drivers/misc/parport_arc.c

   1 /* Low-level parallel port routines for Archimedes onboard hardware
   2  *
   3  * Author: Phil Blundell <Philip.Blundell@pobox.com>
   4  */
   5
   6 /* This driver is for the parallel port hardware found on Acorn's old
   7  * range of Archimedes machines.  The A5000 and newer systems have PC-style
   8  * I/O hardware and should use the parport_pc driver instead.
   9  *
  10  * The Acorn printer port hardware is very simple.  There is a single 8-bit
  11  * write-only latch for the data port and control/status bits are handled
  12  * with various auxilliary input and output lines.  The port is not
  13  * bidirectional, does not support any modes other than SPP, and has only
  14  * a subset of the standard printer control lines connected.
  15  */
  16
  17 #include <linux/tasks.h>
  18 #include <linux/delay.h>
  19 #include <linux/errno.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/ioport.h>
  22 #include <linux/kernel.h>
  23 #include <linux/malloc.h>
  24 #include <linux/parport.h>
  25
  26 #include <asm/ptrace.h>
  27 #include <asm/io.h>
  28 #include <asm/arch/oldlatches.h>
  29 #include <asm/arch/irqs.h>
  30
  31 #define DATA_LATCH    0x3350010
  32
  33 /* ARC can't read from the data latch, so we must use a soft copy. */
  34 static unsigned char data_copy;
  35
  36 static void arc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  37 {
  38         parport_generic_irq(irq, (struct parport *) dev_id, regs);
  39 }
  40
  41 static void arc_write_data(struct parport *p, unsigned char data)
  42 {
  43         data_copy = data;
  44         outb(data, DATA_LATCH);
  45 }
  46
  47 static unsigned char arc_read_data(struct parport *p)
  48 {
  49         return data_copy;
  50 }
  51
  52 static void arc_inc_use_count(void)
  53 {
  54 #ifdef MODULE
  55         MOD_INC_USE_COUNT;
  56 #endif
  57 }
  58
  59 static void arc_dec_use_count(void)
  60 {
  61 #ifdef MODULE
  62         MOD_DEC_USE_COUNT;
  63 #endif
  64 }
  65
  66 static void arc_fill_inode(struct inode *inode, int fill)
  67 {
  68 #ifdef MODULE
  69         if (fill)
  70                 MOD_INC_USE_COUNT;
  71         else
  72                 MOD_DEC_USE_COUNT;
  73 #endif
  74 }
  75
  76 static struct parport_operations parport_arc_ops =
  77 {
  78         arc_write_data,
  79         arc_read_data,
  80
  81         arc_write_control,
  82         arc_read_control,
  83         arc_frob_control,
  84
  85         NULL, /* write_econtrol */
  86         NULL, /* read_econtrol */
  87         NULL, /* frob_econtrol */
  88
  89         arc_write_status,
  90         arc_read_status,
  91
  92         NULL, /* write_fifo */
  93         NULL, /* read_fifo */
  94
  95         NULL, /* change_mode */
  96
  97         arc_release_resources,
  98         arc_claim_resources,
  99
 100         NULL, /* epp_write_data */
 101         NULL, /* epp_read_data */
 102         NULL, /* epp_write_addr */
 103         NULL, /* epp_read_addr */
 104         NULL, /* epp_check_timeout */
 105
 106         NULL, /* epp_write_block */
 107         NULL, /* epp_read_block */
 108
 109         NULL, /* ecp_write_block */
 110         NULL, /* epp_write_block */
 111
 112         arc_init_state,
 113         arc_save_state,
 114         arc_restore_state,
 115
 116         arc_enable_irq,
 117         arc_disable_irq,
 118         arc_interrupt,
 119
 120         arc_inc_use_count,
 121         arc_dec_use_count,
 122         arc_fill_inode
 123 };
 124
 125 /* --- Initialisation code -------------------------------- */
 126
 127 int parport_arc_init(void)
 128 {
 129         /* Archimedes hardware provides only one port, at a fixed address */
 130         struct parport *p;
 131
 132         if (check_region(DATA_LATCH, 4))
 133                 return 0;
 134
 135         if (!(p = parport_register_port(base, IRQ_PRINTERACK,
 136                                         PARPORT_DMA_NONE, &parport_arc_ops)))
 137                 return 0;
 138
 139         p->modes = PARPORT_MODE_ARCSPP;
 140         p->size = 4;
 141
 142         printk(KERN_INFO "%s: Archimedes on-board port, using irq %d\n",
 143                p->irq);
 144         parport_proc_register(p);
 145         p->flags |= PARPORT_FLAG_COMA;
 146
 147         if (parport_probe_hook)
 148                 (*parport_probe_hook)(p);
 149
 150         return 1;
 151 }