drivers/net/wireless/rt2x00/rt2x00mmio.c

   1 /*
   2         Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
   3         <http://rt2x00.serialmonkey.com>
   4
   5         This program is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU General Public License as published by
   7         the Free Software Foundation; either version 2 of the License, or
   8         (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13         GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to the
  17         Free Software Foundation, Inc.,
  18         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22         Module: rt2x00mmio
  23         Abstract: rt2x00 generic mmio device routines.
  24  */
  25
  26 #include <linux/dma-mapping.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/slab.h>
  30
  31 #include "rt2x00.h"
  32 #include "rt2x00mmio.h"
  33
  34 /*
  35  * Register access.
  36  */
  37 int rt2x00mmio_regbusy_read(struct rt2x00_dev *rt2x00dev,
  38                             const unsigned int offset,
  39                             const struct rt2x00_field32 field,
  40                             u32 *reg)
  41 {
  42         unsigned int i;
  43
  44         if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
  45                 return 0;
  46
  47         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
  48                 rt2x00mmio_register_read(rt2x00dev, offset, reg);
  49                 if (!rt2x00_get_field32(*reg, field))
  50                         return 1;
  51                 udelay(REGISTER_BUSY_DELAY);
  52         }
  53
  54         printk_once(KERN_ERR "%s() Indirect register access failed: "
  55               "offset=0x%.08x, value=0x%.08x\n", __func__, offset, *reg);
  56         *reg = ~0;
  57
  58         return 0;
  59 }
  60 EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
  61
  62 bool rt2x00mmio_rxdone(struct rt2x00_dev *rt2x00dev)
  63 {
  64         struct data_queue *queue = rt2x00dev->rx;
  65         struct queue_entry *entry;
  66         struct queue_entry_priv_mmio *entry_priv;
  67         struct skb_frame_desc *skbdesc;
  68         int max_rx = 16;
  69
  70         while (--max_rx) {
  71                 entry = rt2x00queue_get_entry(queue, Q_INDEX);
  72                 entry_priv = entry->priv_data;
  73
  74                 if (rt2x00dev->ops->lib->get_entry_state(entry))
  75                         break;
  76
  77                 /*
  78                  * Fill in desc fields of the skb descriptor
  79                  */
  80                 skbdesc = get_skb_frame_desc(entry->skb);
  81                 skbdesc->desc = entry_priv->desc;
  82                 skbdesc->desc_len = entry->queue->desc_size;
  83
  84                 /*
  85                  * DMA is already done, notify rt2x00lib that
  86                  * it finished successfully.
  87                  */
  88                 rt2x00lib_dmastart(entry);
  89                 rt2x00lib_dmadone(entry);
  90
  91                 /*
  92                  * Send the frame to rt2x00lib for further processing.
  93                  */
  94                 rt2x00lib_rxdone(entry, GFP_ATOMIC);
  95         }
  96
  97         return !max_rx;
  98 }
  99 EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);
 100
 101 void rt2x00mmio_flush_queue(struct data_queue *queue, bool drop)
 102 {
 103         unsigned int i;
 104
 105         for (i = 0; !rt2x00queue_empty(queue) && i < 10; i++)
 106                 msleep(10);
 107 }
 108 EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
 109
 110 /*
 111  * Device initialization handlers.
 112  */
 113 static int rt2x00mmio_alloc_queue_dma(struct rt2x00_dev *rt2x00dev,
 114                                       struct data_queue *queue)
 115 {
 116         struct queue_entry_priv_mmio *entry_priv;
 117         void *addr;
 118         dma_addr_t dma;
 119         unsigned int i;
 120
 121         /*
 122          * Allocate DMA memory for descriptor and buffer.
 123          */
 124         addr = dma_alloc_coherent(rt2x00dev->dev,
 125                                   queue->limit * queue->desc_size,
 126                                   &dma, GFP_KERNEL);
 127         if (!addr)
 128                 return -ENOMEM;
 129
 130         memset(addr, 0, queue->limit * queue->desc_size);
 131
 132         /*
 133          * Initialize all queue entries to contain valid addresses.
 134          */
 135         for (i = 0; i < queue->limit; i++) {
 136                 entry_priv = queue->entries[i].priv_data;
 137                 entry_priv->desc = addr + i * queue->desc_size;
 138                 entry_priv->desc_dma = dma + i * queue->desc_size;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static void rt2x00mmio_free_queue_dma(struct rt2x00_dev *rt2x00dev,
 145                                       struct data_queue *queue)
 146 {
 147         struct queue_entry_priv_mmio *entry_priv =
 148             queue->entries[0].priv_data;
 149
 150         if (entry_priv->desc)
 151                 dma_free_coherent(rt2x00dev->dev,
 152                                   queue->limit * queue->desc_size,
 153                                   entry_priv->desc, entry_priv->desc_dma);
 154         entry_priv->desc = NULL;
 155 }
 156
 157 int rt2x00mmio_initialize(struct rt2x00_dev *rt2x00dev)
 158 {
 159         struct data_queue *queue;
 160         int status;
 161
 162         /*
 163          * Allocate DMA
 164          */
 165         queue_for_each(rt2x00dev, queue) {
 166                 status = rt2x00mmio_alloc_queue_dma(rt2x00dev, queue);
 167                 if (status)
 168                         goto exit;
 169         }
 170
 171         /*
 172          * Register interrupt handler.
 173          */
 174         status = request_irq(rt2x00dev->irq,
 175                              rt2x00dev->ops->lib->irq_handler,
 176                              IRQF_SHARED, rt2x00dev->name, rt2x00dev);
 177         if (status) {
 178                 rt2x00_err(rt2x00dev, "IRQ %d allocation failed (error %d)\n",
 179                            rt2x00dev->irq, status);
 180                 goto exit;
 181         }
 182
 183         return 0;
 184
 185 exit:
 186         queue_for_each(rt2x00dev, queue)
 187                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 188
 189         return status;
 190 }
 191 EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
 192
 193 void rt2x00mmio_uninitialize(struct rt2x00_dev *rt2x00dev)
 194 {
 195         struct data_queue *queue;
 196
 197         /*
 198          * Free irq line.
 199          */
 200         free_irq(rt2x00dev->irq, rt2x00dev);
 201
 202         /*
 203          * Free DMA
 204          */
 205         queue_for_each(rt2x00dev, queue)
 206                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 207 }
 208 EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
 209
 210 /*
 211  * rt2x00mmio module information.
 212  */
 213 MODULE_AUTHOR(DRV_PROJECT);
 214 MODULE_VERSION(DRV_VERSION);
 215 MODULE_DESCRIPTION("rt2x00 mmio library");
 216 MODULE_LICENSE("GPL");