[linux-2.6-block.git] / drivers / mmc / host / tmio_mmc_dma.c

/*
 * linux/drivers/mmc/tmio_mmc_dma.c
 *
 * Copyright (C) 2010-2011 Guennadi Liakhovetski
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * DMA function for TMIO MMC implementations
 */

#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/mfd/tmio.h>
#include <linux/mmc/host.h>
#include <linux/mmc/tmio.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>

#include "tmio_mmc.h"

#define TMIO_MMC_MIN_DMA_LEN 8

static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
{
#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE)
	/* Switch DMA mode on or off - SuperH specific? */
	writew(enable ? 2 : 0, host->ctl + (0xd8 << host->bus_shift));
#endif
}

static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_rx;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	if (ret > 0)
		desc = chan->device->device_prep_slave_sg(chan, sg, ret,
			DMA_FROM_DEVICE, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		if (ret >= 0)
			ret = -EIO;
		host->chan_rx = NULL;
		dma_release_channel(chan);
		/* Free the Tx channel too */
		chan = host->chan_tx;
		if (chan) {
			host->chan_tx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
		tmio_mmc_enable_dma(host, false);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
		desc, cookie, host->sg_len);
}

static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_tx;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		unsigned long flags;
		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	if (ret > 0)
		desc = chan->device->device_prep_slave_sg(chan, sg, ret,
			DMA_TO_DEVICE, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		if (ret >= 0)
			ret = -EIO;
		host->chan_tx = NULL;
		dma_release_channel(chan);
		/* Free the Rx channel too */
		chan = host->chan_rx;
		if (chan) {
			host->chan_rx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
		tmio_mmc_enable_dma(host, false);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
		desc, cookie);
}

void tmio_mmc_start_dma(struct tmio_mmc_host *host,
			       struct mmc_data *data)
{
	if (data->flags & MMC_DATA_READ) {
		if (host->chan_rx)
			tmio_mmc_start_dma_rx(host);
	} else {
		if (host->chan_tx)
			tmio_mmc_start_dma_tx(host);
	}
}

static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
	struct dma_chan *chan = NULL;

	spin_lock_irq(&host->lock);

	if (host && host->data) {
		if (host->data->flags & MMC_DATA_READ)
			chan = host->chan_rx;
		else
			chan = host->chan_tx;
	}

	spin_unlock_irq(&host->lock);

	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);

	if (chan)
		dma_async_issue_pending(chan);
}

static void tmio_mmc_tasklet_fn(unsigned long arg)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;

	spin_lock_irq(&host->lock);

	if (!host->data)
		goto out;

	if (host->data->flags & MMC_DATA_READ)
		dma_unmap_sg(host->chan_rx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_FROM_DEVICE);
	else
		dma_unmap_sg(host->chan_tx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_TO_DEVICE);

	tmio_mmc_do_data_irq(host);
out:
	spin_unlock_irq(&host->lock);
}

/* It might be necessary to make filter MFD specific */
static bool tmio_mmc_filter(struct dma_chan *chan, void *arg)
{
	dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg);
	chan->private = arg;
	return true;
}

void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
{
	/* We can only either use DMA for both Tx and Rx or not use it at all */
	if (pdata->dma) {
		dma_cap_mask_t mask;

		dma_cap_zero(mask);
		dma_cap_set(DMA_SLAVE, mask);

		host->chan_tx = dma_request_channel(mask, tmio_mmc_filter,
						    pdata->dma->chan_priv_tx);
		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
			host->chan_tx);

		if (!host->chan_tx)
			return;

		host->chan_rx = dma_request_channel(mask, tmio_mmc_filter,
						    pdata->dma->chan_priv_rx);
		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
			host->chan_rx);

		if (!host->chan_rx)
			goto ereqrx;

		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
		if (!host->bounce_buf)
			goto ebouncebuf;

		tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
		tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);

		tmio_mmc_enable_dma(host, true);

		return;
ebouncebuf:
		dma_release_channel(host->chan_rx);
		host->chan_rx = NULL;
ereqrx:
		dma_release_channel(host->chan_tx);
		host->chan_tx = NULL;
		return;
	}
}

