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_gen3_compatible = {
79 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
80 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
81 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
82 			  MMC_CAP_CMD23,
83 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
84 	.bus_shift	= 2,
85 	.scc_offset	= 0x1000,
86 	.taps		= rcar_gen3_scc_taps,
87 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
88 };
89 
90 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
91 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
92 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
93 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
94 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
95 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
96 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
97 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
98 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
99 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
100 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
101 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
102 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
103 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
104 	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
105 	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
106 	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
107 	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
108 	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
109 	{ .compatible = "renesas,sdhi-shmobile" },
110 	{},
111 };
112 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
113 
114 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
115 					     bool enable)
116 {
117 	struct renesas_sdhi *priv = host_to_priv(host);
118 
119 	if (!host->chan_tx || !host->chan_rx)
120 		return;
121 
122 	if (priv->dma_priv.enable)
123 		priv->dma_priv.enable(host, enable);
124 }
125 
126 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
127 {
128 	renesas_sdhi_sys_dmac_enable_dma(host, false);
129 
130 	if (host->chan_rx)
131 		dmaengine_terminate_all(host->chan_rx);
132 	if (host->chan_tx)
133 		dmaengine_terminate_all(host->chan_tx);
134 
135 	renesas_sdhi_sys_dmac_enable_dma(host, true);
136 }
137 
138 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
139 {
140 	struct renesas_sdhi *priv = host_to_priv(host);
141 
142 	complete(&priv->dma_priv.dma_dataend);
143 }
144 
145 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
146 {
147 	struct tmio_mmc_host *host = arg;
148 	struct renesas_sdhi *priv = host_to_priv(host);
149 
150 	spin_lock_irq(&host->lock);
151 
152 	if (!host->data)
153 		goto out;
154 
155 	if (host->data->flags & MMC_DATA_READ)
156 		dma_unmap_sg(host->chan_rx->device->dev,
157 			     host->sg_ptr, host->sg_len,
158 			     DMA_FROM_DEVICE);
159 	else
160 		dma_unmap_sg(host->chan_tx->device->dev,
161 			     host->sg_ptr, host->sg_len,
162 			     DMA_TO_DEVICE);
163 
164 	spin_unlock_irq(&host->lock);
165 
166 	wait_for_completion(&priv->dma_priv.dma_dataend);
167 
168 	spin_lock_irq(&host->lock);
169 	tmio_mmc_do_data_irq(host);
170 out:
171 	spin_unlock_irq(&host->lock);
172 }
173 
174 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
175 {
176 	struct renesas_sdhi *priv = host_to_priv(host);
177 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
178 	struct dma_async_tx_descriptor *desc = NULL;
179 	struct dma_chan *chan = host->chan_rx;
180 	dma_cookie_t cookie;
181 	int ret, i;
182 	bool aligned = true, multiple = true;
183 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
184 
185 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
186 		if (sg_tmp->offset & align)
187 			aligned = false;
188 		if (sg_tmp->length & align) {
189 			multiple = false;
190 			break;
191 		}
192 	}
193 
194 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
195 			  (align & PAGE_MASK))) || !multiple) {
196 		ret = -EINVAL;
197 		goto pio;
198 	}
199 
200 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
201 		return;
202 
203 	/* The only sg element can be unaligned, use our bounce buffer then */
204 	if (!aligned) {
205 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
206 		host->sg_ptr = &host->bounce_sg;
207 		sg = host->sg_ptr;
208 	}
209 
210 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
211 	if (ret > 0)
