1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DMA support use of SYS DMAC with SDHI SD/SDIO controller
4  *
5  * Copyright (C) 2016-17 Renesas Electronics Corporation
6  * Copyright (C) 2016-17 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 };
38 
39 static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
40 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL,
41 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
42 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
43 };
44 
45 /* Definitions for sampling clocks */
46 static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
47 	{
48 		.clk_rate = 156000000,
49 		.tap = 0x00000703,
50 	},
51 	{
52 		.clk_rate = 0,
53 		.tap = 0x00000300,
54 	},
55 };
56 
57 static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
58 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
59 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
60 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
61 			  MMC_CAP_CMD23,
62 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
63 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
64 	.dma_rx_offset	= 0x2000,
65 	.scc_offset	= 0x0300,
66 	.taps		= rcar_gen2_scc_taps,
67 	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
68 };
69 
70 /* Definitions for sampling clocks */
71 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
72 	{
73 		.clk_rate = 0,
74 		.tap = 0x00000300,
75 	},
76 };
77 
78 static const struct renesas_sdhi_of_data of_rcar_r8a7795_compatible = {
79 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
80 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2 |
81 			  TMIO_MMC_HAVE_4TAP_HS400,
82 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
83 			  MMC_CAP_CMD23,
84 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
85 	.bus_shift	= 2,
86 	.scc_offset	= 0x1000,
87 	.taps		= rcar_gen3_scc_taps,
88 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
89 };
90 
91 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
92 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
93 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
94 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
95 			  MMC_CAP_CMD23,
96 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
97 	.bus_shift	= 2,
98 	.scc_offset	= 0x1000,
99 	.taps		= rcar_gen3_scc_taps,
100 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
101 };
102 
103 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
104 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
105 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
106 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
107 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
108 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
109 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
110 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
111 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
112 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
113 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
114 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
115 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
116 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
117 	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_r8a7795_compatible, },
118 	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_r8a7795_compatible, },
119 	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
120 	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
121 	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
122 	{ .compatible = "renesas,sdhi-shmobile" },
123 	{},
124 };
125 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
126 
127 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
128 					     bool enable)
129 {
130 	struct renesas_sdhi *priv = host_to_priv(host);
131 
132 	if (!host->chan_tx || !host->chan_rx)
133 		return;
134 
135 	if (priv->dma_priv.enable)
136 		priv->dma_priv.enable(host, enable);
137 }
138 
139 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
140 {
141 	renesas_sdhi_sys_dmac_enable_dma(host, false);
142 
143 	if (host->chan_rx)
144 		dmaengine_terminate_all(host->chan_rx);
145 	if (host->chan_tx)
146 		dmaengine_terminate_all(host->chan_tx);
147 
148 	renesas_sdhi_sys_dmac_enable_dma(host, true);
149 }
150 
151 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
152 {
153 	struct renesas_sdhi *priv = host_to_priv(host);
154 
155 	complete(&priv->dma_priv.dma_dataend);
156 }
157 
158 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
159 {
160 	struct tmio_mmc_host *host = arg;
161 	struct renesas_sdhi *priv = host_to_priv(host);
162 
163 	spin_lock_irq(&host->lock);
164 
165 	if (!host->data)
166 		goto out;
167 
168 	if (host->data->flags & MMC_DATA_READ)
169 		dma_unmap_sg(host->chan_rx->device->dev,
170 			     host->sg_ptr, host->sg_len,
171 			     DMA_FROM_DEVICE);
172 	else
173 		dma_unmap_sg(host->chan_tx->device->dev,
174 			     host->sg_ptr, host->sg_len,
175 			     DMA_TO_DEVICE);
176 
177 	spin_unlock_irq(&host->lock);
178 
179 	wait_for_completion(&priv->dma_priv.dma_dataend);
180 
