2 * linux/drivers/mmc/tmio_mmc_dma.c
4 * Copyright (C) 2010-2011 Guennadi Liakhovetski
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.
10 * DMA function for TMIO MMC implementations
13 #include <linux/device.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/dmaengine.h>
16 #include <linux/mfd/tmio.h>
17 #include <linux/mmc/host.h>
18 #include <linux/mmc/tmio.h>
19 #include <linux/pagemap.h>
20 #include <linux/scatterlist.h>
24 #define TMIO_MMC_MIN_DMA_LEN 8
26 void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
28 if (!host->chan_tx || !host->chan_rx)
31 if (host->dma->enable)
32 host->dma->enable(host, enable);
35 void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
37 tmio_mmc_enable_dma(host, false);
40 dmaengine_terminate_all(host->chan_rx);
42 dmaengine_terminate_all(host->chan_tx);
44 tmio_mmc_enable_dma(host, true);
47 static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
49 struct scatterlist *sg = host->sg_ptr, *sg_tmp;
50 struct dma_async_tx_descriptor *desc = NULL;
51 struct dma_chan *chan = host->chan_rx;
54 bool aligned = true, multiple = true;
55 unsigned int align = (1 << host->pdata->alignment_shift) - 1;
57 for_each_sg(sg, sg_tmp, host->sg_len, i) {
58 if (sg_tmp->offset & align)
60 if (sg_tmp->length & align) {
66 if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
67 (align & PAGE_MASK))) || !multiple) {
72 if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
73 host->force_pio = true;
77 tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
79 /* The only sg element can be unaligned, use our bounce buffer then */
81 sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
82 host->sg_ptr = &host->bounce_sg;
86 ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
88 desc = dmaengine_prep_slave_sg(chan, sg, ret,
89 DMA_DEV_TO_MEM, DMA_CTRL_ACK);
92 cookie = dmaengine_submit(desc);
100 /* DMA failed, fall back to PIO */
101 tmio_mmc_enable_dma(host, false);
104 host->chan_rx = NULL;
105 dma_release_channel(chan);
106 /* Free the Tx channel too */
107 chan = host->chan_tx;
109 host->chan_tx = NULL;
110 dma_release_channel(chan);
112 dev_warn(&host->pdev->dev,
113 "DMA failed: %d, falling back to PIO\n", ret);
117 static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
119 struct scatterlist *sg = host->sg_ptr, *sg_tmp;
120 struct dma_async_tx_descriptor *desc = NULL;
121 struct dma_chan *chan = host->chan_tx;
124 bool aligned = true, multiple = true;
125 unsigned int align = (1 << host->pdata->alignment_shift) - 1;
127 for_each_sg(sg, sg_tmp, host->sg_len, i) {
128 if (sg_tmp->offset & align)
130 if (sg_tmp->length & align) {
136 if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
137 (align & PAGE_MASK))) || !multiple) {
142 if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
143 host->force_pio = true;
147 tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
149 /* The only sg element can be unaligned, use our bounce buffer then */
152 void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
153 sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
154 memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
155 tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
156 host->sg_ptr = &host->bounce_sg;
160 ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
162 desc = dmaengine_prep_slave_sg(chan, sg, ret,
163 DMA_MEM_TO_DEV, DMA_CTRL_ACK);
166 cookie = dmaengine_submit(desc);
174 /* DMA failed, fall back to PIO */
175 tmio_mmc_enable_dma(host, false);
178 host->chan_tx = NULL;
179 dma_release_channel(chan);
180 /* Free the Rx channel too */
181 chan = host->chan_rx;
183 host->chan_rx = NULL;
184 dma_release_channel(chan);
186 dev_warn(&host->pdev->dev,
187 "DMA failed: %d, falling back to PIO\n", ret);
191 void tmio_mmc_start_dma(struct tmio_mmc_host *host,
192 struct mmc_data *data)
194 if (data->flags & MMC_DATA_READ) {
196 tmio_mmc_start_dma_rx(host);
199 tmio_mmc_start_dma_tx(host);
203 static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
205 struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
206 struct dma_chan *chan = NULL;
208 spin_lock_irq(&host->lock);
210 if (host && host->data) {
211 if (host->data->flags & MMC_DATA_READ)
212 chan = host->chan_rx;
214 chan = host->chan_tx;
217 spin_unlock_irq(&host->lock);
219 tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
222 dma_async_issue_pending(chan);
225 static void tmio_mmc_tasklet_fn(unsigned long arg)
227 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
229 spin_lock_irq(&host->lock);
234 if (host->data->flags & MMC_DATA_READ)
235 dma_unmap_sg(host->chan_rx->device->dev,
236 host->sg_ptr, host->sg_len,
239 dma_unmap_sg(host->chan_tx->device->dev,
240 host->sg_ptr, host->sg_len,
243 tmio_mmc_do_data_irq(host);
245 spin_unlock_irq(&host->lock);
248 void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
250 /* We can only either use DMA for both Tx and Rx or not use it at all */
251 if (!host->dma || (!host->pdev->dev.of_node &&
252 (!pdata->chan_priv_tx || !pdata->chan_priv_rx)))
255 if (!host->chan_tx && !host->chan_rx) {
256 struct resource *res = platform_get_resource(host->pdev,
258 struct dma_slave_config cfg = {};
266 dma_cap_set(DMA_SLAVE, mask);
268 host->chan_tx = dma_request_slave_channel_compat(mask,
269 host->dma->filter, pdata->chan_priv_tx,
270 &host->pdev->dev, "tx");
271 dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
277 cfg.direction = DMA_MEM_TO_DEV;
278 cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->bus_shift);
279 cfg.dst_addr_width = host->dma->dma_buswidth;
280 if (!cfg.dst_addr_width)
281 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
283 ret = dmaengine_slave_config(host->chan_tx, &cfg);
287 host->chan_rx = dma_request_slave_channel_compat(mask,
288 host->dma->filter, pdata->chan_priv_rx,
289 &host->pdev->dev, "rx");
290 dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
296 cfg.direction = DMA_DEV_TO_MEM;
297 cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
298 cfg.src_addr_width = host->dma->dma_buswidth;
299 if (!cfg.src_addr_width)
300 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
302 ret = dmaengine_slave_config(host->chan_rx, &cfg);
306 host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
307 if (!host->bounce_buf)
310 tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
311 tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
314 tmio_mmc_enable_dma(host, true);
320 dma_release_channel(host->chan_rx);
321 host->chan_rx = NULL;
324 dma_release_channel(host->chan_tx);
325 host->chan_tx = NULL;
328 void tmio_mmc_release_dma(struct tmio_mmc_host *host)
331 struct dma_chan *chan = host->chan_tx;
332 host->chan_tx = NULL;
333 dma_release_channel(chan);
336 struct dma_chan *chan = host->chan_rx;
337 host->chan_rx = NULL;
338 dma_release_channel(chan);
340 if (host->bounce_buf) {
341 free_pages((unsigned long)host->bounce_buf, 0);
342 host->bounce_buf = NULL;