drivers/net/wireless/ralink/rt2x00/rt2x00mmio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3         Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
   4         <http://rt2x00.serialmonkey.com>
   5
   6  */
   7
   8 /*
   9         Module: rt2x00mmio
  10         Abstract: rt2x00 generic mmio device routines.
  11  */
  12
  13 #include <linux/dma-mapping.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17
  18 #include "rt2x00.h"
  19 #include "rt2x00mmio.h"
  20
  21 /*
  22  * Register access.
  23  */
  24 int rt2x00mmio_regbusy_read(struct rt2x00_dev *rt2x00dev,
  25                             const unsigned int offset,
  26                             const struct rt2x00_field32 field,
  27                             u32 *reg)
  28 {
  29         unsigned int i;
  30
  31         if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
  32                 return 0;
  33
  34         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
  35                 *reg = rt2x00mmio_register_read(rt2x00dev, offset);
  36                 if (!rt2x00_get_field32(*reg, field))
  37                         return 1;
  38                 udelay(REGISTER_BUSY_DELAY);
  39         }
  40
  41         printk_once(KERN_ERR "%s() Indirect register access failed: "
  42               "offset=0x%.08x, value=0x%.08x\n", __func__, offset, *reg);
  43         *reg = ~0;
  44
  45         return 0;
  46 }
  47 EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
  48
  49 bool rt2x00mmio_rxdone(struct rt2x00_dev *rt2x00dev)
  50 {
  51         struct data_queue *queue = rt2x00dev->rx;
  52         struct queue_entry *entry;
  53         struct queue_entry_priv_mmio *entry_priv;
  54         struct skb_frame_desc *skbdesc;
  55         int max_rx = 16;
  56
  57         while (--max_rx) {
  58                 entry = rt2x00queue_get_entry(queue, Q_INDEX);
  59                 entry_priv = entry->priv_data;
  60
  61                 if (rt2x00dev->ops->lib->get_entry_state(entry))
  62                         break;
  63
  64                 /*
  65                  * Fill in desc fields of the skb descriptor
  66                  */
  67                 skbdesc = get_skb_frame_desc(entry->skb);
  68                 skbdesc->desc = entry_priv->desc;
  69                 skbdesc->desc_len = entry->queue->desc_size;
  70
  71                 /*
  72                  * DMA is already done, notify rt2x00lib that
  73                  * it finished successfully.
  74                  */
  75                 rt2x00lib_dmastart(entry);
  76                 rt2x00lib_dmadone(entry);
  77
  78                 /*
  79                  * Send the frame to rt2x00lib for further processing.
  80                  */
  81                 rt2x00lib_rxdone(entry, GFP_ATOMIC);
  82         }
  83
  84         return !max_rx;
  85 }
  86 EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);
  87
  88 void rt2x00mmio_flush_queue(struct data_queue *queue, bool drop)
  89 {
  90         unsigned int i;
  91
  92         for (i = 0; !rt2x00queue_empty(queue) && i < 10; i++)
  93                 msleep(50);
  94 }
  95 EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
  96
  97 /*
  98  * Device initialization handlers.
  99  */
 100 static int rt2x00mmio_alloc_queue_dma(struct rt2x00_dev *rt2x00dev,
 101                                       struct data_queue *queue)
 102 {
 103         struct queue_entry_priv_mmio *entry_priv;
 104         void *addr;
 105         dma_addr_t dma;
 106         unsigned int i;
 107
 108         /*
 109          * Allocate DMA memory for descriptor and buffer.
 110          */
 111         addr = dma_alloc_coherent(rt2x00dev->dev,
 112                                   queue->limit * queue->desc_size, &dma,
 113                                   GFP_KERNEL);
 114         if (!addr)
 115                 return -ENOMEM;
 116
 117         /*
 118          * Initialize all queue entries to contain valid addresses.
 119          */
 120         for (i = 0; i < queue->limit; i++) {
 121                 entry_priv = queue->entries[i].priv_data;
 122                 entry_priv->desc = addr + i * queue->desc_size;
 123                 entry_priv->desc_dma = dma + i * queue->desc_size;
 124         }
 125
 126         return 0;
 127 }
 128
 129 static void rt2x00mmio_free_queue_dma(struct rt2x00_dev *rt2x00dev,
 130                                       struct data_queue *queue)
 131 {
 132         struct queue_entry_priv_mmio *entry_priv =
 133             queue->entries[0].priv_data;
 134
 135         if (entry_priv->desc)
 136                 dma_free_coherent(rt2x00dev->dev,
 137                                   queue->limit * queue->desc_size,
 138                                   entry_priv->desc, entry_priv->desc_dma);
 139         entry_priv->desc = NULL;
 140 }
 141
 142 int rt2x00mmio_initialize(struct rt2x00_dev *rt2x00dev)
 143 {
 144         struct data_queue *queue;
 145         int status;
 146
 147         /*
 148          * Allocate DMA
 149          */
 150         queue_for_each(rt2x00dev, queue) {
 151                 status = rt2x00mmio_alloc_queue_dma(rt2x00dev, queue);
 152                 if (status)
 153                         goto exit;
 154         }
 155
 156         /*
 157          * Register interrupt handler.
 158          */
 159         status = request_irq(rt2x00dev->irq,
 160                              rt2x00dev->ops->lib->irq_handler,
 161                              IRQF_SHARED, rt2x00dev->name, rt2x00dev);
 162         if (status) {
 163                 rt2x00_err(rt2x00dev, "IRQ %d allocation failed (error %d)\n",
 164                            rt2x00dev->irq, status);
 165                 goto exit;
 166         }
 167
 168         return 0;
 169
 170 exit:
 171         queue_for_each(rt2x00dev, queue)
 172                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 173
 174         return status;
 175 }
 176 EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
 177
 178 void rt2x00mmio_uninitialize(struct rt2x00_dev *rt2x00dev)
 179 {
 180         struct data_queue *queue;
 181
 182         /*
 183          * Free irq line.
 184          */
 185         free_irq(rt2x00dev->irq, rt2x00dev);
 186
 187         /*
 188          * Free DMA
 189          */
 190         queue_for_each(rt2x00dev, queue)
 191                 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
 192 }
 193 EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
 194
 195 /*
 196  * rt2x00mmio module information.
 197  */
 198 MODULE_AUTHOR(DRV_PROJECT);
 199 MODULE_VERSION(DRV_VERSION);
 200 MODULE_DESCRIPTION("rt2x00 mmio library");
 201 MODULE_LICENSE("GPL");