drivers/parport/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/threads.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_ADDRESS    0x3350010
  32
  33 /* This is equivalent to the above and only used for request_region. */
  34 #define PORT_BASE       0x80000000 | ((DATA_ADDRESS - IO_BASE) >> 2)
  35
  36 /* The hardware can't read from the data latch, so we must use a soft
  37    copy. */
  38 static unsigned char data_copy;
  39
  40 /* These are pretty simple. We know the irq is never shared and the
  41    kernel does all the magic that's required. */
  42 static void arc_enable_irq(struct parport *p)
  43 {
  44         enable_irq(p->irq);
  45 }
  46
  47 static void arc_disable_irq(struct parport *p)
  48 {
  49         disable_irq(p->irq);
  50 }
  51
  52 static void arc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  53 {
  54         parport_generic_irq(irq, (struct parport *) dev_id, regs);
  55 }
  56
  57 static void arc_write_data(struct parport *p, unsigned char data)
  58 {
  59         data_copy = data;
  60         outb_t(data, DATA_LATCH);
  61 }
  62
  63 static unsigned char arc_read_data(struct parport *p)
  64 {
  65         return data_copy;
  66 }
  67
  68 static void arc_inc_use_count(void)
  69 {
  70 #ifdef MODULE
  71         MOD_INC_USE_COUNT;
  72 #endif
  73 }
  74
  75 static void arc_dec_use_count(void)
  76 {
  77 #ifdef MODULE
  78         MOD_DEC_USE_COUNT;
  79 #endif
  80 }
  81
  82 static void arc_fill_inode(struct inode *inode, int fill)
  83 {
  84 #ifdef MODULE
  85         if (fill)
  86                 MOD_INC_USE_COUNT;
  87         else
  88                 MOD_DEC_USE_COUNT;
  89 #endif
  90 }
  91
  92 static struct parport_operations parport_arc_ops =
  93 {
  94         arc_write_data,
  95         arc_read_data,
  96
  97         arc_write_control,
  98         arc_read_control,
  99         arc_frob_control,
 100
 101         arc_read_status,
 102
 103         arc_enable_irq,
 104         arc_disable_irq,
 105
 106         arc_data_forward,
 107         arc_data_reverse,
 108
 109         arc_interrupt,
 110
 111         arc_init_state,
 112         arc_save_state,
 113         arc_restore_state,
 114
 115         arc_inc_use_count,
 116         arc_dec_use_count,
 117         arc_fill_inode,
 118
 119         parport_ieee1284_epp_write_data,
 120         parport_ieee1284_epp_read_data,
 121         parport_ieee1284_epp_write_addr,
 122         parport_ieee1284_epp_read_addr,
 123
 124         parport_ieee1284_ecp_write_data,
 125         parport_ieee1284_ecp_read_data,
 126         parport_ieee1284_ecp_write_addr,
 127
 128         parport_ieee1284_write_compat,
 129         parport_ieee1284_read_nibble,
 130         parport_ieee1284_read_byte,
 131 };
 132
 133 /* --- Initialisation code -------------------------------- */
 134
 135 int parport_arc_init(void)
 136 {
 137         /* Archimedes hardware provides only one port, at a fixed address */
 138         struct parport *p;
 139
 140         if (check_region(PORT_BASE, 1))
 141                 return 0;
 142
 143         p = parport_register_port (PORT_BASE, IRQ_PRINTERACK,
 144                                    PARPORT_DMA_NONE, &parport_arc_ops);
 145
 146         if (!p)
 147                 return 0;
 148
 149         p->modes = PARPORT_MODE_ARCSPP;
 150         p->size = 1;
 151
 152         printk(KERN_INFO "%s: Archimedes on-board port, using irq %d\n",
 153                p->irq);
 154         parport_proc_register(p);
 155
 156         /* Tell the high-level drivers about the port. */
 157         parport_announce_port (p);
 158
 159         return 1;
 160 }