1// SPDX-License-Identifier: GPL-2.0
2/*
3 * DMA support use of SYS DMAC with SDHI SD/SDIO controller
4 *
5 * Copyright (C) 2016-19 Renesas Electronics Corporation
6 * Copyright (C) 2016-19 Sang Engineering, Wolfram Sang
7 * Copyright (C) 2017 Horms Solutions, Simon Horman
8 * Copyright (C) 2010-2011 Guennadi Liakhovetski
9 */
10
11#include <linux/device.h>
12#include <linux/dma-mapping.h>
13#include <linux/dmaengine.h>
14#include <linux/mfd/tmio.h>
15#include <linux/mmc/host.h>
16#include <linux/mod_devicetable.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/pagemap.h>
21#include <linux/scatterlist.h>
22#include <linux/sys_soc.h>
23
24#include "renesas_sdhi.h"
25#include "tmio_mmc.h"
26
27#define TMIO_MMC_MIN_DMA_LEN 8
28
29static const struct renesas_sdhi_of_data of_default_cfg = {
30	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
31};
32
33static const struct renesas_sdhi_of_data of_rz_compatible = {
34	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_32BIT_DATA_PORT |
35			  TMIO_MMC_HAVE_CBSY,
36	.tmio_ocr_mask	= MMC_VDD_32_33,
37	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
38			  MMC_CAP_WAIT_WHILE_BUSY,
39};
40
41static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
42	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL,
43	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
44			  MMC_CAP_WAIT_WHILE_BUSY,
45	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
46};
47
48/* Definitions for sampling clocks */
49static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
50	{
51		.clk_rate = 156000000,
52		.tap = 0x00000703,
53	},
54	{
55		.clk_rate = 0,
56		.tap = 0x00000300,
57	},
58};
59
60static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
61	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
62			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
63	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
64			  MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY,
65	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
66	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
67	.dma_rx_offset	= 0x2000,
68	.scc_offset	= 0x0300,
69	.taps		= rcar_gen2_scc_taps,
70	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
71	.max_blk_count	= UINT_MAX / TMIO_MAX_BLK_SIZE,
72};
73
74static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
75	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
76	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
77	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
78	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
79	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
80	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
81	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
82	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
83	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
84	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
85	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
86	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
87	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
88	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
89	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
90	{ .compatible = "renesas,sdhi-shmobile" },
91	{},
92};
93MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
94
95static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
96					     bool enable)
97{
98	struct renesas_sdhi *priv = host_to_priv(host);
99
100	if (!host->chan_tx || !host->chan_rx)
101		return;
102
103	if (priv->dma_priv.enable)
104		priv->dma_priv.enable(host, enable);
105}
106
107static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
108{
109	renesas_sdhi_sys_dmac_enable_dma(host, false);
110
111	if (host->chan_rx)
112		dmaengine_terminate_sync(host->chan_rx);
113	if (host->chan_tx)
114		dmaengine_terminate_sync(host->chan_tx);
115
116	renesas_sdhi_sys_dmac_enable_dma(host, true);
117}
118
119static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
120{
121	struct renesas_sdhi *priv = host_to_priv(host);
122
123	complete(&priv->dma_priv.dma_dataend);
124}
125
126static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
127{
128	struct tmio_mmc_host *host = arg;
129	struct renesas_sdhi *priv = host_to_priv(host);
130
131	spin_lock_irq(&host->lock);
132
133	if (!host->data)
134		goto out;
135
136	if (host->data->flags & MMC_DATA_READ)
137		dma_unmap_sg(host->chan_rx->device->dev,
138			     host->sg_ptr, host->sg_len,
139			     DMA_FROM_DEVICE);
140	else
141		dma_unmap_sg(host->chan_tx->device->dev,
142			     host->sg_ptr, host->sg_len,
143			     DMA_TO_DEVICE);
144
145	spin_unlock_irq(&host->lock);
146
147	wait_for_completion(&priv->dma_priv.dma_dataend);
148
149	spin_lock_irq(&host->lock);
