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_device.h>
19 #include <linux/pagemap.h>
20 #include <linux/scatterlist.h>
21 #include <linux/sys_soc.h>
22 
23 #include "renesas_sdhi.h"
24 #include "tmio_mmc.h"
25 
26 #define TMIO_MMC_MIN_DMA_LEN 8
27 
28 static const struct renesas_sdhi_of_data of_default_cfg = {
29 	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
30 };
31 
32 static const struct renesas_sdhi_of_data of_rz_compatible = {
33 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_32BIT_DATA_PORT |
34 			  TMIO_MMC_HAVE_CBSY,
35 	.tmio_ocr_mask	= MMC_VDD_32_33,
36 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
37 			  MMC_CAP_WAIT_WHILE_BUSY,
38 };
39 
40 static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
41 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL,
42 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
43 			  MMC_CAP_WAIT_WHILE_BUSY,
44 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
45 };
46 
47 /* Definitions for sampling clocks */
48 static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
49 	{
50 		.clk_rate = 156000000,
51 		.tap = 0x00000703,
52 	},
53 	{
54 		.clk_rate = 0,
55 		.tap = 0x00000300,
56 	},
57 };
58 
59 static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
60 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
61 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
62 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
63 			  MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY,
64 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
65 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
66 	.dma_rx_offset	= 0x2000,
67 	.scc_offset	= 0x0300,
68 	.taps		= rcar_gen2_scc_taps,
69 	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
70 	.max_blk_count	= UINT_MAX / TMIO_MAX_BLK_SIZE,
71 };
72 
73 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
74 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
75 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
76 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
77 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
78 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
79 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
80 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
81 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
82 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
83 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
84 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
85 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
86 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
87 	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
88 	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
89 	{ .compatible = "renesas,sdhi-shmobile" },
90 	{},
91 };
92 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
93 
94 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
95 					     bool enable)
96 {
97 	struct renesas_sdhi *priv = host_to_priv(host);
98 
99 	if (!host->chan_tx || !host->chan_rx)
100 		return;
101 
102 	if (priv->dma_priv.enable)
103 		priv->dma_priv.enable(host, enable);
104 }
105 
106 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
107 {
108 	renesas_sdhi_sys_dmac_enable_dma(host, false);
109 
110 	if (host->chan_rx)
111 		dmaengine_terminate_all(host->chan_rx);
112 	if (host->chan_tx)
113 		dmaengine_terminate_all(host->chan_tx);
114 
115 	renesas_sdhi_sys_dmac_enable_dma(host, true);
116 }
117 
118 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
119 {
120 	struct renesas_sdhi *priv = host_to_priv(host);
121 
122 	complete(&priv->dma_priv.dma_dataend);
123 }
124 
125 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
126 {
127 	struct tmio_mmc_host *host = arg;
128 	struct renesas_sdhi *priv = host_to_priv(host);
129 
130 	spin_lock_irq(&host->lock);
131 
132 	if (!host->data)
133 		goto out;
134 
135 	if (host->data->flags & MMC_DATA_READ)
136 		dma_unmap_sg(host->chan_rx->device->dev,
137 			     host->sg_ptr, host->sg_len,
138 			     DMA_FROM_DEVICE);
139 	else
140 		dma_unmap_sg(host->chan_tx->device->dev,
141 			     host->sg_ptr, host->sg_len,
142 			     DMA_TO_DEVICE);
143 
144 	spin_unlock_irq(&host->lock);
145 
146 	wait_for_completion(&priv->dma_priv.dma_dataend);
147 
148 	spin_lock_irq(&host->lock);
149 	tmio_mmc_do_data_irq(host);
150 out:
151 	spin_unlock_irq(&host->lock);
152 }
153 
154 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
155 {
156 	struct renesas_sdhi *priv = host_to_priv(host);
157 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
158 	struct dma_async_tx_descriptor *desc = NULL;
159 	struct dma_chan *chan = host->chan_rx;