void tmio_mmc_release_dma(struct tmio_mmc_host *host)
{
	if (host->chan_tx) {
		struct dma_chan *chan = host->chan_tx;
		host->chan_tx = NULL;
		dma_release_channel(chan);
	}
	if (host->chan_rx) {
		struct dma_chan *chan = host->chan_rx;
		host->chan_rx = NULL;
		dma_release_channel(chan);
	}
	if (host->bounce_buf) {
		free_pages((unsigned long)host->bounce_buf, 0);
		host->bounce_buf = NULL;
	}
}
Commit	Line	Data
b6147490 GL	1	/*
	2	* linux/drivers/mmc/tmio_mmc_dma.c
	3	*
	4	* Copyright (C) 2010-2011 Guennadi Liakhovetski
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* DMA function for TMIO MMC implementations
	11	*/
	12
	13	#include <linux/device.h>
	14	#include <linux/dmaengine.h>
	15	#include <linux/mfd/tmio.h>
	16	#include <linux/mmc/host.h>
cba179ae	17	#include <linux/mmc/tmio.h>
b6147490 GL	18	#include <linux/pagemap.h>
	19	#include <linux/scatterlist.h>
	20
	21	#include "tmio_mmc.h"
	22
	23	#define TMIO_MMC_MIN_DMA_LEN 8
	24
	25	static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
	26	{
	27	#if defined(CONFIG_SUPERH) \|\| defined(CONFIG_ARCH_SHMOBILE)
	28	/* Switch DMA mode on or off - SuperH specific? */
	29	writew(enable ? 2 : 0, host->ctl + (0xd8 << host->bus_shift));
	30	#endif
	31	}
	32
	33	static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
	34	{
	35	struct scatterlist sg = host->sg_ptr, sg_tmp;
	36	struct dma_async_tx_descriptor *desc = NULL;
	37	struct dma_chan *chan = host->chan_rx;
	38	struct tmio_mmc_data *pdata = host->pdata;
	39	dma_cookie_t cookie;
	40	int ret, i;
	41	bool aligned = true, multiple = true;
	42	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	43
	44	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	45	if (sg_tmp->offset & align)
	46	aligned = false;
	47	if (sg_tmp->length & align) {
	48	multiple = false;
	49	break;
	50	}
	51	}
	52
	53	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	54	(align & PAGE_MASK))) \|\| !multiple) {
	55	ret = -EINVAL;
	56	goto pio;
	57	}
	58
	59	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	60	host->force_pio = true;
	61	return;
	62	}
	63
	64	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	65
	66	/* The only sg element can be unaligned, use our bounce buffer then */
	67	if (!aligned) {
	68	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	69	host->sg_ptr = &host->bounce_sg;
	70	sg = host->sg_ptr;
	71	}
	72
	73	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	74	if (ret > 0)
	75	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
	76	DMA_FROM_DEVICE, DMA_CTRL_ACK);
	77
	78	if (desc) {
	79	cookie = dmaengine_submit(desc);
	80	if (cookie < 0) {
	81	desc = NULL;
82	ret = cookie;
83	}
84	}
85	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
86	__func__, host->sg_len, ret, cookie, host->mrq);
87
88	pio:
89	if (!desc) {
90	/* DMA failed, fall back to PIO */
91	if (ret >= 0)
92	ret = -EIO;
93	host->chan_rx = NULL;
94	dma_release_channel(chan);
95	/* Free the Tx channel too */
96	chan = host->chan_tx;
97	if (chan) {
98	host->chan_tx = NULL;
99	dma_release_channel(chan);
100	}
101	dev_warn(&host->pdev->dev,
102	"DMA failed: %d, falling back to PIO\n", ret);
103	tmio_mmc_enable_dma(host, false);
104	}
105
106	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
107	desc, cookie, host->sg_len);
108	}
109
110	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
111	{
112	struct scatterlist sg = host->sg_ptr, sg_tmp;
113	struct dma_async_tx_descriptor *desc = NULL;
114	struct dma_chan *chan = host->chan_tx;
115	struct tmio_mmc_data *pdata = host->pdata;
116	dma_cookie_t cookie;
117	int ret, i;
118	bool aligned = true, multiple = true;
119	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
120
121	for_each_sg(sg, sg_tmp, host->sg_len, i) {
122	if (sg_tmp->offset & align)
123	aligned = false;
124	if (sg_tmp->length & align) {
125	multiple = false;
126	break;
127	}
128	}
129
130	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
131	(align & PAGE_MASK))) \|\| !multiple) {
132	ret = -EINVAL;
133	goto pio;
134	}
135
136	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
137	host->force_pio = true;
138	return;
139	}
140
141	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
142
143	/* The only sg element can be unaligned, use our bounce buffer then */
144	if (!aligned) {
145	unsigned long flags;
146	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
