drivers/parport/parport_arc.c

   1 /* Low-level parallel port routines for Archimedes onboard hardware
   2  *
   3  * Author: Phil Blundell <philb@gnu.org>
   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/slab.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 struct parport_operations parport_arc_ops =
  69 {
  70         .write_data     = arc_write_data,
  71         .read_data      = arc_read_data,
  72
  73         .write_control  = arc_write_control,
  74         .read_control   = arc_read_control,
  75         .frob_control   = arc_frob_control,
  76
  77         .read_status    = arc_read_status,
  78
  79         .enable_irq     = arc_enable_irq,
  80         .disable_irq    = arc_disable_irq,
  81
  82         .data_forward   = arc_data_forward,
  83         .data_reverse   = arc_data_reverse,
  84
  85         .init_state     = arc_init_state,
  86         .save_state     = arc_save_state,
  87         .restore_state  = arc_restore_state,
  88
  89         .epp_write_data = parport_ieee1284_epp_write_data,
  90         .epp_read_data  = parport_ieee1284_epp_read_data,
  91         .epp_write_addr = parport_ieee1284_epp_write_addr,
  92         .epp_read_addr  = parport_ieee1284_epp_read_addr,
  93
  94         .ecp_write_data = parport_ieee1284_ecp_write_data,
  95         .ecp_read_data  = parport_ieee1284_ecp_read_data,
  96         .ecp_write_addr = parport_ieee1284_ecp_write_addr,
  97
  98         .compat_write_data      = parport_ieee1284_write_compat,
  99         .nibble_read_data       = parport_ieee1284_read_nibble,
 100         .byte_read_data         = parport_ieee1284_read_byte,
 101
 102         .owner          = THIS_MODULE,
 103 };
 104
 105 /* --- Initialisation code -------------------------------- */
 106
 107 static int parport_arc_init(void)
 108 {
 109         /* Archimedes hardware provides only one port, at a fixed address */
 110         struct parport *p;
 111         struct resource res;
 112         char *fake_name = "parport probe");
 113
 114         res = request_region(PORT_BASE, 1, fake_name);
 115         if (res == NULL)
 116                 return 0;
 117
 118         p = parport_register_port (PORT_BASE, IRQ_PRINTERACK,
 119                                    PARPORT_DMA_NONE, &parport_arc_ops);
 120
 121         if (!p) {
 122                 release_region(PORT_BASE, 1);
 123                 return 0;
 124         }
 125
 126         p->modes = PARPORT_MODE_ARCSPP;
 127         p->size = 1;
 128         rename_region(res, p->name);
 129
 130         printk(KERN_INFO "%s: Archimedes on-board port, using irq %d\n",
 131                p->irq);
 132
 133         /* Tell the high-level drivers about the port. */
 134         parport_announce_port (p);
 135
 136         return 1;
 137 }
 138
 139 module_init(parport_arc_init)