160 	dma_cookie_t cookie;
161 	int ret, i;
162 	bool aligned = true, multiple = true;
163 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
164 
165 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
166 		if (sg_tmp->offset & align)
167 			aligned = false;
168 		if (sg_tmp->length & align) {
169 			multiple = false;
170 			break;
171 		}
172 	}
173 
174 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
175 			  (align & PAGE_MASK))) || !multiple) {
176 		ret = -EINVAL;
177 		goto pio;
178 	}
179 
180 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
181 		return;
182 
183 	/* The only sg element can be unaligned, use our bounce buffer then */
184 	if (!aligned) {
185 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
186 		host->sg_ptr = &host->bounce_sg;
187 		sg = host->sg_ptr;
188 	}
189 
190 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
191 	if (ret > 0)
192 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
193 					       DMA_CTRL_ACK);
194 
195 	if (desc) {
196 		reinit_completion(&priv->dma_priv.dma_dataend);
197 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
198 		desc->callback_param = host;
199 
200 		cookie = dmaengine_submit(desc);
201 		if (cookie < 0) {
202 			desc = NULL;
203 			ret = cookie;
204 		}
205 		host->dma_on = true;
206 	}
207 pio:
208 	if (!desc) {
209 		/* DMA failed, fall back to PIO */
210 		renesas_sdhi_sys_dmac_enable_dma(host, false);
211 		if (ret >= 0)
212 			ret = -EIO;
213 		host->chan_rx = NULL;
214 		dma_release_channel(chan);
215 		/* Free the Tx channel too */
216 		chan = host->chan_tx;
217 		if (chan) {
218 			host->chan_tx = NULL;
219 			dma_release_channel(chan);
220 		}
221 		dev_warn(&host->pdev->dev,
222 			 "DMA failed: %d, falling back to PIO\n", ret);
223 	}
224 }
225 
226 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
227 {
228 	struct renesas_sdhi *priv = host_to_priv(host);
229 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
230 	struct dma_async_tx_descriptor *desc = NULL;
231 	struct dma_chan *chan = host->chan_tx;
232 	dma_cookie_t cookie;
233 	int ret, i;
234 	bool aligned = true, multiple = true;
235 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
236 
237 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
238 		if (sg_tmp->offset & align)
239 			aligned = false;
240 		if (sg_tmp->length & align) {
241 			multiple = false;
242 			break;
243 		}
244 	}
245 
246 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
247 			  (align & PAGE_MASK))) || !multiple) {
248 		ret = -EINVAL;
249 		goto pio;
250 	}
251 
252 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
253 		return;
254 
255 	/* The only sg element can be unaligned, use our bounce buffer then */
256 	if (!aligned) {
257 		unsigned long flags;
258 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
259 
260 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
261 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
262 		tmio_mmc_kunmap_atomic(sg, &flags, 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 	}
284 pio:
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 
303 static 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 
315 static 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 
337 static 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 
413 ebouncebuf:
414 ecfgrx:
415 	dma_release_channel(host->chan_rx);
416 	host->chan_rx = NULL;
417 ereqrx:
418 ecfgtx:
419 	dma_release_channel(host->chan_tx);
420 	host->chan_tx = NULL;
421 }
422 
423 static 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 
443 static 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 
452 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
453 {
454 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
455 }
456 
457 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
458 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
459 				pm_runtime_force_resume)
460 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
461 			   tmio_mmc_host_runtime_resume,
462 			   NULL)
463 };
464 
465 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
466 	.driver		= {
467 		.name	= "sh_mobile_sdhi",
468 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
469 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
470 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
471 	},
472 	.probe		= renesas_sdhi_sys_dmac_probe,
473 	.remove		= renesas_sdhi_remove,
474 };
475 
476 module_platform_driver(renesas_sys_dmac_sdhi_driver);
477 
478 MODULE_DESCRIPTION("Renesas SDHI driver");
479 MODULE_AUTHOR("Magnus Damm");
480 MODULE_LICENSE("GPL v2");
481 MODULE_ALIAS("platform:sh_mobile_sdhi");
482