147	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
148	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
149	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
150	host->sg_ptr = &host->bounce_sg;
151	sg = host->sg_ptr;
152	}
153
154	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
155	if (ret > 0)
156	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
157	DMA_TO_DEVICE, DMA_CTRL_ACK);
158
159	if (desc) {
160	cookie = dmaengine_submit(desc);
161	if (cookie < 0) {
162	desc = NULL;
163	ret = cookie;
164	}
165	}
166	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
167	__func__, host->sg_len, ret, cookie, host->mrq);
168
169	pio:
170	if (!desc) {
171	/* DMA failed, fall back to PIO */
172	if (ret >= 0)
173	ret = -EIO;
174	host->chan_tx = NULL;
175	dma_release_channel(chan);
176	/* Free the Rx channel too */
177	chan = host->chan_rx;
178	if (chan) {
179	host->chan_rx = NULL;
180	dma_release_channel(chan);
181	}
182	dev_warn(&host->pdev->dev,
183	"DMA failed: %d, falling back to PIO\n", ret);
184	tmio_mmc_enable_dma(host, false);
185	}
186
187	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
188	desc, cookie);
189	}
190
191	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
192	struct mmc_data *data)
193	{
194	if (data->flags & MMC_DATA_READ) {
195	if (host->chan_rx)
196	tmio_mmc_start_dma_rx(host);
197	} else {
198	if (host->chan_tx)
199	tmio_mmc_start_dma_tx(host);
200	}
201	}
202
203	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
204	{
205	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
206	struct dma_chan *chan = NULL;
207
208	spin_lock_irq(&host->lock);
209
210	if (host && host->data) {
211	if (host->data->flags & MMC_DATA_READ)
212	chan = host->chan_rx;
213	else
214	chan = host->chan_tx;
215	}
216
217	spin_unlock_irq(&host->lock);
218
219	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
220
221	if (chan)
222	dma_async_issue_pending(chan);
223	}
224
225	static void tmio_mmc_tasklet_fn(unsigned long arg)
226	{
227	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
228
229	spin_lock_irq(&host->lock);
230
231	if (!host->data)
232	goto out;
233
234	if (host->data->flags & MMC_DATA_READ)
235	dma_unmap_sg(host->chan_rx->device->dev,
236	host->sg_ptr, host->sg_len,
237	DMA_FROM_DEVICE);
238	else
239	dma_unmap_sg(host->chan_tx->device->dev,
240	host->sg_ptr, host->sg_len,
241	DMA_TO_DEVICE);
242
243	tmio_mmc_do_data_irq(host);
244	out:
245	spin_unlock_irq(&host->lock);
246	}
247
248	/* It might be necessary to make filter MFD specific */
249	static bool tmio_mmc_filter(struct dma_chan chan, void arg)
250	{
251	dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg);
252	chan->private = arg;
253	return true;
254	}
255
256	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
257	{
258	/* We can only either use DMA for both Tx and Rx or not use it at all */
259	if (pdata->dma) {
260	dma_cap_mask_t mask;
261
262	dma_cap_zero(mask);
263	dma_cap_set(DMA_SLAVE, mask);
264
265	host->chan_tx = dma_request_channel(mask, tmio_mmc_filter,
266	pdata->dma->chan_priv_tx);
267	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
268	host->chan_tx);
269
270	if (!host->chan_tx)
271	return;
272
273	host->chan_rx = dma_request_channel(mask, tmio_mmc_filter,
274	pdata->dma->chan_priv_rx);
275	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
276	host->chan_rx);
277
278	if (!host->chan_rx)
279	goto ereqrx;
280
281	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
282	if (!host->bounce_buf)
283	goto ebouncebuf;
284
285	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
286	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
287
288	tmio_mmc_enable_dma(host, true);
289
290	return;
291	ebouncebuf:
292	dma_release_channel(host->chan_rx);
293	host->chan_rx = NULL;
294	ereqrx:
295	dma_release_channel(host->chan_tx);
296	host->chan_tx = NULL;
297	return;
298	}
299	}
300
301	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
302	{
303	if (host->chan_tx) {
304	struct dma_chan *chan = host->chan_tx;
305	host->chan_tx = NULL;
306	dma_release_channel(chan);
307	}
308	if (host->chan_rx) {
309	struct dma_chan *chan = host->chan_rx;
310	host->chan_rx = NULL;
311	dma_release_channel(chan);
312	}
313	if (host->bounce_buf) {
314	free_pages((unsigned long)host->bounce_buf, 0);
315	host->bounce_buf = NULL;
316	}
317	}