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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  */
rt2x00mmio_regbusy_read(struct rt2x00_dev * rt2x00dev,const unsigned int offset,const struct rt2x00_field32 field,u32 * reg)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 		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 }
58 EXPORT_SYMBOL_GPL(rt2x00mmio_regbusy_read);
59 
rt2x00mmio_rxdone(struct rt2x00_dev * rt2x00dev)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 
rt2x00mmio_flush_queue(struct data_queue * queue,bool drop)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(10);
105 }
106 EXPORT_SYMBOL_GPL(rt2x00mmio_flush_queue);
107 
108 /*
109  * Device initialization handlers.
110  */
rt2x00mmio_alloc_queue_dma(struct rt2x00_dev * rt2x00dev,struct data_queue * queue)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_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 
rt2x00mmio_free_queue_dma(struct rt2x00_dev * rt2x00dev,struct data_queue * queue)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 
rt2x00mmio_initialize(struct rt2x00_dev * rt2x00dev)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 
rt2x00mmio_uninitialize(struct rt2x00_dev * rt2x00dev)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");
213