rt2x00mmio.c

  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, 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(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(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(rt2x00dev->dev,
112				  queue->limit * queue->desc_size, &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(rt2x00dev->dev,
137				  queue->limit * queue->desc_size,
138				  entry_priv->desc, 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(rt2x00dev->irq,
160			     rt2x00dev->ops->lib->irq_handler,
161			     IRQF_SHARED, rt2x00dev->name, 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");