LXR linux/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
  28int 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
  57EXPORT_SYMBOL_GPL(gxio_uart_init);
  58
  59int 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
  70EXPORT_SYMBOL_GPL(gxio_uart_destroy);
  71
  72/* UART register write wrapper. */
  73void 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
  79EXPORT_SYMBOL_GPL(gxio_uart_write);
  80
  81/* UART register read wrapper. */
  82uint64_t gxio_uart_read(gxio_uart_context_t *context, uint64_t offset)
  83{
  84        return __gxio_mmio_read(context->mmio_base + offset);
  85}
  86
  87EXPORT_SYMBOL_GPL(gxio_uart_read);
  88