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 */
24int 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}
47EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
48
49bool 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, index: 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(skb: 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}
86EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);
87
88void 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(msecs: 50);
94}
95EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
96
97/*
98 * Device initialization handlers.
99 */
100static 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(dev: rt2x00dev->dev,
112 size: queue->limit * queue->desc_size, dma_handle: &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
129static 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(dev: rt2x00dev->dev,
137 size: queue->limit * queue->desc_size,
138 cpu_addr: entry_priv->desc, dma_handle: entry_priv->desc_dma);
139 entry_priv->desc = NULL;
140}
141
142int 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(irq: rt2x00dev->irq,
160 handler: rt2x00dev->ops->lib->irq_handler,
161 IRQF_SHARED, name: rt2x00dev->name, dev: 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
170exit:
171 queue_for_each(rt2x00dev, queue)
172 rt2x00mmio_free_queue_dma(rt2x00dev, queue);
173
174 return status;
175}
176EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
177
178void 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}
193EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
194
195/*
196 * rt2x00mmio module information.
197 */
198MODULE_AUTHOR(DRV_PROJECT);
199MODULE_VERSION(DRV_VERSION);
200MODULE_DESCRIPTION("rt2x00 mmio library");
201MODULE_LICENSE("GPL");
202

source code of linux/drivers/net/wireless/ralink/rt2x00/rt2x00mmio.c