150	tmio_mmc_do_data_irq(host);
151out:
152	spin_unlock_irq(&host->lock);
153}
154
155static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
156{
157	struct renesas_sdhi *priv = host_to_priv(host);
158	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
159	struct dma_async_tx_descriptor *desc = NULL;
160	struct dma_chan *chan = host->chan_rx;
161	dma_cookie_t cookie;
162	int ret, i;
163	bool aligned = true, multiple = true;
164	unsigned int align = 1;	/* 2-byte alignment */
165
166	for_each_sg(sg, sg_tmp, host->sg_len, i) {
167		if (sg_tmp->offset & align)
168			aligned = false;
169		if (sg_tmp->length & align) {
170			multiple = false;
171			break;
172		}
173	}
174
175	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
176			  (align & PAGE_MASK))) || !multiple) {
177		ret = -EINVAL;
178		goto pio;
179	}
180
181	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
182		return;
183
184	/* The only sg element can be unaligned, use our bounce buffer then */
185	if (!aligned) {
186		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
187		host->sg_ptr = &host->bounce_sg;
188		sg = host->sg_ptr;
189	}
190
191	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
192	if (ret > 0)
193		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
194					       DMA_CTRL_ACK);
195
196	if (desc) {
197		reinit_completion(&priv->dma_priv.dma_dataend);
198		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
199		desc->callback_param = host;
200
201		cookie = dmaengine_submit(desc);
202		if (cookie < 0) {
203			desc = NULL;
204			ret = cookie;
205		}
206		host->dma_on = true;
207	}
208pio:
209	if (!desc) {
210		/* DMA failed, fall back to PIO */
211		renesas_sdhi_sys_dmac_enable_dma(host, false);
212		if (ret >= 0)
213			ret = -EIO;
214		host->chan_rx = NULL;
215		dma_release_channel(chan);
216		/* Free the Tx channel too */
217		chan = host->chan_tx;
218		if (chan) {
219			host->chan_tx = NULL;
220			dma_release_channel(chan);
221		}
222		dev_warn(&host->pdev->dev,
223			 "DMA failed: %d, falling back to PIO\n", ret);
224	}
225}
226
227static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
228{
229	struct renesas_sdhi *priv = host_to_priv(host);
230	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
231	struct dma_async_tx_descriptor *desc = NULL;
232	struct dma_chan *chan = host->chan_tx;
233	dma_cookie_t cookie;
234	int ret, i;
235	bool aligned = true, multiple = true;
236	unsigned int align = 1;	/* 2-byte alignment */
237
238	for_each_sg(sg, sg_tmp, host->sg_len, i) {
239		if (sg_tmp->offset & align)
240			aligned = false;
241		if (sg_tmp->length & align) {
242			multiple = false;
243			break;
244		}
245	}
246
247	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
248			  (align & PAGE_MASK))) || !multiple) {
249		ret = -EINVAL;
250		goto pio;
251	}
252
253	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
254		return;
255
256	/* The only sg element can be unaligned, use our bounce buffer then */
257	if (!aligned) {
258		void *sg_vaddr = kmap_local_page(sg_page(sg));
259
260		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
261		memcpy(host->bounce_buf, sg_vaddr + sg->offset, host->bounce_sg.length);
262		kunmap_local(sg_vaddr);
263		host->sg_ptr = &host->bounce_sg;
264		sg = host->sg_ptr;
265	}
266
267	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
268	if (ret > 0)
269		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
270					       DMA_CTRL_ACK);
271
272	if (desc) {
273		reinit_completion(&priv->dma_priv.dma_dataend);
274		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
275		desc->callback_param = host;
276
277		cookie = dmaengine_submit(desc);
278		if (cookie < 0) {
279			desc = NULL;
280			ret = cookie;
281		}
282		host->dma_on = true;
283	}
284pio:
285	if (!desc) {
286		/* DMA failed, fall back to PIO */
287		renesas_sdhi_sys_dmac_enable_dma(host, false);
288		if (ret >= 0)
289			ret = -EIO;
290		host->chan_tx = NULL;
291		dma_release_channel(chan);
292		/* Free the Rx channel too */
293		chan = host->chan_rx;
294		if (chan) {
295			host->chan_rx = NULL;
296			dma_release_channel(chan);
297		}
298		dev_warn(&host->pdev->dev,
299			 "DMA failed: %d, falling back to PIO\n", ret);
300	}
301}
302
303static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
304					    struct mmc_data *data)
305{
306	if (data->flags & MMC_DATA_READ) {
307		if (host->chan_rx)
308			renesas_sdhi_sys_dmac_start_dma_rx(host);
309	} else {
310		if (host->chan_tx)
311			renesas_sdhi_sys_dmac_start_dma_tx(host);
312	}
313}
314
315static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
316{
317	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
318	struct dma_chan *chan = NULL;
319
320	spin_lock_irq(&host->lock);
321
