5 = Address read
 * base + 6 = Write register
 * base + 7 = Write register + increment loaded address
 */
#define IO_RANGE 0x8

/**
 * pcccan_request_io: - reserve io memory
 * @io_addr: The reserved memory starts at @io_addr, wich is the module 
 * parameter @io.
 *
 * The function pcccan_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. 
 * %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 in basic CAN mode.
 * Return Value: The function returns zero on success or %-ENODEV on failure
 * File: src/pcccan.c
 */
int pcccan_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;
}

/**
 * pcccan_release_io - free reserved io-memory
 * @io_addr: Start of the memory range to be released.
 *
 * The function pcccan_release_io() is used to free reserved io-memory.
 * In case you have reserved more io memory, don't forget to free it here.
 * IO_RANGE is the io-memory range that gets released, please adjust according
 * your hardware. Example: #define IO_RANGE 0x100 for i82527 chips or
 * #define IO_RANGE 0x20 for sja1000 chips in basic CAN mode.
 * Return Value: The function always returns zero
 * File: src/pcccan.c
 */
int pcccan_release_io(unsigned long io_addr)
{
	release_region(io_addr,IO_RANGE);

	return 0;
}

/**
 * pcccan_reset - hardware reset routine
 * @card: Number of the hardware card.
 *
 * The function pcccan_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.
 * Return Value: The function returns zero on success or %-ENODEV on failure
 * File: src/pcccan.c
 */
int pcccan_reset(int card)
{
	int i=0;

	DEBUGMSG("Resetting pcccan-1 hardware ...\n");
	while (i < 1000000) {
		i++;
		outb(0x0,candevices_p[card]->res_addr);
	}

	/* Check hardware reset status */
	i=0;
	outb(iCPU,candevices_p[card]->io_addr+0x1);
	while ( (inb(candevices_p[card]->io_addr+0x2)&0x80) && (i<=15) ) {
		udelay(20000);
		i++;
	}
	if (i>=15) {
		CANMSG("Reset status timeout!\n");
		CANMSG("Please check your hardware.\n");
		return -ENODEV;
	}
	else
		DEBUGMSG("Chip reset status ok.\n");

	return 0;
} 

#define NR_82527 1
#define NR_SJA1000 0

/**
 * pcccan_init_hw_data - Initialze hardware cards
 * @card: Number of the hardware card.
 *
 * The function pcccan_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.
 * Return Value: The function always returns zero
 * File: src/pcccan.c
 */
int pcccan_init_hw_data(int card) 
{
	candevices_p[card]->res_addr=candevices_p[card]->io_addr;
	candevices_p[card]->nr_82527_chips=NR_82527;
	candevices_p[card]->nr_sja1000_chips=NR_SJA1000;
	candevices_p[card]->flags |= ~PROGRAMMABLE_IRQ;