212 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
213 					       DMA_CTRL_ACK);
214 
215 	if (desc) {
216 		reinit_completion(&priv->dma_priv.dma_dataend);
217 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
218 		desc->callback_param = host;
219 
220 		cookie = dmaengine_submit(desc);
221 		if (cookie < 0) {
222 			desc = NULL;
223 			ret = cookie;
224 		}
225 		host->dma_on = true;
226 	}
227 pio:
228 	if (!desc) {
229 		/* DMA failed, fall back to PIO */
230 		renesas_sdhi_sys_dmac_enable_dma(host, false);
231 		if (ret >= 0)
232 			ret = -EIO;
233 		host->chan_rx = NULL;
234 		dma_release_channel(chan);
235 		/* Free the Tx channel too */
236 		chan = host->chan_tx;
237 		if (chan) {
238 			host->chan_tx = NULL;
239 			dma_release_channel(chan);
240 		}
241 		dev_warn(&host->pdev->dev,
242 			 "DMA failed: %d, falling back to PIO\n", ret);
243 	}
244 }
245 
246 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
247 {
248 	struct renesas_sdhi *priv = host_to_priv(host);
249 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
250 	struct dma_async_tx_descriptor *desc = NULL;
251 	struct dma_chan *chan = host->chan_tx;
252 	dma_cookie_t cookie;
253 	int ret, i;
254 	bool aligned = true, multiple = true;
255 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
256 
257 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
258 		if (sg_tmp->offset & align)
259 			aligned = false;
260 		if (sg_tmp->length & align) {
261 			multiple = false;
262 			break;
263 		}
264 	}
265 
266 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
267 			  (align & PAGE_MASK))) || !multiple) {
268 		ret = -EINVAL;
269 		goto pio;
270 	}
271 
272 	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
273 		return;
274 
275 	/* The only sg element can be unaligned, use our bounce buffer then */
276 	if (!aligned) {
277 		unsigned long flags;
278 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
279 
280 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
281 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
282 		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
283 		host->sg_ptr = &host->bounce_sg;
284 		sg = host->sg_ptr;
285 	}
286 
287 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
288 	if (ret > 0)
289 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
290 					       DMA_CTRL_ACK);
291 
292 	if (desc) {
293 		reinit_completion(&priv->dma_priv.dma_dataend);
294 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
295 		desc->callback_param = host;
296 
297 		cookie = dmaengine_submit(desc);
298 		if (cookie < 0) {
299 			desc = NULL;
300 			ret = cookie;
301 		}
302 		host->dma_on = true;
303 	}
304 pio:
305 	if (!desc) {
306 		/* DMA failed, fall back to PIO */
307 		renesas_sdhi_sys_dmac_enable_dma(host, false);
308 		if (ret >= 0)
309 			ret = -EIO;
310 		host->chan_tx = NULL;
311 		dma_release_channel(chan);
312 		/* Free the Rx channel too */
313 		chan = host->chan_rx;
314 		if (chan) {
315 			host->chan_rx = NULL;
316 			dma_release_channel(chan);
317 		}
318 		dev_warn(&host->pdev->dev,
319 			 "DMA failed: %d, falling back to PIO\n", ret);
320 	}
321 }
322 
323 static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
324 					    struct mmc_data *data)
325 {
326 	if (data->flags & MMC_DATA_READ) {
327 		if (host->chan_rx)
328 			renesas_sdhi_sys_dmac_start_dma_rx(host);
329 	} else {
330 		if (host->chan_tx)
331 			renesas_sdhi_sys_dmac_start_dma_tx(host);
332 	}
333 }
334 
335 static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
336 {
337 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
338 	struct dma_chan *chan = NULL;
339 
340 	spin_lock_irq(&host->lock);
341 
342 	if (host->data) {
343 		if (host->data->flags & MMC_DATA_READ)
344 			chan = host->chan_rx;
345 		else
346 			chan = host->chan_tx;
347 	}
348 
349 	spin_unlock_irq(&host->lock);
350 
351 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
352 
353 	if (chan)
354 		dma_async_issue_pending(chan);
355 }
356 
357 static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
358 					      struct tmio_mmc_data *pdata)
359 {
360 	struct renesas_sdhi *priv = host_to_priv(host);
361 
362 	/* We can only either use DMA for both Tx and Rx or not use it at all */
363 	if (!host->pdev->dev.of_node &&
364 	    (!pdata->chan_priv_tx || !pdata->chan_priv_rx))
365 		return;
366 
367 	if (!host->chan_tx && !host->chan_rx) {