322	if (host->data) {
323		if (host->data->flags & MMC_DATA_READ)
324			chan = host->chan_rx;
325		else
326			chan = host->chan_tx;
327	}
328
329	spin_unlock_irq(&host->lock);
330
331	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
332
333	if (chan)
334		dma_async_issue_pending(chan);
335}
336
337static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
338					      struct tmio_mmc_data *pdata)
339{
340	struct renesas_sdhi *priv = host_to_priv(host);
341
342	/* We can only either use DMA for both Tx and Rx or not use it at all */
343	if (!host->pdev->dev.of_node &&
344	    (!pdata->chan_priv_tx || !pdata->chan_priv_rx))
345		return;
346
347	if (!host->chan_tx && !host->chan_rx) {
348		struct resource *res = platform_get_resource(host->pdev,
349							     IORESOURCE_MEM, 0);
350		struct dma_slave_config cfg = {};
351		dma_cap_mask_t mask;
352		int ret;
353
354		if (!res)
355			return;
356
357		dma_cap_zero(mask);
358		dma_cap_set(DMA_SLAVE, mask);
359
360		host->chan_tx = dma_request_slave_channel_compat(mask,
361					priv->dma_priv.filter, pdata->chan_priv_tx,
362					&host->pdev->dev, "tx");
363		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
364			host->chan_tx);
365
366		if (!host->chan_tx)
367			return;
368
369		cfg.direction = DMA_MEM_TO_DEV;
370		cfg.dst_addr = res->start +
371			(CTL_SD_DATA_PORT << host->bus_shift);
372		cfg.dst_addr_width = priv->dma_priv.dma_buswidth;
373		if (!cfg.dst_addr_width)
374			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
375		cfg.src_addr = 0;
376		ret = dmaengine_slave_config(host->chan_tx, &cfg);
377		if (ret < 0)
378			goto ecfgtx;
379
380		host->chan_rx = dma_request_slave_channel_compat(mask,
381					priv->dma_priv.filter, pdata->chan_priv_rx,
382					&host->pdev->dev, "rx");
383		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
384			host->chan_rx);
385
386		if (!host->chan_rx)
387			goto ereqrx;
388
389		cfg.direction = DMA_DEV_TO_MEM;
390		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
391		cfg.src_addr_width = priv->dma_priv.dma_buswidth;
392		if (!cfg.src_addr_width)
393			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
394		cfg.dst_addr = 0;
395		ret = dmaengine_slave_config(host->chan_rx, &cfg);
396		if (ret < 0)
397			goto ecfgrx;
398
399		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
400		if (!host->bounce_buf)
401			goto ebouncebuf;
402
403		init_completion(&priv->dma_priv.dma_dataend);
404		tasklet_init(&host->dma_issue,
405			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
406			     (unsigned long)host);
407	}
408
409	renesas_sdhi_sys_dmac_enable_dma(host, true);
410
411	return;
412
413ebouncebuf:
414ecfgrx:
415	dma_release_channel(host->chan_rx);
416	host->chan_rx = NULL;
417ereqrx:
418ecfgtx:
419	dma_release_channel(host->chan_tx);
420	host->chan_tx = NULL;
421}
422
423static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
424{
425	if (host->chan_tx) {
426		struct dma_chan *chan = host->chan_tx;
427
428		host->chan_tx = NULL;
429		dma_release_channel(chan);
430	}
431	if (host->chan_rx) {
432		struct dma_chan *chan = host->chan_rx;
433
434		host->chan_rx = NULL;
435		dma_release_channel(chan);
436	}
437	if (host->bounce_buf) {
438		free_pages((unsigned long)host->bounce_buf, 0);
439		host->bounce_buf = NULL;
440	}
441}
442
443static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
444	.start = renesas_sdhi_sys_dmac_start_dma,
445	.enable = renesas_sdhi_sys_dmac_enable_dma,
446	.request = renesas_sdhi_sys_dmac_request_dma,
447	.release = renesas_sdhi_sys_dmac_release_dma,
448	.abort = renesas_sdhi_sys_dmac_abort_dma,
449	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
450};
451
452static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
453{
454	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops,
455				  of_device_get_match_data(&pdev->dev), NULL);
456}
457
458static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
459	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
460				pm_runtime_force_resume)
461	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
462			   tmio_mmc_host_runtime_resume,
463			   NULL)
464};
465
466static struct platform_driver renesas_sys_dmac_sdhi_driver = {
467	.driver		= {
468		.name	= "sh_mobile_sdhi",
469		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
470		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
471		.of_match_table = renesas_sdhi_sys_dmac_of_match,
472	},
473	.probe		= renesas_sdhi_sys_dmac_probe,
474	.remove_new	= renesas_sdhi_remove,
475};
476
477module_platform_driver(renesas_sys_dmac_sdhi_driver);
478
479MODULE_DESCRIPTION("Renesas SDHI driver");
480MODULE_AUTHOR("Magnus Damm");
481MODULE_LICENSE("GPL v2");
482MODULE_ALIAS("platform:sh_mobile_sdhi");
483