[GitHub/mt8127/android_kernel_alcatel_ttab.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/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>
	17	#include <linux/pagemap.h>
	18	#include <linux/scatterlist.h>
	19
	20	#include "tmio_mmc.h"
	21
	22	#define TMIO_MMC_MIN_DMA_LEN 8
	23
	24	static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
	25	{
	26	#if defined(CONFIG_SUPERH) \|\| defined(CONFIG_ARCH_SHMOBILE)
	27	/* Switch DMA mode on or off - SuperH specific? */
	28	writew(enable ? 2 : 0, host->ctl + (0xd8 << host->bus_shift));
	29	#endif
	30	}
	31
	32	static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
	33	{
	34	struct scatterlist sg = host->sg_ptr, sg_tmp;
	35	struct dma_async_tx_descriptor *desc = NULL;
	36	struct dma_chan *chan = host->chan_rx;
	37	struct tmio_mmc_data *pdata = host->pdata;
	38	dma_cookie_t cookie;
	39	int ret, i;
	40	bool aligned = true, multiple = true;
	41	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	42
	43	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	44	if (sg_tmp->offset & align)
	45	aligned = false;
	46	if (sg_tmp->length & align) {
	47	multiple = false;
	48	break;
	49	}
	50	}
	51
	52	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	53	(align & PAGE_MASK))) \|\| !multiple) {
	54	ret = -EINVAL;
	55	goto pio;
	56	}
	57
	58	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	59	host->force_pio = true;
	60	return;
	61	}
	62
	63	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	64
65	/* The only sg element can be unaligned, use our bounce buffer then */
66	if (!aligned) {
67	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
68	host->sg_ptr = &host->bounce_sg;
69	sg = host->sg_ptr;
70	}
71
72	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
73	if (ret > 0)
74	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
75	DMA_FROM_DEVICE, DMA_CTRL_ACK);
76
77	if (desc) {
78	cookie = dmaengine_submit(desc);
79	if (cookie < 0) {
80	desc = NULL;
81	ret = cookie;
82	}
83	}
84	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
85	__func__, host->sg_len, ret, cookie, host->mrq);
86
87	pio:
88	if (!desc) {
89	/* DMA failed, fall back to PIO */
90	if (ret >= 0)
91	ret = -EIO;
92	host->chan_rx = NULL;
93	dma_release_channel(chan);
94	/* Free the Tx channel too */
95	chan = host->chan_tx;
96	if (chan) {
97	host->chan_tx = NULL;
98	dma_release_channel(chan);
99	}
100	dev_warn(&host->pdev->dev,
101	"DMA failed: %d, falling back to PIO\n", ret);
102	tmio_mmc_enable_dma(host, false);
103	}
104
105	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
106	desc, cookie, host->sg_len);
107	}
108
109	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
110	{
111	struct scatterlist sg = host->sg_ptr, sg_tmp;
112	struct dma_async_tx_descriptor *desc = NULL;
113	struct dma_chan *chan = host->chan_tx;
114	struct tmio_mmc_data *pdata = host->pdata;
115	dma_cookie_t cookie;
116	int ret, i;
117	bool aligned = true, multiple = true;
118	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
119
120	for_each_sg(sg, sg_tmp, host->sg_len, i) {
121	if (sg_tmp->offset & align)
122	aligned = false;
123	if (sg_tmp->length & align) {
124	multiple = false;
125	break;
126	}
127	}
128
129	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
130	(align & PAGE_MASK))) \|\| !multiple) {
131	ret = -EINVAL;
132	goto pio;
133	}
134
135	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
136	host->force_pio = true;
137	return;
138	}
139
140	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
141
142	/* The only sg element can be unaligned, use our bounce buffer then */
143	if (!aligned) {
144	unsigned long flags;
145	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
146	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
147	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
148	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
149	host->sg_ptr = &host->bounce_sg;
150	sg = host->sg_ptr;
151	}
152
153	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
154	if (ret > 0)
