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 */
35int 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		rt2x00mmio_register_read(rt2x00dev, offset, reg);
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}
58EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
59
60bool 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}
97EXPORT_SYMBOL_GPL(rt2x00mmio_rxdone);
98
99void 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(10);
105}
106EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
107
108/*
109 * Device initialization handlers.
110 */
111static 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_zalloc_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
140static 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
153int 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
181exit:
182	queue_for_each(rt2x00dev, queue)
183		rt2x00mmio_free_queue_dma(rt2x00dev, queue);
184
185	return status;
186}
187EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
188
189void 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}
204EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
205
206/*
207 * rt2x00mmio module information.
208 */
209MODULE_AUTHOR(DRV_PROJECT);
210MODULE_VERSION(DRV_VERSION);
211MODULE_DESCRIPTION("rt2x00 mmio library");
212MODULE_LICENSE("GPL");
213