	return 0;
}

#define CHIP_TYPE "i82527"
/**
 * pcccan_init_chip_data - Initialize chips
 * @card: Number of the hardware card
 * @chipnr: Number of the CAN chip on the hardware card
 *
 * The function pcccan_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 entry holds the chip clock value in Hz.
 * The entry @sja_cdr_reg holds hardware specific options for the Clock Divider
 * register. Options defined in the %sja1000.h file:
 * %CDR_CLKOUT_MASK, %CDR_CLK_OFF, %CDR_RXINPEN, %CDR_CBP, %CDR_PELICAN
 * The entry @sja_ocr_reg holds hardware specific options for the Output Control
 * register. Options defined in the %sja1000.h file:
 * %OCR_MODE_BIPHASE, %OCR_MODE_TEST, %OCR_MODE_NORMAL, %OCR_MODE_CLOCK,
 * %OCR_TX0_LH, %OCR_TX1_ZZ.
 * The entry @int_clk_reg holds hardware specific options for the Clock Out
 * register. Options defined in the %i82527.h file:
 * %iCLK_CD0, %iCLK_CD1, %iCLK_CD2, %iCLK_CD3, %iCLK_SL0, %iCLK_SL1.
 * The entry @int_bus_reg holds hardware specific options for the Bus 
 * Configuration register. Options defined in the %i82527.h file:
 * %iBUS_DR0, %iBUS_DR1, %iBUS_DT1, %iBUS_POL, %iBUS_CBY.
 * The entry @int_cpu_reg holds hardware specific options for the cpu interface
 * register. Options defined in the %i82527.h file:
 * %iCPU_CEN, %iCPU_MUX, %iCPU_SLP, %iCPU_PWD, %iCPU_DMC, %iCPU_DSC, %iCPU_RST.
 * Return Value: The function always returns zero
 * File: src/pcccan.c
 */
int pcccan_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;
	candevices_p[card]->chip[chipnr]->int_cpu_reg = iCPU_DSC | iCPU_DMC;
	candevices_p[card]->chip[chipnr]->int_clk_reg = iCLK_SL1 | iCLK_CD0;
	candevices_p[card]->chip[chipnr]->int_bus_reg = iBUS_CBY | iBUS_DR1;
	candevices_p[card]->chip[chipnr]->sja_cdr_reg = 0;
	candevices_p[card]->chip[chipnr]->sja_ocr_reg = 0;
	pcccan_irq=candevices_p[card]->chip[chipnr]->chip_irq;
	pcccan_base=candevices_p[card]->chip[chipnr]->chip_base_addr;

	return 0;
}

/**
 * pcccan_init_obj_data - Initialize message buffers
 * @chipnr: Number of the CAN chip
 * @objnr: Number of the message buffer
 *
 * The function pcccan_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.
 * Return Value: The function always returns zero
 * File: src/pcccan.c
 */
int pcccan_init_obj_data(int chipnr, int objnr)
{
	chips_p[chipnr]->msgobj[objnr]->obj_base_addr=(objnr+1)*0x10;
	chips_p[chipnr]->msgobj[objnr]->flags=0;
	
	return 0;
}

/**
 * pcccan_program_irq - program interrupts
 * @card: Number of the hardware card.
 *
 * The function pcccan_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.
 * Return value: The function returns zero on success or %-ENODEV on failure
 * File: src/pcccan.c
 */
int pcccan_program_irq(int card)
{
	return 0;
}

/**
 * pcccan_write_register - Low level write register routine
 * @data: data to be written
 * @address: memory address to write to
 *
 * The function pcccan_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.
 * Return Value: The function does not return a value
 * File: src/pcccan.c
 */
void pcccan_write_register(unsigned char data, unsigned long address)
{
	disable_irq(pcccan_irq);
	outb(address - pcccan_base, pcccan_base+1);
	outb(data, pcccan_base+6);
	enable_irq(pcccan_irq);
}

/**
 * pcccan_read_register - Low level read register routine
 * @address: memory address to read from
 *
 * The function pcccan_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.
 * Return Value: The function returns the value stored in @address
 * File: src/pcccan.c
 */
unsigned pcccan_read_register(unsigned long address)
{
	unsigned ret;
	disable_irq(pcccan_irq);
	outb(address - pcccan_base, pcccan_base+1);
	ret=inb(pcccan_base+2);
	enable_irq(pcccan_irq);
	return ret;

}

/* !!! Don't change this function !!! */
int pcccan_register(struct hwspecops_t *hwspecops)
{
	hwspecops->request_io = pcccan_request_io;
	hwspecops->release_io = pcccan_release_io;
	hwspecops->reset = pcccan_reset;
	hwspecops->init_hw_data = pcccan_init_hw_data;
	hwspecops->init_chip_data = pcccan_init_chip_data;
	hwspecops->init_obj_data = pcccan_init_obj_data;
	hwspecops->write_register = pcccan_write_register;
	hwspecops->read_register = pcccan_read_register;
	hwspecops->program_irq = pcccan_program_irq;
	return 0;
}