181 	spin_lock_irq(&host->lock);
182 	tmio_mmc_do_data_irq(host);
183 out:
184 	spin_unlock_irq(&host->lock);
185 }
186 
187 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
188 {
189 	struct renesas_sdhi *priv = host_to_priv(host);
190 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
191 	struct dma_async_tx_descriptor *desc = NULL;
192 	struct dma_chan *chan = host->chan_rx;
193 	dma_cookie_t cookie;
194 	int ret, i;
195 	bool aligned = true, multiple = true;
196 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
197 
198 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
199 		if (sg_tmp->offset & align)
200 			aligned = false;
201 		if (sg_tmp->length & align) {
202 			multiple = false;
203 			break;
204 		}
205 	}
206 
207 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
208 			  (align & PAGE_MASK))) || !multiple) {
209 		ret = -EINVAL;
210 		goto pio;
211 	}
212 
213 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
214 		return;
215 
216 	/* The only sg element can be unaligned, use our bounce buffer then */
217 	if (!aligned) {
218 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
219 		host->sg_ptr = &host->bounce_sg;
220 		sg = host->sg_ptr;
221 	}
222 
223 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
224 	if (ret > 0)
225 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
226 					       DMA_CTRL_ACK);
227 
228 	if (desc) {
229 		reinit_completion(&priv->dma_priv.dma_dataend);
230 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
231 		desc->callback_param = host;
232 
233 		cookie = dmaengine_submit(desc);
234 		if (cookie < 0) {
235 			desc = NULL;
236 			ret = cookie;
237 		}
238 		host->dma_on = true;
239 	}
240 pio:
241 	if (!desc) {
242 		/* DMA failed, fall back to PIO */
243 		renesas_sdhi_sys_dmac_enable_dma(host, false);
244 		if (ret >= 0)
245 			ret = -EIO;
246 		host->chan_rx = NULL;
247 		dma_release_channel(chan);
248 		/* Free the Tx channel too */
249 		chan = host->chan_tx;
250 		if (chan) {
251 			host->chan_tx = NULL;
252 			dma_release_channel(chan);
253 		}
254 		dev_warn(&host->pdev->dev,
255 			 "DMA failed: %d, falling back to PIO\n", ret);
256 	}
257 }
258 
259 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
260 {
261 	struct renesas_sdhi *priv = host_to_priv(host);
262 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
263 	struct dma_async_tx_descriptor *desc = NULL;
264 	struct dma_chan *chan = host->chan_tx;
265 	dma_cookie_t cookie;
266 	int ret, i;
267 	bool aligned = true, multiple = true;
268 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
269 
270 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
271 		if (sg_tmp->offset & align)
272 			aligned = false;
273 		if (sg_tmp->length & align) {
274 			multiple = false;
275 			break;
276 		}
277 	}
278 
279 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
280 			  (align & PAGE_MASK))) || !multiple) {
281 		ret = -EINVAL;
282 		goto pio;
283 	}
284 
285 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
286 		return;
287 
288 	/* The only sg element can be unaligned, use our bounce buffer then */
289 	if (!aligned) {
290 		unsigned long flags;
291 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
292 
293 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
294 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
295 		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
296 		host->sg_ptr = &host->bounce_sg;
297 		sg = host->sg_ptr;
298 	}
299 
300 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
301 	if (ret > 0)
302 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
303 					       DMA_CTRL_ACK);
304 
305 	if (desc) {
306 		reinit_completion(&priv->dma_priv.dma_dataend);
307 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
308 		desc->callback_param = host;
309 
310 		cookie = dmaengine_submit(desc);
311 		if (cookie < 0) {
312 			desc = NULL;
313 			ret = cookie;
314 		}
315 		host->dma_on = true;
316 	}
317 pio:
318 	if (!desc) {
319 		/* DMA failed, fall back to PIO */
320 		renesas_sdhi_sys_dmac_enable_dma(host, false);
321 		if (ret >= 0)
322 			ret = -EIO;
323 		host->chan_tx = NULL;
324 		dma_release_channel(chan);
325 		/* Free the Rx channel too */
326 		chan = host->chan_rx;
327 		if (chan) {
328 			host->chan_rx = NULL;
329 			dma_release_channel(chan);
330 		}
331 		dev_warn(&host->pdev->dev,
332 			 "DMA failed: %d, falling back to PIO\n", ret);
333 	}
334 }
335 
336 static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
337 					    struct mmc_data *data)
338 {
339 	if (data->flags & MMC_DATA_READ) {
340 		if (host->chan_rx)
341 			renesas_sdhi_sys_dmac_start_dma_rx(host);
342 	} else {
343 		if (host->chan_tx)
344 			renesas_sdhi_sys_dmac_start_dma_tx(host);
345 	}
346 }
347 
348 static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
349 {
350 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
351 	struct dma_chan *chan = NULL;
352 
353 	spin_lock_irq(&host->lock);
354 
355 	if (host->data) {
356 		if (host->data->flags & MMC_DATA_READ)
357 			chan = host->chan_rx;
358 		else
359 			chan = host->chan_tx;
360 	}
