Viewing file:  parport_arc.c (3.26 KB) -rw-r--r--
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/* Low-level parallel port routines for Archimedes onboard hardware
*
* Author: Phil Blundell <Philip.Blundell@pobox.com>
*/
/* This driver is for the parallel port hardware found on Acorn's old
* range of Archimedes machines. The A5000 and newer systems have PC-style
* I/O hardware and should use the parport_pc driver instead.
*
* The Acorn printer port hardware is very simple. There is a single 8-bit
* write-only latch for the data port and control/status bits are handled
* with various auxilliary input and output lines. The port is not
* bidirectional, does not support any modes other than SPP, and has only
* a subset of the standard printer control lines connected.
*/
#include <linux/threads.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/parport.h>
#include <asm/ptrace.h>
#include <asm/io.h>
#include <asm/arch/oldlatches.h>
#include <asm/arch/irqs.h>
#define DATA_ADDRESS 0x3350010
/* This is equivalent to the above and only used for request_region. */
#define PORT_BASE 0x80000000 | ((DATA_ADDRESS - IO_BASE) >> 2)
/* The hardware can't read from the data latch, so we must use a soft
copy. */
static unsigned char data_copy;
/* These are pretty simple. We know the irq is never shared and the
kernel does all the magic that's required. */
static void arc_enable_irq(struct parport *p)
{
enable_irq(p->irq);
}
static void arc_disable_irq(struct parport *p)
{
disable_irq(p->irq);
}
static void arc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
parport_generic_irq(irq, (struct parport *) dev_id, regs);
}
static void arc_write_data(struct parport *p, unsigned char data)
{
data_copy = data;
outb_t(data, DATA_LATCH);
}
static unsigned char arc_read_data(struct parport *p)
{
return data_copy;
}
static void arc_inc_use_count(void)
{
#ifdef MODULE
MOD_INC_USE_COUNT;
#endif
}
static void arc_dec_use_count(void)
{
#ifdef MODULE
MOD_DEC_USE_COUNT;
#endif
}
static struct parport_operations parport_arc_ops =
{
arc_write_data,
arc_read_data,
arc_write_control,
arc_read_control,
arc_frob_control,
arc_read_status,
arc_enable_irq,
arc_disable_irq,
arc_data_forward,
arc_data_reverse,
arc_init_state,
arc_save_state,
arc_restore_state,
arc_inc_use_count,
arc_dec_use_count,
parport_ieee1284_epp_write_data,
parport_ieee1284_epp_read_data,
parport_ieee1284_epp_write_addr,
parport_ieee1284_epp_read_addr,
parport_ieee1284_ecp_write_data,
parport_ieee1284_ecp_read_data,
parport_ieee1284_ecp_write_addr,
parport_ieee1284_write_compat,
parport_ieee1284_read_nibble,
parport_ieee1284_read_byte,
};
/* --- Initialisation code -------------------------------- */
int parport_arc_init(void)
{
/* Archimedes hardware provides only one port, at a fixed address */
struct parport *p;
if (check_region(PORT_BASE, 1))
return 0;
p = parport_register_port (PORT_BASE, IRQ_PRINTERACK,
PARPORT_DMA_NONE, &parport_arc_ops);
if (!p)
return 0;
p->modes = PARPORT_MODE_ARCSPP;
p->size = 1;
printk(KERN_INFO "%s: Archimedes on-board port, using irq %d\n",
p->irq);
parport_proc_register(p);
/* Tell the high-level drivers about the port. */
parport_announce_port (p);
return 1;
}
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