summaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/ralink/rt2x00/rt2x00mmio.c
blob: 528cb0401df1de715643d3d959456af3f793bd18 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

/*
	Module: rt2x00mmio
	Abstract: rt2x00 generic mmio device routines.
 */

#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "rt2x00.h"
#include "rt2x00mmio.h"

/*
 * Register access.
 */
int rt2x00mmio_regbusy_read(struct rt2x00_dev *rt2x00dev,
			    const unsigned int offset,
			    const struct rt2x00_field32 field,
			    u32 *reg)
{
	unsigned int i;

	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		return 0;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
		*reg = rt2x00mmio_register_read(rt2x00dev, offset);
		if (!rt2x00_get_field32(*reg, field))
			return 1;
		udelay(REGISTER_BUSY_DELAY);
	}

	printk_once(KERN_ERR "%s() Indirect register access failed: "
	      "offset=0x%.08x, value=0x%.08x\n", __func__, offset, *reg);
	*reg = ~0;

	return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);

bool rt2x00mmio_rxdone(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue = rt2x00dev->rx;
	struct queue_entry *entry;
	struct queue_entry_priv_mmio *entry_priv;
	struct skb_frame_desc *skbdesc;
	int max_rx = 16;

	while (--max_rx) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX);
		entry_priv = entry->priv_data;

		if (rt2x00dev->ops->lib->get_entry_state(entry))
			break;

		/*
		 * Fill in desc fields of the skb descriptor
		 */
		skbdesc = get_skb_frame_desc(entry->skb);
		skbdesc->desc = entry_priv->desc;
		skbdesc->desc_len = entry->queue->desc_size;

		/*
		 * DMA is already done, notify rt2x00lib that
		 * it finished successfully.
		 */
		rt2x00lib_dmastart(entry);
		rt2x00lib_dmadone(entry);

		/*
		 * Send the frame to rt2x00lib for further processing.
		 */
		rt2x00lib_rxdone(entry, GFP_ATOMIC);
	}

	return !max_rx;
}
EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);

void rt2x00mmio_flush_queue(struct data_queue *queue, bool drop)
{
	unsigned int i;

	for (i = 0; !rt2x00queue_empty(queue) && i < 10; i++)
		msleep(50);
}
EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);

/*
 * Device initialization handlers.
 */
static int rt2x00mmio_alloc_queue_dma(struct rt2x00_dev *rt2x00dev,
				      struct data_queue *queue)
{
	struct queue_entry_priv_mmio *entry_priv;
	void *addr;
	dma_addr_t dma;
	unsigned int i;

	/*
	 * Allocate DMA memory for descriptor and buffer.
	 */
	addr = dma_zalloc_coherent(rt2x00dev->dev,
				   queue->limit * queue->desc_size, &dma,
				   GFP_KERNEL);
	if (!addr)
		return -ENOMEM;

	/*
	 * Initialize all queue entries to contain valid addresses.
	 */
	for (i = 0; i < queue->limit; i++) {
		entry_priv = queue->entries[i].priv_data;
		entry_priv->desc = addr + i * queue->desc_size;
		entry_priv->desc_dma = dma + i * queue->desc_size;
	}

	return 0;
}

static void rt2x00mmio_free_queue_dma(struct rt2x00_dev *rt2x00dev,
				      struct data_queue *queue)
{
	struct queue_entry_priv_mmio *entry_priv =
	    queue->entries[0].priv_data;

	if (entry_priv->desc)
		dma_free_coherent(rt2x00dev->dev,
				  queue->limit * queue->desc_size,
				  entry_priv->desc, entry_priv->desc_dma);
	entry_priv->desc = NULL;
}

int rt2x00mmio_initialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	int status;

	/*
	 * Allocate DMA
	 */
	queue_for_each(rt2x00dev, queue) {
		status = rt2x00mmio_alloc_queue_dma(rt2x00dev, queue);
		if (status)
			goto exit;
	}

	/*
	 * Register interrupt handler.
	 */
	status = request_irq(rt2x00dev->irq,
			     rt2x00dev->ops->lib->irq_handler,
			     IRQF_SHARED, rt2x00dev->name, rt2x00dev);
	if (status) {
		rt2x00_err(rt2x00dev, "IRQ %d allocation failed (error %d)\n",
			   rt2x00dev->irq, status);
		goto exit;
	}

	return 0;

exit:
	queue_for_each(rt2x00dev, queue)
		rt2x00mmio_free_queue_dma(rt2x00dev, queue);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);

void rt2x00mmio_uninitialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;

	/*
	 * Free irq line.
	 */
	free_irq(rt2x00dev->irq, rt2x00dev);

	/*
	 * Free DMA
	 */
	queue_for_each(rt2x00dev, queue)
		rt2x00mmio_free_queue_dma(rt2x00dev, queue);
}
EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);

/*
 * rt2x00mmio module information.
 */
MODULE_AUTHOR(DRV_PROJECT);
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("rt2x00 mmio library");
MODULE_LICENSE("GPL");