drivers/net/wireless/ralink/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, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /*
  20         Module: rt2x00mmio
  21         Abstract: rt2x00 generic mmio device routines.
  22  */
  23
  24 #include <linux/dma-mapping.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28
  29 #include "rt2x00.h"
  30 #include "rt2x00mmio.h"
  31
  32 /*
  33  * Register access.
  34  */
  35 int rt2x00mmio_regbusy_read(struct rt2x00_dev *rt2x00dev,
  36                             const unsigned int offset,
  37                             const struct rt2x00_field32 field,
  38                             u32 *reg)
  39 {
  40         unsigned int i;
  41
  42         if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
  43                 return 0;
  44
  45         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
  46                 *reg = rt2x00mmio_register_read(rt2x00dev, offset);
  47                 if (!rt2x00_get_field32(*reg, field))
  48                         return 1;
  49                 udelay(REGISTER_BUSY_DELAY);
  50         }
  51
  52         printk_once(KERN_ERR "%s() Indirect register access failed: "
  53               "offset=0x%.08x, value=0x%.08x\n", __func__, offset, *reg);
  54         *reg = ~0;
  55
  56         return 0;
  57 }
  58 EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
  59
  60 bool rt2x00mmio_rxdone(struct rt2x00_dev *rt2x00dev)
  61 {
  62         struct data_queue *queue = rt2x00dev->rx;
  63         struct queue_entry *entry;
  64         struct queue_entry_priv_mmio *entry_priv;
  65         struct skb_frame_desc *skbdesc;
  66         int max_rx = 16;
  67
  68         while (--max_rx) {
  69                 entry = rt2x00queue_get_entry(queue, Q_INDEX);
  70                 entry_priv = entry->priv_data;
  71
  72                 if (rt2x00dev->ops->lib->get_entry_state(entry))
  73                         break;
  74
  75                 /*
  76                  * Fill in desc fields of the skb descriptor
  77                  */
  78                 skbdesc = get_skb_frame_desc(entry->skb);
  79                 skbdesc->desc = entry_priv->desc;
  80                 skbdesc->desc_len = entry->queue->desc_size;
  81
  82                 /*
  83                  * DMA is already done, notify rt2x00lib that
  84                  * it finished successfully.
  85                  */
  86                 rt2x00lib_dmastart(entry);
  87                 rt2x00lib_dmadone(entry);
  88
  89                 /*
  90                  * Send the frame to rt2x00lib for further processing.
  91                  */
  92                 rt2x00lib_rxdone(entry, GFP_ATOMIC);
  93         }
  94
  95         return !max_rx;
  96 }
  97 EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);
  98
  99 void rt2x00mmio_flush_queue(struct data_queue *queue, bool drop)
 100 {
 101         unsigned int i;
 102
 103         for (i = 0; !rt2x00queue_empty(queue) && i < 10; i++)
 104                 msleep(50);
 105 }
 106 EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
 107
 108 /*
 109  * Device initialization handlers.
 110  */
 111 static int rt2x00mmio_alloc_queue_dma(struct rt2x00_dev *rt2x00dev,
 112                                       struct data_queue *queue)
 113 {
 114         struct queue_entry_priv_mmio *entry_priv;
 115         void *addr;
 116         dma_addr_t dma;
 117         unsigned int i;
 118
 119         /*
 120          * Allocate DMA memory for descriptor and buffer.
 121          */
 122         addr = dma_alloc_coherent(rt2x00dev->dev,
 123                                   queue->limit * queue->desc_size, &dma,
 124                                   GFP_KERNEL);
 125         if (!addr)
 126                 return -ENOMEM;
 127
 128         /*
 129          * Initialize all queue entries to contain valid addresses.
 130          */
 131         for (i = 0; i < queue->limit; i++) {
 132                 entry_priv = queue->entries[i].priv_data;
 133                 entry_priv->desc = addr + i * queue->desc_size;
 134                 entry_priv->desc_dma = dma + i * queue->desc_size;
 135         }
 136
 137         return 0;
 138 }
 139
 140 static void rt2x00mmio_free_queue_dma(struct rt2x00_dev *rt2x00dev,
 141                                       struct data_queue *queue)
 142 {
 143         struct queue_entry_priv_mmio *entry_priv =
 144             queue->entries[0].priv_data;
 145
 146         if (entry_priv->desc)
 147                 dma_free_coherent(rt2x00dev->dev,
 148                                   queue->limit * queue->desc_size,
 149                                   entry_priv->desc, entry_priv->desc_dma);
 150         entry_priv->desc = NULL;
 151 }
 152
 153 int rt2x00mmio_initialize(struct rt2x00_dev *rt2x00dev)
 154 {
 155         struct data_queue *queue;
 156         int status;
 157
 158         /*
 159          * Allocate DMA
 160          */
 161         queue_for_each(rt2x00dev, queue) {
 162                 status = rt2x00mmio_alloc_queue_dma(rt2x00dev, queue);
 163                 if (status)
 164                         goto exit;
 165         }
 166
 167         /*
 168          * Register interrupt handler.
 169          */
 170         status = request_irq(rt2x00dev->irq,
 171                              rt2x00dev->ops->lib->irq_handler,
 172                              IRQF_SHARED, rt2x00dev->name, rt2x00dev);
 173         if (status) {
 174                 rt2x00_err(rt2x00dev, "IRQ %d allocation failed (error %d)\n",
 175                            rt2x00dev->irq, status);
 176                 goto exit;
 177         }
 178
 179         return 0;
 180
 181 exit:
 182         queue_for_each(rt2x00dev, queue)
 183                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 184
 185         return status;
 186 }
 187 EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
 188
 189 void rt2x00mmio_uninitialize(struct rt2x00_dev *rt2x00dev)
 190 {
 191         struct data_queue *queue;
 192
 193         /*
 194          * Free irq line.
 195          */
 196         free_irq(rt2x00dev->irq, rt2x00dev);
 197
 198         /*
 199          * Free DMA
 200          */
 201         queue_for_each(rt2x00dev, queue)
 202                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 203 }
 204 EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
 205
 206 /*
 207  * rt2x00mmio module information.
 208  */
 209 MODULE_AUTHOR(DRV_PROJECT);
 210 MODULE_VERSION(DRV_VERSION);
 211 MODULE_DESCRIPTION("rt2x00 mmio library");
 212 MODULE_LICENSE("GPL");