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_alloc_coherent(rt2x00dev->dev,
123				  queue->limit * queue->desc_size,
124				  &dma, GFP_KERNEL);
125	if (!addr)
126		return -ENOMEM;
127
128	memset(addr, 0, queue->limit * queue->desc_size);
129
130	/*
131	 * Initialize all queue entries to contain valid addresses.
132	 */
133	for (i = 0; i < queue->limit; i++) {
134		entry_priv = queue->entries[i].priv_data;
135		entry_priv->desc = addr + i * queue->desc_size;
136		entry_priv->desc_dma = dma + i * queue->desc_size;
137	}
138
139	return 0;
140}
141
142static void rt2x00mmio_free_queue_dma(struct rt2x00_dev *rt2x00dev,
143				      struct data_queue *queue)
144{
145	struct queue_entry_priv_mmio *entry_priv =
146	    queue->entries[0].priv_data;
147
148	if (entry_priv->desc)
149		dma_free_coherent(rt2x00dev->dev,
150				  queue->limit * queue->desc_size,
151				  entry_priv->desc, entry_priv->desc_dma);
152	entry_priv->desc = NULL;
153}
154
155int rt2x00mmio_initialize(struct rt2x00_dev *rt2x00dev)
156{
157	struct data_queue *queue;
158	int status;
159
160	/*
161	 * Allocate DMA
162	 */
163	queue_for_each(rt2x00dev, queue) {
164		status = rt2x00mmio_alloc_queue_dma(rt2x00dev, queue);
165		if (status)
166			goto exit;
167	}
168
169	/*
170	 * Register interrupt handler.
171	 */
172	status = request_irq(rt2x00dev->irq,
173			     rt2x00dev->ops->lib->irq_handler,
174			     IRQF_SHARED, rt2x00dev->name, rt2x00dev);
175	if (status) {
176		rt2x00_err(rt2x00dev, "IRQ %d allocation failed (error %d)\n",
177			   rt2x00dev->irq, status);
178		goto exit;
179	}
180
181	return 0;
182
183exit:
184	queue_for_each(rt2x00dev, queue)
185		rt2x00mmio_free_queue_dma(rt2x00dev, queue);
186
187	return status;
188}
189EXPORT_SYMBOL_GPL(rt2x00mmio_initialize);
190
191void rt2x00mmio_uninitialize(struct rt2x00_dev *rt2x00dev)
192{
193	struct data_queue *queue;
194
195	/*
196	 * Free irq line.
197	 */
198	free_irq(rt2x00dev->irq, rt2x00dev);
199
200	/*
201	 * Free DMA
202	 */
203	queue_for_each(rt2x00dev, queue)
204		rt2x00mmio_free_queue_dma(rt2x00dev, queue);
205}
206EXPORT_SYMBOL_GPL(rt2x00mmio_uninitialize);
207
208/*
209 * rt2x00mmio module information.
210 */
211MODULE_AUTHOR(DRV_PROJECT);
212MODULE_VERSION(DRV_VERSION);
213MODULE_DESCRIPTION("rt2x00 mmio library");
214MODULE_LICENSE("GPL");