arch/tile/gxio/uart.c

   1 /*
   2  * Copyright 2013 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 /*
  16  * Implementation of UART gxio calls.
  17  */
  18
  19 #include <linux/io.h>
  20 #include <linux/errno.h>
  21 #include <linux/module.h>
  22
  23 #include <gxio/uart.h>
  24 #include <gxio/iorpc_globals.h>
  25 #include <gxio/iorpc_uart.h>
  26 #include <gxio/kiorpc.h>
  27
  28 int gxio_uart_init(gxio_uart_context_t *context, int uart_index)
  29 {
  30         char file[32];
  31         int fd;
  32
  33         snprintf(file, sizeof(file), "uart/%d/iorpc", uart_index);
  34         fd = hv_dev_open((HV_VirtAddr) file, 0);
  35         if (fd < 0) {
  36                 if (fd >= GXIO_ERR_MIN && fd <= GXIO_ERR_MAX)
  37                         return fd;
  38                 else
  39                         return -ENODEV;
  40         }
  41
  42         context->fd = fd;
  43
  44         /* Map in the MMIO space. */
  45         context->mmio_base = (void __force *)
  46                 iorpc_ioremap(fd, HV_UART_MMIO_OFFSET, HV_UART_MMIO_SIZE);
  47
  48         if (context->mmio_base == NULL) {
  49                 hv_dev_close(context->fd);
  50                 context->fd = -1;
  51                 return -ENODEV;
  52         }
  53
  54         return 0;
  55 }
  56
  57 EXPORT_SYMBOL_GPL(gxio_uart_init);
  58
  59 int gxio_uart_destroy(gxio_uart_context_t *context)
  60 {
  61         iounmap((void __force __iomem *)(context->mmio_base));
  62         hv_dev_close(context->fd);
  63
  64         context->mmio_base = NULL;
  65         context->fd = -1;
  66
  67         return 0;
  68 }
  69
  70 EXPORT_SYMBOL_GPL(gxio_uart_destroy);
  71
  72 /* UART register write wrapper. */
  73 void gxio_uart_write(gxio_uart_context_t *context, uint64_t offset,
  74                      uint64_t word)
  75 {
  76         __gxio_mmio_write(context->mmio_base + offset, word);
  77 }
  78
  79 EXPORT_SYMBOL_GPL(gxio_uart_write);
  80
  81 /* UART register read wrapper. */
  82 uint64_t gxio_uart_read(gxio_uart_context_t *context, uint64_t offset)
  83 {
  84         return __gxio_mmio_read(context->mmio_base + offset);
  85 }
  86
  87 EXPORT_SYMBOL_GPL(gxio_uart_read);