140 lines
3.6 KiB
C
140 lines
3.6 KiB
C
/* Low-level parallel port routines for Archimedes onboard hardware
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*
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* Author: Phil Blundell <philb@gnu.org>
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*/
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/* This driver is for the parallel port hardware found on Acorn's old
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* range of Archimedes machines. The A5000 and newer systems have PC-style
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* I/O hardware and should use the parport_pc driver instead.
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*
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* The Acorn printer port hardware is very simple. There is a single 8-bit
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* write-only latch for the data port and control/status bits are handled
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* with various auxilliary input and output lines. The port is not
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* bidirectional, does not support any modes other than SPP, and has only
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* a subset of the standard printer control lines connected.
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*/
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#include <linux/threads.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/parport.h>
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#include <asm/ptrace.h>
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#include <asm/io.h>
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#include <asm/arch/oldlatches.h>
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#include <asm/arch/irqs.h>
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#define DATA_ADDRESS 0x3350010
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/* This is equivalent to the above and only used for request_region. */
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#define PORT_BASE 0x80000000 | ((DATA_ADDRESS - IO_BASE) >> 2)
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/* The hardware can't read from the data latch, so we must use a soft
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copy. */
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static unsigned char data_copy;
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/* These are pretty simple. We know the irq is never shared and the
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kernel does all the magic that's required. */
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static void arc_enable_irq(struct parport *p)
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{
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enable_irq(p->irq);
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}
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static void arc_disable_irq(struct parport *p)
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{
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disable_irq(p->irq);
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}
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static void arc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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{
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parport_generic_irq(irq, (struct parport *) dev_id, regs);
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}
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static void arc_write_data(struct parport *p, unsigned char data)
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{
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data_copy = data;
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outb_t(data, DATA_LATCH);
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}
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static unsigned char arc_read_data(struct parport *p)
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{
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return data_copy;
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}
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static struct parport_operations parport_arc_ops =
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{
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.write_data = arc_write_data,
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.read_data = arc_read_data,
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.write_control = arc_write_control,
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.read_control = arc_read_control,
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.frob_control = arc_frob_control,
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.read_status = arc_read_status,
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.enable_irq = arc_enable_irq,
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.disable_irq = arc_disable_irq,
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.data_forward = arc_data_forward,
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.data_reverse = arc_data_reverse,
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.init_state = arc_init_state,
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.save_state = arc_save_state,
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.restore_state = arc_restore_state,
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.epp_write_data = parport_ieee1284_epp_write_data,
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.epp_read_data = parport_ieee1284_epp_read_data,
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.epp_write_addr = parport_ieee1284_epp_write_addr,
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.epp_read_addr = parport_ieee1284_epp_read_addr,
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.ecp_write_data = parport_ieee1284_ecp_write_data,
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.ecp_read_data = parport_ieee1284_ecp_read_data,
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.ecp_write_addr = parport_ieee1284_ecp_write_addr,
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.compat_write_data = parport_ieee1284_write_compat,
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.nibble_read_data = parport_ieee1284_read_nibble,
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.byte_read_data = parport_ieee1284_read_byte,
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.owner = THIS_MODULE,
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};
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/* --- Initialisation code -------------------------------- */
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static int parport_arc_init(void)
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{
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/* Archimedes hardware provides only one port, at a fixed address */
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struct parport *p;
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struct resource res;
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char *fake_name = "parport probe");
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res = request_region(PORT_BASE, 1, fake_name);
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if (res == NULL)
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return 0;
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p = parport_register_port (PORT_BASE, IRQ_PRINTERACK,
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PARPORT_DMA_NONE, &parport_arc_ops);
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if (!p) {
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release_region(PORT_BASE, 1);
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return 0;
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}
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p->modes = PARPORT_MODE_ARCSPP;
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p->size = 1;
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rename_region(res, p->name);
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printk(KERN_INFO "%s: Archimedes on-board port, using irq %d\n",
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p->irq);
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/* Tell the high-level drivers about the port. */
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parport_announce_port (p);
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return 1;
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}
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module_init(parport_arc_init)
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