155	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
156	DMA_TO_DEVICE, DMA_CTRL_ACK);
157
158	if (desc) {
159	cookie = dmaengine_submit(desc);
160	if (cookie < 0) {
161	desc = NULL;
162	ret = cookie;
163	}
164	}
165	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
166	__func__, host->sg_len, ret, cookie, host->mrq);
167
168	pio:
169	if (!desc) {
170	/* DMA failed, fall back to PIO */
171	if (ret >= 0)
172	ret = -EIO;
173	host->chan_tx = NULL;
174	dma_release_channel(chan);
175	/* Free the Rx channel too */
176	chan = host->chan_rx;
177	if (chan) {
178	host->chan_rx = NULL;
179	dma_release_channel(chan);
180	}
181	dev_warn(&host->pdev->dev,
182	"DMA failed: %d, falling back to PIO\n", ret);
183	tmio_mmc_enable_dma(host, false);
184	}
185
186	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
187	desc, cookie);
188	}
189
190	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
191	struct mmc_data *data)
192	{
193	if (data->flags & MMC_DATA_READ) {
194	if (host->chan_rx)
195	tmio_mmc_start_dma_rx(host);
196	} else {
197	if (host->chan_tx)
198	tmio_mmc_start_dma_tx(host);
199	}
200	}
201
202	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
203	{
204	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
205	struct dma_chan *chan = NULL;
206
207	spin_lock_irq(&host->lock);
208
209	if (host && host->data) {
210	if (host->data->flags & MMC_DATA_READ)
211	chan = host->chan_rx;
212	else
213	chan = host->chan_tx;
214	}
215
216	spin_unlock_irq(&host->lock);
217
218	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
219
220	if (chan)
221	dma_async_issue_pending(chan);
222	}
223
224	static void tmio_mmc_tasklet_fn(unsigned long arg)
225	{
226	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
227
228	spin_lock_irq(&host->lock);
229
230	if (!host->data)
231	goto out;
232
233	if (host->data->flags & MMC_DATA_READ)
234	dma_unmap_sg(host->chan_rx->device->dev,
235	host->sg_ptr, host->sg_len,
236	DMA_FROM_DEVICE);
237	else
238	dma_unmap_sg(host->chan_tx->device->dev,
239	host->sg_ptr, host->sg_len,
240	DMA_TO_DEVICE);
241
242	tmio_mmc_do_data_irq(host);
243	out:
244	spin_unlock_irq(&host->lock);
245	}
246
247	/* It might be necessary to make filter MFD specific */
248	static bool tmio_mmc_filter(struct dma_chan chan, void arg)
249	{
250	dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg);
251	chan->private = arg;
252	return true;
253	}
254
255	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
256	{
257	/* We can only either use DMA for both Tx and Rx or not use it at all */
258	if (pdata->dma) {
259	dma_cap_mask_t mask;
260
261	dma_cap_zero(mask);
262	dma_cap_set(DMA_SLAVE, mask);
263
264	host->chan_tx = dma_request_channel(mask, tmio_mmc_filter,
265	pdata->dma->chan_priv_tx);
266	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
267	host->chan_tx);
268
269	if (!host->chan_tx)
270	return;
271
272	host->chan_rx = dma_request_channel(mask, tmio_mmc_filter,
273	pdata->dma->chan_priv_rx);
274	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
275	host->chan_rx);
276
277	if (!host->chan_rx)
278	goto ereqrx;
279
280	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
281	if (!host->bounce_buf)
282	goto ebouncebuf;
283
284	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
285	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
286
287	tmio_mmc_enable_dma(host, true);
288
289	return;
290	ebouncebuf:
291	dma_release_channel(host->chan_rx);
292	host->chan_rx = NULL;
293	ereqrx:
294	dma_release_channel(host->chan_tx);
295	host->chan_tx = NULL;
296	return;
297	}
298	}
299
300	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
301	{
302	if (host->chan_tx) {
303	struct dma_chan *chan = host->chan_tx;
304	host->chan_tx = NULL;
305	dma_release_channel(chan);
306	}
307	if (host->chan_rx) {
308	struct dma_chan *chan = host->chan_rx;
309	host->chan_rx = NULL;
310	dma_release_channel(chan);
311	}
312	if (host->bounce_buf) {
313	free_pages((unsigned long)host->bounce_buf, 0);
314	host->bounce_buf = NULL;
315	}
316	}