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/pagemap.h>
19 #include <linux/scatterlist.h>
23 #define TMIO_MMC_MIN_DMA_LEN 8
25 void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
27 if (!host->chan_tx || !host->chan_rx)
30 if (host->dma->enable)
31 host->dma->enable(host, enable);
34 void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
36 tmio_mmc_enable_dma(host, false);
39 dmaengine_terminate_all(host->chan_rx);
41 dmaengine_terminate_all(host->chan_tx);
43 tmio_mmc_enable_dma(host, true);
46 static void tmio_mmc_dma_callback(void *arg)
48 struct tmio_mmc_host *host = arg;
50 spin_lock_irq(&host->lock);
55 if (host->data->flags & MMC_DATA_READ)
56 dma_unmap_sg(host->chan_rx->device->dev,
57 host->sg_ptr, host->sg_len,
60 dma_unmap_sg(host->chan_tx->device->dev,
61 host->sg_ptr, host->sg_len,
64 spin_unlock_irq(&host->lock);
66 wait_for_completion(&host->dma_dataend);
68 spin_lock_irq(&host->lock);
69 tmio_mmc_do_data_irq(host);
71 spin_unlock_irq(&host->lock);
74 static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
76 struct scatterlist *sg = host->sg_ptr, *sg_tmp;
77 struct dma_async_tx_descriptor *desc = NULL;
78 struct dma_chan *chan = host->chan_rx;
81 bool aligned = true, multiple = true;
82 unsigned int align = (1 << host->pdata->alignment_shift) - 1;
84 for_each_sg(sg, sg_tmp, host->sg_len, i) {
85 if (sg_tmp->offset & align)
87 if (sg_tmp->length & align) {
93 if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
94 (align & PAGE_MASK))) || !multiple) {
99 if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
100 host->force_pio = true;
104 tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
106 /* The only sg element can be unaligned, use our bounce buffer then */
108 sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
109 host->sg_ptr = &host->bounce_sg;
113 ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
115 desc = dmaengine_prep_slave_sg(chan, sg, ret,
116 DMA_DEV_TO_MEM, DMA_CTRL_ACK);
119 reinit_completion(&host->dma_dataend);
120 desc->callback = tmio_mmc_dma_callback;
121 desc->callback_param = host;
123 cookie = dmaengine_submit(desc);
131 /* DMA failed, fall back to PIO */
132 tmio_mmc_enable_dma(host, false);
135 host->chan_rx = NULL;
136 dma_release_channel(chan);
137 /* Free the Tx channel too */
138 chan = host->chan_tx;
140 host->chan_tx = NULL;
141 dma_release_channel(chan);
143 dev_warn(&host->pdev->dev,
144 "DMA failed: %d, falling back to PIO\n", ret);
148 static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
150 struct scatterlist *sg = host->sg_ptr, *sg_tmp;
151 struct dma_async_tx_descriptor *desc = NULL;
152 struct dma_chan *chan = host->chan_tx;
155 bool aligned = true, multiple = true;
156 unsigned int align = (1 << host->pdata->alignment_shift) - 1;
158 for_each_sg(sg, sg_tmp, host->sg_len, i) {
159 if (sg_tmp->offset & align)
161 if (sg_tmp->length & align) {
167 if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
168 (align & PAGE_MASK))) || !multiple) {
173 if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
174 host->force_pio = true;
178 tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
180 /* The only sg element can be unaligned, use our bounce buffer then */
183 void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
184 sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
185 memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
186 tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
187 host->sg_ptr = &host->bounce_sg;
191 ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
193 desc = dmaengine_prep_slave_sg(chan, sg, ret,
194 DMA_MEM_TO_DEV, DMA_CTRL_ACK);
197 reinit_completion(&host->dma_dataend);
198 desc->callback = tmio_mmc_dma_callback;
199 desc->callback_param = host;
201 cookie = dmaengine_submit(desc);
209 /* DMA failed, fall back to PIO */
210 tmio_mmc_enable_dma(host, false);
213 host->chan_tx = NULL;
214 dma_release_channel(chan);
215 /* Free the Rx channel too */
216 chan = host->chan_rx;
218 host->chan_rx = NULL;
219 dma_release_channel(chan);
221 dev_warn(&host->pdev->dev,
222 "DMA failed: %d, falling back to PIO\n", ret);
226 void tmio_mmc_start_dma(struct tmio_mmc_host *host,
227 struct mmc_data *data)
229 if (data->flags & MMC_DATA_READ) {
231 tmio_mmc_start_dma_rx(host);
234 tmio_mmc_start_dma_tx(host);
238 static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
240 struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
241 struct dma_chan *chan = NULL;
243 spin_lock_irq(&host->lock);
245 if (host && host->data) {
246 if (host->data->flags & MMC_DATA_READ)
247 chan = host->chan_rx;
249 chan = host->chan_tx;
252 spin_unlock_irq(&host->lock);
254 tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
257 dma_async_issue_pending(chan);
260 void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
262 /* We can only either use DMA for both Tx and Rx or not use it at all */
263 if (!host->dma || (!host->pdev->dev.of_node &&
264 (!pdata->chan_priv_tx || !pdata->chan_priv_rx)))
267 if (!host->chan_tx && !host->chan_rx) {
268 struct resource *res = platform_get_resource(host->pdev,
270 struct dma_slave_config cfg = {};
278 dma_cap_set(DMA_SLAVE, mask);
280 host->chan_tx = dma_request_slave_channel_compat(mask,
281 host->dma->filter, pdata->chan_priv_tx,
282 &host->pdev->dev, "tx");
283 dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
289 cfg.direction = DMA_MEM_TO_DEV;
290 cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->bus_shift);
291 cfg.dst_addr_width = host->dma->dma_buswidth;
292 if (!cfg.dst_addr_width)
293 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
295 ret = dmaengine_slave_config(host->chan_tx, &cfg);
299 host->chan_rx = dma_request_slave_channel_compat(mask,
300 host->dma->filter, pdata->chan_priv_rx,
301 &host->pdev->dev, "rx");
302 dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
308 cfg.direction = DMA_DEV_TO_MEM;
309 cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
310 cfg.src_addr_width = host->dma->dma_buswidth;
311 if (!cfg.src_addr_width)
312 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
314 ret = dmaengine_slave_config(host->chan_rx, &cfg);
318 host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
319 if (!host->bounce_buf)
322 init_completion(&host->dma_dataend);
323 tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
326 tmio_mmc_enable_dma(host, true);
332 dma_release_channel(host->chan_rx);
333 host->chan_rx = NULL;
336 dma_release_channel(host->chan_tx);
337 host->chan_tx = NULL;
340 void tmio_mmc_release_dma(struct tmio_mmc_host *host)
343 struct dma_chan *chan = host->chan_tx;
344 host->chan_tx = NULL;
345 dma_release_channel(chan);
348 struct dma_chan *chan = host->chan_rx;
349 host->chan_rx = NULL;
350 dma_release_channel(chan);
352 if (host->bounce_buf) {
353 free_pages((unsigned long)host->bounce_buf, 0);
354 host->bounce_buf = NULL;