361 
362 	spin_unlock_irq(&host->lock);
363 
364 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
365 
366 	if (chan)
367 		dma_async_issue_pending(chan);
368 }
369 
370 static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
371 					      struct tmio_mmc_data *pdata)
372 {
373 	struct renesas_sdhi *priv = host_to_priv(host);
374 
375 	/* We can only either use DMA for both Tx and Rx or not use it at all */
376 	if (!host->pdev->dev.of_node &&
377 	    (!pdata->chan_priv_tx || !pdata->chan_priv_rx))
378 		return;
379 
380 	if (!host->chan_tx && !host->chan_rx) {
381 		struct resource *res = platform_get_resource(host->pdev,
382 							     IORESOURCE_MEM, 0);
383 		struct dma_slave_config cfg = {};
384 		dma_cap_mask_t mask;
385 		int ret;
386 
387 		if (!res)
388 			return;
389 
390 		dma_cap_zero(mask);
391 		dma_cap_set(DMA_SLAVE, mask);
392 
393 		host->chan_tx = dma_request_slave_channel_compat(mask,
394 					priv->dma_priv.filter, pdata->chan_priv_tx,
395 					&host->pdev->dev, "tx");
396 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
397 			host->chan_tx);
398 
399 		if (!host->chan_tx)
400 			return;
401 
402 		cfg.direction = DMA_MEM_TO_DEV;
403 		cfg.dst_addr = res->start +
404 			(CTL_SD_DATA_PORT << host->bus_shift);
405 		cfg.dst_addr_width = priv->dma_priv.dma_buswidth;
406 		if (!cfg.dst_addr_width)
407 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
408 		cfg.src_addr = 0;
409 		ret = dmaengine_slave_config(host->chan_tx, &cfg);
410 		if (ret < 0)
411 			goto ecfgtx;
412 
413 		host->chan_rx = dma_request_slave_channel_compat(mask,
414 					priv->dma_priv.filter, pdata->chan_priv_rx,
415 					&host->pdev->dev, "rx");
416 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
417 			host->chan_rx);
418 
419 		if (!host->chan_rx)
420 			goto ereqrx;
421 
422 		cfg.direction = DMA_DEV_TO_MEM;
423 		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
424 		cfg.src_addr_width = priv->dma_priv.dma_buswidth;
425 		if (!cfg.src_addr_width)
426 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
427 		cfg.dst_addr = 0;
428 		ret = dmaengine_slave_config(host->chan_rx, &cfg);
429 		if (ret < 0)
430 			goto ecfgrx;
431 
432 		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
433 		if (!host->bounce_buf)
434 			goto ebouncebuf;
435 
436 		init_completion(&priv->dma_priv.dma_dataend);
437 		tasklet_init(&host->dma_issue,
438 			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
439 			     (unsigned long)host);
440 	}
441 
442 	renesas_sdhi_sys_dmac_enable_dma(host, true);
443 
444 	return;
445 
446 ebouncebuf:
447 ecfgrx:
448 	dma_release_channel(host->chan_rx);
449 	host->chan_rx = NULL;
450 ereqrx:
451 ecfgtx:
452 	dma_release_channel(host->chan_tx);
453 	host->chan_tx = NULL;
454 }
455 
456 static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
457 {
458 	if (host->chan_tx) {
459 		struct dma_chan *chan = host->chan_tx;
460 
461 		host->chan_tx = NULL;
462 		dma_release_channel(chan);
463 	}
464 	if (host->chan_rx) {
465 		struct dma_chan *chan = host->chan_rx;
466 
467 		host->chan_rx = NULL;
468 		dma_release_channel(chan);
469 	}
470 	if (host->bounce_buf) {
471 		free_pages((unsigned long)host->bounce_buf, 0);
472 		host->bounce_buf = NULL;
473 	}
474 }
475 
476 static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
477 	.start = renesas_sdhi_sys_dmac_start_dma,
478 	.enable = renesas_sdhi_sys_dmac_enable_dma,
479 	.request = renesas_sdhi_sys_dmac_request_dma,
480 	.release = renesas_sdhi_sys_dmac_release_dma,
481 	.abort = renesas_sdhi_sys_dmac_abort_dma,
482 	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
483 };
484 
485 /*
486  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
487  * implementation. Currently empty as all supported ES versions use
488  * the internal DMAC.
489  */
490 static const struct soc_device_attribute gen3_soc_whitelist[] = {
491         { /* sentinel */ }
492 };
493 
494 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
495 {
496 	if ((of_device_get_match_data(&pdev->dev) == &of_rcar_gen3_compatible ||
497 	    of_device_get_match_data(&pdev->dev) == &of_rcar_r8a7795_compatible) &&
498 	    !soc_device_match(gen3_soc_whitelist))
499 		return -ENODEV;
500 
501 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
502 }
503 
504 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
505 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
506 				pm_runtime_force_resume)
507 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
508 			   tmio_mmc_host_runtime_resume,
509 			   NULL)
510 };
511 
512 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
513 	.driver		= {
514 		.name	= "sh_mobile_sdhi",
515 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
516 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
517 	},
518 	.probe		= renesas_sdhi_sys_dmac_probe,
519 	.remove		= renesas_sdhi_remove,
520 };
521 
522 module_platform_driver(renesas_sys_dmac_sdhi_driver);
523 
524 MODULE_DESCRIPTION("Renesas SDHI driver");
525 MODULE_AUTHOR("Magnus Damm");
526 MODULE_LICENSE("GPL v2");
527 MODULE_ALIAS("platform:sh_mobile_sdhi");
528