368 		struct resource *res = platform_get_resource(host->pdev,
369 							     IORESOURCE_MEM, 0);
370 		struct dma_slave_config cfg = {};
371 		dma_cap_mask_t mask;
372 		int ret;
373 
374 		if (!res)
375 			return;
376 
377 		dma_cap_zero(mask);
378 		dma_cap_set(DMA_SLAVE, mask);
379 
380 		host->chan_tx = dma_request_slave_channel_compat(mask,
381 					priv->dma_priv.filter, pdata->chan_priv_tx,
382 					&host->pdev->dev, "tx");
383 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
384 			host->chan_tx);
385 
386 		if (!host->chan_tx)
387 			return;
388 
389 		cfg.direction = DMA_MEM_TO_DEV;
390 		cfg.dst_addr = res->start +
391 			(CTL_SD_DATA_PORT << host->bus_shift);
392 		cfg.dst_addr_width = priv->dma_priv.dma_buswidth;
393 		if (!cfg.dst_addr_width)
394 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
395 		cfg.src_addr = 0;
396 		ret = dmaengine_slave_config(host->chan_tx, &cfg);
397 		if (ret < 0)
398 			goto ecfgtx;
399 
400 		host->chan_rx = dma_request_slave_channel_compat(mask,
401 					priv->dma_priv.filter, pdata->chan_priv_rx,
402 					&host->pdev->dev, "rx");
403 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
404 			host->chan_rx);
405 
406 		if (!host->chan_rx)
407 			goto ereqrx;
408 
409 		cfg.direction = DMA_DEV_TO_MEM;
410 		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
411 		cfg.src_addr_width = priv->dma_priv.dma_buswidth;
412 		if (!cfg.src_addr_width)
413 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
414 		cfg.dst_addr = 0;
415 		ret = dmaengine_slave_config(host->chan_rx, &cfg);
416 		if (ret < 0)
417 			goto ecfgrx;
418 
419 		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
420 		if (!host->bounce_buf)
421 			goto ebouncebuf;
422 
423 		init_completion(&priv->dma_priv.dma_dataend);
424 		tasklet_init(&host->dma_issue,
425 			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
426 			     (unsigned long)host);
427 	}
428 
429 	renesas_sdhi_sys_dmac_enable_dma(host, true);
430 
431 	return;
432 
433 ebouncebuf:
434 ecfgrx:
435 	dma_release_channel(host->chan_rx);
436 	host->chan_rx = NULL;
437 ereqrx:
438 ecfgtx:
439 	dma_release_channel(host->chan_tx);
440 	host->chan_tx = NULL;
441 }
442 
443 static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
444 {
445 	if (host->chan_tx) {
446 		struct dma_chan *chan = host->chan_tx;
447 
448 		host->chan_tx = NULL;
449 		dma_release_channel(chan);
450 	}
451 	if (host->chan_rx) {
452 		struct dma_chan *chan = host->chan_rx;
453 
454 		host->chan_rx = NULL;
455 		dma_release_channel(chan);
456 	}
457 	if (host->bounce_buf) {
458 		free_pages((unsigned long)host->bounce_buf, 0);
459 		host->bounce_buf = NULL;
460 	}
461 }
462 
463 static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
464 	.start = renesas_sdhi_sys_dmac_start_dma,
465 	.enable = renesas_sdhi_sys_dmac_enable_dma,
466 	.request = renesas_sdhi_sys_dmac_request_dma,
467 	.release = renesas_sdhi_sys_dmac_release_dma,
468 	.abort = renesas_sdhi_sys_dmac_abort_dma,
469 	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
470 };
471 
472 /*
473  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
474  * implementation. Currently empty as all supported ES versions use
475  * the internal DMAC.
476  */
477 static const struct soc_device_attribute gen3_soc_whitelist[] = {
478         { /* sentinel */ }
479 };
480 
481 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
482 {
483 	if (of_device_get_match_data(&pdev->dev) == &of_rcar_gen3_compatible &&
484 	    !soc_device_match(gen3_soc_whitelist))
485 		return -ENODEV;
486 
487 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
488 }
489 
490 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
491 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
492 				pm_runtime_force_resume)
493 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
494 			   tmio_mmc_host_runtime_resume,
495 			   NULL)
496 };
497 
498 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
499 	.driver		= {
500 		.name	= "sh_mobile_sdhi",
501 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
502 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
503 	},
504 	.probe		= renesas_sdhi_sys_dmac_probe,
505 	.remove		= renesas_sdhi_remove,
506 };
507 
508 module_platform_driver(renesas_sys_dmac_sdhi_driver);
509 
510 MODULE_DESCRIPTION("Renesas SDHI driver");
511 MODULE_AUTHOR("Magnus Damm");
512 MODULE_LICENSE("GPL v2");
513 MODULE_ALIAS("platform:sh_mobile_sdhi");
514